Articles | Volume 18, issue 24
Atmos. Chem. Phys., 18, 17895–17907, 2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article 17 Dec 2018
Research article | 17 Dec 2018
Detecting changes in Arctic methane emissions: limitations of the inter-polar difference of atmospheric mole fractions
Oscar B. Dimdore-Miles et al.
No articles found.
Antoine Berchet, Espen Sollum, Rona L. Thompson, Isabelle Pison, Joël Thanwerdas, Grégoire Broquet, Frédéric Chevallier, Tuula Aalto, Adrien Berchet, Peter Bergamaschi, Dominik Brunner, Richard Engelen, Audrey Fortems-Cheiney, Christoph Gerbig, Christine D. Groot Zwaaftink, Jean-Matthieu Haussaire, Stephan Henne, Sander Houweling, Ute Karstens, Werner L. Kutsch, Ingrid T. Luijkx, Guillaume Monteil, Paul I. Palmer, Jacob C. A. van Peet, Wouter Peters, Philippe Peylin, Elise Potier, Christian Rödenbeck, Marielle Saunois, Marko Scholze, Aki Tsuruta, and Yuanhong Zhao
Geosci. Model Dev., 14, 5331–5354,Short summary
We present here the Community Inversion Framework (CIF) to help rationalize development efforts and leverage the strengths of individual inversion systems into a comprehensive framework. The CIF is a programming protocol to allow various inversion bricks to be exchanged among researchers. The ensemble of bricks makes a flexible, transparent and open-source Python-based tool. We describe the main structure and functionalities and demonstrate it in a simple academic case.
Douglas Finch, Paul Palmer, and Tianran Zhang
Atmos. Meas. Tech. Discuss.,
Preprint under review for AMTShort summary
We developed a machine learning model to detect plumes of nitrogen dioxide satellite observations over two years. We find over 310,000 plumes, mainly over cities, industrial regions and areas of oil and gas production. Our model performs well in comparison to other datasets and in some cases, finds emissions that are not included in other datasets. This method could be used to help locate and measure emission hotspots across the globe and help inform climate policies.
Zhu Deng, Philippe Ciais, Zitely A. Tzompa-Sosa, Marielle Saunois, Chunjing Qiu, Chang Tan, Taochun Sun, Piyu Ke, Yanan Cui, Katsumasa Tanaka, Xin Lin, Rona L. Thompson, Hanqin Tian, Yuanzhi Yao, Yuanyuan Huang, Ronny Lauerwald, Atul K. Jain, Xiaoming Xu, Ana Bastos, Stephen Sitch, Paul I. Palmer, Thomas Lauvaux, Alexandre d’Aspremont, Clément Giron, Antoine Benoit, Benjamin Poulter, Jinfeng Chang, Ana Maria Roxana Petrescu, Steven J. Davis, Zhu Liu, Giacomo Grassi, Clément Albergel, and Frédéric Chevallier
Earth Syst. Sci. Data Discuss.,
Preprint under review for ESSDShort summary
In support of the Global Stocktake of the Paris Agreement on Climate change, we proposed a method for reconciling the results of atmospheric inversions with results of UNFCCC national inventory reports. Here, based on a new global harmonized database we compiled from the UNFCCC national reports, and a comprehensive framework presented in this study to process the results of inversions, we compared the results of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).
Thomas E. Taylor, Christopher W. O'Dell, David Crisp, Akhiko Kuze, Hannakaisa Lindqvist, Paul O. Wennberg, Abhishek Chatterjee, Michael Gunson, Annmarie Eldering, Brendan Fisher, Matthäus Kiel, Robert R. Nelson, Aronne Merrelli, Greg Osterman, Frédéric Chevallier, Paul I. Palmer, Liang Feng, Nicholas M. Deutscher, Manvendra K. Dubey, Dietrich G. Feist, Omaira E. Garcia, David Griffith, Frank Hase, Laura T. Iraci, Rigel Kivi, Cheng Liu, Martine De Mazière, Isamu Morino, Justus Notholt, Young-Suk Oh, Hirofumi Ohyama, David F. Pollard, Markus Rettinger, Coleen M. Roehl, Matthias Schneider, Mahesh Kumar Sha, Kei Shiomi, Kimberly Strong, Ralf Sussmann, Yao Té, Voltaire A. Velazco, Mihalis Vrekoussis, Thorsten Warneke, and Debra Wunch
Earth Syst. Sci. Data Discuss.,
Preprint under review for ESSDShort summary
We provide an analysis of an eleven year record of atmospheric carbon dioxide (CO2) concentrations derived using an optimal estimation retrieval algorithm on measurements made by the GOSAT satellite . The new product (version 9) shows improvement over the previous version (v7.3) as evaluated against independent estimates of CO2 from ground-based sensors and atmospheric inversion systems. We also compare the new GOSAT CO2 values to collocated estimates from NASA's Orbiting Carbon Observatory-2.
Caterina Mogno, Paul I. Palmer, Christoph Knote, Fei Yao, and Timothy J. Wallington
Atmos. Chem. Phys., 21, 10881–10909,Short summary
We use a 3-D atmospheric chemistry model to investigate how seasonal emissions sources and meteorological conditions affect the surface distribution of fine particulate matter (PM2.5) and organic aerosol (OA) over the Indo-Gangetic Plain. We find that all seasonal mean values of PM2.5 still exceed safe air quality levels, with human emissions contributing to PM2.5 all year round, open fires during post- and pre-monsoon, and biogenic emissions during monsoon. OA contributes up to 30 % to PM2.5.
Mark Lunt, Alistair Manning, Grant Allen, Tim Arnold, Stéphane Bauguitte, Hartmut Boesch, Anita Ganesan, Aoife Grant, Carole Helfter, Eiko Nemitz, Simon O'Doherty, Paul Palmer, Joseph Pitt, Chris Rennick, Daniel Say, Kieran Stanley, Ann Stavert, Dickon Young, and Matt Rigby
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
We present an evaluation of the UK's methane emissions between 2013 and 2020 using a network of tall tower measurement sites. We find emissions that are consistent in both magnitude and trend with the UK's reported emissions with a declining trend driven by a decrease in emissions from England. The impact of various components of the modelling setup on these findings are explored through a number of sensitivity studies.
Margaret R. Marvin, Paul I. Palmer, Barry G. Latter, Richard Siddans, Brian J. Kerridge, Mohd Talib Latif, and Md Firoz Khan
Atmos. Chem. Phys., 21, 1917–1935,Short summary
We use an atmospheric chemistry model in combination with satellite and surface observations to investigate how biomass burning affects tropospheric ozone over Southeast Asia during its fire seasons. We find that nitrogen oxides from biomass burning were responsible for about 30 % of the regional ozone formation potential, and we estimate that ozone from biomass burning caused more than 400 excess premature deaths in Southeast Asia during the peak burning months of March and September 2014.
James D. Lee, Will S. Drysdale, Doug P. Finch, Shona E. Wilde, and Paul I. Palmer
Atmos. Chem. Phys., 20, 15743–15759,Short summary
Efforts to prevent the COVID-19 virus spreading across the globe have included travel restrictions and the closure of workplaces, leading to a significant drop in emissions of primary air pollutants. This provides for a unique opportunity to examine how air pollutant concentrations respond to an abrupt and prolonged reduction. We examine how NO2 and O3 have been affected at several urban measurement sites in the UK. We look at the change in NO2 compared to previous years and the effect on O3.
Robert J. Parker, Alex Webb, Hartmut Boesch, Peter Somkuti, Rocio Barrio Guillo, Antonio Di Noia, Nikoleta Kalaitzi, Jasdeep S. Anand, Peter Bergamaschi, Frederic Chevallier, Paul I. Palmer, Liang Feng, Nicholas M. Deutscher, Dietrich G. Feist, David W. T. Griffith, Frank Hase, Rigel Kivi, Isamu Morino, Justus Notholt, Young-Suk Oh, Hirofumi Ohyama, Christof Petri, David F. Pollard, Coleen Roehl, Mahesh K. Sha, Kei Shiomi, Kimberly Strong, Ralf Sussmann, Yao Té, Voltaire A. Velazco, Thorsten Warneke, Paul O. Wennberg, and Debra Wunch
Earth Syst. Sci. Data, 12, 3383–3412,Short summary
This work presents the latest release of the University of Leicester GOSAT methane data and acts as the definitive description of this dataset. We detail the processing, validation and evaluation involved in producing these data and highlight its many applications. With now over a decade of global atmospheric methane observations, this dataset has helped, and will continue to help, us better understand the global methane budget and investigate how it may respond to a future changing climate.
Pierre Friedlingstein, Michael O'Sullivan, Matthew W. Jones, Robbie M. Andrew, Judith Hauck, Are Olsen, Glen P. Peters, Wouter Peters, Julia Pongratz, Stephen Sitch, Corinne Le Quéré, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Simone Alin, Luiz E. O. C. Aragão, Almut Arneth, Vivek Arora, Nicholas R. Bates, Meike Becker, Alice Benoit-Cattin, Henry C. Bittig, Laurent Bopp, Selma Bultan, Naveen Chandra, Frédéric Chevallier, Louise P. Chini, Wiley Evans, Liesbeth Florentie, Piers M. Forster, Thomas Gasser, Marion Gehlen, Dennis Gilfillan, Thanos Gkritzalis, Luke Gregor, Nicolas Gruber, Ian Harris, Kerstin Hartung, Vanessa Haverd, Richard A. Houghton, Tatiana Ilyina, Atul K. Jain, Emilie Joetzjer, Koji Kadono, Etsushi Kato, Vassilis Kitidis, Jan Ivar Korsbakken, Peter Landschützer, Nathalie Lefèvre, Andrew Lenton, Sebastian Lienert, Zhu Liu, Danica Lombardozzi, Gregg Marland, Nicolas Metzl, David R. Munro, Julia E. M. S. Nabel, Shin-Ichiro Nakaoka, Yosuke Niwa, Kevin O'Brien, Tsuneo Ono, Paul I. Palmer, Denis Pierrot, Benjamin Poulter, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Jörg Schwinger, Roland Séférian, Ingunn Skjelvan, Adam J. P. Smith, Adrienne J. Sutton, Toste Tanhua, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Guido van der Werf, Nicolas Vuichard, Anthony P. Walker, Rik Wanninkhof, Andrew J. Watson, David Willis, Andrew J. Wiltshire, Wenping Yuan, Xu Yue, and Sönke Zaehle
Earth Syst. Sci. Data, 12, 3269–3340,Short summary
The Global Carbon Budget 2020 describes the data sets and methodology used to quantify the emissions of carbon dioxide and their partitioning among the atmosphere, land, and ocean. These living data are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Ruqian Miao, Qi Chen, Yan Zheng, Xi Cheng, Yele Sun, Paul I. Palmer, Manish Shrivastava, Jianping Guo, Qiang Zhang, Yuhan Liu, Zhaofeng Tan, Xuefei Ma, Shiyi Chen, Limin Zeng, Keding Lu, and Yuanhang Zhang
Atmos. Chem. Phys., 20, 12265–12284,Short summary
In this study we evaluated the model performances for simulating secondary inorganic aerosol (SIA) and organic aerosol (OA) in PM2.5 in China against comprehensive datasets. The potential biases from factors related to meteorology, emission, chemistry, and atmospheric removal are systematically investigated. This study provides a comprehensive understanding of modeling PM2.5, which is important for studies on the effectiveness of emission control strategies.
Marielle Saunois, Ann R. Stavert, Ben Poulter, Philippe Bousquet, Josep G. Canadell, Robert B. Jackson, Peter A. Raymond, Edward J. Dlugokencky, Sander Houweling, Prabir K. Patra, Philippe Ciais, Vivek K. Arora, David Bastviken, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Lori Bruhwiler, Kimberly M. Carlson, Mark Carrol, Simona Castaldi, Naveen Chandra, Cyril Crevoisier, Patrick M. Crill, Kristofer Covey, Charles L. Curry, Giuseppe Etiope, Christian Frankenberg, Nicola Gedney, Michaela I. Hegglin, Lena Höglund-Isaksson, Gustaf Hugelius, Misa Ishizawa, Akihiko Ito, Greet Janssens-Maenhout, Katherine M. Jensen, Fortunat Joos, Thomas Kleinen, Paul B. Krummel, Ray L. Langenfelds, Goulven G. Laruelle, Licheng Liu, Toshinobu Machida, Shamil Maksyutov, Kyle C. McDonald, Joe McNorton, Paul A. Miller, Joe R. Melton, Isamu Morino, Jurek Müller, Fabiola Murguia-Flores, Vaishali Naik, Yosuke Niwa, Sergio Noce, Simon O'Doherty, Robert J. Parker, Changhui Peng, Shushi Peng, Glen P. Peters, Catherine Prigent, Ronald Prinn, Michel Ramonet, Pierre Regnier, William J. Riley, Judith A. Rosentreter, Arjo Segers, Isobel J. Simpson, Hao Shi, Steven J. Smith, L. Paul Steele, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Francesco N. Tubiello, Aki Tsuruta, Nicolas Viovy, Apostolos Voulgarakis, Thomas S. Weber, Michiel van Weele, Guido R. van der Werf, Ray F. Weiss, Doug Worthy, Debra Wunch, Yi Yin, Yukio Yoshida, Wenxin Zhang, Zhen Zhang, Yuanhong Zhao, Bo Zheng, Qing Zhu, Qiuan Zhu, and Qianlai Zhuang
Earth Syst. Sci. Data, 12, 1561–1623,Short summary
Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. We have established a consortium of multidisciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate new research aimed at improving and regularly updating the global methane budget. This is the second version of the review dedicated to the decadal methane budget, integrating results of top-down and bottom-up estimates.
Mark F. Lunt, Paul I. Palmer, Liang Feng, Christopher M. Taylor, Hartmut Boesch, and Robert J. Parker
Atmos. Chem. Phys., 19, 14721–14740,Short summary
Using data from the GOSAT satellite between 2010 and 2016 and a Bayesian inversion approach, we estimate monthly emissions of methane from tropical Africa. We find an increase in methane emissions during this period, driven in part by rising emissions from South Sudan. Using ancillary data we attribute this short-term emissions rise to an increase in the extent of the Sudd wetlands driven by increased outflow from the East African lakes.
Sean Crowell, David Baker, Andrew Schuh, Sourish Basu, Andrew R. Jacobson, Frederic Chevallier, Junjie Liu, Feng Deng, Liang Feng, Kathryn McKain, Abhishek Chatterjee, John B. Miller, Britton B. Stephens, Annmarie Eldering, David Crisp, David Schimel, Ray Nassar, Christopher W. O'Dell, Tomohiro Oda, Colm Sweeney, Paul I. Palmer, and Dylan B. A. Jones
Atmos. Chem. Phys., 19, 9797–9831,Short summary
Space-based retrievals of carbon dioxide offer the potential to provide dense data in regions that are sparsely observed by the surface network. We find that flux estimates that are informed by the Orbiting Carbon Observatory-2 (OCO-2) show different character from that inferred using surface measurements in tropical land regions, particularly in Africa, with a much larger total emission and larger amplitude seasonal cycle.
Joseph R. Pitt, Grant Allen, Stéphane J.-B. Bauguitte, Martin W. Gallagher, James D. Lee, Will Drysdale, Beth Nelson, Alistair J. Manning, and Paul I. Palmer
Atmos. Chem. Phys., 19, 8931–8945,Short summary
This paper presents a new method to assess inventory estimates of greenhouse gas and air pollutant emissions for large cities and their surrounding regions. A case study using data sampled by a research aircraft around London was used to test the method. We found that the UK national inventory agrees with our observations for CO but needed lower emissions for CH4 to agree with the measured data. Repeated studies could help determine how these emissions vary on different timescales.
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.
Paul I. Palmer, Emily L. Wilson, Geronimo L. Villanueva, Giuliano Liuzzi, Liang Feng, Anthony J. DiGregorio, Jianping Mao, Lesley Ott, and Bryan Duncan
Atmos. Meas. Tech., 12, 2579–2594,Short summary
We describe the potential impact of a new, low-cost, portable ground instrument (the mini-LHR) that measures methane and carbon dioxide in the atmospheric column. This region is key in quantifying the global carbon budget but has geographical gaps in measurements left by ground-based networks and space-based observations. A deployment of 50 mini-LHRs would add new data products in the Amazon, the Arctic, and southern Asia and significantly improve knowledge of regional and global carbon budgets.
Emily D. White, Matthew Rigby, Mark F. Lunt, T. Luke Smallman, Edward Comyn-Platt, Alistair J. Manning, Anita L. Ganesan, Simon O'Doherty, Ann R. Stavert, Kieran Stanley, Mathew Williams, Peter Levy, Michel Ramonet, Grant L. Forster, Andrew C. Manning, and Paul I. Palmer
Atmos. Chem. Phys., 19, 4345–4365,Short summary
Understanding carbon dioxide (CO2) fluxes from the terrestrial biosphere on a national scale is important for evaluating land use strategies to mitigate climate change. We estimate emissions of CO2 from the UK biosphere using atmospheric data in a top-down approach. Our findings show that bottom-up estimates from models of biospheric fluxes overestimate the amount of CO2 uptake in summer. This suggests these models wrongly estimate or omit key processes, e.g. land disturbance due to harvest.
Carole Helfter, Neil Mullinger, Massimo Vieno, Simon O'Doherty, Michel Ramonet, Paul I. Palmer, and Eiko Nemitz
Atmos. Chem. Phys., 19, 3043–3063,Short summary
We present a novel approach to estimate the annual budgets of carbon dioxide (881.0 ± 128.5 Tg) and methane (2.55 ± 0.48 Tg) of the British Isles from shipborne measurements taken over a 3-year period (2015–2017). This study brings independent verification of the emission budgets estimated using alternative products and investigates the seasonality of these emissions, which is usually not possible.
Sarah Connors, Alistair J. Manning, Andrew D. Robinson, Stuart N. Riddick, Grant L. Forster, Anita Ganesan, Aoife Grant, Stephen Humphrey, Simon O'Doherty, Dave E. Oram, Paul I. Palmer, Robert L. Skelton, Kieran Stanley, Ann Stavert, Dickon Young, and Neil R. P. Harris
Atmos. Chem. Phys. Discuss.,
Preprint withdrawnShort summary
Methane is an important greenhouse gas & reducing its emissions is a vital part of climate change mitigation to limit global temperature increase to 1.5 °C or 2.0 °C. This paper explains a way to estimate emitted methane over a sub-national area by combining measurements & computer dispersion modelling in a so-called
inversiontechnique. Compared with the current national inventory, our results show lower emissions for Cambridgeshire, possibly due to waste sector emission differences.
Christopher W. O'Dell, Annmarie Eldering, Paul O. Wennberg, David Crisp, Michael R. Gunson, Brendan Fisher, Christian Frankenberg, Matthäus Kiel, Hannakaisa Lindqvist, Lukas Mandrake, Aronne Merrelli, Vijay Natraj, Robert R. Nelson, Gregory B. Osterman, Vivienne H. Payne, Thomas E. Taylor, Debra Wunch, Brian J. Drouin, Fabiano Oyafuso, Albert Chang, James McDuffie, Michael Smyth, David F. Baker, Sourish Basu, Frédéric Chevallier, Sean M. R. Crowell, Liang Feng, Paul I. Palmer, Mavendra Dubey, Omaira E. García, David W. T. Griffith, Frank Hase, Laura T. Iraci, Rigel Kivi, Isamu Morino, Justus Notholt, Hirofumi Ohyama, Christof Petri, Coleen M. Roehl, Mahesh K. Sha, Kimberly Strong, Ralf Sussmann, Yao Te, Osamu Uchino, and Voltaire A. Velazco
Atmos. Meas. Tech., 11, 6539–6576,
Liang Feng, Paul I. Palmer, Robyn Butler, Stephen J. Andrews, Elliot L. Atlas, Lucy J. Carpenter, Valeria Donets, Neil R. P. Harris, Ross J. Salawitch, Laura L. Pan, and Sue M. Schauffler
Atmos. Chem. Phys., 18, 14787–14798,Short summary
We infer surface fluxes of bromoform (CHBr3) and dibromoform (CH2Br2) from CAST and CONTRAST aircraft observations over the western Pacific, using a tagged version of the GEOS-Chem global 3-D atmospheric chemistry model and a Maximum A Posteriori inverse model. Using the aircraft data, we estimate the regional fluxes about 20–40 % smaller than the prior inventories by Ordóñez et al. (2012). We find no evidence to support a robust linear relationship between CHBr3 and CH2Br2 oceanic emissions.
Robyn Butler, Paul I. Palmer, Liang Feng, Stephen J. Andrews, Elliot L. Atlas, Lucy J. Carpenter, Valeria Donets, Neil R. P. Harris, Stephen A. Montzka, Laura L. Pan, Ross J. Salawitch, and Sue M. Schauffler
Atmos. Chem. Phys., 18, 13135–13153,Short summary
Natural sources of short-lived bromoform and dibromomethane are important for determining the inorganic bromine budget in the stratosphere that drives ozone loss. Two new modelling techniques describe how different geographical source regions influence their atmospheric variability over the western Pacific. We find that it is driven primarily by open ocean sources, and we use atmospheric observations to help estimate their contributions to the upper tropospheric inorganic bromine budget.
Neil Humpage, Hartmut Boesch, Paul I. Palmer, Andy Vick, Phil Parr-Burman, Martyn Wells, David Pearson, Jonathan Strachan, and Naidu Bezawada
Atmos. Meas. Tech., 11, 5199–5222,Short summary
We present an overview of the GreenHouse gas Observations of the Stratosphere and Troposphere (GHOST) instrument, a novel shortwave infrared grating spectrometer designed for remote sensing of total column greenhouse gas concentrations from an aircraft. Using laboratory measurements we show that the GHOST design is able to achieve its science objectives. We conclude by describing GHOST's maiden flights on board the NASA Global Hawk UAV during CAST/ATTREX and show some of the initial results.
Paul I. Palmer, Simon O'Doherty, Grant Allen, Keith Bower, Hartmut Bösch, Martyn P. Chipperfield, Sarah Connors, Sandip Dhomse, Liang Feng, Douglas P. Finch, Martin W. Gallagher, Emanuel Gloor, Siegfried Gonzi, Neil R. P. Harris, Carole Helfter, Neil Humpage, Brian Kerridge, Diane Knappett, Roderic L. Jones, Michael Le Breton, Mark F. Lunt, Alistair J. Manning, Stephan Matthiesen, Jennifer B. A. Muller, Neil Mullinger, Eiko Nemitz, Sebastian O'Shea, Robert J. Parker, Carl J. Percival, Joseph Pitt, Stuart N. Riddick, Matthew Rigby, Harjinder Sembhi, Richard Siddans, Robert L. Skelton, Paul Smith, Hannah Sonderfeld, Kieran Stanley, Ann R. Stavert, Angelina Wenger, Emily White, Christopher Wilson, and Dickon Young
Atmos. Chem. Phys., 18, 11753–11777,Short summary
This paper provides an overview of the Greenhouse gAs Uk and Global Emissions (GAUGE) experiment. GAUGE was designed to quantify nationwide GHG emissions of the UK, bringing together measurements and atmospheric transport models. This novel experiment is the first of its kind. We anticipate it will inform the blueprint for countries that are building a measurement infrastructure in preparation for global stocktakes, which are a key part of the Paris Agreement.
Luke Surl, Paul I. Palmer, and Gonzalo González Abad
Atmos. Chem. Phys., 18, 4549–4566,Short summary
We used observations of HCHO formaldehyde columns from the OMI satellite instrument and the GEOS-Chem atmospheric chemistry model to investigate how and why HCHO varies over India. We find that emissions of biogenic VOC from forests are the most powerful driver, with forests' response to seasonal temperature variations causing variation over time. Human-driven emissions of VOC and burning of vegetation have detectable, but more limited, impacts.
Anna Mackie, Paul I. Palmer, and Helen Brindley
Atmos. Chem. Phys., 17, 15095–15119,Short summary
We compare the balance of solar and thermal radiation at the surface and the top of the atmosphere from a forecasting model to observations at a site in Niamey, Niger, in the Sahel. To interpret the energy budgets we examine other factors, such as cloud properties, water vapour and aerosols, which we use to understand the differences between the observation and model. We find that some differences are linked to lack of ice in clouds, underestimated aerosol loading and surface temperatures.
Marielle Saunois, Philippe Bousquet, Ben Poulter, Anna Peregon, Philippe Ciais, Josep G. Canadell, Edward J. Dlugokencky, Giuseppe Etiope, David Bastviken, Sander Houweling, Greet Janssens-Maenhout, Francesco N. Tubiello, Simona Castaldi, Robert B. Jackson, Mihai Alexe, Vivek K. Arora, David J. Beerling, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Lori Bruhwiler, Cyril Crevoisier, Patrick Crill, Kristofer Covey, Christian Frankenberg, Nicola Gedney, Lena Höglund-Isaksson, Misa Ishizawa, Akihiko Ito, Fortunat Joos, Heon-Sook Kim, Thomas Kleinen, Paul Krummel, Jean-François Lamarque, Ray Langenfelds, Robin Locatelli, Toshinobu Machida, Shamil Maksyutov, Joe R. Melton, Isamu Morino, Vaishali Naik, Simon O'Doherty, Frans-Jan W. Parmentier, Prabir K. Patra, Changhui Peng, Shushi Peng, Glen P. Peters, Isabelle Pison, Ronald Prinn, Michel Ramonet, William J. Riley, Makoto Saito, Monia Santini, Ronny Schroeder, Isobel J. Simpson, Renato Spahni, Atsushi Takizawa, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Nicolas Viovy, Apostolos Voulgarakis, Ray Weiss, David J. Wilton, Andy Wiltshire, Doug Worthy, Debra Wunch, Xiyan Xu, Yukio Yoshida, Bowen Zhang, Zhen Zhang, and Qiuan Zhu
Atmos. Chem. Phys., 17, 11135–11161,Short summary
Following the Global Methane Budget 2000–2012 published in Saunois et al. (2016), we use the same dataset of bottom-up and top-down approaches to discuss the variations in methane emissions over the period 2000–2012. The changes in emissions are discussed both in terms of trends and quasi-decadal changes. The ensemble gathered here allows us to synthesise the robust changes in terms of regional and sectorial contributions to the increasing methane emissions.
Liang Feng, Paul I. Palmer, Hartmut Bösch, Robert J. Parker, Alex J. Webb, Caio S. C. Correia, Nicholas M. Deutscher, Lucas G. Domingues, Dietrich G. Feist, Luciana V. Gatti, Emanuel Gloor, Frank Hase, Rigel Kivi, Yi Liu, John B. Miller, Isamu Morino, Ralf Sussmann, Kimberly Strong, Osamu Uchino, Jing Wang, and Andreas Zahn
Atmos. Chem. Phys., 17, 4781–4797,Short summary
We use the GEOS-Chem global 3-D model of atmospheric chemistry and transport and an ensemble Kalman filter to simultaneously infer regional fluxes of methane (CH4) and carbon dioxide (CO2) directly from GOSAT retrievals of XCH4:XCO2, using sparse ground-based CH4 and CO2 mole fraction data to anchor the ratio. Our results show that assimilation of GOSAT data significantly reduced the posterior uncertainty and changed the a priori spatial distribution of CH4 emissions.
Hyeong-Ahn Kwon, Rokjin J. Park, Jaein I. Jeong, Seungun Lee, Gonzalo González Abad, Thomas P. Kurosu, Paul I. Palmer, and Kelly Chance
Atmos. Chem. Phys., 17, 4673–4686,Short summary
A geostationary satellite can measure daytime hourly HCHO columns. Atmospheric conditions such as synoptic meteorology and the presence of other gases and aerosols may affect HCHO measurements. We examine the effects of their temporal variation on the HCHO measurement of a geostationary satellite in East Asia. We find that the hourly variation of other species could be important. Especially the inclusion of hourly aerosol variation in the retrieval could lead to improving HCHO measurements.
Marielle Saunois, Philippe Bousquet, Ben Poulter, Anna Peregon, Philippe Ciais, Josep G. Canadell, Edward J. Dlugokencky, Giuseppe Etiope, David Bastviken, Sander Houweling, Greet Janssens-Maenhout, Francesco N. Tubiello, Simona Castaldi, Robert B. Jackson, Mihai Alexe, Vivek K. Arora, David J. Beerling, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Victor Brovkin, Lori Bruhwiler, Cyril Crevoisier, Patrick Crill, Kristofer Covey, Charles Curry, Christian Frankenberg, Nicola Gedney, Lena Höglund-Isaksson, Misa Ishizawa, Akihiko Ito, Fortunat Joos, Heon-Sook Kim, Thomas Kleinen, Paul Krummel, Jean-François Lamarque, Ray Langenfelds, Robin Locatelli, Toshinobu Machida, Shamil Maksyutov, Kyle C. McDonald, Julia Marshall, Joe R. Melton, Isamu Morino, Vaishali Naik, Simon O'Doherty, Frans-Jan W. Parmentier, Prabir K. Patra, Changhui Peng, Shushi Peng, Glen P. Peters, Isabelle Pison, Catherine Prigent, Ronald Prinn, Michel Ramonet, William J. Riley, Makoto Saito, Monia Santini, Ronny Schroeder, Isobel J. Simpson, Renato Spahni, Paul Steele, Atsushi Takizawa, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Nicolas Viovy, Apostolos Voulgarakis, Michiel van Weele, Guido R. van der Werf, Ray Weiss, Christine Wiedinmyer, David J. Wilton, Andy Wiltshire, Doug Worthy, Debra Wunch, Xiyan Xu, Yukio Yoshida, Bowen Zhang, Zhen Zhang, and Qiuan Zhu
Earth Syst. Sci. Data, 8, 697–751,Short summary
An accurate assessment of the methane budget is important to understand the atmospheric methane concentrations and trends and to provide realistic pathways for climate change mitigation. The various and diffuse sources of methane as well and its oxidation by a very short lifetime radical challenge this assessment. We quantify the methane sources and sinks as well as their uncertainties based on both bottom-up and top-down approaches provided by a broad international scientific community.
Eleonora Aruffo, Fabio Biancofiore, Piero Di Carlo, Marcella Busilacchio, Marco Verdecchia, Barbara Tomassetti, Cesare Dari-Salisburgo, Franco Giammaria, Stephane Bauguitte, James Lee, Sarah Moller, James Hopkins, Shalini Punjabi, Stephen J. Andrews, Alistair C. Lewis, Paul I. Palmer, Edward Hyer, Michael Le Breton, and Carl Percival
Atmos. Meas. Tech., 9, 5591–5606,Short summary
During the BORTAS aircraft campaign, we measured NO2 and their oxidtation products (as peroxy nitrates) with a custom laser-induced fluorescence instrument. Because of the high correlation between known pyrogenic tracers (i.e., carbon monoxide) and peroxy nitrates, we provide two methods to use these species for the identification of biomass burning (BB) plumes. Using an artifical neural network, we improved the BB identification taking into account of a meteorological parameter (pressure).
Dennis Booge, Christa A. Marandino, Cathleen Schlundt, Paul I. Palmer, Michael Schlundt, Elliot L. Atlas, Astrid Bracher, Eric S. Saltzman, and Douglas W. R. Wallace
Atmos. Chem. Phys., 16, 11807–11821,Short summary
Isoprene, a biogenic trace gas, is an important precursor of secondary organic aerosol/cloud condensation nuclei. Here, we use isoprene and related field measurements from three different ocean data sets together with remotely sensed satellite data to model global marine isoprene emissions. Our findings suggest that there is at least one missing oceanic source of isoprene and possibly other unknown factors in the ocean or atmosphere influencing the atmospheric values.
J. M. Barlow, P. I. Palmer, and L. M. Bruhwiler
Atmos. Chem. Phys. Discuss.,
Revised manuscript has not been submittedShort summary
We report significant changes in the amplitude of the atmospheric CH4 seasonal cycle at sites over the Arctic. All corresponding evidence points to a persistent increase in wetlands. We show using a global 3-d chemistry transport model that reductions in North American and European fossil fuel emissions could explain a large portion of the amplitude decrease, but we still require significant, persistent emissions from wetlands to reconcile observed trends in the seasonal cycle.
R. Hossaini, P. K. Patra, A. A. Leeson, G. Krysztofiak, N. L. Abraham, S. J. Andrews, A. T. Archibald, J. Aschmann, E. L. Atlas, D. A. Belikov, H. Bönisch, L. J. Carpenter, S. Dhomse, M. Dorf, A. Engel, W. Feng, S. Fuhlbrügge, P. T. Griffiths, N. R. P. Harris, R. Hommel, T. Keber, K. Krüger, S. T. Lennartz, S. Maksyutov, H. Mantle, G. P. Mills, B. Miller, S. A. Montzka, F. Moore, M. A. Navarro, D. E. Oram, K. Pfeilsticker, J. A. Pyle, B. Quack, A. D. Robinson, E. Saikawa, A. Saiz-Lopez, S. Sala, B.-M. Sinnhuber, S. Taguchi, S. Tegtmeier, R. T. Lidster, C. Wilson, and F. Ziska
Atmos. Chem. Phys., 16, 9163–9187,
Marcella Busilacchio, Piero Di Carlo, Eleonora Aruffo, Fabio Biancofiore, Cesare Dari Salisburgo, Franco Giammaria, Stephane Bauguitte, James Lee, Sarah Moller, James Hopkins, Shalini Punjabi, Stephen Andrews, Alistair C. Lewis, Mark Parrington, Paul I. Palmer, Edward Hyer, and Glenn M. Wolfe
Atmos. Chem. Phys., 16, 3485–3497,Short summary
Boreal fire emissions have little effect on ozone concentrations but evident impact on some NOx reservoirs as peroxy nitrates that we quantified. This should be taken into account since NOx reservoirs can be efficiently transported and may influence the ozone budget far away from the fire emission. The study is based on observations carried out on board the BAe 146 aircraft during BORTAS in Canada. We used a custom laser-induced fluorescence system to measure NO2 and NOx reservoirs.
L. Feng, P. I. Palmer, R. J. Parker, N. M. Deutscher, D. G. Feist, R. Kivi, I. Morino, and R. Sussmann
Atmos. Chem. Phys., 16, 1289–1302,Short summary
There is an on-going debate on the larger European biospheric uptake inferred from GOSAT XCO2 retrievals than those inferred from in situ data. Using a set of 15 experiments, we found that the elevated uptake over Europe could largely be explained by mis-fitting data due to regional XCO2 biases: 50–80 % of the elevated European uptake is due to retrievals outside the immediate European; and a varying monthly bias of up to 0.5 ppm for XCO2 retrievals over Europe could explain most of the remainder.
J. R. Pitt, M. Le Breton, G. Allen, C. J. Percival, M. W. Gallagher, S. J.-B. Bauguitte, S. J. O'Shea, J. B. A. Muller, M. S. Zahniser, J. Pyle, and P. I. Palmer
Atmos. Meas. Tech., 9, 63–77,Short summary
We present details of an Aerodyne quantum cascade laser absorption spectrometer (QCLAS) used to make airborne measurements of N2O and CH4, including its configuration for use on board an aircraft. Two different methods to correct for the influence of water vapour on the measurements are evaluated. We diagnose a sensitivity of the instrument to changes in pressure, introduce a new calibration procedure to account for this effect, and assess its performance.
J. M. Barlow, P. I. Palmer, L. M. Bruhwiler, and P. Tans
Atmos. Chem. Phys., 15, 13739–13758,Short summary
The major results from our analysis include (1) a significant revision to previously reported estimates of phase changes in the seasonal cycle atmospheric CO2, which are more closely related to changes in the terrestrial biosphere; and (2) an indirect observation that is consistent with high northern latitude ecosystems progressively taking up more CO2 during spring and early summer.
H. Lindqvist, C. W. O'Dell, S. Basu, H. Boesch, F. Chevallier, N. Deutscher, L. Feng, B. Fisher, F. Hase, M. Inoue, R. Kivi, I. Morino, P. I. Palmer, R. Parker, M. Schneider, R. Sussmann, and Y. Yoshida
Atmos. Chem. Phys., 15, 13023–13040,Short summary
Atmospheric carbon dioxide concentration varies seasonally mainly due to plant photosynthesis in the Northern Hemisphere. We found that the satellite GOSAT can capture this variability from space to within 1ppm. We also found that models can differ by more than 1ppm. This implies that the satellite measurements could be useful in evaluating models and their prior estimates of carbon dioxide sources and sinks.
R. J. Parker, H. Boesch, K. Byckling, A. J. Webb, P. I. Palmer, L. Feng, P. Bergamaschi, F. Chevallier, J. Notholt, N. Deutscher, T. Warneke, F. Hase, R. Sussmann, S. Kawakami, R. Kivi, D. W. T. Griffith, and V. Velazco
Atmos. Meas. Tech., 8, 4785–4801,Short summary
Atmospheric CH4 is an important greenhouse gas. Long-term global observations are necessary to understand its behaviour, with satellite observations playing a key role. The "proxy" retrieval method is one of the most successful but relies on the contribution from atmospheric CO2 models. This work assesses the significance of the uncertainty from the model CO2 within the retrieval and determines that despite this uncertainty the data are still valuable for determining sources and sinks of CH4.
S. Gonzi, P. I. Palmer, R. Paugam, M. Wooster, and M. N. Deeter
Atmos. Chem. Phys., 15, 4339–4355,
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.
D. P. Finch, P. I. Palmer, and M. Parrington
Atmos. Chem. Phys., 14, 13789–13800,Short summary
We use the GEOS-Chem chemical transport model to quantify the CO sources responsible for the observed CO during the BORTAS-B campaign over Canada in 2011. We found the largest source was biomass burning from Ontario, with smaller sources from fossil fuel emissions from Asia and NE US. We develop an age-of-emission metric and show values in BORTAS-B are consistent with a slowing of photochemistry in plumes. Indirect evidence suggests this slowing is due to aerosols within the plumes.
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.
A. Fraser, P. I. Palmer, L. Feng, H. Bösch, R. Parker, E. J. Dlugokencky, P. B. Krummel, and R. L. Langenfelds
Atmos. Chem. Phys., 14, 12883–12895,Short summary
Satellite measurements of CO2 and CH4 can be subject to regional systematic errors that can consequently compromise their ability to infer robust flux estimates of these two gases. We develop a method to use retrieved ratios of CH4 and CO2 that are less affected by systematic error. We show that additional in situ data are needed to anchor these observed ratios so they can simultaneously infer fluxes of CO2 and CH4. We argue the ratio data will provide a more faithful description of true fluxes.
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,
L. Bruhwiler, E. Dlugokencky, K. Masarie, M. Ishizawa, A. Andrews, J. Miller, C. Sweeney, P. Tans, and D. Worthy
Atmos. Chem. Phys., 14, 8269–8293,
S. J. O'Shea, G. Allen, M. W. Gallagher, S. J.-B. Bauguitte, S. M. Illingworth, M. Le Breton, J. B. A. Muller, C. J. Percival, A. T. Archibald, D. E. Oram, M. Parrington, P. I. Palmer, and A. C. Lewis
Atmos. Chem. Phys., 13, 12451–12467,
D. Griffin, K. A. Walker, J. E. Franklin, M. Parrington, C. Whaley, J. Hopper, J. R. Drummond, P. I. Palmer, K. Strong, T. J. Duck, I. Abboud, P. F. Bernath, C. Clerbaux, P.-F. Coheur, K. R. Curry, L. Dan, E. Hyer, J. Kliever, G. Lesins, M. Maurice, A. Saha, K. Tereszchuk, and D. Weaver
Atmos. Chem. Phys., 13, 10227–10241,
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,
M. D. Gibson, J. R. Pierce, D. Waugh, J. S. Kuchta, L. Chisholm, T. J. Duck, J. T. Hopper, S. Beauchamp, G. H. King, J. E. Franklin, W. R. Leaitch, A. J. Wheeler, Z. Li, G. A. Gagnon, and P. I. Palmer
Atmos. Chem. Phys., 13, 7199–7213,
P. I. Palmer, M. Parrington, J. D. Lee, A. C. Lewis, A. R. Rickard, P. F. Bernath, T. J. Duck, D. L. Waugh, D. W. Tarasick, S. Andrews, E. Aruffo, L. J. Bailey, E. Barrett, S. J.-B. Bauguitte, K. R. Curry, P. Di Carlo, L. Chisholm, L. Dan, G. Forster, J. E. Franklin, M. D. Gibson, D. Griffin, D. Helmig, J. R. Hopkins, J. T. Hopper, M. E. Jenkin, D. Kindred, J. Kliever, M. Le Breton, S. Matthiesen, M. Maurice, S. Moller, D. P. Moore, D. E. Oram, S. J. O'Shea, R. C. Owen, C. M. L. S. Pagniello, S. Pawson, C. J. Percival, J. R. Pierce, S. Punjabi, R. M. Purvis, J. J. Remedios, K. M. Rotermund, K. M. Sakamoto, A. M. da Silva, K. B. Strawbridge, K. Strong, J. Taylor, R. Trigwell, K. A. Tereszchuk, K. A. Walker, D. Weaver, C. Whaley, and J. C. Young
Atmos. Chem. Phys., 13, 6239–6261,
A. Fraser, P. I. Palmer, L. Feng, H. Boesch, A. Cogan, R. Parker, E. J. Dlugokencky, P. J. Fraser, P. B. Krummel, R. L. Langenfelds, S. O'Doherty, R. G. Prinn, L. P. Steele, M. van der Schoot, and R. F. Weiss
Atmos. Chem. Phys., 13, 5697–5713,
C. J. Hardacre, P. I. Palmer, K. Baumanns, M. Rounsevell, and D. Murray-Rust
Atmos. Chem. Phys., 13, 5451–5472,
D. A. Belikov, S. Maksyutov, M. Krol, A. Fraser, M. Rigby, H. Bian, A. Agusti-Panareda, D. Bergmann, P. Bousquet, P. Cameron-Smith, M. P. Chipperfield, A. Fortems-Cheiney, E. Gloor, K. Haynes, P. Hess, S. Houweling, S. R. Kawa, R. M. Law, Z. Loh, L. Meng, P. I. Palmer, P. K. Patra, R. G. Prinn, R. Saito, and C. Wilson
Atmos. Chem. Phys., 13, 1093–1114,
A. C. Lewis, M. J. Evans, J. R. Hopkins, S. Punjabi, K. A. Read, R. M. Purvis, S. J. Andrews, S. J. Moller, L. J. Carpenter, J. D. Lee, A. R. Rickard, P. I. Palmer, and M. Parrington
Atmos. Chem. Phys., 13, 851–867,
Related subject area
Subject: Gases | Research Activity: Atmospheric Modelling | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)Heterogeneity and chemical reactivity of the remote troposphere defined by aircraft measurementsA mass-balance-based emission inventory of non-methane volatile organic compounds (NMVOCs) for solvent use in ChinaOpinion: The germicidal effect of ambient air (open-air factor) revisitedImpact of Athabasca oil sands operations on mercury levels in air and depositionStudy of different Carbon Bond 6 (CB6) mechanisms by using a concentration sensitivity analysisAccelerating methane growth rate from 2010 to 2017: leading contributions from the tropics and East AsiaObservation and modelling of ozone-destructive halogen chemistry in a passively degassing volcanic plumeModeling study of the impact of SO2 volcanic passive emissions on the tropospheric sulfur budgetThe impact of organic pollutants from Indonesian peatland fires on the tropospheric and lower stratospheric compositionComprehensive evaluations of diurnal NO2 measurements during DISCOVER-AQ 2011: effects of resolution-dependent representation of NOx emissionsDownscaling system for modeling of atmospheric composition on regional, urban and street scalesSatellite soil moisture data assimilation impacts on modeling weather variables and ozone in the southeastern US – Part 1: An overviewDevelopment of ozone reactivity scales for volatile organic compounds in a Chinese megacityMeasured and modelled air quality trends in Italy over the period 2003–2010Large and increasing methane emissions from eastern Amazonia derived from satellite data, 2010–2018Contrasting chemical environments in summertime for atmospheric ozone across major Chinese industrial regions: the effectiveness of emission control strategiesUnexpected enhancement of ozone exposure and health risks during National Day in ChinaRole of oceanic ozone deposition in explaining temporal variability in surface ozone at High Arctic sitesTechnical note: Quality assessment of ozone reanalysis products over subarctic Europe for biome modeling and ozone risk mappingOxidation of low-molecular-weight organic compounds in cloud droplets: global impact on tropospheric oxidantsBias-correcting carbon fluxes derived from land-surface satellite data for retrospective and near-real-time assimilation systemsCharacterizing model errors in chemical transport modeling of methane: using GOSAT XCH4 data with weak-constraint four-dimensional variational data assimilationEstimation of fire-induced carbon emissions from Equatorial Asia in 2015 using in situ aircraft and ship observationsInfluence of weather situation on non-CO2 aviation climate effects: the REACT4C climate change functionsImpact of international shipping emissions on ozone and PM2.5 in East Asia during summer: the important role of HONO and ClNO2The role of emission reductions and the meteorological situation for air quality improvements during the COVID-19 lockdown period in Central EuropeModelling the impacts of iodine chemistry on the northern Indian Ocean marine boundary layerGlobal tropospheric halogen (Cl, Br, I) chemistry and its impact on oxidantsTime-dependent 3D simulations of tropospheric ozone depletion events in the Arctic spring using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem)Assessing and improving cloud-height-based parameterisations of global lightning flash rate, and their impact on lightning-produced NOx and tropospheric composition in a chemistry–climate modelImpact of regional Northern Hemisphere mid-latitude anthropogenic sulfur dioxide emissions on local and remote tropospheric oxidantsImpact of organic molecular structure on the estimation of atmospherically relevant physicochemical parametersSpatial and temporal variability in the hydroxyl (OH) radical: understanding the role of large-scale climate features and their influence on OH through its dynamical and photochemical driversAnalysis of atmospheric ammonia over South and East Asia based on the MOZART-4 model and its comparison with satellite and surface observationsAir quality and health benefits from ultra-low emission control policy indicated by continuous emission monitoring: a case study in the Yangtze River Delta region, ChinaBackground conditions for an urban greenhouse gas network in the Washington, DC, and Baltimore metropolitan regionExplicit modeling of isoprene chemical processing in polluted air masses in suburban areas of the Yangtze River Delta region: radical cycling and formation of ozone and formaldehydeEvaluating consistency between total column CO2 retrievals from OCO-2 and the in-situ network over North America: Implications for carbon flux estimationEvaluation of the LOTOS-EUROS NO2 simulations using ground-based measurements and S5P/TROPOMI observations over GreeceReactive organic carbon emissions from volatile chemical productsA three-dimensional-model inversion of methyl chloroform to constrain the atmospheric oxidative capacityTechnical note: On comparing greenhouse gas emission metricsLate-spring and summertime tropospheric ozone and NO2 in western Siberia and the Russian Arctic: regional model evaluation and sensitivities10-year satellite-constrained fluxes of ammonia improve performance of chemistry transport modelsRevealing the sulfur dioxide emission reductions in China by assimilating surface observations in WRF-ChemTropospheric ozone in CMIP6 simulationsIdentifying forecast uncertainties for biogenic gases in the Po Valley related to model configuration in EURAD-IM during PEGASOS 2012Impact of reduced anthropogenic emissions during COVID-19 on air quality in IndiaA comparison of long-term trends in observations and emission inventories of NOxAttribution of the accelerating increase in atmospheric methane during 2010–2018 by inverse analysis of GOSAT observations
Hao Guo, Clare M. Flynn, Michael J. Prather, Sarah A. Strode, Stephen D. Steenrod, Louisa Emmons, Forrest Lacey, Jean-Francois Lamarque, Arlene M. Fiore, Gus Correa, Lee T. Murray, Glenn M. Wolfe, Jason M. St. Clair, Michelle Kim, John Crounse, Glenn Diskin, Joshua DiGangi, Bruce C. Daube, Roisin Commane, Kathryn McKain, Jeff Peischl, Thomas B. Ryerson, Chelsea Thompson, Thomas F. Hanisco, Donald Blake, Nicola J. Blake, Eric C. Apel, Rebecca S. Hornbrook, James W. Elkins, Eric J. Hintsa, Fred L. Moore, and Steven Wofsy
Atmos. Chem. Phys., 21, 13729–13746,Short summary
The NASA Atmospheric Tomography (ATom) mission built a climatology of the chemical composition of tropospheric air parcels throughout the middle of the Pacific and Atlantic oceans. The level of detail allows us to reconstruct the photochemical budgets of O3 and CH4 over these vast, remote regions. We find that most of the chemical heterogeneity is captured at the resolution used in current global chemistry models and that the majority of reactivity occurs in the
hottest20 % of parcels.
Ziwei Mo, Ru Cui, Bin Yuan, Huihua Cai, Brian C. McDonald, Meng Li, Junyu Zheng, and Min Shao
Atmos. Chem. Phys., 21, 13655–13666,Short summary
There is a lack of detailed understanding of NMVOC emissions from the use of volatile chemical products (VCPs) in China. This study used a mass balance method to compile a long-term emission inventory for solvent use (including coatings, adhesives, inks, pesticides, cleaners and personal care products) in China during 2000–2017. The striking growth and recent trend of solvent use NMVOC emissions can give important implications for air quality modeling and NMVOC control strategies in China.
R. Anthony Cox, Markus Ammann, John N. Crowley, Paul T. Griffiths, Hartmut Herrmann, Erik H. Hoffmann, Michael E. Jenkin, V. Faye McNeill, Abdelwahid Mellouki, Christopher J. Penkett, Andreas Tilgner, and Timothy J. Wallington
Atmos. Chem. Phys., 21, 13011–13018,Short summary
The term open-air factor was coined in the 1960s, establishing that rural air had powerful germicidal properties possibly resulting from immediate products of the reaction of ozone with alkenes, unsaturated compounds ubiquitously present in natural and polluted environments. We have re-evaluated those early experiments, applying the recently substantially improved knowledge, and put them into the context of the lifetime of aerosol-borne pathogens that are so important in the Covid-19 pandemic.
Ashu Dastoor, Andrei Ryjkov, Gregor Kos, Junhua Zhang, Jane Kirk, Matthew Parsons, and Alexandra Steffen
Atmos. Chem. Phys., 21, 12783–12807,Short summary
An assessment of mercury levels in air and deposition in the Athabasca oil sands region (AOSR) in Northern Alberta, Canada, was conducted to investigate the contribution of Hg emitted from oil sands activities to the surrounding landscape using a 3D process-based Hg model in 2012–2015. Oil sands Hg emissions are found to be important sources of Hg contamination to the local landscape in proximity to the processing activities, particularly in wintertime.
Le Cao, Simeng Li, and Luhang Sun
Atmos. Chem. Phys., 21, 12687–12714,Short summary
Gas-phase chemical reaction mechanisms, e.g., CB6 mechanism, are essential parts of the atmospheric transport model. In order to better understand the changes caused by the updates between different versions of the CB6 mechanism, in this study, the behavior of three different CB6 mechanisms in simulating ozone, nitrogen oxides and formaldehyde under two different emission conditions was analyzed using a concentration sensitivity analysis, and the reasons causing the deviations were figured out.
Yi Yin, Frederic Chevallier, Philippe Ciais, Philippe Bousquet, Marielle Saunois, Bo Zheng, John Worden, A. Anthony Bloom, Robert J. Parker, Daniel J. Jacob, Edward J. Dlugokencky, and Christian Frankenberg
Atmos. Chem. Phys., 21, 12631–12647,Short summary
The growth of methane, the second-most important anthropogenic greenhouse gas after carbon dioxide, has been accelerating in recent years. Using an ensemble of multi-tracer atmospheric inversions constrained by surface or satellite observations, we show that global methane emissions increased by nearly 1 % per year from 2010–2017, with leading contributions from the tropics and East Asia.
Luke Surl, Tjarda Roberts, and Slimane Bekki
Atmos. Chem. Phys., 21, 12413–12441,Short summary
Many different chemical reactions happen when the gases from a volcano mix with air, but what effects do they have? We present aircraft measurements which show that there is less ozone within the plume of Etna than outside it. We have also made a computer model of this chemistry. This model can reproduce the effects seen when halogens (bromine and chlorine) are included in the volcanic emissions. We look closely at the simulation to discover how complicated halogen reactions cause ozone loss.
Claire Lamotte, Jonathan Guth, Virginie Marécal, Martin Cussac, Paul David Hamer, Nicolas Theys, and Philipp Schneider
Atmos. Chem. Phys., 21, 11379–11404,Short summary
Improvements are made in a global chemical transfer model by considering a new volcanic SO2 emissions inventory, with more volcanoes referenced and more information on the altitude of injection. Better constraining volcanic emissions with this inventory improves the global, but mostly local, tropospheric sulfur composition. The tropospheric sulfur budget shows a nonlinearity to the volcanic contribution, especially to the sulfate aerosol burden and sulfur wet deposition.
Simon Rosanka, Bruno Franco, Lieven Clarisse, Pierre-François Coheur, Andrea Pozzer, Andreas Wahner, and Domenico Taraborrelli
Atmos. Chem. Phys., 21, 11257–11288,Short summary
The strong El Niño in 2015 led to a particular dry season in Indonesia and favoured severe peatland fires. The smouldering conditions of these fires and the high carbon content of peat resulted in high volatile organic compound (VOC) emissions. By using a comprehensive atmospheric model, we show that these emissions have a significant impact on the tropospheric composition and oxidation capacity. These emissions are transported into to the lower stratosphere, resulting in a depletion of ozone.
Jianfeng Li, Yuhang Wang, Ruixiong Zhang, Charles Smeltzer, Andrew Weinheimer, Jay Herman, K. Folkert Boersma, Edward A. Celarier, Russell W. Long, James J. Szykman, Ruben Delgado, Anne M. Thompson, Travis N. Knepp, Lok N. Lamsal, Scott J. Janz, Matthew G. Kowalewski, Xiong Liu, and Caroline R. Nowlan
Atmos. Chem. Phys., 21, 11133–11160,Short summary
Comprehensive evaluations of simulated diurnal cycles of NO2 and NOy concentrations, vertical profiles, and tropospheric vertical column densities at two different resolutions with various measurements during the DISCOVER-AQ 2011 campaign show potential distribution biases of NOx emissions in the National Emissions Inventory 2011 at both 36 and 4 km resolutions, providing another possible explanation for the overestimation of model results.
Roman Nuterman, Alexander Mahura, Alexander Baklanov, Bjarne Amstrup, and Ashraf Zakey
Atmos. Chem. Phys., 21, 11099–11112,Short summary
The street air pollution is usually higher than the pollution at regional and urban scales. It mostly associated with both local emission sources and urban weather conditions. We present the downscaling system for regional, subregional-urban and street scales and evaluate it for acute air-pollution episode. Its evaluation showed a good prediction score across various spatiotemporal scales as well as feasibility of deterministic modelling approach for the operational street scale forecasting.
Min Huang, James H. Crawford, Joshua P. DiGangi, Gregory R. Carmichael, Kevin W. Bowman, Sujay V. Kumar, and Xiwu Zhan
Atmos. Chem. Phys., 21, 11013–11040,Short summary
This study evaluates the impact of satellite soil moisture data assimilation on modeled weather and ozone fields at various altitudes above the southeastern US during the summer. It emphasizes the importance of soil moisture in the understanding of surface ozone pollution and upper tropospheric chemistry, as well as air pollutants’ source–receptor relationships between the US and its downwind areas.
Yingnan Zhang, Likun Xue, William P. L. Carter, Chenglei Pei, Tianshu Chen, Jiangshan Mu, Yujun Wang, Qingzhu Zhang, and Wenxing Wang
Atmos. Chem. Phys., 21, 11053–11068,Short summary
We developed the localized incremental reactivity (IR) for VOCs in a Chinese megacity and elucidated their applications in calculating the ozone formation potential (OFP). The IR scales showed a strong dependence on chemical mechanisms. Both emission- and observation-based inputs are suitable for the MIR calculation but not the case under mixed-limited or NOx-limited O3 formation regimes. We provide suggestions for the application of IR and OFP scales to aid in VOC control in China.
Ilaria D'Elia, Gino Briganti, Lina Vitali, Antonio Piersanti, Gaia Righini, Massimo D'Isidoro, Andrea Cappelletti, Mihaela Mircea, Mario Adani, Gabriele Zanini, and Luisella Ciancarella
Atmos. Chem. Phys., 21, 10825–10849,Short summary
We present an analysis of modelled trends of PM10, NO2, and O3 airborne concentrations over the Italian territory in 2003–2010. Our analysis shows a general downward simulated trend for all pollutants, with good agreement between observed and modelled values and the model widening both coverage and significance of air concentration trends. Due to the complex atmospheric dynamics, emission reductions do not always result in decreasing concentrations, especially for secondary pollutants.
Chris Wilson, Martyn P. Chipperfield, Manuel Gloor, Robert J. Parker, Hartmut Boesch, Joey McNorton, Luciana V. Gatti, John B. Miller, Luana S. Basso, and Sarah A. Monks
Atmos. Chem. Phys., 21, 10643–10669,Short summary
Methane (CH4) is an important greenhouse gas emitted from wetlands like those found in the basin of the Amazon River. Using an atmospheric model and observations from GOSAT, we quantified CH4 emissions from Amazonia during the previous decade. We found that the largest emissions came from a region in the eastern basin and that emissions there were rising faster than in other areas of South America. This finding was supported by CH4 observations made on aircraft within the basin.
Zhenze Liu, Ruth M. Doherty, Oliver Wild, Michael Hollaway, and Fiona M. O’Connor
Atmos. Chem. Phys., 21, 10689–10706,Short summary
Surface ozone (O3) has become the main cause of atmospheric pollution in the summertime in China since 2013. We find that 70 % reductions in NOx emissions are required to reduce O3 pollution in most of industrial regions of China, and controls in VOC emissions are very important. The new chemical scheme developed for a global chemistry–climate model not only captures the regional air pollution but also benefits the future studies of regional air-quality–climate interactions.
Peng Wang, Juanyong Shen, Men Xia, Shida Sun, Yanli Zhang, Hongliang Zhang, and Xinming Wang
Atmos. Chem. Phys., 21, 10347–10356,Short summary
Ozone (O3) pollution has received extensive attention due to worsening air quality and rising health risks. The Chinese National Day holiday (CNDH), which is associated with intensive commercial and tourist activities, serves as a valuable experiment to evaluate the O3 response during the holiday. We find sharply increasing trends of observed O3 concentrations throughout China during the CNDH, leading to 33 % additional total daily deaths.
Johannes G. M. Barten, Laurens N. Ganzeveld, Gert-Jan Steeneveld, and Maarten C. Krol
Atmos. Chem. Phys., 21, 10229–10248,Short summary
We present an evaluation of ocean and snow/ice O3 deposition in explaining observed hourly surface O3 at 25 pan-Arctic sites using an atmospheric meteorology/chemistry model. The model includes a mechanistic representation of ocean O3 deposition as a function of ocean biogeochemical and mixing conditions. The mechanistic representation agrees better with O3 observations in terms of magnitude and temporal variability especially in the High Arctic (> 70° N).
Stefanie Falk, Ane Victoria Vollsnes, Aud Eriksen, Frode Stordal, and Terje Koren Berntsen
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
We evaluate regional and global models for ozone modeling and damage risk mapping of vegetation over subarctic Europe. Our analysis suggests that low-resolution global models do not reproduce the observed ozone seasonal cycle at ground level underestimating ozone by 30–50 %. High-resolution regional models capture the seasonal cycle well still underestimating ozone by up to 20 %. Our proposed gap-filling method for site observations shows a 78 % accuracy compared to the regional model (73 %).
Simon Rosanka, Rolf Sander, Bruno Franco, Catherine Wespes, Andreas Wahner, and Domenico Taraborrelli
Atmos. Chem. Phys., 21, 9909–9930,Short summary
In-cloud destruction of ozone depends on hydroperoxyl radicals in cloud droplets, where they are produced by oxygenated volatile organic compound (OVOC) oxygenation. Only rudimentary representations of these processes, if any, are currently available in global atmospheric models. By using a comprehensive atmospheric model that includes a complex in-cloud OVOC oxidation scheme, we show that atmospheric oxidants are reduced and models ignoring this process will underpredict clouds as ozone sinks.
Brad Weir, Lesley E. Ott, George J. Collatz, Stephan R. Kawa, Benjamin Poulter, Abhishek Chatterjee, Tomohiro Oda, and Steven Pawson
Atmos. Chem. Phys., 21, 9609–9628,Short summary
We present a collection of carbon surface fluxes, the Low-order Flux Inversion (LoFI), derived from satellite observations of the Earth's surface and calibrated to match long-term inventories and atmospheric and oceanic records. Simulations using LoFI reproduce background atmospheric carbon dioxide measurements with comparable skill to the leading surface flux products. Available both retrospectively and as a forecast, LoFI enables the study of the carbon cycle as it occurs.
Ilya Stanevich, Dylan B. A. Jones, Kimberly Strong, Martin Keller, Daven K. Henze, Robert J. Parker, Hartmut Boesch, Debra Wunch, Justus Notholt, Christof Petri, Thorsten Warneke, Ralf Sussmann, Matthias Schneider, Frank Hase, Rigel Kivi, Nicholas M. Deutscher, Voltaire A. Velazco, Kaley A. Walker, and Feng Deng
Atmos. Chem. Phys., 21, 9545–9572,Short summary
We explore the utility of a weak-constraint (WC) four-dimensional variational (4D-Var) data assimilation scheme for mitigating systematic errors in methane simulation in the GEOS-Chem model. We use data from the Greenhouse Gases Observing Satellite (GOSAT) and show that, compared to the traditional 4D-Var approach, the WC scheme improves the agreement between the model and independent observations. We find that the WC corrections to the model provide insight into the source of the errors.
Yosuke Niwa, Yousuke Sawa, Hideki Nara, Toshinobu Machida, Hidekazu Matsueda, Taku Umezawa, Akihiko Ito, Shin-Ichiro Nakaoka, Hiroshi Tanimoto, and Yasunori Tohjima
Atmos. Chem. Phys., 21, 9455–9473,Short summary
Fires in Equatorial Asia release a large amount of carbon into the atmosphere. Extensively using high-precision atmospheric carbon dioxide (CO2) data from a commercial aircraft observation project, we estimated fire carbon emissions in Equatorial Asia induced by the big El Niño event in 2015. Additional shipboard measurement data elucidated the validity of the analysis and the best estimate indicated 273 Tg C for fire emissions during September–October 2015.
Christine Frömming, Volker Grewe, Sabine Brinkop, Patrick Jöckel, Amund S. Haslerud, Simon Rosanka, Jesper van Manen, and Sigrun Matthes
Atmos. Chem. Phys., 21, 9151–9172,Short summary
The influence of weather situations on non-CO2 aviation climate impact is investigated to identify systematic weather-related sensitivities. If aircraft avoid the most sensitive areas, climate impact might be reduced. Enhanced significance is found for emission in relation to high-pressure systems, jet stream, polar night, and tropopause altitude. The results represent a comprehensive data set for studies aiming at weather-dependent flight trajectory optimization to reduce total climate impact.
Jianing Dai and Tao Wang
Atmos. Chem. Phys., 21, 8747–8759,Short summary
We used the WRF–Chem model with the latest HONO and ClNO2 processes to investigate their effects on the concentrations of ROx radicals, O3, and PM2.5 in Asia during summer. The results show that the ship-derived HONO and ClNO2 increased the ROx radical concentration by 2–3 times and subsequently increased the O3 and PM2.5 concentrations in marine areas. These findings indicate the importance of these nitrogen processes in the evaluation of the impact of ship emissions on air quality.
Volker Matthias, Markus Quante, Jan A. Arndt, Ronny Badeke, Lea Fink, Ronny Petrik, Josefine Feldner, Daniel Schwarzkopf, Eliza-Maria Link, Martin O. P. Ramacher, and Ralf Wedemann
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
COVID-19 lockdown measures in spring 2020 led to cleaner air in Central Europe. Densely populated areas benefitted mainly from largely reduced NO2 concentrations, while rural areas experienced lower reductions in NO2 but also lower ozone concentrations. Very low particulate matter (PM) concentrations in parts of Europe were not an effect of lockdown measures. Model simulations show that modified weather conditions are more significant for ozone and PM than severe traffic emission reductions.
Anoop S. Mahajan, Qinyi Li, Swaleha Inamdar, Kirpa Ram, Alba Badia, and Alfonso Saiz-Lopez
Atmos. Chem. Phys., 21, 8437–8454,Short summary
Using a regional model, we show that iodine-catalysed reactions cause large regional changes in the chemical composition in the northern Indian Ocean, with peak changes of up to 25 % in O3, 50 % in nitrogen oxides (NO and NO2), 15 % in hydroxyl radicals (OH), 25 % in hydroperoxyl radicals (HO2), and up to a 50 % change in the nitrate radical (NO3). These results show the importance of including iodine chemistry in modelling the atmosphere in this region.
Xuan Wang, Daniel J. Jacob, William Downs, Shuting Zhai, Lei Zhu, Viral Shah, Christopher D. Holmes, Tomás Sherwen, Becky Alexander, Mathew J. Evans, Sebastian D. Eastham, J. Andrew Neuman, Patrick Veres, Theodore K. Koenig, Rainer Volkamer, L. Gregory Huey, Thomas J. Bannan, Carl J. Percival, Ben H. Lee, and Joel A. Thornton
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Halogen radicals have a broad range of implications for tropospheric chemistry, air quality, and climate. We present an updated a new mechanistic description and comprehensive simulation of tropospheric halogens in a global 3-D model, and compare the model results with surface and aircraft measurements. We find that halogen chemistry decreases the global tropospheric burden of ozone by 11 %, NOx by 6 %, and OH by 4 %.
Maximilian Herrmann, Holger Sihler, Udo Frieß, Thomas Wagner, Ulrich Platt, and Eva Gutheil
Atmos. Chem. Phys., 21, 7611–7638,Short summary
Time-dependent 3D numerical simulations of tropospheric bromine release and ozone depletion events (ODEs) in the Arctic polar spring of 2009 are compared to observations. Simulation results agree well with the observations at both Utqiaġvik, Alaska, and at Summit, Greenland. In a parameter study, different settings for the bromine release mechanism are evaluated. An enhancement of the bromine release mechanism improves the agreement regarding the occurrence of ODEs with the observations.
Ashok K. Luhar, Ian E. Galbally, Matthew T. Woodhouse, and Nathan Luke Abraham
Atmos. Chem. Phys., 21, 7053–7082,Short summary
Lightning-generated nitrogen oxides (LNOx) greatly influence tropospheric photochemistry. The most common parameterisation of lightning flash rate used to calculate LNOx in global composition models underestimates measurements over the ocean by a factor of 20–25. We formulate and validate an alternative parameterisation to remedy this problem. The new scheme causes an increase in the ozone burden by 8.5 % and the hydroxyl radical by 13 %, and these have implications for climate and air quality.
Daniel M. Westervelt, Arlene M. Fiore, Colleen B. Baublitz, and Gustavo Correa
Atmos. Chem. Phys., 21, 6799–6810,Short summary
Particulate air pollution in the atmosphere can impact the availability of gas-phase chemical constituents, which can then have feedbacks on gas-phase air pollutants. We use a chemistry–climate computer model to simulate the impact of particulate pollution from three major world regions on gas-phase chemical constituents. We find that surface-level ozone air pollution decreases by up to 5 ppbv over China in response to Chinese particulate air pollution, which has implications for policy.
Gabriel Isaacman-VanWertz and Bernard Aumont
Atmos. Chem. Phys., 21, 6541–6563,Short summary
There are tens of thousands of different chemical compounds in the atmosphere. To tackle this complexity, there are a wide range of different methods to estimate their physical and chemical properties. We use these methods to understand how much the detailed structure of a molecule impacts its properties, and the extent to which properties can be estimated without knowing this level of detail. We find that structure matters, but methods lacking that level of detail still perform reasonably well.
Daniel C. Anderson, Bryan N. Duncan, Arlene M. Fiore, Colleen B. Baublitz, Melanie B. Follette-Cook, Julie M. Nicely, and Glenn M. Wolfe
Atmos. Chem. Phys., 21, 6481–6508,Short summary
We demonstrate that large-scale climate features are the primary driver of year-to-year variability in simulated values of the hydroxyl radical, the primary atmospheric oxidant, over 1980–2018. The El Niño–Southern Oscillation is the dominant mode of hydroxyl variability, resulting in large-scale global decreases in OH during El Niño events. Other climate modes, such as the Australian monsoon and the North Atlantic Oscillation, have impacts of similar magnitude but on on more localized scales.
Pooja V. Pawar, Sachin D. Ghude, Chinmay Jena, Andrea Móring, Mark A. Sutton, Santosh Kulkarni, Deen Mani Lal, Divya Surendran, Martin Van Damme, Lieven Clarisse, Pierre-François Coheur, Xuejun Liu, Gaurav Govardhan, Wen Xu, Jize Jiang, and Tapan Kumar Adhya
Atmos. Chem. Phys., 21, 6389–6409,Short summary
In this study, simulations of atmospheric ammonia (NH3) with MOZART-4 and HTAP-v2 are compared with satellite (IASI) and ground-based measurements to understand the spatial and temporal variability of NH3 over two emission hotspot regions of Asia, the IGP and the NCP. Our simulations indicate that the formation of ammonium aerosols is quicker over the NCP than the IGP, leading to smaller NH3 columns over the higher NH3-emitting NCP compared to the IGP region for comparable emissions.
Yan Zhang, Yu Zhao, Meng Gao, Xin Bo, and Chris P. Nielsen
Atmos. Chem. Phys., 21, 6411–6430,Short summary
We combined air quality and exposure response models to analyze the benefits for air quality and human health of China’s ultra-low emission policy in one of its most developed regions. Atmospheric observations and the air quality model were also used to demonstrate improvement of emission inventories incorporating online emission monitoring data. With implementation of the policy in both power and industrial sectors, the attributable deaths due to PM2.5 exposure are estimated to decrease 5.5 %.
Anna Karion, Israel Lopez-Coto, Sharon M. Gourdji, Kimberly Mueller, Subhomoy Ghosh, William Callahan, Michael Stock, Elizabeth DiGangi, Steve Prinzivalli, and James Whetstone
Atmos. Chem. Phys., 21, 6257–6273,Short summary
Estimating city emissions based on atmospheric observations requires that the portion of observed greenhouse gases that originated in the city be separated from the portion that originated outside the city, also known as the background concentration. Here, we investigate different methods to determine background concentrations for the Washington, DC, and Baltimore, MD, region and evaluate how well those methods work and the uncertainties they involve.
Kun Zhang, Ling Huang, Qing Li, Juntao Huo, Yusen Duan, Yuhang Wang, Elly Yaluk, Yangjun Wang, Qingyan Fu, and Li Li
Atmos. Chem. Phys., 21, 5905–5917,Short summary
Recently, high O3 concentrations were frequently observed in rural areas of the Yangtze River Delta (YRD) region under stagnant conditions. Using an online measurement and observation-based model, we investigated the budget of ROx radicals and the influence of isoprene chemistry on O3 formation. Our results underline that isoprene chemistry in the rural atmosphere becomes important with the participation of anthropogenic NOx.
Bharat Rastogi, John B. Miller, Micheal Trudeau, Arlyn E. Andrews, Lei Hu, Marikate Mountain, Thomas Nehrkorn, John Mund, Kaiyu Guan, and Caroline B. Alden
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Predicting Earth's climate is difficult partly due to uncertainty in forecasting how much CO2 can be removed by oceans and plants, because we cannot measure these exchanges directly on large scales. Satellites such as NASA's OCO-2 can provide part of the needed information, but data need to be highly precise and accurate. We evaluate these data and find small biases in certain months that are similar to the signals of interest. We argue that continued improvement in these data is necessary.
Ioanna Skoulidou, Maria-Elissavet Koukouli, Astrid Manders, Arjo Segers, Dimitris Karagkiozidis, Myrto Gratsea, Dimitris Balis, Alkiviadis Bais, Evangelos Gerasopoulos, Trisevgeni Stavrakou, Jos van Geffen, Henk Eskes, and Andreas Richter
Atmos. Chem. Phys., 21, 5269–5288,Short summary
The performance of LOTOS-EUROS v2.2.001 regional chemical transport model NO2 simulations is investigated over Greece from June to December 2018. Comparison with in situ NO2 measurements shows a spatial correlation coefficient of 0.86, while the model underestimates the concentrations mostly during daytime (12 to 15:00 local time). Further, the simulated tropospheric NO2 columns are evaluated against ground-based MAX-DOAS NO2 measurements and S5P/TROPOMI observations for July and December 2018.
Karl M. Seltzer, Elyse Pennington, Venkatesh Rao, Benjamin N. Murphy, Madeleine Strum, Kristin K. Isaacs, and Havala O. T. Pye
Atmos. Chem. Phys., 21, 5079–5100,Short summary
Volatile chemical products (VCPs) are an increasingly important source of anthropogenic reactive organic carbon emissions. Here, we develop VCPy, a new framework to model organic emissions from VCPs throughout the United States. At the national-level, VCPy emissions are broadly consistent with the US EPA’s 2017 National Emission Inventory, however county-level and categorical estimates can differ substantially. An observational evaluation indicates high fidelity in the methods employed here.
Stijn Naus, Stephen A. Montzka, Prabir K. Patra, and Maarten C. Krol
Atmos. Chem. Phys., 21, 4809–4824,Short summary
Following up on previous box model studies, we employ a 3D transport model to estimate variations in the hydroxyl radical (OH) from observations of methyl chloroform (MCF). We derive small interannual OH variations that are consistent with variations in the El Niño–Southern Oscillation. We also find evidence for the release of MCF from oceans in atmospheric gradients of MCF. Both findings highlight the added value of a 3D transport model since box model studies did not identify these effects.
Ian Enting and Nathan Clisby
Atmos. Chem. Phys., 21, 4699–4708,Short summary
We provide a new framework for comparing short-lived greenhouse gases to long-lived greenhouse gases such as carbon dioxide using methane as an example. This can clarify the differences between various proposals that have been introduced in order to overcome the use of global warming potentials as a measure of greenhouse gas equivalence.
Thomas Thorp, Stephen R. Arnold, Richard J. Pope, Dominick V. Spracklen, Luke Conibear, Christoph Knote, Mikhail Arshinov, Boris Belan, Eija Asmi, Tuomas Laurila, Andrei I. Skorokhod, Tuomo Nieminen, and Tuukka Petäjä
Atmos. Chem. Phys., 21, 4677–4697,Short summary
We compare modelled near-surface pollutants with surface and satellite observations to better understand the controls on the regional concentrations of pollution in western Siberia for late spring and summer in 2011. We find two commonly used emission inventories underestimate human emissions when compared to observations. Transport emissions are the main source of pollutants within the region during this period, whilst fire emissions peak during June and are only significant south of 60° N.
Nikolaos Evangeliou, Yves Balkanski, Sabine Eckhardt, Anne Cozic, Martin Van Damme, Pierre-François Coheur, Lieven Clarisse, Mark W. Shephard, Karen E. Cady-Pereira, and Didier Hauglustaine
Atmos. Chem. Phys., 21, 4431–4451,Short summary
Ammonia, a substance that has played a key role in sustaining life, has been increasing in the atmosphere, affecting climate and humans. Understanding the reasons for this increase is important for the beneficial use of ammonia. The evolution of satellite products gives us the opportunity to calculate ammonia emissions easier. We calculated global ammonia emissions over the last 10 years, incorporated them into a chemistry model and recorded notable improvement in reproducing observations.
Tie Dai, Yueming Cheng, Daisuke Goto, Yingruo Li, Xiao Tang, Guangyu Shi, and Teruyuki Nakajima
Atmos. Chem. Phys., 21, 4357–4379,Short summary
The anthropogenic emission of sulfur dioxide (SO2) over China has significantly declined as a consequence of the clean air actions. We have developed a new emission inversion system to dynamically update the SO2 emission grid by grid over China by assimilating ground-based SO2 observations. The inverted SO2 emission over China in November 2016 on average had declined by 49.4 % since 2010, which is well in agreement with the bottom-up estimation of 48.0 %.
Paul T. Griffiths, Lee T. Murray, Guang Zeng, Youngsub Matthew Shin, N. Luke Abraham, Alexander T. Archibald, Makoto Deushi, Louisa K. Emmons, Ian E. Galbally, Birgit Hassler, Larry W. Horowitz, James Keeble, Jane Liu, Omid Moeini, Vaishali Naik, Fiona M. O'Connor, Naga Oshima, David Tarasick, Simone Tilmes, Steven T. Turnock, Oliver Wild, Paul J. Young, and Prodromos Zanis
Atmos. Chem. Phys., 21, 4187–4218,Short summary
We analyse the CMIP6 Historical and future simulations for tropospheric ozone, a species which is important for many aspects of atmospheric chemistry. We show that the current generation of models agrees well with observations, being particularly successful in capturing trends in surface ozone and its vertical distribution in the troposphere. We analyse the factors that control ozone and show that they evolve over the period of the CMIP6 experiments.
Annika Vogel and Hendrik Elbern
Atmos. Chem. Phys., 21, 4039–4057,Short summary
Forecasts of biogenic trace gases highly depend on the model setup and input fields. This study identifies sources of related forecast uncertainties for biogenic gases. Exceptionally high differences in both biogenic emissions and pollutant transport in the Po Valley are identified to be caused by the representation of the land surface and boundary layer dynamics. Consequently, changes in the model configuration are shown to induce significantly different local concentrations of biogenic gases.
Mengyuan Zhang, Arpit Katiyar, Shengqiang Zhu, Juanyong Shen, Men Xia, Jinlong Ma, Sri Harsha Kota, Peng Wang, and Hongliang Zhang
Atmos. Chem. Phys., 21, 4025–4037,Short summary
We studied changes in air quality in India induced by the COVID-19 lockdown through both surface observations and the CMAQ model. Our results show that emission reductions improved the air quality across India during the lockdown. On average, the levels of PM2.5 and O3 decreased by 28 % and 15 %, indicating positive effects of lockdown measures. We suggest that more stringent and localized emission control strategies should be implemented in India to mitigate air pollutions.
Elena Macdonald, Noelia Otero, and Tim Butler
Atmos. Chem. Phys., 21, 4007–4023,Short summary
NO2 limit values are still regularly exceeded in many European cities despite decreasing emissions. Measurements of NOx concentrations from stations across Europe were systematically analysed to assess long-term changes observed in urban areas. We compared trends in concentration increments to trends in total and traffic emissions to find potential discrepancies. The results can help in evaluating inaccuracies in emission inventories and in improving spatial imbalances in data availability.
Yuzhong Zhang, Daniel J. Jacob, Xiao Lu, Joannes D. Maasakkers, Tia R. Scarpelli, Jian-Xiong Sheng, Lu Shen, Zhen Qu, Melissa P. Sulprizio, Jinfeng Chang, A. Anthony Bloom, Shuang Ma, John Worden, Robert J. Parker, and Hartmut Boesch
Atmos. Chem. Phys., 21, 3643–3666,Short summary
We use 2010–2018 satellite observations of atmospheric methane to interpret the factors controlling atmospheric methane and its accelerating increase during the period. The 2010–2018 increase in global methane emissions is driven by tropical and boreal wetlands and tropical livestock (South Asia, Africa, Brazil), with an insignificant positive trend in emissions from the fossil fuel sector. The peak methane growth rates in 2014–2015 are also contributed by low OH and high fire emissions.
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The Arctic is experiencing warming trends higher than the global mean. Arctic ecosystems are a large store of carbon. As the soil organic carbon thaws and decomposes, some fraction of this store will eventually be released to the atmosphere as methane. We show that a previously used measurement-based metric to identify changes in Arctic methane emissions does not reliably quantify these changes because it neglects the effect of atmospheric transport. A better metric will combine data and models.
The Arctic is experiencing warming trends higher than the global mean. Arctic ecosystems are a...