Articles | Volume 20, issue 20
Atmos. Chem. Phys., 20, 11893–11906, 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article 22 Oct 2020
Research article | 22 Oct 2020
Using a coupled large-eddy simulation–aerosol radiation model to investigate urban haze: sensitivity to aerosol loading and meteorological conditions
Jessica Slater et al.
No articles found.
Jessica Slater, Hugh Coe, Gordon McFiggans, Juha Tonttila, and Sami Romakkaniemi
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
This paper shows the specific impact of black carbon (BC) on the aerosol-planetary boundary layer (PBL) feedback and its influence on a Beijing haze episode. Overall, this paper shows that strong temperature inversions prevent BC heating within the PBL from significantly increasing PBL height, while BC above the PBL suppresses PBL development significantly through the day. From this we suggest a method by which both locally and regionally emitted BC may impact Beijing haze episodes.
Aristeidis Voliotis, Yu Wang, Yunqi Shao, Mao Du, Thomas J. Bannan, Carl J. Percival, Spyros N. Pandis, M. Rami Alfarra, and Gordon McFiggans
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
Secondary organic aerosol (SOA) formation from mixtures of volatile precursors can be affected by the molecular interactions of the products. Composition and volatility measurements of SOA formed from mixtures of anthropogenic and biogenic precursors reveal processes that can increase or decrease the SOA volatility. The unique products of the mixture are more oxygenated and less volatile than those from either precursor. Analytical context is provided to explore the SOA volatility in mixtures.
Michael Priestley, Thomas J. Bannan, Michael Le Breton, Stephen D. Worrall, Sungah Kang, Iida Pullinen, Sebastian Schmitt, Ralf Tillmann, Einhard Kleist, Defeng Zhao, Jürgen Wildt, Olga Garmash, Archit Mehra, Asan Bacak, Dudley E. Shallcross, Astrid Kiendler-Scharr, Åsa M. Hallquist, Mikael Ehn, Hugh Coe, Carl J. Percival, Mattias Hallquist, Thomas F. Mentel, and Gordon McFiggans
Atmos. Chem. Phys., 21, 3473–3490,Short summary
A significant fraction of emissions from human activity consists of aromatic hydrocarbons, e.g. benzene, which oxidise to form new compounds important for particle growth. Characterisation of benzene oxidation products highlights the range of species produced as well as their chemical properties and contextualises them within relevant frameworks, e.g. MCM. Cluster analysis of the oxidation product time series distinguishes behaviours of CHON compounds that could aid in identifying functionality.
Yu Wang, Aristeidis Voliotis, Yunqi Shao, Taomou Zong, Xiangxinyue Meng, Mao Du, Dawei Hu, Ying Chen, Zhijun Wu, M. Rami Alfarra, and Gordon McFiggans
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
Aerosol phase behaviour plays a profound role in atmospheric physicochemical processes. We designed dedicated chamber experiments to study phase state of secondary organic aerosol from biogenic and anthropogenic mixed precursors. Our results highlight the key role of organic-inorganic-ratio and relative humidity in phase state, but the sources and organic composition is less important. This result provides a solid laboratory evidence for understanding aerosol phase in complex atmosphere.
Lisa K. Whalley, Eloise J. Slater, Robert Woodward-Massey, Chunxiang Ye, James D. Lee, Freya Squires, James R. Hopkins, Rachel E. Dunmore, Marvin Shaw, Jacqueline F. Hamilton, Alastair C. Lewis, Archit Mehra, Stephen D. Worrall, Asan Bacak, Thomas J. Bannan, Hugh Coe, Carl J. Percival, Bin Ouyang, Roderic L. Jones, Leigh R. Crilley, Louisa J. Kramer, William J. Bloss, Tuan Vu, Simone Kotthaus, Sue Grimmond, Yele Sun, Weiqi Xu, Siyao Yue, Lujie Ren, W. Joe F. Acton, C. Nicholas Hewitt, Xinming Wang, Pingqing Fu, and Dwayne E. Heard
Atmos. Chem. Phys., 21, 2125–2147,Short summary
To understand how emission controls will impact ozone, an understanding of the sources and sinks of OH and the chemical cycling between peroxy radicals is needed. This paper presents measurements of OH, HO2 and total RO2 taken in central Beijing. The radical observations are compared to a detailed chemistry model, which shows that under low NO conditions, there is a missing OH source. Under high NOx conditions, the model under-predicts RO2 and impacts our ability to model ozone.
Antti Ruuskanen, Sami Romakkaniemi, Harri Kokkola, Antti Arola, Santtu Mikkonen, Harri Portin, Annele Virtanen, Kari E. J. Lehtinen, Mika Komppula, and Ari Leskinen
Atmos. Chem. Phys., 21, 1683–1695,Short summary
The study focuses mainly on cloud-scavenging efficiency of absorbing particulate matter (mainly black carbon) but additionally covers cloud-scavenging efficiency of scattering particles and statistics of cloud condensation nuclei. The main findings give insight into how black carbon is distributed in different particle sizes and the sensitivity to cloud scavenged. The main findings are useful for large-scale modelling for evaluating cloud scavenging.
Mike J. Newland, Daniel J. Bryant, Rachel E. Dunmore, Thomas J. Bannan, W. Joe F. Acton, Ben Langford, James R. Hopkins, Freya A. Squires, William Dixon, William S. Drysdale, Peter D. Ivatt, Mathew J. Evans, Peter M. Edwards, Lisa K. Whalley, Dwayne E. Heard, Eloise J. Slater, Robert Woodward-Massey, Chunxiang Ye, Archit Mehra, Stephen D. Worrall, Asan Bacak, Hugh Coe, Carl J. Percival, C. Nicholas Hewitt, James D. Lee, Tianqu Cui, Jason D. Surratt, Xinming Wang, Alastair C. Lewis, Andrew R. Rickard, and Jacqueline F. Hamilton
Atmos. Chem. Phys., 21, 1613–1625,Short summary
We report the formation of secondary pollutants in the urban megacity of Beijing that are typically associated with remote regions such as rainforests. This is caused by extremely low levels of nitric oxide (NO), typically expected to be high in urban areas, observed in the afternoon. This work has significant implications for how we understand atmospheric chemistry in the urban environment and thus for how to implement effective policies to improve urban air quality.
Simon Patrick O'Meara, Shuxuan Xu, David Topping, M. Rami Alfarra, Gerard Capes, Douglas Lowe, Yunqi Shao, and Gordon McFiggans
Geosci. Model Dev., 14, 675–702,Short summary
User-friendly and open-source software for simulating aerosol chambers is a valuable tool for research scientists in designing and analysing their experiments. This paper describes a new version of such software and will therefore provide a useful reference for those applying it. Central to the paper is an assessment of the software's accuracy through comparison against previously published simulations.
Huihui Wu, Jonathan W. Taylor, Justin M. Langridge, Chenjie Yu, James D. Allan, Kate Szpek, Michael I. Cotterell, Paul I. Williams, Michael Flynn, Patrick Barker, Cathryn Fox, Grant Allen, James Lee, and Hugh Coe
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Seasonal biomass burning over West Africa is a globally significant source of carbonaceous particles in the atmosphere, which have important climate impacts but are poorly constrained. We conducted in-situ airborne measurements to investigate the evolution of smoke aerosol properties in this region. We observed absorption enhancement for both the black carbon and brown carbon after emission, which provide new field results and constraints on aerosol parameterisations for future climate models.
Bjorn Stevens, Sandrine Bony, David Farrell, Felix Ament, Alan Blyth, Christopher Fairall, Johannes Karstensen, Patricia K. Quinn, Sabrina Speich, Claudia Acquistapace, Franziska Aemisegger, Anna Lea Albright, Hugo Bellenger, Eberhard Bodenschatz, Kathy-Ann Caesar, Rebecca Chewitt-Lucas, Gijs de Boer, Julien Delanoë, Leif Denby, Florian Ewald, Benjamin Fildier, Marvin Forde, Geet George, Silke Gross, Martin Hagen, Andrea Hausold, Karen J. Heywood, Lutz Hirsch, Marek Jacob, Friedhelm Jansen, Stefan Kinne, Daniel Klocke, Tobias Kölling, Heike Konow, Marie Lothon, Wiebke Mohr, Ann Kristin Naumann, Louise Nuijens, Léa Olivier, Robert Pincus, Mira Pöhlker, Gilles Reverdin, Gregory Roberts, Sabrina Schnitt, Hauke Schulz, A. Pier Siebesma, Claudia Christine Stephan, Peter Sullivan, Ludovic Touzé-Peiffer, Jessica Vial, Raphaela Vogel, Paquita Zuidema, Nicola Alexander, Lyndon Alves, Sophian Arixi, Hamish Asmath, Gholamhossein Bagheri, Katharina Baier, Adriana Bailey, Dariusz Baranowski, Alexandre Baron, Sébastien Barrau, Paul A. Barrett, Frédéric Batier, Andreas Behrendt, Arne Bendinger, Florent Beucher, Sebastien Bigorre, Edmund Blades, Peter Blossey, Olivier Bock, Steven Böing, Pierre Bosser, Denis Bourras, Pascale Bouruet-Aubertot, Keith Bower, Pierre Branellec, Hubert Branger, Michal Brennek, Alan Brewer, Pierre-Etienne Brilouet, Björn Brügmann, Stefan A. Buehler, Elmo Burke, Ralph Burton, Radiance Calmer, Jean-Christophe Canonici, Xavier Carton, Gregory Cato Jr., Jude Andre Charles, Patrick Chazette, Yanxu Chen, Michal T. Chilinski, Thomas Choularton, Patrick Chuang, Shamal Clarke, Hugh Coe, Céline Cornet, Pierre Coutris, Fleur Couvreux, Susanne Crewell, Timothy Cronin, Zhiqiang Cui, Yannis Cuypers, Alton Daley, Gillian M. Damerell, Thibaut Dauhut, Hartwig Deneke, Jean-Philippe Desbios, Steffen Dörner, Sebastian Donner, Vincent Douet, Kyla Drushka, Marina Dütsch, André Ehrlich, Kerry Emanuel, Alexandros Emmanouilidis, Jean-Claude Etienne, Sheryl Etienne-Leblanc, Ghislain Faure, Graham Feingold, Luca Ferrero, Andreas Fix, Cyrille Flamant, Piotr Jacek Flatau, Gregory R. Foltz, Linda Forster, Iulian Furtuna, Alan Gadian, Joseph Galewsky, Martin Gallagher, Peter Gallimore, Cassandra Gaston, Chelle Gentemann, Nicolas Geyskens, Andreas Giez, John Gollop, Isabelle Gouirand, Christophe Gourbeyre, Dörte de Graaf, Geiske E. de Groot, Robert Grosz, Johannes Güttler, Manuel Gutleben, Kashawn Hall, George Harris, Kevin C. Helfer, Dean Henze, Calvert Herbert, Bruna Holanda, Antonio Ibanez-Landeta, Janet Intrieri, Suneil Iyer, Fabrice Julien, Heike Kalesse, Jan Kazil, Alexander Kellman, Abiel T. Kidane, Ulrike Kirchner, Marcus Klingebiel, Mareike Körner, Leslie Ann Kremper, Jan Kretzschmar, Ovid Krüger, Wojciech Kumala, Armin Kurz, Pierre L'Hégaret, Matthieu Labaste, Tom Lachlan-Cope, Arlene Laing, Peter Landschützer, Theresa Lang, Diego Lange, Ingo Lange, Clément Laplace, Gauke Lavik, Rémi Laxenaire, Caroline Le Bihan, Mason Leandro, Nathalie Lefevre, Marius Lena, Donald Lenschow, Qiang Li, Gary Lloyd, Sebastian Los, Niccolò Losi, Oscar Lovell, Christopher Luneau, Przemyslaw Makuch, Szymon Malinowski, Gaston Manta, Eleni Marinou, Nicholas Marsden, Sebastien Masson, Nicolas Maury, Bernhard Mayer, Margarette Mayers-Als, Christophe Mazel, Wayne McGeary, James C. McWilliams, Mario Mech, Melina Mehlmann, Agostino Niyonkuru Meroni, Theresa Mieslinger, Andreas Minikin, Peter Minnett, Gregor Möller, Yanmichel Morfa Avalos, Caroline Muller, Ionela Musat, Anna Napoli, Almuth Neuberger, Christophe Noisel, David Noone, Freja Nordsiek, Jakub L. Nowak, Lothar Oswald, Douglas J. Parker, Carolyn Peck, Renaud Person, Miriam Philippi, Albert Plueddemann, Christopher Pöhlker, Veronika Pörtge, Ulrich Pöschl, Lawrence Pologne, Michał Posyniak, Marc Prange, Estefanía Quiñones Meléndez, Jule Radtke, Karim Ramage, Jens Reimann, Lionel Renault, Klaus Reus, Ashford Reyes, Joachim Ribbe, Maximilian Ringel, Markus Ritschel, Cesar B. Rocha, Nicolas Rochetin, Johannes Röttenbacher, Callum Rollo, Haley Royer, Pauline Sadoulet, Leo Saffin, Sanola Sandiford, Irina Sandu, Michael Schäfer, Vera Schemann, Imke Schirmacher, Oliver Schlenczek, Jerome Schmidt, Marcel Schröder, Alfons Schwarzenboeck, Andrea Sealy, Christoph J. Senff, Ilya Serikov, Samkeyat Shohan, Elizabeth Siddle, Alexander Smirnov, Florian Späth, Branden Spooner, M. Katharina Stolla, Wojciech Szkółka, Simon P. de Szoeke, Stéphane Tarot, Eleni Tetoni, Elizabeth Thompson, Jim Thomson, Lorenzo Tomassini, Julien Totems, Alma Anna Ubele, Leonie Villiger, Jan von Arx, Thomas Wagner, Andi Walther, Ben Webber, Manfred Wendisch, Shanice Whitehall, Anton Wiltshire, Allison A. Wing, Martin Wirth, Jonathan Wiskandt, Kevin Wolf, Ludwig Worbes, Ethan Wright, Volker Wulfmeyer, Shanea Young, Chidong Zhang, Dongxiao Zhang, Florian Ziemen, Tobias Zinner, and Martin Zöger
Earth Syst. Sci. Data Discuss.,
Preprint under review for ESSDShort summary
The EUREC4A field campaign, designed to test hypothesized mechanisms by which clouds respond to warming and benchmark next generation Earth-system models, is presented. EUREC4A comprised roughly five weeks of measurements in the downstream winter trades of the North Atlantic – eastward and south-eastward of Barbados. It was the first campaign that attempted to characterize the full range of processes and scales influencing tradewind clouds.
Jim M. Haywood, Steven J. Abel, Paul A. Barrett, Nicolas Bellouin, Alan Blyth, Keith N. Bower, Melissa Brooks, Ken Carslaw, Haochi Che, Hugh Coe, Michael I. Cotterell, Ian Crawford, Zhiqiang Cui, Nicholas Davies, Beth Dingley, Paul Field, Paola Formenti, Hamish Gordon, Martin de Graaf, Ross Herbert, Ben Johnson, Anthony C. Jones, Justin M. Langridge, Florent Malavelle, Daniel G. Partridge, Fanny Peers, Jens Redemann, Philip Stier, Kate Szpek, Jonathan W. Taylor, Duncan Watson-Parris, Robert Wood, Huihui Wu, and Paquita Zuidema
Atmos. Chem. Phys., 21, 1049–1084,Short summary
Every year, the seasonal cycle of biomass burning from agricultural practices in Africa creates a huge plume of smoke that travels many thousands of kilometres over the Atlantic Ocean. This study provides an overview of a measurement campaign called the cloud–aerosol–radiation interaction and forcing for year 2017 (CLARIFY-2017) and documents the rationale, deployment strategy, observations, and key results from the campaign which utilized the heavily equipped FAAM atmospheric research aircraft.
Juha Tonttila, Ali Afzalifar, Harri Kokkola, Tomi Raatikainen, Hannele Korhonen, and Sami Romakkaniemi
Atmos. Chem. Phys., 21, 1035–1048,Short summary
The focus of this study is on rain enhancement by deliberate injection of small particles into clouds (
cloud seeding). The particles, usually released from an aircraft, are expected to enhance cloud droplet growth, but its practical feasibility is somewhat uncertain. To improve upon this, we simulate the seeding effects with a numerical model. The model reproduces the main features seen in field observations, with a strong sensitivity to the total mass of the injected particle material.
Zixia Liu, Martin Osborne, Jim Haywood, Karen Anderson, Jamie D. Shulter, Andy Wilson, Justin Langridge, Steve H. L. Yim, Hugh Coe, Suresh Babu, Sreedharan K. Satheesh, Paquita Zuidema, Tao Huang, and Jack C. H. Cheng
Atmos. Meas. Tech. Discuss.,
Preprint under review for AMTShort summary
This paper shows the performance of an advanced aerosol observation instrument (POPS) on a quadcopter drone. The results suggest that the impact of the UAV rotors on the POPS does not unduly affect the performance of the POPS for wind speed less than 2.6 m/s, but when operating under higher wind speed of up to 7.6 m/s, larger discrepancies are noted. Plus, it appears that the POPS measures sub-micron aerosol particles more accurately than super-micron aerosol particles on the drone.
Rutambhara Joshi, Dantong Liu, Eiko Nemitz, Ben Langford, Neil Mullinger, Freya Squires, James Lee, Yunfei Wu, Xiaole Pan, Pingqing Fu, Simone Kotthaus, Sue Grimmond, Qiang Zhang, Ruili Wu, Oliver Wild, Michael Flynn, Hugh Coe, and James Allan
Atmos. Chem. Phys., 21, 147–162,Short summary
Black carbon (BC) is a component of particulate matter which has significant effects on climate and human health. Sources of BC include biomass burning, transport, industry and domestic cooking and heating. In this study, we measured BC emissions in Beijing, finding a dominance of traffic emissions over all other sources. The quantitative method presented here has benefits for revising widely used emissions inventories and for understanding BC sources with impacts on air quality and climate.
Mohanan R. Manoj, Sreedharan K. Satheesh, Krishnaswamy K. Moorthy, Jamie Trembath, and Hugh Coe
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Vertical distributions of atmospheric aerosols and the ability of aerosols to form clouds has been studied across the Indo-Gangetic Plain based on air-borne measurements carried out during the SWAAMI field campaign studying the Indian monsoon. The ability of the aerosols to act as cloud forming nuclei showed contrasting features, increasing with increase in altitude, prior to the onset of monsoon, reversing the trend to decrease with increase in altitude during the active phase of the monsoon.
Patrick A. Barker, Grant Allen, Martin Gallagher, Joseph R. Pitt, Rebecca E. Fisher, Thomas Bannan, Euan G. Nisbet, Stéphane J.-B. Bauguitte, Dominika Pasternak, Samuel Cliff, Marina B. Schimpf, Archit Mehra, Keith N. Bower, James D. Lee, Hugh Coe, and Carl J. Percival
Atmos. Chem. Phys., 20, 15443–15459,Short summary
Africa is estimated to account for approximately 52 % of global biomass burning (BB) carbon emissions. Despite this, there has been little previous in situ study of African BB emissions. This work presents BB emission factors for various atmospheric trace gases sampled from an aircraft in two distinct areas of Africa (Senegal and Uganda). Intracontinental variability in biomass burning methane emission is identified, which is attributed to difference in the specific fuel mixtures burnt.
Xiaoxia Shang, Elina Giannakaki, Stephanie Bohlmann, Maria Filioglou, Annika Saarto, Antti Ruuskanen, Ari Leskinen, Sami Romakkaniemi, and Mika Komppula
Atmos. Chem. Phys., 20, 15323–15339,Short summary
Measurements of the multi-wavelength Raman polarization lidar PollyXT have been combined with measurements of pollen type and concentration using a traditional pollen sampler at a rural forest site in Kuopio, Finland. The depolarization ratio was enhanced when there were pollen grains in the atmosphere, illustrating the potential of lidar to track pollen grains in the atmosphere. The depolarization ratio of pure pollen particles was assessed for birch and pine pollen using a novel algorithm.
Eemeli Holopainen, Harri Kokkola, Anton Laakso, and Thomas Kühn
Geosci. Model Dev., 13, 6215–6235,Short summary
This paper introduces an in-cloud wet deposition scheme for liquid and ice phase clouds for global aerosol–climate models. With the default setup, our wet deposition scheme behaves spuriously and better representation can be achieved with this scheme when black carbon is mixed with soluble compounds at emission time. This work is done as many of the global models fail to reproduce the transport of black carbon to the Arctic, which may be due to the poor representation of wet removal in models.
Douglas Morrison, Ian Crawford, Nicholas Marsden, Michael Flynn, Katie Read, Luis Neves, Virginia Foot, Paul Kaye, Warren Stanley, Hugh Coe, David Topping, and Martin Gallagher
Atmos. Chem. Phys., 20, 14473–14490,Short summary
We provide conservative estimates of the concentrations of bacteria within transatlantic dust clouds, originating from the African continent. We observe significant seasonal differences in the overall concentrations of particles but no seasonal variation in the ratio between bacteria and dust. With bacteria contributing to ice formation at warmer temperatures than dust, our observations should improve the accuracy of climate models.
Benjamin A. Nault, Duseong S. Jo, Brian C. McDonald, Pedro Campuzano-Jost, Douglas A. Day, Weiwei Hu, Jason C. Schroder, James Allan, Donald R. Blake, Manjula R. Canagaratna, Hugh Coe, Matthew M. Coggon, Peter F. DeCarlo, Glenn S. Diskin, Rachel Dunmore, Frank Flocke, Alan Fried, Jessica B. Gilman, Georgios Gkatzelis, Jacqui F. Hamilton, Thomas F. Hanisco, Patrick L. Hayes, Daven K. Henze, Alma Hodzic, James Hopkins, Min Hu, L. Greggory Huey, B. Thomas Jobson, William C. Kuster, Alastair Lewis, Meng Li, Jin Liao, M. Omar Nawaz, Ilana B. Pollack, Jeffrey Peischl, Bernhard Rappenglück, Claire E. Reeves, Dirk Richter, James M. Roberts, Thomas B. Ryerson, Min Shao, Jacob M. Sommers, James Walega, Carsten Warneke, Petter Weibring, Glenn M. Wolfe, Dominique E. Young, Bin Yuan, Qiang Zhang, Joost A. de Gouw, and Jose L. Jimenez
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
Secondary organic aerosol (SOA) is an important aspect of poor air quality for urban regions around the world, where a large fraction of the population lives. However, there is still large uncertainty in predicting SOA in urban regions. Here, we used data from 11 urban campaigns and show that the variability in SOA production in these regions are predictable and explained by key emissions. These results are used to estimate the premature mortality associated to SOA in urban regions.
Huihui Wu, Jonathan W. Taylor, Kate Szpek, Justin M. Langridge, Paul I. Williams, Michael Flynn, James D. Allan, Steven J. Abel, Joseph Pitt, Michael I. Cotterell, Cathryn Fox, Nicholas W. Davies, Jim Haywood, and Hugh Coe
Atmos. Chem. Phys., 20, 12697–12719,Short summary
Airborne measurements of highly aged biomass burning aerosols (BBAs) over the remote southeast Atlantic provide unique aerosol parameters for climate models. Our observations demonstrate the persistence of strongly absorbing BBAs across wide regions of the South Atlantic. We also found significant vertical variation in the single-scattering albedo of these BBAs, as a function of relative chemical composition and size. Aerosol properties in the marine BL are suggested to be separated from the FT.
Jaakko Ahola, Hannele Korhonen, Juha Tonttila, Sami Romakkaniemi, Harri Kokkola, and Tomi Raatikainen
Atmos. Chem. Phys., 20, 11639–11654,Short summary
In this study, we present an improved cloud model that reproduces the behaviour of mixed-phase clouds containing liquid droplets and ice crystals in more detail than before. This model is a convenient computational tool that enables the study of phenomena that cannot fit into a laboratory. These clouds have a significant role in climate, but they are not yet properly understood. Here, we show the advantages of the new model in a case study focusing on Arctic mixed-phase clouds.
Zainab Bibi, Hugh Coe, James Brooks, Paul I. Williams, Ernesto Reyes-Villegas, Michael Priestley, Carl Percival, and James D. Allan
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
We are presenting a new method to apportion Black Carbon/soot into multiple sources through the inclusion of fullerene and metal data into SP-AMS factorisation. While this is itself would be considered a technical development, we can present a budget of contributions to measured BC during the event studied, including the conclusion that fireworks contributed little compared to the bonfire, traffic and domestic wood burning emissions.
Sobhan Kumar Kompalli, Surendran Nair Suresh Babu, Krishnaswamy Krishnamoorthy, Sreedharan Krishnakumari Satheesh, Mukunda M. Gogoi, Vijayakumar S. Nair, Jayachandran V, Dantong Liu, Michael Flynn, and Hugh Coe
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACP
Jonathan W. Taylor, Huihui Wu, Kate Szpek, Keith Bower, Ian Crawford, Michael J. Flynn, Paul I. Williams, James Dorsey, Justin M. Langridge, Michael I. Cotterell, Cathryn Fox, Nicholas W. Davies, Jim M. Haywood, and Hugh Coe
Atmos. Chem. Phys., 20, 11201–11221,Short summary
Every year, huge plumes of smoke hundreds of miles wide travel over the south Atlantic Ocean from fires in central and southern Africa. These plumes absorb the sun’s energy and warm the climate. We used airborne optical instrumentation to determine how absorbing the smoke was as well as the relative importance of black and brown carbon. We also tested different ways of simulating these properties that could be used in a climate model.
Konstantinos-Matthaios Doulgeris, Mika Komppula, Sami Romakkaniemi, Antti-Pekka Hyvärinen, Veli-Matti Kerminen, and David Brus
Atmos. Meas. Tech., 13, 5129–5147,Short summary
We intercompared three cloud spectrometers ground setups in conditions with frequently occurring supercooled clouds. The measurements were conducted during the Pallas Cloud Experiment (PaCE) in 2013, in the Finnish sub-Arctic region at Sammaltunturi station. The main meteorological parameters influencing the spectrometers' performance was the wind direction. Final recommendations and our view on the main limitations of each spectrometer ground setup are presented.
Archit Mehra, Jordan E. Krechmer, Andrew Lambe, Chinmoy Sarkar, Leah Williams, Farzaneh Khalaj, Alex Guenther, John Jayne, Hugh Coe, Douglas Worsnop, Celia Faiola, and Manjula Canagaratna
Atmos. Chem. Phys., 20, 10953–10965,Short summary
Emissions of volatile organic compounds (VOCs) from plants are important for tropospheric ozone and secondary organic aerosol (SOA) formation. Real plant emissions are much more diverse than the few proxies widely used for studies of plant SOA. Here we present the first study of SOA from Californian sage plants and the oxygenated monoterpenes representing their major emissions. We identify SOA products and show the importance of the formation of highly oxygenated organic molecules and oligomers.
Innocent Kudzotsa, Harri Kokkola, Juha Tonttila, Tomi Raatikainen, and Sami Romakkaniemi
Atmos. Chem. Phys. Discuss.,
Revised manuscript has not been submitted
Ernesto Reyes-Villegas, Upasana Panda, Eoghan Darbyshire, James M. Cash, Rutambhara Joshi, Ben Langford, Chiara F. Di Marco, Neil Mullinger, W. Joe F. Acton, Will Drysdale, Eiko Nemitz, Michael Flynn, Aristeidis Voliotis, Gordon McFiggans, Hugh Coe, James Lee, C. Nicholas Hewitt, Mathew R. Heal, Sachin S. Gunthe, Shivani, Ranu Gadi, Siddhartha Singh, Vijay Soni, and James D. Allan
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
The work presented in this manuscript shows the first multisite online measurements of PM1 in Delhi, India. It covers measurements over different seasons in Old and New Delhi during 2018. OA source apportionment was performed using PMF. Traffic showed to be the main primary aerosol source for both OA and BC, as seen with the PMF analysis and aethalometer model analysis. This indicates that in Delhi control of primary traffic exhaust emissions would make a significant reduction to air pollution.
David Topping, David Watts, Hugh Coe, James Evans, Thomas J. Bannan, Douglas Lowe, Caroline Jay, and Jonathan W. Taylor
Geosci. Model Dev. Discuss.,
Revised manuscript has not been submittedShort summary
Time-series forecasting methods have often been used to mitigate some of the challenges associated with deploying chemical transport models. In this study we deploy and evaluate Facebook’s Prophetmodel v0.6 in predicting hourly concentrations of Nitrogen Dioxide [NO2]. et. Overall we find the Prophet model offers a relatively effective and simple way to make predictions about NO2 at local levels.
Archit Mehra, Yuwei Wang, Jordan E. Krechmer, Andrew Lambe, Francesca Majluf, Melissa A. Morris, Michael Priestley, Thomas J. Bannan, Daniel J. Bryant, Kelly L. Pereira, Jacqueline F. Hamilton, Andrew R. Rickard, Mike J. Newland, Harald Stark, Philip Croteau, John T. Jayne, Douglas R. Worsnop, Manjula R. Canagaratna, Lin Wang, and Hugh Coe
Atmos. Chem. Phys., 20, 9783–9803,Short summary
Aromatic volatile organic compounds (VOCs) emitted from anthropogenic activity are important for tropospheric ozone and secondary organic aerosol (SOA) formation. Here we present a detailed chemical characterisation of SOA from four C9-aromatic isomers and a polycyclic aromatic hydrocarbon (PAH). We identify and compare their oxidation products in the gas and particle phases, showing the different relative importance of oxidation pathways and proportions of highly oxygenated organic molecules.
Yuwei Wang, Archit Mehra, Jordan E. Krechmer, Gan Yang, Xiaoyu Hu, Yiqun Lu, Andrew Lambe, Manjula Canagaratna, Jianmin Chen, Douglas Worsnop, Hugh Coe, and Lin Wang
Atmos. Chem. Phys., 20, 9563–9579,Short summary
A series of OH-initiated oxidation experiments of trimethylbenzene were investigated in the absence and presence of NOx. Many C9 products with 1–11 oxygen atoms and C18 products presumably formed from dimerization of C9 peroxy radicals were observed, hinting at the extensive existence of autoxidation and accretion reaction pathways. The presence of NOx would suppress the formation of highly oxygenated C18 molecules and enhance the formation of organonitrates and even dinitrate compounds.
Jill S. Johnson, Leighton A. Regayre, Masaru Yoshioka, Kirsty J. Pringle, Steven T. Turnock, Jo Browse, David M. H. Sexton, John W. Rostron, Nick A. J. Schutgens, Daniel G. Partridge, Dantong Liu, James D. Allan, Hugh Coe, Aijun Ding, David D. Cohen, Armand Atanacio, Ville Vakkari, Eija Asmi, and Ken S. Carslaw
Atmos. Chem. Phys., 20, 9491–9524,Short summary
We use over 9000 monthly aggregated grid-box measurements of aerosol to constrain the uncertainty in the HadGEM3-UKCA climate model. Measurements of AOD, PM2.5, particle number concentrations, sulfate and organic mass concentrations are compared to 1 million
variantsof the model using an implausibility metric. Despite many compensating effects in the model, the procedure constrains the probability distributions of many parameters, and direct radiative forcing uncertainty is reduced by 34 %.
Maria Filioglou, Elina Giannakaki, John Backman, Jutta Kesti, Anne Hirsikko, Ronny Engelmann, Ewan O'Connor, Jari T. T. Leskinen, Xiaoxia Shang, Hannele Korhonen, Heikki Lihavainen, Sami Romakkaniemi, and Mika Komppula
Atmos. Chem. Phys., 20, 8909–8922,Short summary
Dust optical properties are region-dependent. Saharan, Asian, and Arabian dusts do not pose similar optical properties in terms of lidar ratios; thus, a universal lidar ratio for dust particles will lead to biases. The present study analyses observations over the United Arab Emirates, quantifying the optical and geometrical extents of the aerosol layers in the area, providing at the same time the Arabian dust properties along with chemical analysis of dust samples collected in the region.
Daniel J. Bryant, William J. Dixon, James R. Hopkins, Rachel E. Dunmore, Kelly L. Pereira, Marvin Shaw, Freya A. Squires, Thomas J. Bannan, Archit Mehra, Stephen D. Worrall, Asan Bacak, Hugh Coe, Carl J. Percival, Lisa K. Whalley, Dwayne E. Heard, Eloise J. Slater, Bin Ouyang, Tianqu Cui, Jason D. Surratt, Di Liu, Zongbo Shi, Roy Harrison, Yele Sun, Weiqi Xu, Alastair C. Lewis, James D. Lee, Andrew R. Rickard, and Jacqueline F. Hamilton
Atmos. Chem. Phys., 20, 7531–7552,Short summary
Using the chemical composition of offline filter samples, we report that a large share of oxidized organic aerosol in Beijing during summer is due to isoprene secondary organic aerosol (iSOA). iSOA organosulfates showed a strong correlation with the product of ozone and particulate sulfate. This highlights the role of both photochemistry and the availability of particulate sulfate in heterogeneous reactions and further demonstrates that iSOA formation is controlled by anthropogenic emissions.
Thomas Kühn, Kaarle Kupiainen, Tuuli Miinalainen, Harri Kokkola, Ville-Veikko Paunu, Anton Laakso, Juha Tonttila, Rita Van Dingenen, Kati Kulovesi, Niko Karvosenoja, and Kari E. J. Lehtinen
Atmos. Chem. Phys., 20, 5527–5546,Short summary
We investigate the effects of black carbon (BC) mitigation on Arctic climate and human health, accounting for the concurrent reduction of other aerosol species. While BC is attributed a net warming effect on climate, most other aerosol species cool the planet. We find that the direct radiative effect of mitigating BC induces cooling, while aerosol–cloud effects offset this cooling and introduce large uncertainties. Furthermore, the reduced aerosol emissions reduce human mortality considerably.
William T. Morgan, James D. Allan, Stéphane Bauguitte, Eoghan Darbyshire, Michael J. Flynn, James Lee, Dantong Liu, Ben Johnson, Jim Haywood, Karla M. Longo, Paulo E. Artaxo, and Hugh Coe
Atmos. Chem. Phys., 20, 5309–5326,Short summary
We flew a large atmospheric research aircraft across a number of different environments in the Amazon basin during the 2012 biomass burning season. Smoke from fires builds up and has a significant impact on weather, climate, health and natural ecosystems. Our goal was to quantify changes in the properties of the smoke emitted by fires as it is transported through the atmosphere. We found that the major control on the properties of the smoke was due to differences in the fires themselves.
Siddika Celik, Frank Drewnick, Friederike Fachinger, James Brooks, Eoghan Darbyshire, Hugh Coe, Jean-Daniel Paris, Philipp G. Eger, Jan Schuladen, Ivan Tadic, Nils Friedrich, Dirk Dienhart, Bettina Hottmann, Horst Fischer, John N. Crowley, Hartwig Harder, and Stephan Borrmann
Atmos. Chem. Phys., 20, 4713–4734,Short summary
Analysis of 252 ship emission plumes in the Mediterranean Sea and around the Arabian Peninsula examined particulate- and gas-phase characteristics. By identifying the corresponding ships, source features and plume age were determined. Emission factors (amount of pollutant per kilogram of fuel burned) were calculated and investigated for dependencies on source characteristics, atmospheric conditions, and transport time, providing insight into the most relevant influences on ship emissions.
Sobhan Kumar Kompalli, Surendran Nair Suresh Babu, Sreedharan Krishnakumari Satheesh, Krishnaswamy Krishna Moorthy, Trupti Das, Ramasamy Boopathy, Dantong Liu, Eoghan Darbyshire, James D. Allan, James Brooks, Michael J. Flynn, and Hugh Coe
Atmos. Chem. Phys., 20, 3965–3985,
Mohanan R. Manoj, Sreedharan K. Satheesh, Krishnaswamy K. Moorthy, and Hugh Coe
Atmos. Chem. Phys., 20, 4031–4046,Short summary
The study reports the observation of highly absorbing aerosol layers at high altitudes (1–2.5 km) prior to monsoon and during its development over the Indian region and quantifies its climate impacts. The absorption of solar radiation in these layers perturbs the onset of monsoon through the impact on the atmospheric stability. When height-resolved values of single scattering albedo (SSA) are used in a radiative transfer model, a maximum heating ~1 K d (~twice that using SSA) is obtained.
Chenjie Yu, Dantong Liu, Kurtis Broda, Rutambhara Joshi, Jason Olfert, Yele Sun, Pingqing Fu, Hugh Coe, and James D. Allan
Atmos. Chem. Phys., 20, 3645–3661,Short summary
This study presents the first atmospheric application of a new morphology-independent measurement for the quantification of the mixing state of rBC-containing particles in urban Beijing as part of the UK–China APHH campaign. An inversion method has been applied for better quantification of rBC mixing state. The mass-resolved rBC mixing state information presented here has implications for detailed models of BC, its optical properties and its atmospheric life cycle.
Sidhant J. Pai, Colette L. Heald, Jeffrey R. Pierce, Salvatore C. Farina, Eloise A. Marais, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Ann M. Middlebrook, Hugh Coe, John E. Shilling, Roya Bahreini, Justin H. Dingle, and Kennedy Vu
Atmos. Chem. Phys., 20, 2637–2665,Short summary
Aerosols in the atmosphere have significant health and climate impacts. Organic aerosol (OA) accounts for a large fraction of the total aerosol burden, but models have historically struggled to accurately simulate it. This study compares two very different OA model schemes and evaluates them against a suite of globally distributed airborne measurements with the goal of providing insight into the strengths and weaknesses of each approach across different environments.
Yu Wang, Ying Chen, Zhijun Wu, Dongjie Shang, Yuxuan Bian, Zhuofei Du, Sebastian H. Schmitt, Rong Su, Georgios I. Gkatzelis, Patrick Schlag, Thorsten Hohaus, Aristeidis Voliotis, Keding Lu, Limin Zeng, Chunsheng Zhao, M. Rami Alfarra, Gordon McFiggans, Alfred Wiedensohler, Astrid Kiendler-Scharr, Yuanhang Zhang, and Min Hu
Atmos. Chem. Phys., 20, 2161–2175,Short summary
Severe haze events, with high particulate nitrate (pNO3−) burden, frequently prevail in Beijing. In this study, we demonstrate a mutual-promotion effect between aerosol water uptake and pNO3− formation backed up by theoretical calculations and field observations throughout a typical pNO3−-dominated haze event in Beijing wintertime. This self-amplified mutual-promotion effect between aerosol water content and particulate nitrate can rapidly deteriorate air quality and degrade visibility.
Kathryn Fowler, Paul Connolly, and David Topping
Atmos. Chem. Phys., 20, 683–698,Short summary
Observations of low–temperature cirrus clouds have found unexpectedly low ice crystal numbers and high supersaturations, suggesting an incomplete understanding of the freezing mechanisms under these conditions. The existence of viscous organic aerosol has offered alternative ice nucleation pathways, which have been observed in laboratory studies. We have developed the first cloud parcel model to investigate the effect of viscosity on ice nucleation.
Olga Garmash, Matti P. Rissanen, Iida Pullinen, Sebastian Schmitt, Oskari Kausiala, Ralf Tillmann, Defeng Zhao, Carl Percival, Thomas J. Bannan, Michael Priestley, Åsa M. Hallquist, Einhard Kleist, Astrid Kiendler-Scharr, Mattias Hallquist, Torsten Berndt, Gordon McFiggans, Jürgen Wildt, Thomas F. Mentel, and Mikael Ehn
Atmos. Chem. Phys., 20, 515–537,Short summary
Highly oxygenated organic molecules (HOMs) facilitate aerosol formation in the atmosphere. Using NO3− chemical ionization mass spectrometry we investigated HOM composition and yield in oxidation of aromatic compounds at different reactant concentrations, in the presence of NOx and seed aerosol. Higher OH concentrations increased HOM yield, suggesting multiple oxidation steps, and affected HOM composition, potentially explaining in part discrepancies in published secondary organic aerosol yields.
Ying Chen, Oliver Wild, Edmund Ryan, Saroj Kumar Sahu, Douglas Lowe, Scott Archer-Nicholls, Yu Wang, Gordon McFiggans, Tabish Ansari, Vikas Singh, Ranjeet S. Sokhi, Alex Archibald, and Gufran Beig
Atmos. Chem. Phys., 20, 499–514,Short summary
PM2.5 and O3 are two major air pollutants. Some mitigation strategies focusing on reducing PM2.5 may lead to substantial increase in O3. We use statistical emulation combined with atmospheric transport model to perform thousands of sensitivity numerical studies to identify the major sources of PM2.5 and O3 and to develop strategies targeted at both pollutants. Our scientific evidence suggests that regional coordinated emission control is required to mitigate PM2.5 whilst preventing O3 increase.
Sophie L. Haslett, Jonathan W. Taylor, Mathew Evans, Eleanor Morris, Bernhard Vogel, Alima Dajuma, Joel Brito, Anneke M. Batenburg, Stephan Borrmann, Johannes Schneider, Christiane Schulz, Cyrielle Denjean, Thierry Bourrianne, Peter Knippertz, Régis Dupuy, Alfons Schwarzenböck, Daniel Sauer, Cyrille Flamant, James Dorsey, Ian Crawford, and Hugh Coe
Atmos. Chem. Phys., 19, 15217–15234,Short summary
Three aircraft datasets from the DACCIWA campaign in summer 2016 are used here to show there is a background mass of pollution present in the lower atmosphere in southern West Africa. We suggest that this likely comes from biomass burning in central and southern Africa, which has been carried into the region over the Atlantic Ocean. This would have a negative health impact on populations living near the coast and may alter the impact of growing city emissions on cloud formation and the monsoon.
Leigh R. Crilley, Louisa J. Kramer, Bin Ouyang, Jun Duan, Wenqian Zhang, Shengrui Tong, Maofa Ge, Ke Tang, Min Qin, Pinhua Xie, Marvin D. Shaw, Alastair C. Lewis, Archit Mehra, Thomas J. Bannan, Stephen D. Worrall, Michael Priestley, Asan Bacak, Hugh Coe, James Allan, Carl J. Percival, Olalekan A. M. Popoola, Roderic L. Jones, and William J. Bloss
Atmos. Meas. Tech., 12, 6449–6463,Short summary
Nitrous acid (HONO) is key species for understanding tropospheric chemistry, yet accurate and precise measurements are challenging. Here we report an inter–comparison exercise of a number of instruments that measured HONO in a highly polluted location (Beijing). All instruments agreed on the temporal trends yet displayed divergence in absolute concentrations. The cause of this divergence was unclear, but it may in part be due to spatial variability in instrument location.
Stephanie Bohlmann, Xiaoxia Shang, Elina Giannakaki, Maria Filioglou, Annika Saarto, Sami Romakkaniemi, and Mika Komppula
Atmos. Chem. Phys., 19, 14559–14569,Short summary
Measurements of the multiwavelength Raman polarization lidar PollyXT have been combined with measurements of pollen type and concentration using a traditional pollen sampler at the rural forest site in Vehmasmäki, Finland. High particle depolarization ratios were observed during an intense pollination event of birch pollen occasionally mixed with spruce pollen. Our observations illustrate the potential of the particle depolarization ratio to track pollen grains in the atmosphere.
Anina Gilgen, Stiig Wilkenskjeld, Jed O. Kaplan, Thomas Kühn, and Ulrike Lohmann
Clim. Past, 15, 1885–1911,Short summary
Using the global aerosol–climate model ECHAM-HAM-SALSA, the effect of humans on European climate in the Roman Empire was quantified. Both land use and novel estimates of anthropogenic aerosol emissions were considered. We conducted simulations with fixed sea-surface temperatures to gain a first impression about the anthropogenic impact. While land use effects induced a regional warming for one of the reconstructions, aerosol emissions led to a cooling associated with aerosol–cloud interactions.
James Brooks, Dantong Liu, James D. Allan, Paul I. Williams, Jim Haywood, Ellie J. Highwood, Sobhan K. Kompalli, S. Suresh Babu, Sreedharan K. Satheesh, Andrew G. Turner, and Hugh Coe
Atmos. Chem. Phys., 19, 13079–13096,Short summary
Our study presents an analysis of the vertical and horizontal black carbon properties across northern India using aircraft measurements. The Indo-Gangetic Plain saw the greatest black carbon mass concentrations during the pre-monsoon season. Two black carbon modes were recorded: a small black carbon mode (traffic emissions) in the north-west and a moderately coated mode (solid-fuel emissions) in the Indo-Gangetic Plain. In the vertical profile, absorption properties increase with height.
Duncan Watson-Parris, Nick Schutgens, Carly Reddington, Kirsty J. Pringle, Dantong Liu, James D. Allan, Hugh Coe, Ken S. Carslaw, and Philip Stier
Atmos. Chem. Phys., 19, 11765–11790,Short summary
The vertical distribution of aerosol in the atmosphere affects its ability to act as cloud condensation nuclei and changes the amount of sunlight it absorbs or reflects. Common global measurements of aerosol provide no information about this vertical distribution. Using a global collection of in situ aircraft measurements to compare with an aerosol–climate model (ECHAM-HAM), we explore the key processes controlling this distribution and find that wet removal plays a key role.
Carly L. Reddington, William T. Morgan, Eoghan Darbyshire, Joel Brito, Hugh Coe, Paulo Artaxo, Catherine E. Scott, John Marsham, and Dominick V. Spracklen
Atmos. Chem. Phys., 19, 9125–9152,Short summary
We use an aerosol model and observations to explore model representation of aerosol emissions from fires in the Amazon. We find that observed aerosol concentrations are captured by the model over deforestation fires in the western Amazon but underestimated over savanna fires in the Cerrado environment. The model underestimates observed aerosol optical depth (AOD) even when the observed aerosol vertical profile is reproduced. We suggest this may be due to uncertainties in the AOD calculation.
Jonathan W. Taylor, Sophie L. Haslett, Keith Bower, Michael Flynn, Ian Crawford, James Dorsey, Tom Choularton, Paul J. Connolly, Valerian Hahn, Christiane Voigt, Daniel Sauer, Régis Dupuy, Joel Brito, Alfons Schwarzenboeck, Thierry Bourriane, Cyrielle Denjean, Phil Rosenberg, Cyrille Flamant, James D. Lee, Adam R. Vaughan, Peter G. Hill, Barbara Brooks, Valéry Catoire, Peter Knippertz, and Hugh Coe
Atmos. Chem. Phys., 19, 8503–8522,Short summary
Low-level clouds cover a wide area of southern West Africa (SWA) and play an important role in the region's climate, reflecting sunlight away from the surface. We performed aircraft measurements of aerosols and clouds over SWA during the 2016 summer monsoon and found pollution, and polluted clouds, across the whole region. Smoke from biomass burning in Central Africa is transported to West Africa, causing a polluted background which limits the effect of local pollution on cloud properties.
Jamie M. Kelly, Ruth M. Doherty, Fiona M. O'Connor, Graham W. Mann, Hugh Coe, and Dantong Liu
Geosci. Model Dev., 12, 2539–2569,Short summary
This study develops the representation of secondary organic aerosol (SOA) within a global chemistry–climate model (UKCA). Both dry and wet deposition within the UKCA model are extended to consider precursors of SOA. The oxidation mechanism describing SOA formation is also extended by adding a reaction intermediate, with SOA yields that are dependent on oxidant concentrations.
Zongbo Shi, Tuan Vu, Simone Kotthaus, Roy M. Harrison, Sue Grimmond, Siyao Yue, Tong Zhu, James Lee, Yiqun Han, Matthias Demuzere, Rachel E. Dunmore, Lujie Ren, Di Liu, Yuanlin Wang, Oliver Wild, James Allan, W. Joe Acton, Janet Barlow, Benjamin Barratt, David Beddows, William J. Bloss, Giulia Calzolai, David Carruthers, David C. Carslaw, Queenie Chan, Lia Chatzidiakou, Yang Chen, Leigh Crilley, Hugh Coe, Tie Dai, Ruth Doherty, Fengkui Duan, Pingqing Fu, Baozhu Ge, Maofa Ge, Daobo Guan, Jacqueline F. Hamilton, Kebin He, Mathew Heal, Dwayne Heard, C. Nicholas Hewitt, Michael Hollaway, Min Hu, Dongsheng Ji, Xujiang Jiang, Rod Jones, Markus Kalberer, Frank J. Kelly, Louisa Kramer, Ben Langford, Chun Lin, Alastair C. Lewis, Jie Li, Weijun Li, Huan Liu, Junfeng Liu, Miranda Loh, Keding Lu, Franco Lucarelli, Graham Mann, Gordon McFiggans, Mark R. Miller, Graham Mills, Paul Monk, Eiko Nemitz, Fionna O'Connor, Bin Ouyang, Paul I. Palmer, Carl Percival, Olalekan Popoola, Claire Reeves, Andrew R. Rickard, Longyi Shao, Guangyu Shi, Dominick Spracklen, David Stevenson, Yele Sun, Zhiwei Sun, Shu Tao, Shengrui Tong, Qingqing Wang, Wenhua Wang, Xinming Wang, Xuejun Wang, Zifang Wang, Lianfang Wei, Lisa Whalley, Xuefang Wu, Zhijun Wu, Pinhua Xie, Fumo Yang, Qiang Zhang, Yanli Zhang, Yuanhang Zhang, and Mei Zheng
Atmos. Chem. Phys., 19, 7519–7546,Short summary
APHH-Beijing is a collaborative international research programme to study the sources, processes and health effects of air pollution in Beijing. This introduction to the special issue provides an overview of (i) the APHH-Beijing programme, (ii) the measurement and modelling activities performed as part of it and (iii) the air quality and meteorological conditions during joint intensive field campaigns as a core activity within APHH-Beijing.
Dantong Liu, Rutambhara Joshi, Junfeng Wang, Chenjie Yu, James D. Allan, Hugh Coe, Michael J. Flynn, Conghui Xie, James Lee, Freya Squires, Simone Kotthaus, Sue Grimmond, Xinlei Ge, Yele Sun, and Pingqing Fu
Atmos. Chem. Phys., 19, 6749–6769,Short summary
This study provides source attribution and characterization of BC in the Beijing urban environment in both winter and summer. For the first time, the physically and chemically based source apportionments are compared to evaluate the primary source contribution and secondary processing of BC-containing particles. A method is proposed to isolate the BC from the transportation sector and coal combustion sources.
Eoghan Darbyshire, William T. Morgan, James D. Allan, Dantong Liu, Michael J. Flynn, James R. Dorsey, Sebastian J. O'Shea, Douglas Lowe, Kate Szpek, Franco Marenco, Ben T. Johnson, Stephane Bauguitte, Jim M. Haywood, Joel F. Brito, Paulo Artaxo, Karla M. Longo, and Hugh Coe
Atmos. Chem. Phys., 19, 5771–5790,Short summary
A novel analysis of aerosol and gas-phase vertical profiles shows a marked regional pollution contrast: composition is driven by the fire regime and vertical distribution is driven by thermodynamics. These drivers ought to be well represented in simulations to ensure realistic prediction of climate and air quality impacts. The BC : CO ratio in haze and plumes increases with altitude – long-range transport or fire stage coupled to plume dynamics may be responsible. Further enquiry is advocated.
James Brooks, James D. Allan, Paul I. Williams, Dantong Liu, Cathryn Fox, Jim Haywood, Justin M. Langridge, Ellie J. Highwood, Sobhan K. Kompalli, Debbie O'Sullivan, Suresh S. Babu, Sreedharan K. Satheesh, Andrew G. Turner, and Hugh Coe
Atmos. Chem. Phys., 19, 5615–5634,Short summary
Our study, for the first time, presents measurements of aerosol chemical composition and physical characteristics across northern India in the pre-monsoon and monsoon seasons of 2016 using the FAAM BAe-146 UK research aircraft. Across northern India, an elevated aerosol layer dominated by sulfate aerosol exists that diminishes with monsoon arrival. The Indo-Gangetic Plain (IGP) boundary layer is dominated by organics, whereas outside the IGP sulfate dominates with increased scattering aerosol.
Mona Kurppa, Antti Hellsten, Pontus Roldin, Harri Kokkola, Juha Tonttila, Mikko Auvinen, Christoph Kent, Prashant Kumar, Björn Maronga, and Leena Järvi
Geosci. Model Dev., 12, 1403–1422,Short summary
This paper describes the implementation of a sectional aerosol module, SALSA, into the PALM model system 6.0. The first evaluation study shows excellent agreements with measurements. Furthermore, we show that ignoring the dry deposition of aerosol particles can overestimate aerosol number concentrations by 20 %, whereas condensation and dissolutional growth increase the total aerosol mass by over 10 % in this specific urban environment.
Thomas J. Bannan, Michael Le Breton, Michael Priestley, Stephen D. Worrall, Asan Bacak, Nicholas A. Marsden, Archit Mehra, Julia Hammes, Mattias Hallquist, M. Rami Alfarra, Ulrich K. Krieger, Jonathan P. Reid, John Jayne, Wade Robinson, Gordon McFiggans, Hugh Coe, Carl J. Percival, and Dave Topping
Atmos. Meas. Tech., 12, 1429–1439,Short summary
The Filter Inlet for Gases and AEROsols (FIGAERO) is an inlet designed to be coupled with a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) and provides simultaneous molecular information relating to both the gas- and particle-phase samples. This method has been used to extract vapour pressures of compounds whilst giving quantitative concentrations in the particle phase. Here we detail an ideal set of benchmark compounds for characterization of the FIGAERO.
Nicholas A. Marsden, Romy Ullrich, Ottmar Möhler, Stine Eriksen Hammer, Konrad Kandler, Zhiqiang Cui, Paul I. Williams, Michael J. Flynn, Dantong Liu, James D. Allan, and Hugh Coe
Atmos. Chem. Phys., 19, 2259–2281,Short summary
The composition of airborne dust influences climate and ecosystems but its measurements presents a huge analytical challenge. Using online single-particle mass spectrometry, we demonstrate differences in mineralogy and mixing state can be detected in real time in both laboratory studies and ambient measurements. The results provide insights into the temporal and spatial evolution of dust properties that will be useful for aerosol–cloud interaction studies and dust cycle modelling.
Sophie L. Haslett, Jonathan W. Taylor, Konrad Deetz, Bernhard Vogel, Karmen Babić, Norbert Kalthoff, Andreas Wieser, Cheikh Dione, Fabienne Lohou, Joel Brito, Régis Dupuy, Alfons Schwarzenboeck, Paul Zieger, and Hugh Coe
Atmos. Chem. Phys., 19, 1505–1520,Short summary
As the population in West Africa grows and air pollution increases, it is becoming ever more important to understand the effects of this pollution on the climate and on health. Aerosol particles can grow by absorbing water from the air around them. This paper shows that during the monsoon season, aerosol particles in the region are likely to grow significantly because of the high moisture in the air. This means that climate effects from increasing pollution will be enhanced.
Junfeng Wang, Dantong Liu, Xinlei Ge, Yangzhou Wu, Fuzhen Shen, Mindong Chen, Jian Zhao, Conghui Xie, Qingqing Wang, Weiqi Xu, Jie Zhang, Jianlin Hu, James Allan, Rutambhara Joshi, Pingqing Fu, Hugh Coe, and Yele Sun
Atmos. Chem. Phys., 19, 447–458,Short summary
This work is part of the UK-China APHH campaign. We used a laser-only Aerodyne soot particle aerosol mass spectrometer, for the first time, to investigate the concentrations, size distributions and chemical compositions for those ambient submicron aerosol particles only with black carbon as cores. Our findings are valuable to understand the BC properties and processes in the densely populated megacities.
Conghui Xie, Weiqi Xu, Junfeng Wang, Qingqing Wang, Dantong Liu, Guiqian Tang, Ping Chen, Wei Du, Jian Zhao, Yingjie Zhang, Wei Zhou, Tingting Han, Qingyun Bian, Jie Li, Pingqing Fu, Zifa Wang, Xinlei Ge, James Allan, Hugh Coe, and Yele Sun
Atmos. Chem. Phys., 19, 165–179,Short summary
We present the first simultaneous real-time online measurements of aerosol optical properties at ground level and at 260 m on a meteorological tower in urban Beijing in winter. The vertical similarities and differences in scattering and absorption coefficients were characterized. The increases in MAC of BC were mainly associated with the coating materials on rBC. Coal combustion was the dominant source contribution of brown carbon followed by biomass burning and SOA in winter in Beijing.
Claire L. Ryder, Franco Marenco, Jennifer K. Brooke, Victor Estelles, Richard Cotton, Paola Formenti, James B. McQuaid, Hannah C. Price, Dantong Liu, Patrick Ausset, Phil D. Rosenberg, Jonathan W. Taylor, Tom Choularton, Keith Bower, Hugh Coe, Martin Gallagher, Jonathan Crosier, Gary Lloyd, Eleanor J. Highwood, and Benjamin J. Murray
Atmos. Chem. Phys., 18, 17225–17257,Short summary
Every year, millions of tons of Saharan dust particles are carried across the Atlantic by the wind, where they can affect weather patterns and climate. Their sizes span orders of magnitude, but the largest (over 10 microns – around the width of a human hair) are difficult to measure and few observations exist. Here we show new aircraft observations of large dust particles, finding more than we would expect, and we quantify their properties which allow them to interact with atmospheric radiation.
Dawei Hu, David Topping, and Gordon McFiggans
Atmos. Chem. Phys., 18, 14925–14937,Short summary
Co-condensation of inorganic or organic vapours on growing droplets could significantly enhance both CCN and cloud droplet number concentration, thereby influencing climate. Until now, there has been very few direct observational evidence of this process. We exposed involatile inorganic particles to a moist atmosphere containing a controlled amount of an organic semi-volatile vapour. We measured a much greater growth of the particles than if they had only been exposed to water vapour.
Christopher Dearden, Adrian Hill, Hugh Coe, and Tom Choularton
Atmos. Chem. Phys., 18, 14253–14269,Short summary
We perform computer simulations of the life cycle of low-lying clouds over southern West Africa during the monsoon season. Such clouds tend not to produce much precipitation, but they do affect the regional climate by modifying the amount of sunlight reaching the surface. The aim of this work is to understand the factors that influence the growth and break-up of these clouds. We show that the number of water droplets contained within the clouds affects how quickly they dissipate.
Konrad Deetz, Heike Vogel, Sophie Haslett, Peter Knippertz, Hugh Coe, and Bernhard Vogel
Atmos. Chem. Phys., 18, 14271–14295,Short summary
Water uptake can significantly increase the size and therefore alters the optical properties of aerosols. Our model study reveals that the high moisture and aerosol burden in the southern West African monsoon layer makes it favorable to quantify properties that determine the aerosol liquid water content and its impact on the aerosol optical depth and radiative transfer. Especially in moist tropical environments the relative humidity impact on AOD has to be considered in atmospheric models.
Harri Kokkola, Thomas Kühn, Anton Laakso, Tommi Bergman, Kari E. J. Lehtinen, Tero Mielonen, Antti Arola, Scarlet Stadtler, Hannele Korhonen, Sylvaine Ferrachat, Ulrike Lohmann, David Neubauer, Ina Tegen, Colombe Siegenthaler-Le Drian, Martin G. Schultz, Isabelle Bey, Philip Stier, Nikos Daskalakis, Colette L. Heald, and Sami Romakkaniemi
Geosci. Model Dev., 11, 3833–3863,Short summary
In this paper we present a global aerosol–chemistry–climate model with the focus on its representation for atmospheric aerosol particles. In the model, aerosols are simulated using the aerosol module SALSA2.0, which in this paper is compared to satellite, ground, and aircraft-based observations of the properties of atmospheric aerosol. Based on this study, the model simulated aerosol properties compare well with the observations.
Michael Priestley, Michael le Breton, Thomas J. Bannan, Stephen D. Worrall, Asan Bacak, Andrew R. D. Smedley, Ernesto Reyes-Villegas, Archit Mehra, James Allan, Ann R. Webb, Dudley E. Shallcross, Hugh Coe, and Carl J. Percival
Atmos. Chem. Phys., 18, 13481–13493,
Wei Zhou, Jian Zhao, Bin Ouyang, Archit Mehra, Weiqi Xu, Yuying Wang, Thomas J. Bannan, Stephen D. Worrall, Michael Priestley, Asan Bacak, Qi Chen, Conghui Xie, Qingqing Wang, Junfeng Wang, Wei Du, Yingjie Zhang, Xinlei Ge, Penglin Ye, James D. Lee, Pingqing Fu, Zifa Wang, Douglas Worsnop, Roderic Jones, Carl J. Percival, Hugh Coe, and Yele Sun
Atmos. Chem. Phys., 18, 11581–11597,Short summary
We present measurements of gas-phase N2O5 and ClNO2 by ToF-CIMS during summer in urban Beijing as part of the APHH campaign. High reactivity of N2O5 indicative of active nocturnal chemistry was observed. The lifetime of N2O5 as a function of aerosol surface area and relative humidity was characterized, and N2O5 uptake coefficients were estimated. We also found that the N2O5 loss in this study is mainly attributed to its indirect loss via reactions of NO3 with VOCs and NO.
Matthew Crooks, Paul Connolly, and Gordon McFiggans
Geosci. Model Dev., 11, 3261–3278,Short summary
Clouds form when water condenses onto particles in the atmosphere and the size and chemical composition of these particles can have a large influence over how much water condenses and the subsequent formation of cloud. Additional gases exist in the atmosphere that can condense onto the aerosol particles and change their composition. We present a fast and efficient method of calculating the effect of atmospheric gases on the formation of cloud that can be used in climate and weather models.
Scarlet Stadtler, Thomas Kühn, Sabine Schröder, Domenico Taraborrelli, Martin G. Schultz, and Harri Kokkola
Geosci. Model Dev., 11, 3235–3260,Short summary
Atmospheric aerosols interact with our climate system and have adverse health effects. Nevertheless, these particles are a source of uncertainty in climate projections and the formation process of secondary aerosols formed by organic gas-phase precursors is particularly not fully understood. In order to gain a deeper understanding of secondary organic aerosol formation, this model system explicitly represents gas-phase and aerosol formation processes. Finally, this allows for process discussion.
Kelly L. Pereira, Rachel Dunmore, James Whitehead, M. Rami Alfarra, James D. Allan, Mohammed S. Alam, Roy M. Harrison, Gordon McFiggans, and Jacqueline F. Hamilton
Atmos. Chem. Phys., 18, 11073–11096,Short summary
Exhaust emissions from a light-duty diesel engine were introduced into an atmospheric simulation chamber which was used as a holding-cell for sampling, allowing instruments capable of providing detailed chemical speciation of exhaust gas emissions to be used. The effect of different engine conditions on the exhaust gas composition was investigated. The exhaust composition changed considerably due to two influencing factors, engine combustion and diesel oxidative catalyst efficiency.
Robin G. Stevens, Katharina Loewe, Christopher Dearden, Antonios Dimitrelos, Anna Possner, Gesa K. Eirund, Tomi Raatikainen, Adrian A. Hill, Benjamin J. Shipway, Jonathan Wilkinson, Sami Romakkaniemi, Juha Tonttila, Ari Laaksonen, Hannele Korhonen, Paul Connolly, Ulrike Lohmann, Corinna Hoose, Annica M. L. Ekman, Ken S. Carslaw, and Paul R. Field
Atmos. Chem. Phys., 18, 11041–11071,Short summary
We perform a model intercomparison of summertime high Arctic clouds. Observed concentrations of aerosol particles necessary for cloud formation fell to extremely low values, coincident with a transition from cloudy to nearly cloud-free conditions. Previous analyses have suggested that at these low concentrations, the radiative properties of the clouds are determined primarily by these particle concentrations. The model results strongly support this hypothesis.
Konrad Deetz, Heike Vogel, Peter Knippertz, Bianca Adler, Jonathan Taylor, Hugh Coe, Keith Bower, Sophie Haslett, Michael Flynn, James Dorsey, Ian Crawford, Christoph Kottmeier, and Bernhard Vogel
Atmos. Chem. Phys., 18, 9767–9788,Short summary
Highly resolved process study simulations for 2–3 July are conducted with COSMO-ART to assess the aerosol direct and indirect effect on meteorological conditions over southern West Africa. The meteorological phenomena of Atlantic inflow and stratus-to-cumulus transition are identified as highly susceptible to the aerosol direct effect, leading to a spatial shift of the Atlantic inflow front and a temporal shift of the stratus-to-cumulus transition with changes in the aerosol amount.
Wiebke Frey, Dawei Hu, James Dorsey, M. Rami Alfarra, Aki Pajunoja, Annele Virtanen, Paul Connolly, and Gordon McFiggans
Atmos. Chem. Phys., 18, 9393–9409,Short summary
The coupled system of the Manchester Aerosol Chamber and Manchester Ice Cloud Chamber was used to study the ice-forming abilities of secondary organic aerosol particles under mixed-phase cloud conditions. Given the vast abundance of secondary organic particles in the atmosphere, they might present an important contribution to ice-nucleating particles. However, we find that in the studied temperature range (20 to 28 °C) the secondary organic particles do not nucleate ice particles.
Ian Boutle, Jeremy Price, Innocent Kudzotsa, Harri Kokkola, and Sami Romakkaniemi
Atmos. Chem. Phys., 18, 7827–7840,Short summary
Aerosol processes are a key mechanism in the development of fog. Poor representation of aerosol–fog interaction can result in large biases in fog forecasts, such as surface temperatures which are too high and fog which is too deep and long lived. A relatively simple representation of aerosol–fog interaction can actually lead to significant improvements in forecasting. Aerosol–fog interaction can have a large effect on the climate system but is poorly represented in climate models.
Sekou Keita, Cathy Liousse, Véronique Yoboué, Pamela Dominutti, Benjamin Guinot, Eric-Michel Assamoi, Agnès Borbon, Sophie L. Haslett, Laetitia Bouvier, Aurélie Colomb, Hugh Coe, Aristide Akpo, Jacques Adon, Julien Bahino, Madina Doumbia, Julien Djossou, Corinne Galy-Lacaux, Eric Gardrat, Sylvain Gnamien, Jean F. Léon, Money Ossohou, E. Touré N'Datchoh, and Laurent Roblou
Atmos. Chem. Phys., 18, 7691–7708,Short summary
This study provides emission factor (EF) data for elemental and organic carbon, total particulate matter and 58 volatile organic compound species for combustion sources specific to Africa to establish emission inventories with less uncertainty. EFs obtained in this study are generally higher than those in the literature whose values are used in emissions inventories for Africa. This shows that particles and VOC emissions were sometimes underestimated and underlines this study's importance.
Emma L. Simpson, Paul J. Connolly, and Gordon McFiggans
Atmos. Chem. Phys., 18, 7237–7250,Short summary
This study explores the process of ice formation in clouds by conducting computer model simulations and laboratory experiments in a cloud chamber. We show that the formation of ice in clouds can be limited by the presence of atmospheric aerosol particles and that further research is required to identify the requirements for freezing, e.g. minimum mass of water, in order to accurately calculate ice formation and thus improve climate and weather prediction.
Martin G. Schultz, Scarlet Stadtler, Sabine Schröder, Domenico Taraborrelli, Bruno Franco, Jonathan Krefting, Alexandra Henrot, Sylvaine Ferrachat, Ulrike Lohmann, David Neubauer, Colombe Siegenthaler-Le Drian, Sebastian Wahl, Harri Kokkola, Thomas Kühn, Sebastian Rast, Hauke Schmidt, Philip Stier, Doug Kinnison, Geoffrey S. Tyndall, John J. Orlando, and Catherine Wespes
Geosci. Model Dev., 11, 1695–1723,Short summary
The chemistry–climate model ECHAM-HAMMOZ contains a detailed representation of tropospheric and stratospheric reactive chemistry and state-of-the-art parameterizations of aerosols. It thus allows for detailed investigations of chemical processes in the climate system. Evaluation of the model with various observational data yields good results, but the model has a tendency to produce too much OH in the tropics. This highlights the important interplay between atmospheric chemistry and dynamics.
Amy K. Hodgson, William T. Morgan, Sebastian O'Shea, Stéphane Bauguitte, James D. Allan, Eoghan Darbyshire, Michael J. Flynn, Dantong Liu, James Lee, Ben Johnson, Jim M. Haywood, Karla M. Longo, Paulo E. Artaxo, and Hugh Coe
Atmos. Chem. Phys., 18, 5619–5638,Short summary
We flew a large atmospheric research aircraft across a number of different biomass burning environments in the Amazon Basin in September and October 2012. In this paper, we focus on smoke sampled very close to fresh fires (only 600–900 m above the fires and smoke that was 4–6 min old) to examine the chemical components that make up the smoke and their abundance. We found substantial differences in the emitted smoke that are due to the fuel type and combustion processes driving the fires.
Riinu Ots, Mathew R. Heal, Dominique E. Young, Leah R. Williams, James D. Allan, Eiko Nemitz, Chiara Di Marco, Anais Detournay, Lu Xu, Nga L. Ng, Hugh Coe, Scott C. Herndon, Ian A. Mackenzie, David C. Green, Jeroen J. P. Kuenen, Stefan Reis, and Massimo Vieno
Atmos. Chem. Phys., 18, 4497–4518,Short summary
The main hypothesis of this paper is that people who live in large cities in the UK disobey the
smoke control lawas it has not been actively enforced for decades now. However, the use of wood in residential heating has increased, partly due to renewable energy targets, but also for discretionary (i.e. pleasant fireplaces) reasons. Our study is based mainly in London, but similar struggles with urban air quality due to residential wood and coal burning are seen in other major European cities.
James D. Lee, Stephen D. Mobbs, Axel Wellpott, Grant Allen, Stephane J.-B. Bauguitte, Ralph R. Burton, Richard Camilli, Hugh Coe, Rebecca E. Fisher, James L. France, Martin Gallagher, James R. Hopkins, Mathias Lanoiselle, Alastair C. Lewis, David Lowry, Euan G. Nisbet, Ruth M. Purvis, Sebastian O'Shea, John A. Pyle, and Thomas B. Ryerson
Atmos. Meas. Tech., 11, 1725–1739,Short summary
This work describes measurements, made from an aircraft platform, of the emission of methane and other organic gases from an uncontrolled leak from an oil platform in the North Sea (Total Elgin). The measurements made helped the platform operators to devise a strategy for repairing the leak and serve as a methodology for assessing future similar incidents.
Ernesto Reyes-Villegas, Michael Priestley, Yu-Chieh Ting, Sophie Haslett, Thomas Bannan, Michael Le Breton, Paul I. Williams, Asan Bacak, Michael J. Flynn, Hugh Coe, Carl Percival, and James D. Allan
Atmos. Chem. Phys., 18, 4093–4111,Short summary
This work presents the analysis of a special event with high biomass burning emissions, named Bonfire Night. Nitrogen chemistry was observed and it was possible to study the night time chemistry. It was possible to quantify particulate organic oxides of nitrogen (PON) concentrations of 2.8 µg m−3 using 46 : 30 ratios from aerosol mass spectrometry measurements. The use of the receptor model positive matrix factorization (PMF) allowed to separate organic aerosols into different sources.
Antti Lipponen, Tero Mielonen, Mikko R. A. Pitkänen, Robert C. Levy, Virginia R. Sawyer, Sami Romakkaniemi, Ville Kolehmainen, and Antti Arola
Atmos. Meas. Tech., 11, 1529–1547,Short summary
Atmospheric aerosols are small solid or liquid particles suspended in the atmosphere and they have a significant effect on the climate. Satellite data are used to get global estimates of atmospheric aerosols. In this work, a statistics-based Bayesian aerosol retrieval algorithm was developed to improve the accuracy and quantify the uncertainties related to the aerosol estimates. The algorithm is tested with NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data.
Dantong Liu, Jonathan W. Taylor, Jonathan Crosier, Nicholas Marsden, Keith N. Bower, Gary Lloyd, Claire L. Ryder, Jennifer K. Brooke, Richard Cotton, Franco Marenco, Alan Blyth, Zhiqiang Cui, Victor Estelles, Martin Gallagher, Hugh Coe, and Tom W. Choularton
Atmos. Chem. Phys., 18, 3817–3838,Short summary
This article presents measurements of aerosol properties off the coast of west Africa during August 2015. For the first time, an airborne laser-induced incandescence instrument was deployed to measure the hematite content of dust. The single scattering albedo of dust was found to be influenced by the hematite content, but depended on the dust source and potential dust age. This highlights the importance of size-dependent composition in determining the optical properties of dust.
Kathryn Fowler, Paul J. Connolly, David O. Topping, and Simon O'Meara
Atmos. Chem. Phys., 18, 1629–1642,Short summary
This is the first time the Maxwell–Stefan framework has been applied to an atmospheric aerosol core–shell model and shows that there is a complex interplay between the viscous and solubility effects on aerosol composition. Understanding aerosol composition is essential to accurately model their interactions within atmospheric systems. We use simple binary systems to demonstrate how viscosity and solubility both play a role in affecting the rate of diffusion through aerosol particles.
Gillian Young, Paul J. Connolly, Christopher Dearden, and Thomas W. Choularton
Atmos. Chem. Phys., 18, 1475–1494,Short summary
Large-scale subsidence, associated with high-pressure systems, is often used in cloud-resolving models to maintain the height of boundary layer clouds; however, its influence on the small-scale interactions in mixed-phase clouds has not been previously investigated. Using large-eddy simulations, we have identified a relationship between subsidence and convection development in such clouds, with implications for mixed-phase boundary layer clouds forming in the ocean-exposed Arctic regions.
Joel Brito, Evelyn Freney, Pamela Dominutti, Agnes Borbon, Sophie L. Haslett, Anneke M. Batenburg, Aurelie Colomb, Regis Dupuy, Cyrielle Denjean, Frederic Burnet, Thierry Bourriane, Adrien Deroubaix, Karine Sellegri, Stephan Borrmann, Hugh Coe, Cyrille Flamant, Peter Knippertz, and Alfons Schwarzenboeck
Atmos. Chem. Phys., 18, 757–772,Short summary
This work focuses on sources of submicron aerosol particles over southern West Africa (SWA). Results have shown that isoprene, a gas-phase compound of biogenic origin, is responsible for roughly 25 % of the organic aerosol (OA) loading, under most background or urban plumes alike. This fraction represents a lower estimate from the biogenic contribution in this fairly polluted region. This work sheds light upon the role of anthropogenic and biogenic emissions on the pollution burden over SWA.
Sophie L. Haslett, J. Chris Thomas, William T. Morgan, Rory Hadden, Dantong Liu, James D. Allan, Paul I. Williams, Sekou Keita, Cathy Liousse, and Hugh Coe
Atmos. Chem. Phys., 18, 385–403,Short summary
Wood burning is chaotic, so the particles emitted can be difficult to study in a repeatable way. Here, we addressed this problem by carefully controlling small wood fires in the lab. We saw three burning phases, which could be told apart chemically; we also saw evidence of these in measurements of wood burning in London in 2012. Controlled experiments like this help us to understand why emissions are so variable and to recognise burning conditions just from the particles seen in the atmosphere.
Nicholas A. Marsden, Michael J. Flynn, James D. Allan, and Hugh Coe
Atmos. Meas. Tech., 11, 195–213,Short summary
Mineralogy of silicate mineral dust has a strong influence on climate and ecosystems due to variation in physiochemical properties that result from differences in composition and crystal structure (mineral phase). Traditional offline methods of analysing mineral phase are labour intensive and the temporal resolution of the data is lost. We introduce a novel technique that enables the online differentiation of mineral phase in silicate particles by single-particle mass spectrometry.
Olivia Goulden, Matthew Crooks, and Paul Connolly
Atmos. Chem. Phys., 18, 275–287,Short summary
The formation of cloud from the condensation of water vapour in the atmosphere on aerosol particles is highly dependent of the chemical properties of the particles. The chemistry is further complicated by the presence of condensible gases in the atmosphere other than water. We provide several methods of including the complicated chemical properties of the aerosol particles and condensing gases into single parameter descriptions, which are suitable for inclusion in large-scale models.
Maria Filioglou, Anna Nikandrova, Sami Niemelä, Holger Baars, Tero Mielonen, Ari Leskinen, David Brus, Sami Romakkaniemi, Elina Giannakaki, and Mika Komppula
Atmos. Meas. Tech., 10, 4303–4316,
Simon O'Meara, David O. Topping, Rahul A. Zaveri, and Gordon McFiggans
Atmos. Chem. Phys., 17, 10477–10494,Short summary
To simulate particle-phase diffusion, an analytical expression is desired because it takes less calculation time than a differential equation. Here a correction is found for the analytical solution for when diffusivity is dependent on composition, thereby making it more widely applicable than before. Consequently, we are able to more realistically evaluate the rate limitation (if any) imposed by particle-phase diffusion on component partitioning between the gas and particle phase.
Leonid Nichman, Emma Järvinen, James Dorsey, Paul Connolly, Jonathan Duplissy, Claudia Fuchs, Karoliina Ignatius, Kamalika Sengupta, Frank Stratmann, Ottmar Möhler, Martin Schnaiter, and Martin Gallagher
Atmos. Meas. Tech., 10, 3231–3248,Short summary
Optical probes are frequently used for the detection of cloud particles. The detected microphysical properties may affect particle growth and accretion mechanisms and the light scattering properties of cirrus clouds. In the CLOUD chamber study at CERN, we compared four optical measurement techniques. We show that shape derivation alone is not sufficient to determine the phase of the small cloud particles. None of the instruments were able to unambiguously determine the phase of small particles.
Sami Romakkaniemi, Zubair Maalick, Antti Hellsten, Antti Ruuskanen, Olli Väisänen, Irshad Ahmad, Juha Tonttila, Santtu Mikkonen, Mika Komppula, and Thomas Kühn
Atmos. Chem. Phys., 17, 7955–7964,Short summary
Surface topography affects aerosol–cloud interactions in boundary layer clouds. Local topography effects should be screened out from in situ observations before results can be generalised into a larger scale. Here we present modelling and observational results from a measurement station residing in a 75 m tower on top of a 150 m hill, and analyse how landscape affects the cloud formation, and which factors should be taken into account when aerosol effect on cloud droplet formation is studied.
Anton Laakso, Hannele Korhonen, Sami Romakkaniemi, and Harri Kokkola
Atmos. Chem. Phys., 17, 6957–6974,Short summary
Based on simulations, equatorial stratospheric sulfur injections have shown to be an efficient strategy to counteract ongoing global warming. However, equatorial injections would result in relatively larger cooling in low latitudes than in high latitudes. This together with greenhouse-gas-induced warming would lead to cooling in the Equator and warming in the high latitudes. Results of this study show that a more optimal cooling effect is achieved by varying the injection area seasonally.
Antti Arola, Thomas F. Eck, Harri Kokkola, Mikko R. A. Pitkänen, and Sami Romakkaniemi
Atmos. Chem. Phys., 17, 5991–6001,Short summary
One of the issues that hinder the measurement-based assessment of aerosol–cloud interactions by remote sensing methods is that typically aerosols and clouds cannot be measured simultaneously by passive remote sensing methods. AERONET includes the SDA product that provides the fine-mode AOD also in mixed cloud–aerosol observations. These measurements have not yet been fully exploited in studies of aerosol–cloud interactions. We applied SDA for this kind of analysis.
Huan Yao, Yu Song, Mingxu Liu, Scott Archer-Nicholls, Douglas Lowe, Gordon McFiggans, Tingting Xu, Pin Du, Jianfeng Li, Yusheng Wu, Min Hu, Chun Zhao, and Tong Zhu
Atmos. Chem. Phys., 17, 5205–5219,
Gillian Young, Paul J. Connolly, Hazel M. Jones, and Thomas W. Choularton
Atmos. Chem. Phys., 17, 4209–4227,Short summary
Arctic mixed-phase clouds are poorly represented in numerical models, due in part to an overpredicted ice phase. Here, we examine the sensitivity of cloud structure, evolution, and lifetime to modelled primary ice number concentrations over three different surfaces – sea ice, marginal ice, and ocean – to investigate the dependency on both the ice phase and dynamics induced from surface fluxes.
Juha Tonttila, Zubair Maalick, Tomi Raatikainen, Harri Kokkola, Thomas Kühn, and Sami Romakkaniemi
Geosci. Model Dev., 10, 169–188,Short summary
Novel techniques for modelling the aerosol–cloud interactions are implemented in a cloud-resolving model. The new methods improve the representation of the poorly constrained effects of cloud processing, precipitation and the wet removal of particles on the aerosol population and the associated feedbacks. The detailed representation of these processes yields more realistic simulation of the evolution of boundary layer clouds and fogs, as compared to results obtained using more simple methods.
Alexandra Tsekeri, Vassilis Amiridis, Franco Marenco, Athanasios Nenes, Eleni Marinou, Stavros Solomos, Phil Rosenberg, Jamie Trembath, Graeme J. Nott, James Allan, Michael Le Breton, Asan Bacak, Hugh Coe, Carl Percival, and Nikolaos Mihalopoulos
Atmos. Meas. Tech., 10, 83–107,Short summary
The In situ/Remote sensing aerosol Retrieval Algorithm (IRRA) provides vertical profiles of aerosol optical, microphysical and hygroscopic properties from airborne in situ and remote sensing measurements. The algorithm is highly advantageous for aerosol characterization in humid conditions, employing the ISORROPIA II model for acquiring the particle hygroscopic growth. IRRA can find valuable applications in aerosol–cloud interaction schemes and in validation of active space-borne sensors.
Ernesto Reyes-Villegas, David C. Green, Max Priestman, Francesco Canonaco, Hugh Coe, André S. H. Prévôt, and James D. Allan
Atmos. Chem. Phys., 16, 15545–15559,Short summary
For the first time in the UK, an Aerosol Chemical Speciation Monitor was used to measure aerosol concentrations in London in March–December 2013, with further organic aerosol (OA) source apportionment using the ME-2 factorization tool. Five OA sources were identified: biomass burning OA, hydrocarbon-like OA, cooking OA, semivolatile oxygenated OA and low-volatility oxygenated OA. This information can be used to take future action on the respective legislation in order to improve the air quality.
Nicholas Marsden, Michael J. Flynn, Jonathan W. Taylor, James D. Allan, and Hugh Coe
Atmos. Meas. Tech., 9, 6051–6068,
Ben T. Johnson, James M. Haywood, Justin M. Langridge, Eoghan Darbyshire, William T. Morgan, Kate Szpek, Jennifer K. Brooke, Franco Marenco, Hugh Coe, Paulo Artaxo, Karla M. Longo, Jane P. Mulcahy, Graham W. Mann, Mohit Dalvi, and Nicolas Bellouin
Atmos. Chem. Phys., 16, 14657–14685,Short summary
Biomass burning is a large source of carbonaceous aerosols, which scatter and absorb solar radiation, and modify cloud properties. We evaluate the simulation of biomass burning aerosol processes and properties in the HadGEM3 climate model using observations, including those from the South American Biomass Burning Analysis. We find that modelled aerosol optical depths are underestimated unless aerosol emissions (Global Fire Emission Database v3) are increased by a factor of 1.6–2.0.
Gillian Young, Hazel M. Jones, Thomas W. Choularton, Jonathan Crosier, Keith N. Bower, Martin W. Gallagher, Rhiannon S. Davies, Ian A. Renfrew, Andrew D. Elvidge, Eoghan Darbyshire, Franco Marenco, Philip R. A. Brown, Hugo M. A. Ricketts, Paul J. Connolly, Gary Lloyd, Paul I. Williams, James D. Allan, Jonathan W. Taylor, Dantong Liu, and Michael J. Flynn
Atmos. Chem. Phys., 16, 13945–13967,Short summary
Clouds are intricately coupled to the Arctic sea ice. Our inability to accurately model cloud fractions causes large uncertainties in predicted radiative interactions in this region, therefore, affecting sea ice forecasts. Here, we present measurements of cloud microphysics, aerosol properties, and thermodynamic structure over the transition from sea ice to ocean to improve our understanding of the relationship between the Arctic atmosphere and clouds which develop in this region.
Riinu Ots, Massimo Vieno, James D. Allan, Stefan Reis, Eiko Nemitz, Dominique E. Young, Hugh Coe, Chiara Di Marco, Anais Detournay, Ian A. Mackenzie, David C. Green, and Mathew R. Heal
Atmos. Chem. Phys., 16, 13773–13789,Short summary
Emissions of cooking organic aerosol (COA; from charbroiling, frying, etc.) are currently absent in European emissions inventories yet measurements have pointed to significant COA concentrations. In this study, emissions of COA were developed for the UK by model iteration against year-long measurements at two sites in London. Modelled COA dropped rapidly outside of major urban areas, suggesting that although a notable component in UK urban air, COA does not have a significant effect on rural PM.
François Benduhn, Graham W. Mann, Kirsty J. Pringle, David O. Topping, Gordon McFiggans, and Kenneth S. Carslaw
Geosci. Model Dev., 9, 3875–3906,Short summary
We present a new mathematical formalism that serves to represent exchanges of inorganic matter between the atmosphere gas phase and the aerosol aqueous phase. In a global modelling framework, taking into account these processes may help represent many important features more accurately, such as the formation of cloud droplets or the radiative properties of the atmosphere. The formalism strives to keep an appropriate balance between accuracy and computation efficiency requirements.
Matthew Crooks, Paul Connolly, David Topping, and Gordon McFiggans
Geosci. Model Dev., 9, 3617–3637,Short summary
Semi-volatile compounds, like water, can exist in both vapour phases and condensed phases within a system. This paper presents a method of calculating the condensed and vapour phases of semi-volatile compounds at equilibrium, in particular, when the condensed mass occurs within particles of different sizes and chemical composition. The applications of interest to the authors are those of atmospheric importance such as cloud droplet formation and reflection or absorption of solar radiation.
Olli Väisänen, Antti Ruuskanen, Arttu Ylisirniö, Pasi Miettinen, Harri Portin, Liqing Hao, Ari Leskinen, Mika Komppula, Sami Romakkaniemi, Kari E. J. Lehtinen, and Annele Virtanen
Atmos. Chem. Phys., 16, 10385–10398,Short summary
In-cloud measurements of aerosol hygroscopicity and cloud droplet activation were conducted in Kuopio, Finland. According to the observations, the less hygroscopic accumulation mode particles were present in the non-activated aerosol, whereas the more hygroscopic particles were scavenged into cloud droplets. The results illustrate the sensitivity of cloud droplet formation to varying chemical composition and highlight the need for proper treatment of anthropogenic aerosols in CCN predictions.
James D. Whitehead, Eoghan Darbyshire, Joel Brito, Henrique M. J. Barbosa, Ian Crawford, Rafael Stern, Martin W. Gallagher, Paul H. Kaye, James D. Allan, Hugh Coe, Paulo Artaxo, and Gordon McFiggans
Atmos. Chem. Phys., 16, 9727–9743,Short summary
We present measurements of aerosols during the transition from wet to dry seasons at a pristine rainforest site in central Amazonia. By excluding pollution episodes, we focus on natural biogenic aerosols. Submicron aerosols are dominated by organic material, similar to previous wet season measurements. Larger particles are dominated by biological material, mostly fungal spores, with higher concentrations at night. This study provides important data on the nature of particles above the Amazon.
Tero Mielonen, Anca Hienola, Thomas Kühn, Joonas Merikanto, Antti Lipponen, Tommi Bergman, Hannele Korhonen, Pekka Kolmonen, Larisa Sogacheva, Darren Ghent, Antti Arola, Gerrit de Leeuw, and Harri Kokkola
Atmos. Chem. Phys. Discuss.,
Revised manuscript not acceptedShort summary
We studied the temperature dependence of AOD and its radiative effects over the southeastern US. We used spaceborne observations of AOD, LST and tropospheric NO2 with simulations of ECHAM-HAMMOZ. The level of AOD in this region is governed by anthropogenic emissions but the temperature dependency is most likely caused by BVOC emissions. According to the observations and simulations, the regional clear-sky DRE for biogenic aerosols is −0.43 ± 0.88 W/m2/K and −0.86 ± 0.06 W/m2/K, respectively.
Riinu Ots, Dominique E. Young, Massimo Vieno, Lu Xu, Rachel E. Dunmore, James D. Allan, Hugh Coe, Leah R. Williams, Scott C. Herndon, Nga L. Ng, Jacqueline F. Hamilton, Robert Bergström, Chiara Di Marco, Eiko Nemitz, Ian A. Mackenzie, Jeroen J. P. Kuenen, David C. Green, Stefan Reis, and Mathew R. Heal
Atmos. Chem. Phys., 16, 6453–6473,Short summary
This study investigates the contribution of diesel vehicle emissions to organic aerosol formation and particulate matter concentrations in London. Comparisons of simulated pollutant concentrations with observations show good agreement and give confidence in the skill of the model applied. The contribution of diesel vehicle emissions, which are currently not included in official emissions inventories, is demonstrated to be substantial, indicating that more research on this topic is required.
Scott Archer-Nicholls, Douglas Lowe, David M. Schultz, and Gordon McFiggans
Atmos. Chem. Phys., 16, 5573–5594,Short summary
The response of the Weather Research and Forecasting model with Chemistry to forcings by biomass burning aerosol were investigated in high-resolution nested domains over Brazil. The aerosol-layer was found to have a negative direct effect at the top of the atmosphere, but this was largely cancelled by a semi-direct effect which inhibited afternoon cloud formation. The cloud response to the aerosol was found to be highly sensitive to model resolution and the use of convective parameterisation.
Simon O'Meara, David O. Topping, and Gordon McFiggans
Atmos. Chem. Phys., 16, 5299–5313,Short summary
To understand the effect of atmospheric particulate matter on climate and human health we need to know how it evolves. We investigate how best to estimate diffusion of components through particles by comparing diffusion times from three approaches to solving Fick's Law and find that they agree. This means that scientists can simulate Fickian diffusion through atmospheric particles using the approach best suited to their requirements and have confidence that their model is mathematically sound.
Robert J. Farrington, Paul J. Connolly, Gary Lloyd, Keith N. Bower, Michael J. Flynn, Martin W. Gallagher, Paul R. Field, Chris Dearden, and Thomas W. Choularton
Atmos. Chem. Phys., 16, 4945–4966,Short summary
This paper assesses the reasons for high ice number concentrations observed in orographic clouds by comparing observations with model simulations over Jungfraujoch, Switzerland. The results suggest that ice nuclei do not significantly contribute to the high concentrations and that a surface source of ice crystals is responsible for the witnessed ice number concentrations.
G. Young, H. M. Jones, E. Darbyshire, K. J. Baustian, J. B. McQuaid, K. N. Bower, P. J. Connolly, M. W. Gallagher, and T. W. Choularton
Atmos. Chem. Phys., 16, 4063–4079,
Leonid Nichman, Claudia Fuchs, Emma Järvinen, Karoliina Ignatius, Niko Florian Höppel, Antonio Dias, Martin Heinritzi, Mario Simon, Jasmin Tröstl, Andrea Christine Wagner, Robert Wagner, Christina Williamson, Chao Yan, Paul James Connolly, James Robert Dorsey, Jonathan Duplissy, Sebastian Ehrhart, Carla Frege, Hamish Gordon, Christopher Robert Hoyle, Thomas Bjerring Kristensen, Gerhard Steiner, Neil McPherson Donahue, Richard Flagan, Martin William Gallagher, Jasper Kirkby, Ottmar Möhler, Harald Saathoff, Martin Schnaiter, Frank Stratmann, and António Tomé
Atmos. Chem. Phys., 16, 3651–3664,Short summary
Processes in the atmosphere are often governed by the physical and chemical properties of small cloud particles. Ice, water, and mixed clouds, as well as viscous aerosols, were formed under controlled conditions at the CLOUD-CERN facility. The experimental results show a link between cloud particle properties and their unique optical fingerprints. The classification map presented here allows easier discrimination between various particles such as viscous organic aerosol, salt, ice, and liquid.
David Topping, Mark Barley, Michael K. Bane, Nicholas Higham, Bernard Aumont, Nicholas Dingle, and Gordon McFiggans
Geosci. Model Dev., 9, 899–914,Short summary
In this paper we describe the development and application of a new web-based and open-source facility, UManSysProp (http://umansysprop .seaes.manchester.ac.uk), for automating predictions of molecular and atmospheric aerosol properties. Current facilities include pure component vapour pressures, critical properties, and sub-cooled densities of organic molecules; activity coefficient predictions for mixed inorganic-organic liquid systems; hygroscopic growth factors and CCN activation potential.
I. Crawford, G. Lloyd, E. Herrmann, C. R. Hoyle, K. N. Bower, P. J. Connolly, M. J. Flynn, P. H. Kaye, T. W. Choularton, and M. W. Gallagher
Atmos. Chem. Phys., 16, 2273–2284,Short summary
In this manuscript we discuss observations of fluorescent aerosol and their interactions with cloud at a high-alpine site in the wintertime under background conditions. We find the majority of the fluorescent aerosol to be consistent in nature to mineral dust and no apparent trend was observed between the fluorescent aerosol fraction and meteorological or cloud microphysical parameters, suggesting that particle fluorescence does not impact cloud evolution or formation at the site.
L. Xu, L. R. Williams, D. E. Young, J. D. Allan, H. Coe, P. Massoli, E. Fortner, P. Chhabra, S. Herndon, W. A. Brooks, J. T. Jayne, D. R. Worsnop, A. C. Aiken, S. Liu, K. Gorkowski, M. K. Dubey, Z. L. Fleming, S. Visser, A. S. H. Prévôt, and N. L. Ng
Atmos. Chem. Phys., 16, 1139–1160,Short summary
We investigate the spatial distribution of submicron aerosol in the greater London area as part of the Clean Air for London (ClearfLo) project in winter 2012. Although the concentrations of organic aerosol (OA) are similar between a rural and an urban site, the OA sources are different. We also examine the volatility of submicron aerosol at the rural site and find that the non-volatile organics have similar sources or have undergone similar chemical processing as refractory black carbon.
J. Grazioli, G. Lloyd, L. Panziera, C. R. Hoyle, P. J. Connolly, J. Henneberger, and A. Berne
Atmos. Chem. Phys., 15, 13787–13802,Short summary
This study investigates the microphysics of winter alpine snowfall occurring in mixed-phase clouds in an inner-Alpine valley during CLACE2014. From polarimetric radar and in situ observations, riming is shown to be an important process leading to more intense snowfall. Riming is usually associated with more intense turbulence providing supercooled liquid water. Distinct features are identified in the vertical structure of polarimetric radar variables.
G. Lloyd, T. W. Choularton, K. N. Bower, M. W. Gallagher, P. J. Connolly, M. Flynn, R. Farrington, J. Crosier, O. Schlenczek, J. Fugal, and J. Henneberger
Atmos. Chem. Phys., 15, 12953–12969,Short summary
The paper explores the microphysical structure of clouds at the high-alpine measurement site Jungfraujoch, Switzerland. High concentrations of ice crystals were measured by a range of instruments. The presence of these high concentrations could not be explained through conventional understanding of ice formation processes in clouds and the possibility that the surface provides a significant source of ice crystals is investigated.
A. Arola, G. L. Schuster, M. R. A. Pitkänen, O. Dubovik, H. Kokkola, A. V. Lindfors, T. Mielonen, T. Raatikainen, S. Romakkaniemi, S. N. Tripathi, and H. Lihavainen
Atmos. Chem. Phys., 15, 12731–12740,Short summary
There have been relatively few measurement-based estimates for the direct radiative effect of brown carbon so far. This is first time that the direct radiative effect of brown carbon is estimated by exploiting the AERONET-retrieved imaginary indices. We estimated it for four sites in the Indo-Gangetic Plain: Karachi, Lahore, Kanpur and Gandhi College.
M. Paramonov, V.-M. Kerminen, M. Gysel, P. P. Aalto, M. O. Andreae, E. Asmi, U. Baltensperger, A. Bougiatioti, D. Brus, G. P. Frank, N. Good, S. S. Gunthe, L. Hao, M. Irwin, A. Jaatinen, Z. Jurányi, S. M. King, A. Kortelainen, A. Kristensson, H. Lihavainen, M. Kulmala, U. Lohmann, S. T. Martin, G. McFiggans, N. Mihalopoulos, A. Nenes, C. D. O'Dowd, J. Ovadnevaite, T. Petäjä, U. Pöschl, G. C. Roberts, D. Rose, B. Svenningsson, E. Swietlicki, E. Weingartner, J. Whitehead, A. Wiedensohler, C. Wittbom, and B. Sierau
Atmos. Chem. Phys., 15, 12211–12229,Short summary
The research paper presents the first comprehensive overview of field measurements with the CCN Counter performed at a large number of locations around the world within the EUCAARI framework. The paper sheds light on the CCN number concentrations and activated fractions around the world and their dependence on the water vapour supersaturation ratio, the dependence of aerosol hygroscopicity on particle size, and seasonal and diurnal variation of CCN activation and hygroscopic properties.
W. W. Hu, P. Campuzano-Jost, B. B. Palm, D. A. Day, A. M. Ortega, P. L. Hayes, J. E. Krechmer, Q. Chen, M. Kuwata, Y. J. Liu, S. S. de Sá, K. McKinney, S. T. Martin, M. Hu, S. H. Budisulistiorini, M. Riva, J. D. Surratt, J. M. St. Clair, G. Isaacman-Van Wertz, L. D. Yee, A. H. Goldstein, S. Carbone, J. Brito, P. Artaxo, J. A. de Gouw, A. Koss, A. Wisthaler, T. Mikoviny, T. Karl, L. Kaser, W. Jud, A. Hansel, K. S. Docherty, M. L. Alexander, N. H. Robinson, H. Coe, J. D. Allan, M. R. Canagaratna, F. Paulot, and J. L. Jimenez
Atmos. Chem. Phys., 15, 11807–11833,Short summary
This work summarized all the studies reporting isoprene epoxydiols-derived secondary organic aerosol (IEPOX-SOA) measured globally by aerosol mass spectrometer and compare them with modeled gas-phase IEPOX, with results suggestive of the importance of IEPOX-SOA for regional and global OA budgets. A real-time tracer of IEPOX-SOA is thoroughly evaluated for the first time by combing multiple field and chamber studies. A quick and easy empirical method on IEPOX-SOA estimation is also presented.
D. Liu, B. Quennehen, E. Darbyshire, J. D. Allan, P. I. Williams, J. W. Taylor, S. J.-B. Bauguitte, M. J. Flynn, D. Lowe, M. W. Gallagher, K. N. Bower, T. W. Choularton, and H. Coe
Atmos. Chem. Phys., 15, 11537–11555,Short summary
We show that during the springtime of 2013, the anthropogenic pollution particularly from sources in Asia, contributed significantly to black carbon across the European Arctic free troposphere. In contrast to previous studies, the contribution from open wildfires was minimal. Given that Asian pollution is likely to continue to rise over the coming years, it is likely that the radiative forcing in the Arctic will also continue to increase.
S. Visser, J. G. Slowik, M. Furger, P. Zotter, N. Bukowiecki, F. Canonaco, U. Flechsig, K. Appel, D. C. Green, A. H. Tremper, D. E. Young, P. I. Williams, J. D. Allan, H. Coe, L. R. Williams, C. Mohr, L. Xu, N. L. Ng, E. Nemitz, J. F. Barlow, C. H. Halios, Z. L. Fleming, U. Baltensperger, and A. S. H. Prévôt
Atmos. Chem. Phys., 15, 11291–11309,Short summary
Trace element measurements in three particle size ranges (PM10-2.5, PM2.5-1.0 and PM1.0-0.3) were performed with 2h time resolution at kerbside, urban background and rural sites during the ClearfLo winter 2012 campaign in London. The environment-dependent variability of emissions was characterized using the Multilinear Engine implementation of the positive matrix factorization model. A total of nine different factors were resolved from local, regional and natural origin.
C. Emersic, P. J. Connolly, S. Boult, M. Campana, and Z. Li
Atmos. Chem. Phys., 15, 11311–11326,
E. Athanasopoulou, A. P. Protonotariou, E. Bossioli, A. Dandou, M. Tombrou, J. D. Allan, H. Coe, N. Mihalopoulos, J. Kalogiros, A. Bacak, J. Sciare, and G. Biskos
Atmos. Chem. Phys., 15, 8401–8421,Short summary
A model system is evaluated versus ground and airborne aerosol measurements, towards the identification of its competencies and deficiencies over the eastern Mediterranean (EM) during summer. Secondary organic aerosol (OA) formation is investigated towards improving OA behaviour. Biomass burning is a significant particle source, largely explaining OA underestimation (ca. 50%). More than 70% of the aerosol mass over the EM is related to trans-boundary transport during strong northeastern winds.
M. J. Alvarado, C. R. Lonsdale, R. J. Yokelson, S. K. Akagi, H. Coe, J. S. Craven, E. V. Fischer, G. R. McMeeking, J. H. Seinfeld, T. Soni, J. W. Taylor, D. R. Weise, and C. E. Wold
Atmos. Chem. Phys., 15, 6667–6688,Short summary
Being able to understand and simulate the chemical evolution of biomass burning smoke plumes under a wide variety of conditions is a critical part of forecasting the impact of these fires on air quality, atmospheric composition, and climate. Here we use an improved model of this chemistry to simulate the evolution of ozone and secondary organic aerosol within a young biomass burning smoke plume from the Williams prescribed burn in chaparral, which was sampled over California in November 2009.
D. E. Young, J. D. Allan, P. I. Williams, D. C. Green, M. J. Flynn, R. M. Harrison, J. Yin, M. W. Gallagher, and H. Coe
Atmos. Chem. Phys., 15, 6351–6366,Short summary
For the first time, the behaviour of non-refractory inorganic and organic submicron particulates through an entire annual cycle is investigated at a UK urban background site. We show secondary aerosols account for a significant fraction of the submicron aerosol burden, high concentration events are governed by different factors depending on season, and on an annual basis there is no variability in the extent of secondary organic aerosol oxidation.
J. Tonttila, E. J. O'Connor, A. Hellsten, A. Hirsikko, C. O'Dowd, H. Järvinen, and P. Räisänen
Atmos. Chem. Phys., 15, 5873–5885,
J. D. Allan, P. I. Williams, J. Najera, J. D. Whitehead, M. J. Flynn, J. W. Taylor, D. Liu, E. Darbyshire, L. J. Carpenter, R. Chance, S. J. Andrews, S. C. Hackenberg, and G. McFiggans
Atmos. Chem. Phys., 15, 5599–5609,Short summary
New particle formation (NPF) is an important contributor to aerosol number concentrations in the Arctic and thus has a major role in dictating cloud properties and climate in this region. Here we present direct evidence that the oxidation of iodine in the atmosphere causes NPF in the Greenland Sea. This is important because this is a NPF mechanism that has not previously been considered in modelling studies at these latitudes.
M. Dalirian, H. Keskinen, L. Ahlm, A. Ylisirniö, S. Romakkaniemi, A. Laaksonen, A. Virtanen, and I. Riipinen
Atmos. Chem. Phys., 15, 3815–3829,
J. W. Taylor, J. D. Allan, D. Liu, M. Flynn, R. Weber, X. Zhang, B. L. Lefer, N. Grossberg, J. Flynn, and H. Coe
Atmos. Meas. Tech., 8, 1701–1718,Short summary
When using the SP2 to report black carbon core/shell coating thickness, the core density and refractive index must be estimated from literature values. We systematically vary the assumed parameters and the instrument calibration, and quantify the effects in the derived coatings. The technique is highly sensitive to the core refractive index but has only a minor sensitivity to the core density and coating refractive index. We identify the most appropriate values to use in future analysis.
Q. Chen, D. K. Farmer, L. V. Rizzo, T. Pauliquevis, M. Kuwata, T. G. Karl, A. Guenther, J. D. Allan, H. Coe, M. O. Andreae, U. Pöschl, J. L. Jimenez, P. Artaxo, and S. T. Martin
Atmos. Chem. Phys., 15, 3687–3701,Short summary
Submicron particle mass concentration in the Amazon during the wet season of 2008 was dominated by organic material. The PMF analysis finds a comparable importance of gas-phase (gas-to-particle condensation) and particle-phase (reactive uptake of isoprene oxidation products, especially of epoxydiols to acidic haze, fog, or cloud droplets) production of secondary organic material during the study period, together accounting for >70% of the organic-particle mass concentration.
I. Steinke, C. Hoose, O. Möhler, P. Connolly, and T. Leisner
Atmos. Chem. Phys., 15, 3703–3717,Short summary
Ice nucleation in clouds has a significant influence on the global radiative budget and the hydrological cycle. Several studies have investigated the ice formation in droplets and parameterizations have been developed in order to include immersion freezing in climate models. In contrast, there are fewer studies regarding the conversion of water vapor into ice (so-called deposition nucleation) which is the topic of this paper which investigates deposition nucleation by Arizona Test dust in detail
G. Lloyd, T. W. Choularton, K. N. Bower, J. Crosier, H. Jones, J. R. Dorsey, M. W. Gallagher, P. Connolly, A. C. R. Kirchgaessner, and T. Lachlan-Cope
Atmos. Chem. Phys., 15, 3719–3737,Short summary
Measurements of cloud microphysics are reported from the Aerosol-Cloud Coupling And Climate Interactions (ACCACIA) campaign. Concentrations of ice particles from two spring and two summer cases are compared with particular attention to the role of secondary ice in these clouds. In addition aerosol measurements were used as input to a primary ice nucleation parameterisation which was compared with observed values of primary ice in these clouds. We found higher concentrations of ice during summer.
M. D. Jolleys, H. Coe, G. McFiggans, J. W. Taylor, S. J. O'Shea, M. Le Breton, S. J.-B. Bauguitte, S. Moller, P. Di Carlo, E. Aruffo, P. I. Palmer, J. D. Lee, C. J. Percival, and M. W. Gallagher
Atmos. Chem. Phys., 15, 3077–3095,Short summary
Particulate emissions in the form of organic aerosol from boreal forest fires in Canada have been measured during an aircraft measurement campaign. Ratios of the amount of aerosol emitted relative to gas species such as CO were calculated and show high levels of variability throughout the campaign. This variability is affected by both changes in fire conditions, as fires tended to die down later in the measurement period, and by changes to the aerosol due to chemical reactions in the atmosphere.
S. Archer-Nicholls, D. Lowe, E. Darbyshire, W. T. Morgan, M. M. Bela, G. Pereira, J. Trembath, J. W. Kaiser, K. M. Longo, S. R. Freitas, H. Coe, and G. McFiggans
Geosci. Model Dev., 8, 549–577,Short summary
The regional WRF-Chem model was used to study aerosol particles from biomass burning in South America. The modelled estimates of fire plume injection heights were found to be too high, with serious implications for modelled aerosol vertical distribution, transport and impacts on local climate. A modified emission scenario was developed which improved the predicted injection height. Model results were compared and evaluated against in situ measurements from the 2012 SAMBBA flight campaign.
D. E. Young, J. D. Allan, P. I. Williams, D. C. Green, R. M. Harrison, J. Yin, M. J. Flynn, M. W. Gallagher, and H. Coe
Atmos. Chem. Phys., 15, 2429–2443,Short summary
Two solid fuel organic aerosol (SFOA) factors, both associated with domestic space heating activities, were derived from positive matrix factorisation (PMF) applied to organic aerosol data from an aerosol mass spectrometer (AMS) deployed at an urban background site in London during winter 2012. The factors controlling the split between the two SFOA factors were assessed, and it is concluded the split is likely governed predominantly by differences in burn conditions.
J. Yin, S. A. Cumberland, R. M. Harrison, J. Allan, D. E. Young, P. I. Williams, and H. Coe
Atmos. Chem. Phys., 15, 2139–2158,Short summary
Breathing particles from polluted air is known to cause increased health complaints and higher death rates. Airborne particles come from a range of sources; in order to implement cost-effective control measures, it is necessary to understand the amount contributed by each. In this paper, two advanced procedures for estimating the contributions of particle sources in London are compared with one another, revealing a wide range of sources including traffic, woodsmoke and cooking particles.
K. M. Sakamoto, J. D. Allan, H. Coe, J. W. Taylor, T. J. Duck, and J. R. Pierce
Atmos. Chem. Phys., 15, 1633–1646,
D. Lowe, S. Archer-Nicholls, W. Morgan, J. Allan, S. Utembe, B. Ouyang, E. Aruffo, M. Le Breton, R. A. Zaveri, P. Di Carlo, C. Percival, H. Coe, R. Jones, and G. McFiggans
Atmos. Chem. Phys., 15, 1385–1409,
W. T. Morgan, B. Ouyang, J. D. Allan, E. Aruffo, P. Di Carlo, O. J. Kennedy, D. Lowe, M. J. Flynn, P. D. Rosenberg, P. I. Williams, R. Jones, G. B. McFiggans, and H. Coe
Atmos. Chem. Phys., 15, 973–990,Short summary
This paper used observations from a research aircraft flying around the UK to investigate how air pollution in north-western Europe can alter nighttime chemical reactions in the atmosphere. These chemical reactions can worsen air quality in the region, as well as influence regional climate change. Ammonium nitrate aerosol appears to play an important role. The paper indicates that representation of these chemical reactions is poorly represented in models used for air quality and climate.
J. Tonttila, H. Järvinen, and P. Räisänen
Atmos. Chem. Phys., 15, 703–714,
J. W. Taylor, J. D. Allan, G. Allen, H. Coe, P. I. Williams, M. J. Flynn, M. Le Breton, J. B. A. Muller, C. J. Percival, D. Oram, G. Forster, J. D. Lee, A. R. Rickard, M. Parrington, and P. I. Palmer
Atmos. Chem. Phys., 14, 13755–13771,Short summary
We present a case study of BC wet removal by examining aerosol properties in three biomass burning plumes, one of which passed through a precipitating cloud. Nucleation scavenging preferentially removed the largest and most coated BC-containing particles. Calculated single-scattering albedo (SSA) showed little variation, as a large number of non-BC particles were also present in the precipitation-affected plume.
L. Q. Hao, A. Kortelainen, S. Romakkaniemi, H. Portin, A. Jaatinen, A. Leskinen, M. Komppula, P. Miettinen, D. Sueper, A. Pajunoja, J. N. Smith, K. E. J. Lehtinen, D. R. Worsnop, A. Laaksonen, and A. Virtanen
Atmos. Chem. Phys., 14, 13483–13495,Short summary
Positive matrix factorization (PMF) was applied to the unified high-resolution mass spectra organic species with NO+ and NO2+ ions from the measurement in a mixed region between the boreal forestland and the urban area. The PMF analysis succeeded in separating the mixed spectra into three distinct organic factors and one inorganic factor. The particulate organic nitrate was distinguished by PMF for the first time, with a contribution of one-third of the total nitrate mass.
J. Brito, L. V. Rizzo, W. T. Morgan, H. Coe, B. Johnson, J. Haywood, K. Longo, S. Freitas, M. O. Andreae, and P. Artaxo
Atmos. Chem. Phys., 14, 12069–12083,Short summary
This paper details the physical--chemical characteristics of aerosols in a region strongly impacted by biomass burning in the western part of the Brazilian Amazon region. For such, a large suite of state-of-the-art instruments for realtime analysis was deployed at a ground site. Among the key findings, we observe the strong prevalence of organic aerosols associated to fire emissions, with important climate effects, and indications of its very fast processing in the atmosphere.
S. Decesari, J. Allan, C. Plass-Duelmer, B. J. Williams, M. Paglione, M. C. Facchini, C. O'Dowd, R. M. Harrison, J. K. Gietl, H. Coe, L. Giulianelli, G. P. Gobbi, C. Lanconelli, C. Carbone, D. Worsnop, A. T. Lambe, A. T. Ahern, F. Moretti, E. Tagliavini, T. Elste, S. Gilge, Y. Zhang, and M. Dall'Osto
Atmos. Chem. Phys., 14, 12109–12132,Short summary
We made use of multiple spectrometric techniques for characterizing the aerosol chemical composition and mixing in the Po Valley in the summer. The oxygenated organic aerosol (OOA) concentrations were correlated with simple tracers for recirculated planetary boundary layer air. A full internal mixing between black carbon (BC) and the non-refractory aerosol components was never observed. Local sources in the Po Valley were responsible for the production of organic particles unmixed with BC.
J. D. Whitehead, M. Irwin, J. D. Allan, N. Good, and G. McFiggans
Atmos. Chem. Phys., 14, 11833–11841,Short summary
Water uptake of ambient particles was measured by 2 independent techniques at a wide range of locations between 2007 and 2013. The agreement between the techniques was mixed and hence the number of potential cloud seeds calculated from the measurements frequently showed discrepancies. Whilst there is sensitivity to how well we measure the size of the particles, much of the difference depends on how the particles behave when exposed to moisture in the different techniques (and in the atmosphere).
S. Archer-Nicholls, D. Lowe, S. Utembe, J. Allan, R. A. Zaveri, J. D. Fast, Ø. Hodnebrog, H. Denier van der Gon, and G. McFiggans
Geosci. Model Dev., 7, 2557–2579,
M. J. Lawler, J. Whitehead, C. O'Dowd, C. Monahan, G. McFiggans, and J. N. Smith
Atmos. Chem. Phys., 14, 11557–11569,Short summary
This work describes the chemical and physical characterization of very small (< 100 nm diameter) particles in the marine atmosphere. We show that sea salt is present even at very small sizes and present evidence that organic species are important contributors to apparent new particle formation events over the ocean.
J. D. Allan, W. T. Morgan, E. Darbyshire, M. J. Flynn, P. I. Williams, D. E. Oram, P. Artaxo, J. Brito, J. D. Lee, and H. Coe
Atmos. Chem. Phys., 14, 11393–11407,
X. Wang, C. L. Heald, D. A. Ridley, J. P. Schwarz, J. R. Spackman, A. E. Perring, H. Coe, D. Liu, and A. D. Clarke
Atmos. Chem. Phys., 14, 10989–11010,
S. V. Henriksson, J.-P. Pietikäinen, A.-P. Hyvärinen, P. Räisänen, K. Kupiainen, J. Tonttila, R. Hooda, H. Lihavainen, D. O'Donnell, L. Backman, Z. Klimont, and A. Laaksonen
Atmos. Chem. Phys., 14, 10177–10192,
D. Liu, J. D. Allan, D. E. Young, H. Coe, D. Beddows, Z. L. Fleming, M. J. Flynn, M. W. Gallagher, R. M. Harrison, J. Lee, A. S. H. Prevot, J. W. Taylor, J. Yin, P. I. Williams, and P. Zotter
Atmos. Chem. Phys., 14, 10061–10084,
J. E. Franklin, J. R. Drummond, D. Griffin, J. R. Pierce, D. L. Waugh, P. I. Palmer, M. Parrington, J. D. Lee, A. C. Lewis, A. R. Rickard, J. W. Taylor, J. D. Allan, H. Coe, K. A. Walker, L. Chisholm, T. J. Duck, J. T. Hopper, Y. Blanchard, M. D. Gibson, K. R. Curry, K. M. Sakamoto, G. Lesins, L. Dan, J. Kliever, and A. Saha
Atmos. Chem. Phys., 14, 8449–8460,
E. Simpson, P. Connolly, and G. McFiggans
Geosci. Model Dev., 7, 1535–1542,
H. Portin, A. Leskinen, L. Hao, A. Kortelainen, P. Miettinen, A. Jaatinen, A. Laaksonen, K. E. J. Lehtinen, S. Romakkaniemi, and M. Komppula
Atmos. Chem. Phys., 14, 6021–6034,
S. Romakkaniemi, A. Jaatinen, A. Laaksonen, A. Nenes, and T. Raatikainen
Atmos. Meas. Tech., 7, 1377–1384,
P. J. Connolly, D. O. Topping, F. Malavelle, and G. McFiggans
Atmos. Chem. Phys., 14, 2289–2302,
H. Kokkola, P. Yli-Pirilä, M. Vesterinen, H. Korhonen, H. Keskinen, S. Romakkaniemi, L. Hao, A. Kortelainen, J. Joutsensaari, D. R. Worsnop, A. Virtanen, and K. E. J. Lehtinen
Atmos. Chem. Phys., 14, 1689–1700,
D. Stone, M. J. Evans, H. Walker, T. Ingham, S. Vaughan, B. Ouyang, O. J. Kennedy, M. W. McLeod, R. L. Jones, J. Hopkins, S. Punjabi, R. Lidster, J. F. Hamilton, J. D. Lee, A. C. Lewis, L. J. Carpenter, G. Forster, D. E. Oram, C. E. Reeves, S. Bauguitte, W. Morgan, H. Coe, E. Aruffo, C. Dari-Salisburgo, F. Giammaria, P. Di Carlo, and D. E. Heard
Atmos. Chem. Phys., 14, 1299–1321,
T. Korhola, H. Kokkola, H. Korhonen, A.-I. Partanen, A. Laaksonen, K. E. J. Lehtinen, and S. Romakkaniemi
Geosci. Model Dev., 7, 161–174,
A. Lipponen, V. Kolehmainen, S. Romakkaniemi, and H. Kokkola
Geosci. Model Dev., 6, 2087–2098,
M. R. Alfarra, N. Good, K. P. Wyche, J. F. Hamilton, P. S. Monks, A. C. Lewis, and G. McFiggans
Atmos. Chem. Phys., 13, 11769–11789,
S. Bezantakos, K. Barmpounis, M. Giamarelou, E. Bossioli, M. Tombrou, N. Mihalopoulos, K. Eleftheriadis, J. Kalogiros, J. D. Allan, A. Bacak, C. J. Percival, H. Coe, and G. Biskos
Atmos. Chem. Phys., 13, 11595–11608,
J. F. Hamilton, M. R. Alfarra, N. Robinson, M. W. Ward, A. C. Lewis, G. B. McFiggans, H. Coe, and J. D. Allan
Atmos. Chem. Phys., 13, 11295–11305,
R. Saleh, C. J. Hennigan, G. R. McMeeking, W. K. Chuang, E. S. Robinson, H. Coe, N. M. Donahue, and A. L. Robinson
Atmos. Chem. Phys., 13, 7683–7693,
J. Tonttila, P. Räisänen, and H. Järvinen
Atmos. Chem. Phys., 13, 7551–7565,
M. Parrington, P. I. Palmer, A. C. Lewis, J. D. Lee, A. R. Rickard, P. Di Carlo, J. W. Taylor, J. R. Hopkins, S. Punjabi, D. E. Oram, G. Forster, E. Aruffo, S. J. Moller, S. J.-B. Bauguitte, J. D. Allan, H. Coe, and R. J. Leigh
Atmos. Chem. Phys., 13, 7321–7341,
P. J. Connolly, G. Vaughan, P. Cook, G. Allen, H. Coe, T. W. Choularton, C. Dearden, and A. Hill
Atmos. Chem. Phys., 13, 7133–7152,
C. L. Reddington, G. McMeeking, G. W. Mann, H. Coe, M. G. Frontoso, D. Liu, M. Flynn, D. V. Spracklen, and K. S. Carslaw
Atmos. Chem. Phys., 13, 4917–4939,
J. Skrotzki, P. Connolly, M. Schnaiter, H. Saathoff, O. Möhler, R. Wagner, M. Niemand, V. Ebert, and T. Leisner
Atmos. Chem. Phys., 13, 4451–4466,
D. Liu, J. Allan, J. Whitehead, D. Young, M. Flynn, H. Coe, G. McFiggans, Z. L. Fleming, and B. Bandy
Atmos. Chem. Phys., 13, 2015–2029,
M. Laborde, M. Schnaiter, C. Linke, H. Saathoff, K.-H. Naumann, O. Möhler, S. Berlenz, U. Wagner, J. W. Taylor, D. Liu, M. Flynn, J. D. Allan, H. Coe, K. Heimerl, F. Dahlkötter, B. Weinzierl, A. G. Wollny, M. Zanatta, J. Cozic, P. Laj, R. Hitzenberger, J. P. Schwarz, and M. Gysel
Atmos. Meas. Tech., 5, 3077–3097,
T. Hamburger, G. McMeeking, A. Minikin, A. Petzold, H. Coe, and R. Krejci
Atmos. Chem. Phys., 12, 11533–11554,
Related subject area
Subject: Dynamics | Research Activity: Atmospheric Modelling | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)Robust winter warming over Eurasia under stratospheric sulfate geoengineering – the role of stratospheric dynamicsParameterizing the vertical downward dispersion of ship exhaust gas in the near fieldAnthropogenic aerosol forcing of the Atlantic meridional overturning circulation and the associated mechanisms in CMIP6 modelsSensitivities of the Madden–Julian oscillation forecasts to configurations of physics in the ECMWF global modelSensitivity of modeled Indian monsoon to Chinese and Indian aerosol emissionsThe spring transition of the North Pacific jet and its relation to deep stratosphere-to-troposphere mass transport over western North AmericaVery long-period oscillations in the atmosphere (0–110 km)Identification of molecular cluster evaporation rates, cluster formation enthalpies and entropies by Monte Carlo methodThe “urban meteorology island”: a multi-model ensemble analysisValidation of reanalysis Southern Ocean atmosphere trends using sea ice dataRevisiting the trend in the occurrences of the “warm Arctic–cold Eurasian continent” temperature patternA microphysics guide to cirrus – Part 2: Climatologies of clouds and humidity from observationsCeilometers as planetary boundary layer height detectors and a corrective tool for COSMO and IFS modelsThe potential for geostationary remote sensing of NO2 to improve weather predictionConfinement of air in the Asian monsoon anticyclone and pathways of convective air to the stratosphere during the summer seasonConvective self–aggregation in a mean flowOn the climate sensitivity and historical warming evolution in recent coupled model ensemblesSurface processes in the 7 November 2014 medicane from air–sea coupled high-resolution numerical modellingHadley cell expansion in CMIP6 modelsAtmospheric teleconnection processes linking winter air stagnation and haze extremes in China with regional Arctic sea ice declineDehydration and low ozone in the tropopause layer over the Asian monsoon caused by tropical cyclones: Lagrangian transport calculations using ERA-Interim and ERA5 reanalysis dataCharacterization of the air–sea exchange mechanisms during a Mediterranean heavy precipitation event using realistic sea state modellingTransport of short-lived halocarbons to the stratosphere over the Pacific OceanA very high-resolution assessment and modelling of urban air qualitySurface temperature response to the major volcanic eruptions in multiple reanalysis data setsRole of eyewall and rainband eddy forcing in tropical cyclone intensificationA double ITCZ phenomenology of wind errors in the equatorial Atlantic in seasonal forecasts with ECMWF modelsAnalysis of total column CO2 and CH4 measurements in Berlin with WRF-GHGQuantifying the contribution of anthropogenic influence to the East Asian winter monsoon in 1960–2012Land cover and its transformation in the backward trajectory footprint region of the Amazon Tall Tower ObservatoryLarge-scale dynamics of tropical cyclone formation associated with ITCZ breakdownA numerical process study on the rapid transport of stratospheric air down to the surface over western North America and the Tibetan PlateauGlobal tropopause altitudes in radiosondes and reanalysesHeat transport pathways into the Arctic and their connections to surface air temperaturesTornado-scale vortices in the tropical cyclone boundary layer: numerical simulation with the WRF–LES frameworkDissipation rate of turbulent kinetic energy in stably stratified sheared flowsTwo pathways of how remote SST anomalies drive the interannual variability of autumnal haze days in the Beijing–Tianjin–Hebei region, ChinaLong-term simulation of the boundary layer flow over the double-ridge site during the Perdigão 2017 field campaignAnthropogenic fine particulate matter pollution will be exacerbated in eastern China due to 21st century GHG warmingOn the role of thermal expansion and compression in large-scale atmospheric energy and mass transportsChanges in sea-surface temperature and atmospheric circulation patterns associated with reductions in Arctic sea ice cover in recent decadesA multi-model comparison of meteorological drivers of surface ozone over EuropeMulti-model comparison of urban heat island modelling approachesA statistical examination of the effects of stratospheric sulfate geoengineering on tropical storm genesisCan explicit convection improve modelled dust in summertime West Africa?Tropical atmospheric circulation response to the G1 sunshade geoengineering radiative forcing experimentMultivariate analysis of Kelvin wave seasonal variability in ECMWF L91 analysesSpatial and temporal variability of interhemispheric transport timesA new index for the wintertime southern hemispheric split jetMeteorological controls on atmospheric particulate pollution during hazard reduction burns
Antara Banerjee, Amy H. Butler, Lorenzo M. Polvani, Alan Robock, Isla R. Simpson, and Lantao Sun
Atmos. Chem. Phys., 21, 6985–6997,Short summary
We find that simulated stratospheric sulfate geoengineering could lead to warmer Eurasian winters alongside a drier Mediterranean and wetting to the north. These effects occur due to the strengthening of the Northern Hemisphere stratospheric polar vortex, which shifts the North Atlantic Oscillation to a more positive phase. We find the effects in our simulations to be much more significant than the wintertime effects of large tropical volcanic eruptions which inject much less sulfate aerosol.
Ronny Badeke, Volker Matthias, and David Grawe
Atmos. Chem. Phys., 21, 5935–5951,Short summary
This work aims to describe the physical distribution of ship exhaust gases in the near field, e.g., inside of a harbor. Results were calculated with a mathematical model for different meteorological and technical conditions. It has been shown that large vessels like cruise ships have a significant effect of up to 55 % downward movement of exhaust gas, as they can disturb the ground near wind circulation. This needs to be considered in urban air pollution studies.
Taufiq Hassan, Robert J. Allen, Wei Liu, and Cynthia A. Randles
Atmos. Chem. Phys., 21, 5821–5846,Short summary
State-of-the-art climate models yield robust, externally forced changes in the Atlantic meridional overturning circulation (AMOC), the bulk of which are due to anthropogenic aerosol perturbations to net surface shortwave radiation and sea surface temperature. AMOC-related feedbacks act to reinforce this aerosol-forced response, largely due to changes in sea surface salinity (and hence sea surface density), with temperature- and cloud-related feedbacks acting to mute the initial response.
Jun-Ichi Yano and Nils P. Wedi
Atmos. Chem. Phys., 21, 4759–4778,Short summary
Sensitivities of forecasts of the Madden–Julian oscillation (MJO) to various different configurations of the physics are examined with the global model of ECMWF's Integrated Forecasting System (IFS). The motivation for the study was to simulate the MJO as a nonlinear free wave. To emulate free dynamics in the IFS, various momentum dissipation terms (
friction) as well as diabatic heating were selectively turned off over the tropics for the range of the latitudes from 20° S to 20° N.
Peter Sherman, Meng Gao, Shaojie Song, Alex T. Archibald, Nathan Luke Abraham, Jean-François Lamarque, Drew Shindell, Gregory Faluvegi, and Michael B. McElroy
Atmos. Chem. Phys., 21, 3593–3605,Short summary
The aims here are to assess the role of aerosols in India's monsoon precipitation and to determine the relative contributions from Chinese and Indian emissions using CMIP6 models. We find that increased sulfur emissions reduce precipitation, which is primarily dynamically driven due to spatial shifts in convection over the region. A significant increase in precipitation (up to ~ 20 %) is found only when both Indian and Chinese sulfate emissions are regulated.
Melissa L. Breeden, Amy H. Butler, John R. Albers, Michael Sprenger, and Andrew O'Neil Langford
Atmos. Chem. Phys., 21, 2781–2794,Short summary
Prior research has found a maximum in deep stratosphere-to-troposphere mass/ozone transport over the western United States in boreal spring, which can enhance surface ozone concentrations, reducing air quality. We find that the winter-to-summer evolution of the north Pacific jet increases the frequency of stratospheric intrusions that drive transport, helping explain the observed maximum. The El Niño–Southern Oscillation affects the timing of the spring jet transition and therefore transport.
Dirk Offermann, Christoph Kalicinsky, Ralf Koppmann, and Johannes Wintel
Atmos. Chem. Phys., 21, 1593–1611,Short summary
Atmospheric oscillations with periods of up to several 100 years exist at altitudes up to 110 km. They are also seen in computer models (GCMs) of the atmospheric. They are often attributed to external influences from the sun, from the oceans, or from atmospheric constituents. This is difficult to verify as the atmosphere cannot be manipulated in an experiment. However, a GCM can be changed arbitrarily. Doing so, we find that long-period oscillations may be excited internally in the atmosphere.
Anna Shcherbacheva, Tracey Balehowsky, Jakub Kubečka, Tinja Olenius, Tapio Helin, Heikki Haario, Marko Laine, Theo Kurtén, and Hanna Vehkamäki
Atmos. Chem. Phys., 20, 15867–15906,Short summary
Atmospheric new particle formation and cluster growth to aerosol particles is an important field of research, in particular due to the climate change phenomenon. Evaporation rates are very difficult to account for but they are important to explain the formation and growth of particles. Different quantum chemistry (QC) methods produce substantially different values for the evaporation rates. We propose a novel approach for inferring evaporation rates of clusters from available measurements.
Jan Karlický, Peter Huszár, Tereza Nováková, Michal Belda, Filip Švábik, Jana Ďoubalová, and Tomáš Halenka
Atmos. Chem. Phys., 20, 15061–15077,Short summary
Cities are characterized by their impact on various meteorological variables. Our study aims to generalize these modifications into a single phenomenon – the urban meteorology island (UMI). A wide ensemble of Weather Research and Forecasting (WRF) and Regional Climate Model (RegCM) simulations investigated urban-induced modifications as individual UMI components. Significant changes are found in most of the discussed meteorological variables with a strong impact of specific model simulations.
William R. Hobbs, Andrew R. Klekociuk, and Yuhang Pan
Atmos. Chem. Phys., 20, 14757–14768,Short summary
Reanalysis products are an invaluable tool for representing variability and long-term trends in regions with limited in situ data. However, validation of these products is difficult because of that lack of station data. Here we present a novel assessment of eight reanalyses over the polar Southern Ocean, leveraging the close relationship between trends in sea ice cover and surface air temperature, that provides clear guidance on the most reliable product for Antarctic research.
Lejiang Yu, Shiyuan Zhong, Cuijuan Sui, and Bo Sun
Atmos. Chem. Phys., 20, 13753–13770,Short summary
The recent increasing trend of "warm Arctic, cold continents" has attracted much attention, but it remains debatable as to what forces are behind this phenomenon. Sea surface temperature (SST) over the central North Pacific and the North Atlantic oceans influences the trend. On an interdecadal timescale, the recent increase in the occurrences of the warm Arctic–cold Eurasia pattern is a fragment of the interdecadal variability of SST over the Atlantic Ocean and over the central Pacific Ocean.
Martina Krämer, Christian Rolf, Nicole Spelten, Armin Afchine, David Fahey, Eric Jensen, Sergey Khaykin, Thomas Kuhn, Paul Lawson, Alexey Lykov, Laura L. Pan, Martin Riese, Andrew Rollins, Fred Stroh, Troy Thornberry, Veronika Wolf, Sarah Woods, Peter Spichtinger, Johannes Quaas, and Odran Sourdeval
Atmos. Chem. Phys., 20, 12569–12608,Short summary
To improve the representations of cirrus clouds in climate predictions, extended knowledge of their properties and geographical distribution is required. This study presents extensive airborne in situ and satellite remote sensing climatologies of cirrus and humidity, which serve as a guide to cirrus clouds. Further, exemplary radiative characteristics of cirrus types and also in situ observations of tropical tropopause layer cirrus and humidity in the Asian monsoon anticyclone are shown.
Leenes Uzan, Smadar Egert, Pavel Khain, Yoav Levi, Elyakom Vadislavsky, and Pinhas Alpert
Atmos. Chem. Phys., 20, 12177–12192,Short summary
Detection of the planetary boundary layer (PBL) height is crucial to various fields, from air pollution assessment to weather prediction. We examined the diurnal summer PBL height by eight ceilometers in Israel, radiosonde profiles, the global IFS, and regional COSMO models. Our analysis utilized the bulk Richardson number method, the parcel method, and the wavelet covariance transform method. A novel correction tool to improve model results against in-situ ceilometer measurements is introduced.
Xueling Liu, Arthur P. Mizzi, Jeffrey L. Anderson, Inez Fung, and Ronald C. Cohen
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Observations of winds in the planetary boundary layer remain sparse making it challenging to simulate and predict atmospheric conditions that are most important for describing and predicting urban air quality. Here we investigate the application of data assimilation of NO2 columns as will be observed from geostationary orbit to improve predictions and retrospective analysis of wind fields in the boundary layer.
Bernard Legras and Silvia Bucci
Atmos. Chem. Phys., 20, 11045–11064,Short summary
The Asian monsoon is the most active region bringing surface compounds by convection to the stratosphere during summer. We study the transport pathways and the trapping within the upper-layer anticyclonic circulation. Above 15 km, the confinement can be represented by a uniform ascent over continental Asia of about 200 m per day and a uniform loss to other regions with a characteristic time of 2 weeks. We rule out the presence of a
chimneyproposed in previous studies over the Tibetan Plateau.
Hyunju Jung, Ann Kristin Naumann, and Bjorn Stevens
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
We aim to analyze the behavior of organized convection in a large-scale flow by imposing a mean flow to an idealized simulation. In the mean flow organized convection initially propagates slower than the mean wind speed and becomes stationary. Surface fluxes response to the surface wind asymmetry as a result of the mean flow. While the role of the surface enthalpy flux is minor, the surface momentum flux act as a drag on the surface wind and annihilate the asymmetries, causing the stationarity.
Clare Marie Flynn and Thorsten Mauritsen
Atmos. Chem. Phys., 20, 7829–7842,Short summary
The range of climate sensitivity of models participating in CMIP6 has increased relative to models participating in CMIP5 due to decreases in the total feedback parameter. This is caused by increases in the shortwave all-sky and clear-sky feedbacks, particularly over the Southern Ocean. These shifts between CMIP6 and CMIP5 did not arise by chance. Both CMIP5 and CMIP6 models are found to exhibit aerosol forcing that is too strong, causing too much cooling relative to observations.
Marie-Noëlle Bouin and Cindy Lebeaupin Brossier
Atmos. Chem. Phys., 20, 6861–6881,Short summary
A coupled, kilometre-scale simulation of a medicane is used to assess the impact of the ocean feedback and role of surface fluxes. Sea surface temperature (SST) drop is much weaker than for tropical cyclones, resulting in no impact on the cyclone. Surface fluxes depend mainly on wind and SST for evaporation and on air temperature for sensible heat. Processes in the Mediterranean, like advection of continental air, rain evaporation and dry air intrusion, play a role in cyclone development.
Kevin M. Grise and Sean M. Davis
Atmos. Chem. Phys., 20, 5249–5268,Short summary
As Earth's climate warms, the tropical overturning circulation (Hadley circulation) is projected to expand, potentially pushing subtropical dry zones further poleward. This study examines projections of the Hadley circulation from the latest generation of computer models and finds several notable differences from older models. For example, the Northern Hemisphere circulation has expanded northward at a greater rate in recent decades than would be expected from increasing greenhouse gases alone.
Yufei Zou, Yuhang Wang, Zuowei Xie, Hailong Wang, and Philip J. Rasch
Atmos. Chem. Phys., 20, 4999–5017,Short summary
We analyze the relationship between winter air stagnation and pollution extremes over eastern China and preceding Arctic sea ice loss based on climate modeling and dynamic diagnoses. We find significant increases in both the probability and intensity of air stagnation extremes in the modeling result driven by regional sea ice and sea surface temperature changes over the Pacific sector of the Arctic. We reveal the considerable impact of the Arctic climate change on mid-latitude weather extremes.
Dan Li, Bärbel Vogel, Rolf Müller, Jianchun Bian, Gebhard Günther, Felix Ploeger, Qian Li, Jinqiang Zhang, Zhixuan Bai, Holger Vömel, and Martin Riese
Atmos. Chem. Phys., 20, 4133–4152,Short summary
Low ozone and low water vapour signatures in the UTLS were investigated using balloon-borne measurements and trajectory calculations. The results show that deep convection in tropical cyclones over the western Pacific transports boundary air parcels with low ozone into the tropopause region. Subsequently, these air parcels are dehydrated when passing the lowest temperature region (< 190 K) during quasi-horizontal advection.
César Sauvage, Cindy Lebeaupin Brossier, Marie-Noëlle Bouin, and Véronique Ducrocq
Atmos. Chem. Phys., 20, 1675–1699,Short summary
Air–sea exchanges during Mediterranean heavy precipitation events are key and their representation must be improved for high-resolution weather forecasts. This study investigates the mechanisms acting at the air–sea interface during a case that occurred in southern France. To focus on the impact of sea state, we developed and used an original coupled air–wave model. Results show modifications of the forecast for the air–sea fluxes, the near-surface wind and the location of precipitation.
Michal T. Filus, Elliot L. Atlas, Maria A. Navarro, Elena Meneguz, David Thomson, Matthew J. Ashfold, Lucy J. Carpenter, Stephen J. Andrews, and Neil R. P. Harris
Atmos. Chem. Phys., 20, 1163–1181,Short summary
The effectiveness of transport of short-lived halocarbons to the upper troposphere and lower stratosphere remains an important unknown in quantifying the supply of ozone-depleting substances to the stratosphere. In early 2014, a major field campaign in Guam in the western Pacific, involving UK and US research aircraft, sampled the tropical troposphere and lower stratosphere. The resulting measurements of CH3I, CHBr3 and CH2Br2 are compared here with calculations from a Lagrangian model.
Tobias Wolf, Lasse H. Pettersson, and Igor Esau
Atmos. Chem. Phys., 20, 625–647,Short summary
Exceedances of legal thresholds for urban air pollution are of wide concern. We demonstrate the usefulness of very high-resolution modelling for the assessment of air pollution in the urban space on the example of Bergen, Norway. Vulnerability maps highlight areas with high pollutant loading and pathways for pollutant dispersion. This supports the understanding of urban air pollution beyond existing, scarce monitoring networks and possibly the mitigation of impacts on the local population.
Masatomo Fujiwara, Patrick Martineau, and Jonathon S. Wright
Atmos. Chem. Phys., 20, 345–374,Short summary
The global response of surface air temperature (SST) to the eruptions of Mount Agung in 1963, El Chichón in 1982, and Mount Pinatubo in 1991 is investigated using 11 global atmospheric reanalysis data sets. Multiple linear regression is applied, with a set of climatic indices orthogonalized, and the residuals are investigated. It is found that careful treatment of tropical SST variability is necessary to evaluate the surface response to volcanic eruptions in observations and reanalyses.
Ping Zhu, Bryce Tyner, Jun A. Zhang, Eric Aligo, Sundararaman Gopalakrishnan, Frank D. Marks, Avichal Mehra, and Vijay Tallapragada
Atmos. Chem. Phys., 19, 14289–14310,Short summary
Producing timely and accurate intensity forecasts of tropical cyclones (TCs) continues to be one of the most difficult challenges in numerical weather prediction. The difficulty stems from the fact that TC intensification is not only modulated by environmental conditions but also largely depends on TC internal dynamics. The study shows that asymmetric eyewall and rainband eddy forcing above the boundary layer plays an important role in spinning up a TC vortex including rapid intensification.
Jonathan K. P. Shonk, Teferi D. Demissie, and Thomas Toniazzo
Atmos. Chem. Phys., 19, 11383–11399,Short summary
Modern climate models are affected by systematic biases that harm their ability to produce reliable seasonal forecasts and climate projections. In this study, we investigate causes of biases in wind patterns over the tropical Atlantic during northern spring in three related models. We find that the wind biases are associated with an increase in excess rainfall and convergence in the tropical western Atlantic at the start of April, leading to the redirection of trade winds away from the Equator.
Xinxu Zhao, Julia Marshall, Stephan Hachinger, Christoph Gerbig, Matthias Frey, Frank Hase, and Jia Chen
Atmos. Chem. Phys., 19, 11279–11302,Short summary
The Weather Research and Forecasting model (WRF), coupled with greenhouse gas (GHG) modules (WRF-GHG), is considered to be a suitable basis for precise GHG transport analysis in urban areas, especially when combined with differential column methodology (DCM). DCM is an effective method not only for comparing models to observations independently of biases caused, for example, by initial conditions, but also for detecting and understanding sources of GHG emissions quantitatively in urban areas.
Xin Hao, Shengping He, Huijun Wang, and Tingting Han
Atmos. Chem. Phys., 19, 9903–9911,Short summary
The East Asian winter monsoon (EAWM) can be greatly influenced by many factors that can be classified as anthropogenic forcing and natural forcing. Our results show that the increasing anthropogenic emissions in the past decades may have contributed to the weakening of the EAWM, the frequency of occurrence of strong EAWM may have decreased by 45 % due to the anthropogenic forcing, and the anthropogenic forcing is a dominant contributor to the occurrence of a weak EAWM.
Christopher Pöhlker, David Walter, Hauke Paulsen, Tobias Könemann, Emilio Rodríguez-Caballero, Daniel Moran-Zuloaga, Joel Brito, Samara Carbone, Céline Degrendele, Viviane R. Després, Florian Ditas, Bruna A. Holanda, Johannes W. Kaiser, Gerhard Lammel, Jošt V. Lavrič, Jing Ming, Daniel Pickersgill, Mira L. Pöhlker, Maria Praß, Nina Löbs, Jorge Saturno, Matthias Sörgel, Qiaoqiao Wang, Bettina Weber, Stefan Wolff, Paulo Artaxo, Ulrich Pöschl, and Meinrat O. Andreae
Atmos. Chem. Phys., 19, 8425–8470,Short summary
The Amazon Tall Tower Observatory (ATTO) has been established to monitor the rain forest's biosphere–atmosphere exchange, which experiences the combined pressures from human-made deforestation and progressing climate change. This work is meant to be a reference study, which characterizes various geospatial properties of the ATTO footprint region and shows how the human-made transformation of Amazonia may impact future atmospheric observations at ATTO.
Quan Wang, Chanh Kieu, and The-Anh Vu
Atmos. Chem. Phys., 19, 8383–8397,Short summary
This study presents an analytical model to study large-scale tropical cyclone (TC) formation that can help us understand the maximum capacity of the Earth's atmosphere to produce TCs. Using a barotropic model for the intertropical convergence zone and recent advances in nonlinear dynamical transition, it is found that the Earth's atmosphere can support a limited number of TCs at any given time (<12) in the current climate, thus providing new theoretical insights into the TC formation process.
Bojan Škerlak, Stephan Pfahl, Michael Sprenger, and Heini Wernli
Atmos. Chem. Phys., 19, 6535–6549,Short summary
Upper-level fronts are often associated with the rapid transport of stratospheric air to the lower troposphere, leading to significantly enhanced ozone concentrations. This paper considers the multi-scale nature that is needed to bring stratospheric air down to the surface. The final transport step to the surface can be related to frontal zones and the associated vertical winds or to near-horizontal tracer transport followed by entrainment into a growing planetary boundary layer.
Tao Xian and Cameron R. Homeyer
Atmos. Chem. Phys., 19, 5661–5678,Short summary
Global characteristics and trends in the tropopause (the boundary between troposphere and stratosphere) over a 35-year period (1981–2015) are evaluated using both observations and models. The use of two coordinate systems reveals previously undiagnosed changes in the tropopause altitude within the tropics and extratropics and these results have important implications for studies of climate and atmospheric composition (especially that related to stratosphere–troposphere exchange).
Daniel Mewes and Christoph Jacobi
Atmos. Chem. Phys., 19, 3927–3937,Short summary
Horizontal moist static energy (MSE) transport patterns were extracted from reanalysis data using an artificial neuronal network for the winter months. The results show that during the last 30 years transport pathways that favour MSE transport through the North Atlantic are getting more frequent. This North Atlantic pathway is connected to positive temperature anomalies over the central Arctic, which implies a connection between Arctic amplification and the change in horizontal heat transport.
Liguang Wu, Qingyuan Liu, and Yubin Li
Atmos. Chem. Phys., 19, 2477–2487,Short summary
The tornado-scale vortex in the tropical cyclone boundary layer has been speculated in intense hurricanes. A numerical experiment is conducted using the Advanced Weather Research and Forecast model by incorporating the large-eddy simulation technique. The simulated tornado-scale vortex shows the similar features as revealed with the limited observational data. The presence of the tornado-scale vortex also leads to significant gradients in the near surface wind speed and wind gusts.
Sergej Zilitinkevich, Oleg Druzhinin, Andrey Glazunov, Evgeny Kadantsev, Evgeny Mortikov, Iryna Repina, and Yulia Troitskaya
Atmos. Chem. Phys., 19, 2489–2496,Short summary
We consider the budget of turbulent kinetic energy (TKE) in stably stratified flows. TKE is generated by velocity shear, then partially converted to potential energy, but basically cascades towards very small eddies and dissipates into heat. The TKE dissipation rate is vital for comprehending and modelling turbulent flows in geophysics, astrophysics, and engineering. Until now its dependence on static stability remained unclear. We define it theoretically and validate against experimental data.
Jing Wang, Zhiwei Zhu, Li Qi, Qiaohua Zhao, Jinhai He, and Julian X. L. Wang
Atmos. Chem. Phys., 19, 1521–1535,Short summary
Less attention has been paid to haze weather during the autumn season. Here, we unravel the mechanism of how SST anomalies over the subtropical North Atlantic and western North Pacific drive the interannual variability of the autumnal haze days in the Beijing–Tianjin–Hebei region. The two pathways of SST anomaly forcings can result in an anticyclonic (cyclonic) anomaly over Northeast Asia, leading to a lower-level southerly (northerly) anomaly and in turn more (fewer) haze days in this region.
Johannes Wagner, Thomas Gerz, Norman Wildmann, and Kira Gramitzky
Atmos. Chem. Phys., 19, 1129–1146,Short summary
Long-term WRF-LES simulations were performed with a horizontal resolution of 200 m for a period of 49 days during the Perdigão campaign. Simulation results were used to characterize the meteorological conditions and to analyse characteristic flow patterns. It could be shown that thermally driven flows including low-level jets frequently occurred during the observation period. Model results were in very good agreement with observations in spite of the long simulation time.
Huopo Chen, Huijun Wang, Jianqi Sun, Yangyang Xu, and Zhicong Yin
Atmos. Chem. Phys., 19, 233–243,Short summary
Our results show that the anthropogenic air pollution over eastern China will increase considerably at the end of 21st century, even though we keep the aerosol emission constant throughout the experiment. Furthermore, estimation shows that the effect of climate change induced by the GHG warming can account for 11%–28% of the changes of anthropogenic air pollution days over this region.
Melville E. Nicholls and Roger A. Pielke Sr.
Atmos. Chem. Phys., 18, 15975–16003,Short summary
The current understanding of atmospheric energy and mass transports is that the general circulation moves energy and mass from place to place in a relatively slow manner at the speed of the winds. This study challenges this view and provides evidence that considerable transfer can occur at the speed of sound. This transport mechanism is probably not adequately represented in current global models, which potentially could be a source of error that has yet to be evaluated.
Lejiang Yu and Shiyuan Zhong
Atmos. Chem. Phys., 18, 14149–14159,Short summary
The Arctic sea ice has been declining at a rapid pace in recent decades, which has been attributed largely to global warming. Using a relatively novel statistical method called self-organizing maps (SOM), we show that a large portion of the autumn Arctic sea ice decline in the past four decades may be explained by atmospheric circulation anomalies associated with anomalous sea-surface temperature patterns over the North Pacific and North Atlantic through ocean–atmosphere interactions.
Noelia Otero, Jana Sillmann, Kathleen A. Mar, Henning W. Rust, Sverre Solberg, Camilla Andersson, Magnuz Engardt, Robert Bergström, Bertrand Bessagnet, Augustin Colette, Florian Couvidat, Cournelius Cuvelier, Svetlana Tsyro, Hilde Fagerli, Martijn Schaap, Astrid Manders, Mihaela Mircea, Gino Briganti, Andrea Cappelletti, Mario Adani, Massimo D'Isidoro, María-Teresa Pay, Mark Theobald, Marta G. Vivanco, Peter Wind, Narendra Ojha, Valentin Raffort, and Tim Butler
Atmos. Chem. Phys., 18, 12269–12288,Short summary
This paper evaluates the capability of air-quality models to capture the observed relationship between surface ozone concentrations and meteorology over Europe. The air-quality models tended to overestimate the influence of maximum temperature and surface solar radiation. None of the air-quality models captured the strength of the observed relationship between ozone and relative humidity appropriately, underestimating the effect of relative humidity, a key factor in the ozone removal processes.
Jan Karlický, Peter Huszár, Tomáš Halenka, Michal Belda, Michal Žák, Petr Pišoft, and Jiří Mikšovský
Atmos. Chem. Phys., 18, 10655–10674,Short summary
Our work presents a comparison of modelled and observed urban-induced meteorological changes in long-term perspective using 10-year simulations. It contains an evaluation of models' urban parameterizations, investigations of the benefits of more sophisticated urban parameterizations with respect to simple approaches and evaluation of urban-induced meteorological changes from the perspective of pollutant dispersion.
Qin Wang, John C. Moore, and Duoying Ji
Atmos. Chem. Phys., 18, 9173–9188,Short summary
(1) Genesis potential and ventilation indices are assessed in 6 ESMs running RCP4.5 and G4, in 6 tropical cyclone genesis basins. (2) Genesis potential is reasonably well parameterized by simple surface temperature, but other factors are important in different basins and models such as relative humidity and wind shear. (3) The Northern Hemisphere basins behave rather differently from the southern ones, and these dominate TC statistics. G4 leads to significantly fewer TCs globally than RCP4.5.
Alexander J. Roberts, Margaret J. Woodage, John H. Marsham, Ellie J. Highwood, Claire L. Ryder, Willie McGinty, Simon Wilson, and Julia Crook
Atmos. Chem. Phys., 18, 9025–9048,Short summary
The summer Saharan dust hotspot is seasonally tied to the occurrence of convective storms. Global weather and climate models parameterise convection and so are unable to represent their associated dust uplift (haboobs). However, this work shows that even when simulations represent convection explicitly: (1) dust fields are not strongly affected, (2) convective storms are too small, (3) haboobs are too weak and (4) the land surface (bare soil and soil moisture) is dominant in controlling dust.
Anboyu Guo, John C. Moore, and Duoying Ji
Atmos. Chem. Phys., 18, 8689–8706,Short summary
This is an examination of both the zonal and meridional tropical circulations under G1 geoengineering using eight ESMs. Drivers of the changes are examined, with meridional temperature gradient being the dominant factor. The Hadley circulation is changed under G1 differently for each hemisphere, but changes are small compared with abrupt4xCO2. Changes in the Walker circulation are subtle but potentially important in some regions, and ENSO impacts circulations only slightly differently under G1.
Marten Blaauw and Nedjeljka Žagar
Atmos. Chem. Phys., 18, 8313–8330,Short summary
The equatorial Kelvin wave (KW) is the most studied wave feature of the tropical atmosphere, yet not well quantified. Our study simultaneously analyses wind and temperature fields of KWs from ECMWF analyses without any prior data filtering. We provide the KW energy spectrum and its seasonal variability for three KW frequency ranges. We developed a webpage to show the spatial structure of KWs propagating in time through the ECMWF data, http://modes.fmf.uni-lj.si, updated on a daily basis.
Xiaokang Wu, Huang Yang, Darryn W. Waugh, Clara Orbe, Simone Tilmes, and Jean-Francois Lamarque
Atmos. Chem. Phys., 18, 7439–7452,Short summary
The seasonal and interannual variability of transport times from northern mid-latitudes into the southern hemisphere is examined using simulations of
agetracers. The largest variability occurs near the surface close to the tropical convergence zones, but the peak is further south and there is a smaller tropical–extratropical contrast for tracers with more rapid loss. Hence the variability of trace gases in the southern extratropics will vary with their chemical lifetime.
Stella Babian, Jens Grieger, and Ulrich Cubasch
Atmos. Chem. Phys., 18, 6749–6760,Short summary
One of the most prominent asymmetric features of the southern hemispheric (SH) circulation is the split jet over Australia and New Zealand in austral winter. We propose a new, hemispherical index that is based on the principal components (PCs) of the zonal wind field for the SH winter. The new PC-based index (PSI) suggests that the SH split jet is strongly associated with the AAO. Furthermore, both flavors of ENSO and the PSA-1 pattern produce favorable conditions for a SH split event.
Giovanni Di Virgilio, Melissa Anne Hart, and Ningbo Jiang
Atmos. Chem. Phys., 18, 6585–6599,Short summary
Hazard reduction burns (HRBs) may prevent wildfires, but both generate PM2.5 air pollution. We identify the meteorological factors linked to high PM2.5 pollution & assess how they differ between HRB days with low vs. high PM2.5. Boundary layer, cloud cover, temperature & wind speed strongly influence PM2.5, with these factors being more variable & higher in magnitude during mornings & evenings of HRB days when PM2.5 remains low, indicating how HRB timing can be altered to reduce air pollution.
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The feedback effect between aerosol particles, radiation and meteorology reduces turbulent motion and results in increased surface aerosol concentrations during Beijing haze. Observational analysis and regional modelling studies have examined the feedback effect but these studies are limited. In this work, we set up a high-resolution model for the Beijing environment to examine the sensitivity of the aerosol feedback effect to initial meteorological conditions and aerosol loading.
The feedback effect between aerosol particles, radiation and meteorology reduces turbulent...