Articles | Volume 16, issue 4
https://doi.org/10.5194/acp-16-2185-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/acp-16-2185-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
25 Feb 2016
Research article |
| 25 Feb 2016
Unexpectedly high ultrafine aerosol concentrations above East Antarctic sea ice
Centre for Atmospheric Chemistry, University of Wollongong, Wollongong, Australia
now at: CSIRO Oceans and Atmosphere Business Unit, Aspendale,
Australia
A. R. Klekociuk
Australian Antarctic Division, Hobart, Australia
Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, Australia
R. Schofield
School of Earth Sciences, University of Melbourne, Melbourne, Australia
ARC Centre of Excellence for Climate System Science, University of New South Wales, Sydney, Australia
M. Keywood
CSIRO Oceans and Atmosphere Business Unit, Aspendale, Australia
J. Ward
CSIRO Oceans and Atmosphere Business Unit, Aspendale, Australia
S. R. Wilson
Centre for Atmospheric Chemistry, University of Wollongong, Wollongong, Australia
Related authors
Tahereh Alinejadtabrizi, Yi Huang, Francisco Lang, Steven Siems, Michael Manton, Luis Ackermann, Melita Keywood, Ruhi Humphries, Paul Krummel, Alastair Williams, and Greg Ayers
Atmos. Chem. Phys., 25, 2631–2648, https://doi.org/10.5194/acp-25-2631-2025, https://doi.org/10.5194/acp-25-2631-2025, 2025
Short summary
Short summary
Clouds over the Southern Ocean are crucial to Earth's energy balance, but understanding the factors that control them is complex. Our research examines how weather patterns affect tiny particles called cloud condensation nuclei (CCN), which influence cloud properties. Using data from Kennaook / Cape Grim, we found that winter air from Antarctica brings cleaner conditions with lower CCN, while summer patterns from Australia transport more particles. Precipitation also helps reduce CCN in winter.
Sonya L. Fiddes, Matthew T. Woodhouse, Marc D. Mallet, Liam Lamprey, Ruhi S. Humphries, Alain Protat, Simon P. Alexander, Hakase Hayashida, Samuel G. Putland, Branka Miljevic, and Robyn Schofield
EGUsphere, https://doi.org/10.5194/egusphere-2024-3125, https://doi.org/10.5194/egusphere-2024-3125, 2024
Short summary
Short summary
The interaction between natural marine aerosols, clouds and radiation in the Southern Ocean is a major source of uncertainty in climate models. We evaluate the Australian climate model using aerosol observations and find it underestimates aerosol number often by over 50 %. Model changes were tested to improve aerosol concentrations, but some of our changes had severe negative effects on the larger climate system, highlighting issues in aerosol-cloud interaction modelling.
Jhonathan Ramirez-Gamboa, Clare Paton-Walsh, Melita Keywood, Ruhi Humphries, Asher Mouat, Jennifer Kaiser, Malcom Possell, Jack Simmons, and Travis Naylor
EGUsphere, https://doi.org/10.5194/egusphere-2024-2062, https://doi.org/10.5194/egusphere-2024-2062, 2024
Short summary
Short summary
Tiny air particles (aerosols) influence clouds, sunlight, and air chemistry. Our study examined how these particles form in a plant-rich region of Southeast Australia. We found frequent new particle formation (NPF) events, often linked to pollution plumes. VOCs from plants and other factors like humidity influence NPF and aerosol growth. Nighttime NPF requires further study. Overall, plant emissions play a key role in aerosol formation in this region.
Ruhi S. Humphries, Melita D. Keywood, Jason P. Ward, James Harnwell, Simon P. Alexander, Andrew R. Klekociuk, Keiichiro Hara, Ian M. McRobert, Alain Protat, Joel Alroe, Luke T. Cravigan, Branka Miljevic, Zoran D. Ristovski, Robyn Schofield, Stephen R. Wilson, Connor J. Flynn, Gourihar R. Kulkarni, Gerald G. Mace, Greg M. McFarquhar, Scott D. Chambers, Alastair G. Williams, and Alan D. Griffiths
Atmos. Chem. Phys., 23, 3749–3777, https://doi.org/10.5194/acp-23-3749-2023, https://doi.org/10.5194/acp-23-3749-2023, 2023
Short summary
Short summary
Observations of aerosols in pristine regions are rare but are vital to constraining the natural baseline from which climate simulations are calculated. Here we present recent seasonal observations of aerosols from the Southern Ocean and contrast them with measurements from Antarctica, Australia and regionally relevant voyages. Strong seasonal cycles persist, but striking differences occur at different latitudes. This study highlights the need for more long-term observations in remote regions.
Gerald G. Mace, Sally Benson, Ruhi Humphries, Peter M. Gombert, and Elizabeth Sterner
Atmos. Chem. Phys., 23, 1677–1685, https://doi.org/10.5194/acp-23-1677-2023, https://doi.org/10.5194/acp-23-1677-2023, 2023
Short summary
Short summary
The number of cloud droplets per unit volume is a significantly important property of clouds that controls their reflective properties. Computer models of the Earth's atmosphere and climate have low skill at predicting the reflective properties of Southern Ocean clouds. Here we investigate the properties of those clouds using satellite data and find that the cloud droplet number and cloud albedo in the Southern Ocean are related to the oceanic phytoplankton abundance near Antarctica.
Sonya L. Fiddes, Matthew T. Woodhouse, Steve Utembe, Robyn Schofield, Simon P. Alexander, Joel Alroe, Scott D. Chambers, Zhenyi Chen, Luke Cravigan, Erin Dunne, Ruhi S. Humphries, Graham Johnson, Melita D. Keywood, Todd P. Lane, Branka Miljevic, Yuko Omori, Alain Protat, Zoran Ristovski, Paul Selleck, Hilton B. Swan, Hiroshi Tanimoto, Jason P. Ward, and Alastair G. Williams
Atmos. Chem. Phys., 22, 2419–2445, https://doi.org/10.5194/acp-22-2419-2022, https://doi.org/10.5194/acp-22-2419-2022, 2022
Short summary
Short summary
Coral reefs have been found to produce the climatically relevant chemical compound dimethyl sulfide (DMS). It has been suggested that corals can modify their environment via the production of DMS. We use an atmospheric chemistry model to test this theory at a regional scale for the first time. We find that it is unlikely that coral-reef-derived DMS has an influence over local climate, in part due to the proximity to terrestrial and anthropogenic aerosol sources.
Ruhi S. Humphries, Melita D. Keywood, Sean Gribben, Ian M. McRobert, Jason P. Ward, Paul Selleck, Sally Taylor, James Harnwell, Connor Flynn, Gourihar R. Kulkarni, Gerald G. Mace, Alain Protat, Simon P. Alexander, and Greg McFarquhar
Atmos. Chem. Phys., 21, 12757–12782, https://doi.org/10.5194/acp-21-12757-2021, https://doi.org/10.5194/acp-21-12757-2021, 2021
Short summary
Short summary
The Southern Ocean region is one of the most pristine in the world and serves as an important proxy for the pre-industrial atmosphere. Improving our understanding of the natural processes in this region is likely to result in the largest reductions in the uncertainty of climate and earth system models. In this paper we present a statistical summary of the latitudinal gradient of aerosol and cloud condensation nuclei concentrations obtained from five voyages spanning the Southern Ocean.
Jack B. Simmons, Ruhi S. Humphries, Stephen R. Wilson, Scott D. Chambers, Alastair G. Williams, Alan D. Griffiths, Ian M. McRobert, Jason P. Ward, Melita D. Keywood, and Sean Gribben
Atmos. Chem. Phys., 21, 9497–9513, https://doi.org/10.5194/acp-21-9497-2021, https://doi.org/10.5194/acp-21-9497-2021, 2021
Short summary
Short summary
Aerosols have a climate forcing effect in the Earth's atmosphere. Few measurements exist of aerosols in the Southern Ocean, a region key to our understanding of this effect. In this study, aerosol measurements from a summer 2017 campaign in the East Antarctic seasonal ice zone are examined. Higher concentrations of aerosols were found in dry air with origins from above the Antarctic continent compared to other periods of the voyage.
Kevin J. Sanchez, Gregory C. Roberts, Georges Saliba, Lynn M. Russell, Cynthia Twohy, J. Michael Reeves, Ruhi S. Humphries, Melita D. Keywood, Jason P. Ward, and Ian M. McRobert
Atmos. Chem. Phys., 21, 3427–3446, https://doi.org/10.5194/acp-21-3427-2021, https://doi.org/10.5194/acp-21-3427-2021, 2021
Short summary
Short summary
Measurements of particles and their properties were made from aircraft over the Southern Ocean. Aerosol transported from the Antarctic coast is shown to greatly enhance particle concentrations over the Southern Ocean. The occurrence of precipitation was shown to be associated with the lowest particle concentrations over the Southern Ocean. These particles are important due to their ability to enhance cloud droplet concentrations, resulting in more sunlight being reflected by the clouds.
Joel Alroe, Luke T. Cravigan, Branka Miljevic, Graham R. Johnson, Paul Selleck, Ruhi S. Humphries, Melita D. Keywood, Scott D. Chambers, Alastair G. Williams, and Zoran D. Ristovski
Atmos. Chem. Phys., 20, 8047–8062, https://doi.org/10.5194/acp-20-8047-2020, https://doi.org/10.5194/acp-20-8047-2020, 2020
Short summary
Short summary
We present findings from an austral summer voyage across the full latitudinal width of the Southern Ocean, south of Australia. Aerosol properties were strongly influenced by marine biological activity, synoptic-scale weather systems, and long-range transport of continental-influenced air masses. The meteorological history of the sampled air masses is shown to have a vital limiting influence on cloud condensation nuclei and the accuracy of modelled sea spray aerosol concentrations.
Melita Keywood, Paul Selleck, Fabienne Reisen, David Cohen, Scott Chambers, Min Cheng, Martin Cope, Suzanne Crumeyrolle, Erin Dunne, Kathryn Emmerson, Rosemary Fedele, Ian Galbally, Rob Gillett, Alan Griffiths, Elise-Andree Guerette, James Harnwell, Ruhi Humphries, Sarah Lawson, Branka Miljevic, Suzie Molloy, Jennifer Powell, Jack Simmons, Zoran Ristovski, and Jason Ward
Earth Syst. Sci. Data, 11, 1883–1903, https://doi.org/10.5194/essd-11-1883-2019, https://doi.org/10.5194/essd-11-1883-2019, 2019
Short summary
Short summary
The Sydney Particle Study increased scientific knowledge of the processes leading to particle formation and transformations in Sydney through two comprehensive observation programs which are described in detail here. The data set and its analysis underpin comprehensive chemical transport modelling tools that can be used to assist in the development of a long-term control strategy for particles in Sydney and thus reduce the impact of particles on human health.
Ruhi S. Humphries, Ian M. McRobert, Will A. Ponsonby, Jason P. Ward, Melita D. Keywood, Zoe M. Loh, Paul B. Krummel, and James Harnwell
Atmos. Meas. Tech., 12, 3019–3038, https://doi.org/10.5194/amt-12-3019-2019, https://doi.org/10.5194/amt-12-3019-2019, 2019
Short summary
Short summary
Undertaking atmospheric observations from ships provides important data in regions where measurements are impossible by other means. However, making measurements so close to a diesel exhaust plume is difficult. In this paper, we describe an algorithm that utilises ongoing measurements of aerosol number concentrations, black carbon mass concentrations, and mixing ratios of carbon monoxide and carbon dioxide to accurately distinguish between exhaust and background data periods.
Clare Paton-Walsh, Élise-Andrée Guérette, Dagmar Kubistin, Ruhi Humphries, Stephen R. Wilson, Doreena Dominick, Ian Galbally, Rebecca Buchholz, Mahendra Bhujel, Scott Chambers, Min Cheng, Martin Cope, Perry Davy, Kathryn Emmerson, David W. T. Griffith, Alan Griffiths, Melita Keywood, Sarah Lawson, Suzie Molloy, Géraldine Rea, Paul Selleck, Xue Shi, Jack Simmons, and Voltaire Velazco
Earth Syst. Sci. Data, 9, 349–362, https://doi.org/10.5194/essd-9-349-2017, https://doi.org/10.5194/essd-9-349-2017, 2017
Short summary
Short summary
The MUMBA campaign provides a detailed snapshot of the atmospheric composition in an urban coastal environment with strong biogenic sources nearby. This campaign involved collaboration between several institutes and was undertaken to provide a case study for atmospheric models in a poorly sampled region of the globe.
R. S. Humphries, R. Schofield, M. D. Keywood, J. Ward, J. R. Pierce, C. M. Gionfriddo, M. T. Tate, D. P. Krabbenhoft, I. E. Galbally, S. B. Molloy, A. R. Klekociuk, P. V. Johnston, K. Kreher, A. J. Thomas, A. D. Robinson, N. R. P. Harris, R. Johnson, and S. R. Wilson
Atmos. Chem. Phys., 15, 13339–13364, https://doi.org/10.5194/acp-15-13339-2015, https://doi.org/10.5194/acp-15-13339-2015, 2015
Short summary
Short summary
An atmospheric new particle formation event that was observed in the pristine East Antarctic pack ice during a springtime voyage in 2012 is characterised in terms of formation and growth rates. Known nucleation mechanisms (e.g. those involving sulfate, iodine and organics) were unable to explain observations; however, correlations with total gaseous mercury were found, leading to the suggestion of a possible mercury-driven nucleation mechanism not previously described.
Tahereh Alinejadtabrizi, Yi Huang, Francisco Lang, Steven Siems, Michael Manton, Luis Ackermann, Melita Keywood, Ruhi Humphries, Paul Krummel, Alastair Williams, and Greg Ayers
Atmos. Chem. Phys., 25, 2631–2648, https://doi.org/10.5194/acp-25-2631-2025, https://doi.org/10.5194/acp-25-2631-2025, 2025
Short summary
Short summary
Clouds over the Southern Ocean are crucial to Earth's energy balance, but understanding the factors that control them is complex. Our research examines how weather patterns affect tiny particles called cloud condensation nuclei (CCN), which influence cloud properties. Using data from Kennaook / Cape Grim, we found that winter air from Antarctica brings cleaner conditions with lower CCN, while summer patterns from Australia transport more particles. Precipitation also helps reduce CCN in winter.
Sonya L. Fiddes, Matthew T. Woodhouse, Marc D. Mallet, Liam Lamprey, Ruhi S. Humphries, Alain Protat, Simon P. Alexander, Hakase Hayashida, Samuel G. Putland, Branka Miljevic, and Robyn Schofield
EGUsphere, https://doi.org/10.5194/egusphere-2024-3125, https://doi.org/10.5194/egusphere-2024-3125, 2024
Short summary
Short summary
The interaction between natural marine aerosols, clouds and radiation in the Southern Ocean is a major source of uncertainty in climate models. We evaluate the Australian climate model using aerosol observations and find it underestimates aerosol number often by over 50 %. Model changes were tested to improve aerosol concentrations, but some of our changes had severe negative effects on the larger climate system, highlighting issues in aerosol-cloud interaction modelling.
Jhonathan Ramirez-Gamboa, Clare Paton-Walsh, Melita Keywood, Ruhi Humphries, Asher Mouat, Jennifer Kaiser, Malcom Possell, Jack Simmons, and Travis Naylor
EGUsphere, https://doi.org/10.5194/egusphere-2024-2062, https://doi.org/10.5194/egusphere-2024-2062, 2024
Short summary
Short summary
Tiny air particles (aerosols) influence clouds, sunlight, and air chemistry. Our study examined how these particles form in a plant-rich region of Southeast Australia. We found frequent new particle formation (NPF) events, often linked to pollution plumes. VOCs from plants and other factors like humidity influence NPF and aerosol growth. Nighttime NPF requires further study. Overall, plant emissions play a key role in aerosol formation in this region.
Robert G. Ryan, Lilani Toms-Hardman, Alexander Smirnov, Daniel Harrison, and Robyn Schofield
EGUsphere, https://doi.org/10.5194/egusphere-2024-1111, https://doi.org/10.5194/egusphere-2024-1111, 2024
Short summary
Short summary
Measurements of aerosol vertical distribution are key for understanding how they interact with clouds and sunlight. Such measurements are currently lacking at the Great Barrier Reef, limiting our ability to validate climate models in this sensitive, ecologically rich environment. Here we use a range of techniques to quantify the vertical variation of aerosols above the Great Barrier Reef for the first time, using the comparison of techniques to also infer aerosol spatial variation.
Ruhi S. Humphries, Melita D. Keywood, Jason P. Ward, James Harnwell, Simon P. Alexander, Andrew R. Klekociuk, Keiichiro Hara, Ian M. McRobert, Alain Protat, Joel Alroe, Luke T. Cravigan, Branka Miljevic, Zoran D. Ristovski, Robyn Schofield, Stephen R. Wilson, Connor J. Flynn, Gourihar R. Kulkarni, Gerald G. Mace, Greg M. McFarquhar, Scott D. Chambers, Alastair G. Williams, and Alan D. Griffiths
Atmos. Chem. Phys., 23, 3749–3777, https://doi.org/10.5194/acp-23-3749-2023, https://doi.org/10.5194/acp-23-3749-2023, 2023
Short summary
Short summary
Observations of aerosols in pristine regions are rare but are vital to constraining the natural baseline from which climate simulations are calculated. Here we present recent seasonal observations of aerosols from the Southern Ocean and contrast them with measurements from Antarctica, Australia and regionally relevant voyages. Strong seasonal cycles persist, but striking differences occur at different latitudes. This study highlights the need for more long-term observations in remote regions.
Gerald G. Mace, Sally Benson, Ruhi Humphries, Peter M. Gombert, and Elizabeth Sterner
Atmos. Chem. Phys., 23, 1677–1685, https://doi.org/10.5194/acp-23-1677-2023, https://doi.org/10.5194/acp-23-1677-2023, 2023
Short summary
Short summary
The number of cloud droplets per unit volume is a significantly important property of clouds that controls their reflective properties. Computer models of the Earth's atmosphere and climate have low skill at predicting the reflective properties of Southern Ocean clouds. Here we investigate the properties of those clouds using satellite data and find that the cloud droplet number and cloud albedo in the Southern Ocean are related to the oceanic phytoplankton abundance near Antarctica.
M. White, X. Huang, N. Langenheim, T. Yang, R. Schofield, M. Young, S. J. Livesley, S. Seneviratne, and M. Stevenson
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., X-4-W3-2022, 269–276, https://doi.org/10.5194/isprs-annals-X-4-W3-2022-269-2022, https://doi.org/10.5194/isprs-annals-X-4-W3-2022-269-2022, 2022
Adrien Guyot, Alain Protat, Simon P. Alexander, Andrew R. Klekociuk, Peter Kuma, and Adrian McDonald
Atmos. Meas. Tech., 15, 3663–3681, https://doi.org/10.5194/amt-15-3663-2022, https://doi.org/10.5194/amt-15-3663-2022, 2022
Short summary
Short summary
Ceilometers are instruments that are widely deployed as part of operational networks. They are usually not able to detect cloud phase. Here, we propose an evaluation of various methods to detect supercooled liquid water with ceilometer observations, using an extensive dataset from Davis, Antarctica. Our results highlight the possibility for ceilometers to detect supercooled liquid water in clouds.
Zhenyi Chen, Robyn Schofield, Melita Keywood, Sam Cleland, Alastair G. Williams, Alan Griffiths, Stephen Wilson, Peter Rayner, and Xiaowen Shu
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-104, https://doi.org/10.5194/acp-2022-104, 2022
Revised manuscript not accepted
Short summary
Short summary
This study studied the marine boundary layer (MBL) process and aerosol properties in the Southern Ocean using miniMPL, ceilometer and sodar. Compared to the gradient method, the Image Edge Detection Algorithm provides more reliable boundary layer height estimations, especially when a convective MBL with stratification existed. The diurnal characteristic of BLH with the veering of the wind vector was also observed. Under the continental sources, the MBL maintained a well-mixed layer of 0.3 km.
Sonya L. Fiddes, Matthew T. Woodhouse, Steve Utembe, Robyn Schofield, Simon P. Alexander, Joel Alroe, Scott D. Chambers, Zhenyi Chen, Luke Cravigan, Erin Dunne, Ruhi S. Humphries, Graham Johnson, Melita D. Keywood, Todd P. Lane, Branka Miljevic, Yuko Omori, Alain Protat, Zoran Ristovski, Paul Selleck, Hilton B. Swan, Hiroshi Tanimoto, Jason P. Ward, and Alastair G. Williams
Atmos. Chem. Phys., 22, 2419–2445, https://doi.org/10.5194/acp-22-2419-2022, https://doi.org/10.5194/acp-22-2419-2022, 2022
Short summary
Short summary
Coral reefs have been found to produce the climatically relevant chemical compound dimethyl sulfide (DMS). It has been suggested that corals can modify their environment via the production of DMS. We use an atmospheric chemistry model to test this theory at a regional scale for the first time. We find that it is unlikely that coral-reef-derived DMS has an influence over local climate, in part due to the proximity to terrestrial and anthropogenic aerosol sources.
Clémence Rose, Martine Collaud Coen, Elisabeth Andrews, Yong Lin, Isaline Bossert, Cathrine Lund Myhre, Thomas Tuch, Alfred Wiedensohler, Markus Fiebig, Pasi Aalto, Andrés Alastuey, Elisabeth Alonso-Blanco, Marcos Andrade, Begoña Artíñano, Todor Arsov, Urs Baltensperger, Susanne Bastian, Olaf Bath, Johan Paul Beukes, Benjamin T. Brem, Nicolas Bukowiecki, Juan Andrés Casquero-Vera, Sébastien Conil, Konstantinos Eleftheriadis, Olivier Favez, Harald Flentje, Maria I. Gini, Francisco Javier Gómez-Moreno, Martin Gysel-Beer, Anna Gannet Hallar, Ivo Kalapov, Nikos Kalivitis, Anne Kasper-Giebl, Melita Keywood, Jeong Eun Kim, Sang-Woo Kim, Adam Kristensson, Markku Kulmala, Heikki Lihavainen, Neng-Huei Lin, Hassan Lyamani, Angela Marinoni, Sebastiao Martins Dos Santos, Olga L. Mayol-Bracero, Frank Meinhardt, Maik Merkel, Jean-Marc Metzger, Nikolaos Mihalopoulos, Jakub Ondracek, Marco Pandolfi, Noemi Pérez, Tuukka Petäjä, Jean-Eudes Petit, David Picard, Jean-Marc Pichon, Veronique Pont, Jean-Philippe Putaud, Fabienne Reisen, Karine Sellegri, Sangeeta Sharma, Gerhard Schauer, Patrick Sheridan, James Patrick Sherman, Andreas Schwerin, Ralf Sohmer, Mar Sorribas, Junying Sun, Pierre Tulet, Ville Vakkari, Pieter Gideon van Zyl, Fernando Velarde, Paolo Villani, Stergios Vratolis, Zdenek Wagner, Sheng-Hsiang Wang, Kay Weinhold, Rolf Weller, Margarita Yela, Vladimir Zdimal, and Paolo Laj
Atmos. Chem. Phys., 21, 17185–17223, https://doi.org/10.5194/acp-21-17185-2021, https://doi.org/10.5194/acp-21-17185-2021, 2021
Short summary
Short summary
Aerosol particles are a complex component of the atmospheric system the effects of which are among the most uncertain in climate change projections. Using data collected at 62 stations, this study provides the most up-to-date picture of the spatial distribution of particle number concentration and size distribution worldwide, with the aim of contributing to better representation of aerosols and their interactions with clouds in models and, therefore, better evaluation of their impact on climate.
Alexander D. Fraser, Robert A. Massom, Mark S. Handcock, Phillip Reid, Kay I. Ohshima, Marilyn N. Raphael, Jessica Cartwright, Andrew R. Klekociuk, Zhaohui Wang, and Richard Porter-Smith
The Cryosphere, 15, 5061–5077, https://doi.org/10.5194/tc-15-5061-2021, https://doi.org/10.5194/tc-15-5061-2021, 2021
Short summary
Short summary
Landfast ice is sea ice that remains stationary by attaching to Antarctica's coastline and grounded icebergs. Although a variable feature, landfast ice exerts influence on key coastal processes involving pack ice, the ice sheet, ocean, and atmosphere and is of ecological importance. We present a first analysis of change in landfast ice over an 18-year period and quantify trends (−0.19 ± 0.18 % yr−1). This analysis forms a reference of landfast-ice extent and variability for use in other studies.
Camilla K. Crockart, Tessa R. Vance, Alexander D. Fraser, Nerilie J. Abram, Alison S. Criscitiello, Mark A. J. Curran, Vincent Favier, Ailie J. E. Gallant, Christoph Kittel, Helle A. Kjær, Andrew R. Klekociuk, Lenneke M. Jong, Andrew D. Moy, Christopher T. Plummer, Paul T. Vallelonga, Jonathan Wille, and Lingwei Zhang
Clim. Past, 17, 1795–1818, https://doi.org/10.5194/cp-17-1795-2021, https://doi.org/10.5194/cp-17-1795-2021, 2021
Short summary
Short summary
We present preliminary analyses of the annual sea salt concentrations and snowfall accumulation in a new East Antarctic ice core, Mount Brown South. We compare this record with an updated Law Dome (Dome Summit South site) ice core record over the period 1975–2016. The Mount Brown South record preserves a stronger and inverse signal for the El Niño–Southern Oscillation (in austral winter and spring) compared to the Law Dome record (in summer).
Ruhi S. Humphries, Melita D. Keywood, Sean Gribben, Ian M. McRobert, Jason P. Ward, Paul Selleck, Sally Taylor, James Harnwell, Connor Flynn, Gourihar R. Kulkarni, Gerald G. Mace, Alain Protat, Simon P. Alexander, and Greg McFarquhar
Atmos. Chem. Phys., 21, 12757–12782, https://doi.org/10.5194/acp-21-12757-2021, https://doi.org/10.5194/acp-21-12757-2021, 2021
Short summary
Short summary
The Southern Ocean region is one of the most pristine in the world and serves as an important proxy for the pre-industrial atmosphere. Improving our understanding of the natural processes in this region is likely to result in the largest reductions in the uncertainty of climate and earth system models. In this paper we present a statistical summary of the latitudinal gradient of aerosol and cloud condensation nuclei concentrations obtained from five voyages spanning the Southern Ocean.
Jack B. Simmons, Ruhi S. Humphries, Stephen R. Wilson, Scott D. Chambers, Alastair G. Williams, Alan D. Griffiths, Ian M. McRobert, Jason P. Ward, Melita D. Keywood, and Sean Gribben
Atmos. Chem. Phys., 21, 9497–9513, https://doi.org/10.5194/acp-21-9497-2021, https://doi.org/10.5194/acp-21-9497-2021, 2021
Short summary
Short summary
Aerosols have a climate forcing effect in the Earth's atmosphere. Few measurements exist of aerosols in the Southern Ocean, a region key to our understanding of this effect. In this study, aerosol measurements from a summer 2017 campaign in the East Antarctic seasonal ice zone are examined. Higher concentrations of aerosols were found in dry air with origins from above the Antarctic continent compared to other periods of the voyage.
Sonya L. Fiddes, Matthew T. Woodhouse, Todd P. Lane, and Robyn Schofield
Atmos. Chem. Phys., 21, 5883–5903, https://doi.org/10.5194/acp-21-5883-2021, https://doi.org/10.5194/acp-21-5883-2021, 2021
Short summary
Short summary
Coral reefs are known to produce the aerosol precursor dimethyl sulfide (DMS). Currently, this source of coral DMS is unaccounted for in climate modelling, and the impact of coral reef extinction on aerosol and climate is unknown. In this study, we address this problem using a coupled chemistry–climate model for the first time. We find that coral reefs make a minimal contribution to the aerosol population and are unlikely to play a role in climate modulation.
Kevin J. Sanchez, Gregory C. Roberts, Georges Saliba, Lynn M. Russell, Cynthia Twohy, J. Michael Reeves, Ruhi S. Humphries, Melita D. Keywood, Jason P. Ward, and Ian M. McRobert
Atmos. Chem. Phys., 21, 3427–3446, https://doi.org/10.5194/acp-21-3427-2021, https://doi.org/10.5194/acp-21-3427-2021, 2021
Short summary
Short summary
Measurements of particles and their properties were made from aircraft over the Southern Ocean. Aerosol transported from the Antarctic coast is shown to greatly enhance particle concentrations over the Southern Ocean. The occurrence of precipitation was shown to be associated with the lowest particle concentrations over the Southern Ocean. These particles are important due to their ability to enhance cloud droplet concentrations, resulting in more sunlight being reflected by the clouds.
Robert G. Ryan, Jeremy D. Silver, Richard Querel, Dan Smale, Steve Rhodes, Matt Tully, Nicholas Jones, and Robyn Schofield
Atmos. Meas. Tech., 13, 6501–6519, https://doi.org/10.5194/amt-13-6501-2020, https://doi.org/10.5194/amt-13-6501-2020, 2020
Short summary
Short summary
Models have identified Australasia as a formaldehyde (HCHO) hotspot from vegetation sources, but few measurement studies exist to verify this. We compare, and find good agreement between, HCHO measurements using three – two ground-based and one satellite-based – different spectroscopic techniques in Australia and New Zealand. This gives confidence in using satellite observations to study HCHO and associated air chemistry and pollution problems in this under-studied part of the world.
William R. Hobbs, Andrew R. Klekociuk, and Yuhang Pan
Atmos. Chem. Phys., 20, 14757–14768, https://doi.org/10.5194/acp-20-14757-2020, https://doi.org/10.5194/acp-20-14757-2020, 2020
Short summary
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.
Paolo Laj, Alessandro Bigi, Clémence Rose, Elisabeth Andrews, Cathrine Lund Myhre, Martine Collaud Coen, Yong Lin, Alfred Wiedensohler, Michael Schulz, John A. Ogren, Markus Fiebig, Jonas Gliß, Augustin Mortier, Marco Pandolfi, Tuukka Petäja, Sang-Woo Kim, Wenche Aas, Jean-Philippe Putaud, Olga Mayol-Bracero, Melita Keywood, Lorenzo Labrador, Pasi Aalto, Erik Ahlberg, Lucas Alados Arboledas, Andrés Alastuey, Marcos Andrade, Begoña Artíñano, Stina Ausmeel, Todor Arsov, Eija Asmi, John Backman, Urs Baltensperger, Susanne Bastian, Olaf Bath, Johan Paul Beukes, Benjamin T. Brem, Nicolas Bukowiecki, Sébastien Conil, Cedric Couret, Derek Day, Wan Dayantolis, Anna Degorska, Konstantinos Eleftheriadis, Prodromos Fetfatzis, Olivier Favez, Harald Flentje, Maria I. Gini, Asta Gregorič, Martin Gysel-Beer, A. Gannet Hallar, Jenny Hand, Andras Hoffer, Christoph Hueglin, Rakesh K. Hooda, Antti Hyvärinen, Ivo Kalapov, Nikos Kalivitis, Anne Kasper-Giebl, Jeong Eun Kim, Giorgos Kouvarakis, Irena Kranjc, Radovan Krejci, Markku Kulmala, Casper Labuschagne, Hae-Jung Lee, Heikki Lihavainen, Neng-Huei Lin, Gunter Löschau, Krista Luoma, Angela Marinoni, Sebastiao Martins Dos Santos, Frank Meinhardt, Maik Merkel, Jean-Marc Metzger, Nikolaos Mihalopoulos, Nhat Anh Nguyen, Jakub Ondracek, Noemi Pérez, Maria Rita Perrone, Jean-Eudes Petit, David Picard, Jean-Marc Pichon, Veronique Pont, Natalia Prats, Anthony Prenni, Fabienne Reisen, Salvatore Romano, Karine Sellegri, Sangeeta Sharma, Gerhard Schauer, Patrick Sheridan, James Patrick Sherman, Maik Schütze, Andreas Schwerin, Ralf Sohmer, Mar Sorribas, Martin Steinbacher, Junying Sun, Gloria Titos, Barbara Toczko, Thomas Tuch, Pierre Tulet, Peter Tunved, Ville Vakkari, Fernando Velarde, Patricio Velasquez, Paolo Villani, Sterios Vratolis, Sheng-Hsiang Wang, Kay Weinhold, Rolf Weller, Margarita Yela, Jesus Yus-Diez, Vladimir Zdimal, Paul Zieger, and Nadezda Zikova
Atmos. Meas. Tech., 13, 4353–4392, https://doi.org/10.5194/amt-13-4353-2020, https://doi.org/10.5194/amt-13-4353-2020, 2020
Short summary
Short summary
The paper establishes the fiducial reference of the GAW aerosol network providing the fully characterized value chain to the provision of four climate-relevant aerosol properties from ground-based sites. Data from almost 90 stations worldwide are reported for a reference year, 2017, providing a unique and very robust view of the variability of these variables worldwide. Current gaps in the GAW network are analysed and requirements for the Global Climate Monitoring System are proposed.
Martine Collaud Coen, Elisabeth Andrews, Andrés Alastuey, Todor Petkov Arsov, John Backman, Benjamin T. Brem, Nicolas Bukowiecki, Cédric Couret, Konstantinos Eleftheriadis, Harald Flentje, Markus Fiebig, Martin Gysel-Beer, Jenny L. Hand, András Hoffer, Rakesh Hooda, Christoph Hueglin, Warren Joubert, Melita Keywood, Jeong Eun Kim, Sang-Woo Kim, Casper Labuschagne, Neng-Huei Lin, Yong Lin, Cathrine Lund Myhre, Krista Luoma, Hassan Lyamani, Angela Marinoni, Olga L. Mayol-Bracero, Nikos Mihalopoulos, Marco Pandolfi, Natalia Prats, Anthony J. Prenni, Jean-Philippe Putaud, Ludwig Ries, Fabienne Reisen, Karine Sellegri, Sangeeta Sharma, Patrick Sheridan, James Patrick Sherman, Junying Sun, Gloria Titos, Elvis Torres, Thomas Tuch, Rolf Weller, Alfred Wiedensohler, Paul Zieger, and Paolo Laj
Atmos. Chem. Phys., 20, 8867–8908, https://doi.org/10.5194/acp-20-8867-2020, https://doi.org/10.5194/acp-20-8867-2020, 2020
Short summary
Short summary
Long-term trends of aerosol radiative properties (52 stations) prove that aerosol load has significantly decreased over the last 20 years. Scattering trends are negative in Europe (EU) and North America (NA), not ss in Asia, and show a mix of positive and negative trends at polar stations. Absorption has mainly negative trends. The single scattering albedo has positive trends in Asia and eastern EU and negative in western EU and NA, leading to a global positive median trend of 0.02 % per year.
W. John R. French, Andrew R. Klekociuk, and Frank J. Mulligan
Atmos. Chem. Phys., 20, 8691–8708, https://doi.org/10.5194/acp-20-8691-2020, https://doi.org/10.5194/acp-20-8691-2020, 2020
Short summary
Short summary
We explore a quasi-quadrennial oscillation (QQO; 3–4 K amplitude, ~ 4-year period) in mesopause region temperatures observed in 24 years of hydroxyl airglow measurements over Davis, Antarctica (68° S, 78° E). Correlation and composite analysis using meteorological reanalysis and satellite data reveals complex patterns on the QQO timescale in both hemispheres. Modulation of the meridional circulation, linked to the propagation of gravity waves, plays a significant role in producing the QQO response.
Joel Alroe, Luke T. Cravigan, Branka Miljevic, Graham R. Johnson, Paul Selleck, Ruhi S. Humphries, Melita D. Keywood, Scott D. Chambers, Alastair G. Williams, and Zoran D. Ristovski
Atmos. Chem. Phys., 20, 8047–8062, https://doi.org/10.5194/acp-20-8047-2020, https://doi.org/10.5194/acp-20-8047-2020, 2020
Short summary
Short summary
We present findings from an austral summer voyage across the full latitudinal width of the Southern Ocean, south of Australia. Aerosol properties were strongly influenced by marine biological activity, synoptic-scale weather systems, and long-range transport of continental-influenced air masses. The meteorological history of the sampled air masses is shown to have a vital limiting influence on cloud condensation nuclei and the accuracy of modelled sea spray aerosol concentrations.
Daniele Visioni, Giovanni Pitari, Vincenzo Rizi, Marco Iarlori, Irene Cionni, Ilaria Quaglia, Hideharu Akiyoshi, Slimane Bekki, Neal Butchart, Martin Chipperfield, Makoto Deushi, Sandip S. Dhomse, Rolando Garcia, Patrick Joeckel, Douglas Kinnison, Jean-François Lamarque, Marion Marchand, Martine Michou, Olaf Morgenstern, Tatsuya Nagashima, Fiona M. O'Connor, Luke D. Oman, David Plummer, Eugene Rozanov, David Saint-Martin, Robyn Schofield, John Scinocca, Andrea Stenke, Kane Stone, Kengo Sudo, Taichu Y. Tanaka, Simone Tilmes, Holger Tost, Yousuke Yamashita, and Guang Zeng
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-525, https://doi.org/10.5194/acp-2020-525, 2020
Preprint withdrawn
Short summary
Short summary
In this work we analyse the trend in ozone profiles taken at L'Aquila (Italy, 42.4° N) for seventeen years, between 2000 and 2016 and compare them against already available measured ozone trends. We try to understand and explain the observed trends at various heights in light of the simulations from seventeen different model, highlighting the contribution of changes in circulation and chemical ozone loss during this time period.
W. John R. French, Frank J. Mulligan, and Andrew R. Klekociuk
Atmos. Chem. Phys., 20, 6379–6394, https://doi.org/10.5194/acp-20-6379-2020, https://doi.org/10.5194/acp-20-6379-2020, 2020
Short summary
Short summary
In this study, we analyse 24 years of atmospheric temperatures from the mesopause region (~87 km altitude) derived from ground-based spectrometer observations of hydroxyl airglow at Davis station, Antarctica (68° S, 78° E). These data are used to quantify the effect of the solar cycle and the long-term trend due to increasing greenhouse gas emissions on the atmosphere at this level. A record-low winter-average temperature is reported for 2018 and comparisons are made with satellite observations.
Julie M. Nicely, Bryan N. Duncan, Thomas F. Hanisco, Glenn M. Wolfe, Ross J. Salawitch, Makoto Deushi, Amund S. Haslerud, Patrick Jöckel, Béatrice Josse, Douglas E. Kinnison, Andrew Klekociuk, Michael E. Manyin, Virginie Marécal, Olaf Morgenstern, Lee T. Murray, Gunnar Myhre, Luke D. Oman, Giovanni Pitari, Andrea Pozzer, Ilaria Quaglia, Laura E. Revell, Eugene Rozanov, Andrea Stenke, Kane Stone, Susan Strahan, Simone Tilmes, Holger Tost, Daniel M. Westervelt, and Guang Zeng
Atmos. Chem. Phys., 20, 1341–1361, https://doi.org/10.5194/acp-20-1341-2020, https://doi.org/10.5194/acp-20-1341-2020, 2020
Short summary
Short summary
Differences in methane lifetime among global models are large and poorly understood. We use a neural network method and simulations from the Chemistry Climate Model Initiative to quantify the factors influencing methane lifetime spread among models and variations over time. UV photolysis, tropospheric ozone, and nitrogen oxides drive large model differences, while the same factors plus specific humidity contribute to a decreasing trend in methane lifetime between 1980 and 2015.
Melita Keywood, Paul Selleck, Fabienne Reisen, David Cohen, Scott Chambers, Min Cheng, Martin Cope, Suzanne Crumeyrolle, Erin Dunne, Kathryn Emmerson, Rosemary Fedele, Ian Galbally, Rob Gillett, Alan Griffiths, Elise-Andree Guerette, James Harnwell, Ruhi Humphries, Sarah Lawson, Branka Miljevic, Suzie Molloy, Jennifer Powell, Jack Simmons, Zoran Ristovski, and Jason Ward
Earth Syst. Sci. Data, 11, 1883–1903, https://doi.org/10.5194/essd-11-1883-2019, https://doi.org/10.5194/essd-11-1883-2019, 2019
Short summary
Short summary
The Sydney Particle Study increased scientific knowledge of the processes leading to particle formation and transformations in Sydney through two comprehensive observation programs which are described in detail here. The data set and its analysis underpin comprehensive chemical transport modelling tools that can be used to assist in the development of a long-term control strategy for particles in Sydney and thus reduce the impact of particles on human health.
Yuke Wang, Valerii Shulga, Gennadi Milinevsky, Aleksey Patoka, Oleksandr Evtushevsky, Andrew Klekociuk, Wei Han, Asen Grytsai, Dmitry Shulga, Valery Myshenko, and Oleksandr Antyufeyev
Atmos. Chem. Phys., 19, 10303–10317, https://doi.org/10.5194/acp-19-10303-2019, https://doi.org/10.5194/acp-19-10303-2019, 2019
Short summary
Short summary
The major sudden stratospheric warming (SSW) dramatically changed atmospheric conditions. This event is accompanied by a sharp increase in the polar stratosphere temperature, zonal wind reverse, and strong changes in the polar mesosphere. These changes affect even the midlatitude mesosphere, which is not widely covered by observations. Our newly installed microwave radiometer allowed for studying mesospheric zonal wind and CO variations to understand the SSW 2018 effects at midlatitudes.
Ruhi S. Humphries, Ian M. McRobert, Will A. Ponsonby, Jason P. Ward, Melita D. Keywood, Zoe M. Loh, Paul B. Krummel, and James Harnwell
Atmos. Meas. Tech., 12, 3019–3038, https://doi.org/10.5194/amt-12-3019-2019, https://doi.org/10.5194/amt-12-3019-2019, 2019
Short summary
Short summary
Undertaking atmospheric observations from ships provides important data in regions where measurements are impossible by other means. However, making measurements so close to a diesel exhaust plume is difficult. In this paper, we describe an algorithm that utilises ongoing measurements of aerosol number concentrations, black carbon mass concentrations, and mixing ratios of carbon monoxide and carbon dioxide to accurately distinguish between exhaust and background data periods.
Huang Yang, Darryn W. Waugh, Clara Orbe, Guang Zeng, Olaf Morgenstern, Douglas E. Kinnison, Jean-Francois Lamarque, Simone Tilmes, David A. Plummer, Patrick Jöckel, Susan E. Strahan, Kane A. Stone, and Robyn Schofield
Atmos. Chem. Phys., 19, 5511–5528, https://doi.org/10.5194/acp-19-5511-2019, https://doi.org/10.5194/acp-19-5511-2019, 2019
Short summary
Short summary
We evaluate the performance of a suite of models in simulating the large-scale transport from the northern midlatitudes to the Arctic using a CO-like idealized tracer. We find a large multi-model spread of the Arctic concentration of this CO-like tracer that is well correlated with the differences in the location of the midlatitude jet as well as the northern Hadley Cell edge. Our results suggest the Hadley Cell is key and zonal-mean transport by surface meridional flow needs better constraint.
Roland Eichinger, Simone Dietmüller, Hella Garny, Petr Šácha, Thomas Birner, Harald Bönisch, Giovanni Pitari, Daniele Visioni, Andrea Stenke, Eugene Rozanov, Laura Revell, David A. Plummer, Patrick Jöckel, Luke Oman, Makoto Deushi, Douglas E. Kinnison, Rolando Garcia, Olaf Morgenstern, Guang Zeng, Kane Adam Stone, and Robyn Schofield
Atmos. Chem. Phys., 19, 921–940, https://doi.org/10.5194/acp-19-921-2019, https://doi.org/10.5194/acp-19-921-2019, 2019
Short summary
Short summary
To shed more light upon the changes in stratospheric circulation in the 21st century, climate projection simulations of 10 state-of-the-art global climate models, spanning from 1960 to 2100, are analyzed. The study shows that in addition to changes in transport, mixing also plays an important role in stratospheric circulation and that the properties of mixing vary over time. Furthermore, the influence of mixing is quantified and a dynamical framework is provided to understand the changes.
Laura E. Revell, Andrea Stenke, Fiona Tummon, Aryeh Feinberg, Eugene Rozanov, Thomas Peter, N. Luke Abraham, Hideharu Akiyoshi, Alexander T. Archibald, Neal Butchart, Makoto Deushi, Patrick Jöckel, Douglas Kinnison, Martine Michou, Olaf Morgenstern, Fiona M. O'Connor, Luke D. Oman, Giovanni Pitari, David A. Plummer, Robyn Schofield, Kane Stone, Simone Tilmes, Daniele Visioni, Yousuke Yamashita, and Guang Zeng
Atmos. Chem. Phys., 18, 16155–16172, https://doi.org/10.5194/acp-18-16155-2018, https://doi.org/10.5194/acp-18-16155-2018, 2018
Short summary
Short summary
Global models such as those participating in the Chemistry-Climate Model Initiative (CCMI) consistently simulate biases in tropospheric ozone compared with observations. We performed an advanced statistical analysis with one of the CCMI models to understand the cause of the bias. We found that emissions of ozone precursor gases are the dominant driver of the bias, implying either that the emissions are too large, or that the way in which the model handles emissions needs to be improved.
Robert G. Ryan, Steve Rhodes, Matthew Tully, Stephen Wilson, Nicholas Jones, Udo Frieß, and Robyn Schofield
Atmos. Chem. Phys., 18, 13969–13985, https://doi.org/10.5194/acp-18-13969-2018, https://doi.org/10.5194/acp-18-13969-2018, 2018
Short summary
Short summary
Nitrous acid (HONO) plays a crucial role in the self-cleansing capacity of the atmosphere but its formation mechanisms and spatial distributions are not well understood. This paper presents spectroscopic measurements of HONO, NO2 and aerosol measurements from Melbourne, Australia. HONO levels are at a maximum in the middle of the day, which is unprecedented for an urban area, and these measurements provide evidence for the existence of a strong ground-based, daytime nitrogen oxide source.
Blanca Ayarzagüena, Lorenzo M. Polvani, Ulrike Langematz, Hideharu Akiyoshi, Slimane Bekki, Neal Butchart, Martin Dameris, Makoto Deushi, Steven C. Hardiman, Patrick Jöckel, Andrew Klekociuk, Marion Marchand, Martine Michou, Olaf Morgenstern, Fiona M. O'Connor, Luke D. Oman, David A. Plummer, Laura Revell, Eugene Rozanov, David Saint-Martin, John Scinocca, Andrea Stenke, Kane Stone, Yousuke Yamashita, Kohei Yoshida, and Guang Zeng
Atmos. Chem. Phys., 18, 11277–11287, https://doi.org/10.5194/acp-18-11277-2018, https://doi.org/10.5194/acp-18-11277-2018, 2018
Short summary
Short summary
Stratospheric sudden warmings (SSWs) are natural major disruptions of the polar stratospheric circulation that also affect surface weather. In the literature there are conflicting claims as to whether SSWs will change in the future. The confusion comes from studies using different models and methods. Here we settle the question by analysing 12 models with a consistent methodology, to show that no robust changes in frequency and other features are expected over the 21st century.
Sonya L. Fiddes, Matthew T. Woodhouse, Zebedee Nicholls, Todd P. Lane, and Robyn Schofield
Atmos. Chem. Phys., 18, 10177–10198, https://doi.org/10.5194/acp-18-10177-2018, https://doi.org/10.5194/acp-18-10177-2018, 2018
Short summary
Short summary
The role of natural aerosol in the climate system is uncertain. A key contributor to marine aerosol is dimethyl sulfide (DMS), released by phytoplankton in the oceans. We study the effect of DMS on clouds and rain using a climate model with a detailed aerosol scheme. We show that DMS acts to reduce rainfall in cloud deck regions, leading to longer lived clouds and a large impact on solar energy reaching the surface. Further study of these areas will improve future climate projections.
Sandip S. Dhomse, Douglas Kinnison, Martyn P. Chipperfield, Ross J. Salawitch, Irene Cionni, Michaela I. Hegglin, N. Luke Abraham, Hideharu Akiyoshi, Alex T. Archibald, Ewa M. Bednarz, Slimane Bekki, Peter Braesicke, Neal Butchart, Martin Dameris, Makoto Deushi, Stacey Frith, Steven C. Hardiman, Birgit Hassler, Larry W. Horowitz, Rong-Ming Hu, Patrick Jöckel, Beatrice Josse, Oliver Kirner, Stefanie Kremser, Ulrike Langematz, Jared Lewis, Marion Marchand, Meiyun Lin, Eva Mancini, Virginie Marécal, Martine Michou, Olaf Morgenstern, Fiona M. O'Connor, Luke Oman, Giovanni Pitari, David A. Plummer, John A. Pyle, Laura E. Revell, Eugene Rozanov, Robyn Schofield, Andrea Stenke, Kane Stone, Kengo Sudo, Simone Tilmes, Daniele Visioni, Yousuke Yamashita, and Guang Zeng
Atmos. Chem. Phys., 18, 8409–8438, https://doi.org/10.5194/acp-18-8409-2018, https://doi.org/10.5194/acp-18-8409-2018, 2018
Short summary
Short summary
We analyse simulations from the Chemistry-Climate Model Initiative (CCMI) to estimate the return dates of the stratospheric ozone layer from depletion by anthropogenic chlorine and bromine. The simulations from 20 models project that global column ozone will return to 1980 values in 2047 (uncertainty range 2042–2052). Return dates in other regions vary depending on factors related to climate change and importance of chlorine and bromine. Column ozone in the tropics may continue to decline.
Clara Orbe, Huang Yang, Darryn W. Waugh, Guang Zeng, Olaf Morgenstern, Douglas E. Kinnison, Jean-Francois Lamarque, Simone Tilmes, David A. Plummer, John F. Scinocca, Beatrice Josse, Virginie Marecal, Patrick Jöckel, Luke D. Oman, Susan E. Strahan, Makoto Deushi, Taichu Y. Tanaka, Kohei Yoshida, Hideharu Akiyoshi, Yousuke Yamashita, Andreas Stenke, Laura Revell, Timofei Sukhodolov, Eugene Rozanov, Giovanni Pitari, Daniele Visioni, Kane A. Stone, Robyn Schofield, and Antara Banerjee
Atmos. Chem. Phys., 18, 7217–7235, https://doi.org/10.5194/acp-18-7217-2018, https://doi.org/10.5194/acp-18-7217-2018, 2018
Short summary
Short summary
In this study we compare a few atmospheric transport properties among several numerical models that are used to study the influence of atmospheric chemistry on climate. We show that there are large differences among models in terms of the timescales that connect the Northern Hemisphere midlatitudes, where greenhouse gases and ozone-depleting substances are emitted, to the Southern Hemisphere. Our results may have important implications for how models represent atmospheric composition.
Simone Dietmüller, Roland Eichinger, Hella Garny, Thomas Birner, Harald Boenisch, Giovanni Pitari, Eva Mancini, Daniele Visioni, Andrea Stenke, Laura Revell, Eugene Rozanov, David A. Plummer, John Scinocca, Patrick Jöckel, Luke Oman, Makoto Deushi, Shibata Kiyotaka, Douglas E. Kinnison, Rolando Garcia, Olaf Morgenstern, Guang Zeng, Kane Adam Stone, and Robyn Schofield
Atmos. Chem. Phys., 18, 6699–6720, https://doi.org/10.5194/acp-18-6699-2018, https://doi.org/10.5194/acp-18-6699-2018, 2018
Olaf Morgenstern, Kane A. Stone, Robyn Schofield, Hideharu Akiyoshi, Yousuke Yamashita, Douglas E. Kinnison, Rolando R. Garcia, Kengo Sudo, David A. Plummer, John Scinocca, Luke D. Oman, Michael E. Manyin, Guang Zeng, Eugene Rozanov, Andrea Stenke, Laura E. Revell, Giovanni Pitari, Eva Mancini, Glauco Di Genova, Daniele Visioni, Sandip S. Dhomse, and Martyn P. Chipperfield
Atmos. Chem. Phys., 18, 1091–1114, https://doi.org/10.5194/acp-18-1091-2018, https://doi.org/10.5194/acp-18-1091-2018, 2018
Short summary
Short summary
We assess how ozone as simulated by a group of chemistry–climate models responds to variations in man-made climate gases and ozone-depleting substances. We find some agreement, particularly in the middle and upper stratosphere, but also considerable disagreement elsewhere. Such disagreement affects the reliability of future ozone projections based on these models, and also constitutes a source of uncertainty in climate projections using prescribed ozone derived from these simulations.
Marc D. Mallet, Maximilien J. Desservettaz, Branka Miljevic, Andelija Milic, Zoran D. Ristovski, Joel Alroe, Luke T. Cravigan, E. Rohan Jayaratne, Clare Paton-Walsh, David W. T. Griffith, Stephen R. Wilson, Graham Kettlewell, Marcel V. van der Schoot, Paul Selleck, Fabienne Reisen, Sarah J. Lawson, Jason Ward, James Harnwell, Min Cheng, Rob W. Gillett, Suzie B. Molloy, Dean Howard, Peter F. Nelson, Anthony L. Morrison, Grant C. Edwards, Alastair G. Williams, Scott D. Chambers, Sylvester Werczynski, Leah R. Williams, V. Holly L. Winton, Brad Atkinson, Xianyu Wang, and Melita D. Keywood
Atmos. Chem. Phys., 17, 13681–13697, https://doi.org/10.5194/acp-17-13681-2017, https://doi.org/10.5194/acp-17-13681-2017, 2017
Short summary
Short summary
Fires play an important role within atmosphere. Gaseous and aerosol emissions influence Earth's temperature but these emissions can vary drastically across region and season. The SAFIRED (Savannah Fires in the Early Dry Season) campaign was undertaken at the Australian Tropical Research Station in north Australia during the 2014 early dry season. This paper presents an overview of the fires in this region, the measurements of their emissions and the implications of these fires on the atmosphere.
Sarah J. Lawson, Martin Cope, Sunhee Lee, Ian E. Galbally, Zoran Ristovski, and Melita D. Keywood
Atmos. Chem. Phys., 17, 11707–11726, https://doi.org/10.5194/acp-17-11707-2017, https://doi.org/10.5194/acp-17-11707-2017, 2017
Short summary
Short summary
A high-resolution chemical transport model was used to reproduce observed smoke plumes. The model output was highly sensitive to fire emission factors and meteorology, particularly for secondary pollutant ozone. Aged urban air (age = 2 days) was the major source of ozone observed, with minor contributions from the fire. This work highlights the importance of assessing model sensitivity and the use of modelling to determine the contribution from different sources to atmospheric composition.
Dean Howard, Peter F. Nelson, Grant C. Edwards, Anthony L. Morrison, Jenny A. Fisher, Jason Ward, James Harnwell, Marcel van der Schoot, Brad Atkinson, Scott D. Chambers, Alan D. Griffiths, Sylvester Werczynski, and Alastair G. Williams
Atmos. Chem. Phys., 17, 11623–11636, https://doi.org/10.5194/acp-17-11623-2017, https://doi.org/10.5194/acp-17-11623-2017, 2017
Short summary
Short summary
Mercury, a toxic metal, can be transported globally through the atmosphere, with deposition to ecosystems an important pathway to human exposure. 2 years of atmospheric mercury monitoring in tropical Australia supports recent evidence that Southern Hemisphere concentrations are lower than previously thought. Exchange between the atmosphere and ecosystems can take place on daily scales, with night deposition offset by morning re-emission. This could be an important transport pathway for mercury.
Jesse W. Greenslade, Simon P. Alexander, Robyn Schofield, Jenny A. Fisher, and Andrew K. Klekociuk
Atmos. Chem. Phys., 17, 10269–10290, https://doi.org/10.5194/acp-17-10269-2017, https://doi.org/10.5194/acp-17-10269-2017, 2017
Short summary
Short summary
An analysis of data from ozonesondes released at three southern oceanic sites shows the impact of stratospheric ozone in this region. Using a novel method of transport classification, this work estimates the seasonality and quantity of stratospherically sourced ozone. We find that ozone is transported most frequently in summer due to regional-scale low-pressure weather systems. We also estimate a stratospheric ozone source of 2.0–3.3 Tg/year over three Southern Ocean regions.
Clare Paton-Walsh, Élise-Andrée Guérette, Dagmar Kubistin, Ruhi Humphries, Stephen R. Wilson, Doreena Dominick, Ian Galbally, Rebecca Buchholz, Mahendra Bhujel, Scott Chambers, Min Cheng, Martin Cope, Perry Davy, Kathryn Emmerson, David W. T. Griffith, Alan Griffiths, Melita Keywood, Sarah Lawson, Suzie Molloy, Géraldine Rea, Paul Selleck, Xue Shi, Jack Simmons, and Voltaire Velazco
Earth Syst. Sci. Data, 9, 349–362, https://doi.org/10.5194/essd-9-349-2017, https://doi.org/10.5194/essd-9-349-2017, 2017
Short summary
Short summary
The MUMBA campaign provides a detailed snapshot of the atmospheric composition in an urban coastal environment with strong biogenic sources nearby. This campaign involved collaboration between several institutes and was undertaken to provide a case study for atmospheric models in a poorly sampled region of the globe.
Chris S.~M. Turney, Andrew Klekociuk, Christopher J. Fogwill, Violette Zunz, Hugues Goosse, Claire L. Parkinson, Gilbert Compo, Matthew Lazzara, Linda Keller, Rob Allan, Jonathan G. Palmer, Graeme Clark, and Ezequiel Marzinelli
The Cryosphere Discuss., https://doi.org/10.5194/tc-2017-51, https://doi.org/10.5194/tc-2017-51, 2017
Revised manuscript not accepted
Short summary
Short summary
We demonstrate that a mid-twentieth century decrease in geopotential height in the southwest Pacific marks a Rossby wave response to equatorial Pacific warming, leading to enhanced easterly airflow off George V Land. Our results suggest that in contrast to ozone hole-driven changes in the Amundsen Sea, the 1979–2015 increase in sea ice extent off George V Land may be in response to reduced northward Ekman drift and enhanced (near-coast) production as a consequence of low latitude forcing.
Iain M. Reid, Andrew J. Spargo, Jonathan M. Woithe, Andrew R. Klekociuk, Joel P. Younger, and Gulamabas G. Sivjee
Ann. Geophys., 35, 567–582, https://doi.org/10.5194/angeo-35-567-2017, https://doi.org/10.5194/angeo-35-567-2017, 2017
Short summary
Short summary
We measured temperatures in the atmosphere at heights near 90 km using nightglow emissions and compared them with satellite measurements and with measurements made with a meteor radar. We found good agreement between the techniques, which improved when we used the meteor radar and satellite data to measure densities at two heights separated by about 10 km to estimate the nightglow emission height.
John L. Gras and Melita Keywood
Atmos. Chem. Phys., 17, 4419–4432, https://doi.org/10.5194/acp-17-4419-2017, https://doi.org/10.5194/acp-17-4419-2017, 2017
Short summary
Short summary
Long-term observations at regionally representative sites can be used to challenge regional or global numerical models that underpin climate projections. Analysis of multi-decadal observations of aerosol microphysical properties in the remote marine boundary layer of the Southern Hemisphere characterises production and removal of marine aerosol on both short-term weather-related and underlying seasonal scales.
Andelija Milic, Marc D. Mallet, Luke T. Cravigan, Joel Alroe, Zoran D. Ristovski, Paul Selleck, Sarah J. Lawson, Jason Ward, Maximilien J. Desservettaz, Clare Paton-Walsh, Leah R. Williams, Melita D. Keywood, and Branka Miljevic
Atmos. Chem. Phys., 17, 3945–3961, https://doi.org/10.5194/acp-17-3945-2017, https://doi.org/10.5194/acp-17-3945-2017, 2017
Short summary
Short summary
This study reports chemical characterization of fresh and processed aerosols sampled over a month-long field campaign, during the intense fire period in Australian tropical savannah region. The study illustrates diversity in fire emissions and importance of processed fire emissions and formation of secondary species, including biogenic secondary species, in northern Australia.
Marc D. Mallet, Luke T. Cravigan, Andelija Milic, Joel Alroe, Zoran D. Ristovski, Jason Ward, Melita Keywood, Leah R. Williams, Paul Selleck, and Branka Miljevic
Atmos. Chem. Phys., 17, 3605–3617, https://doi.org/10.5194/acp-17-3605-2017, https://doi.org/10.5194/acp-17-3605-2017, 2017
Short summary
Short summary
This paper presents data on the size, composition and concentration of aerosol particles emitted from north Australian savannah fires and how these properties influence cloud condensation nuclei (CCN) concentrations. Both the size and composition of aerosol were found to be important in determining CCN. Despite large CCNc enhancements during periods of close biomass burning, the aerosol was very weakly hygroscopic which should be accounted for in climate models to avoid large CCNc overestimates.
Olaf Morgenstern, Michaela I. Hegglin, Eugene Rozanov, Fiona M. O'Connor, N. Luke Abraham, Hideharu Akiyoshi, Alexander T. Archibald, Slimane Bekki, Neal Butchart, Martyn P. Chipperfield, Makoto Deushi, Sandip S. Dhomse, Rolando R. Garcia, Steven C. Hardiman, Larry W. Horowitz, Patrick Jöckel, Beatrice Josse, Douglas Kinnison, Meiyun Lin, Eva Mancini, Michael E. Manyin, Marion Marchand, Virginie Marécal, Martine Michou, Luke D. Oman, Giovanni Pitari, David A. Plummer, Laura E. Revell, David Saint-Martin, Robyn Schofield, Andrea Stenke, Kane Stone, Kengo Sudo, Taichu Y. Tanaka, Simone Tilmes, Yousuke Yamashita, Kohei Yoshida, and Guang Zeng
Geosci. Model Dev., 10, 639–671, https://doi.org/10.5194/gmd-10-639-2017, https://doi.org/10.5194/gmd-10-639-2017, 2017
Short summary
Short summary
We present a review of the make-up of 20 models participating in the Chemistry–Climate Model Initiative (CCMI). In comparison to earlier such activities, most of these models comprise a whole-atmosphere chemistry, and several of them include an interactive ocean module. This makes them suitable for studying the interactions of tropospheric air quality, stratospheric ozone, and climate. The paper lays the foundation for other studies using the CCMI simulations for scientific analysis.
Asen Grytsai, Andrew Klekociuk, Gennadi Milinevsky, Oleksandr Evtushevsky, and Kane Stone
Atmos. Chem. Phys., 17, 1741–1758, https://doi.org/10.5194/acp-17-1741-2017, https://doi.org/10.5194/acp-17-1741-2017, 2017
Short summary
Short summary
Twenty years ago we discovered that the ozone hole shape is asymmetric. This asymmetry is minimum over the Weddell Sea region and maximum over the Ross Sea area. Later we detected that the position of the ozone minimum is shifting east. We have continued to follow this event, and a couple years ago we revealed that the shift is slowing down and starting to move back. We connect all this movement with ozone hole increase; since 2000 the ozone layer has been stabilizing and recently recovering.
V. Holly L. Winton, Ross Edwards, Andrew R. Bowie, Melita Keywood, Alistair G. Williams, Scott D. Chambers, Paul W. Selleck, Maximilien Desservettaz, Marc D. Mallet, and Clare Paton-Walsh
Atmos. Chem. Phys., 16, 12829–12848, https://doi.org/10.5194/acp-16-12829-2016, https://doi.org/10.5194/acp-16-12829-2016, 2016
Short summary
Short summary
The deposition of soluble aerosol iron (Fe) can initiate nitrogen fixation and trigger toxic algal blooms in nitrate-poor tropical waters. We present dry season soluble Fe data from northern Australia that reflect coincident dust and biomass burning sources of soluble Fe. Our results show that while biomass burning species are not a direct source of soluble Fe, biomass burning may substantially enhance the solubility of mineral dust with fractional Fe solubility up to 12 % in mixed aerosols.
Kathryn M. Emmerson, Ian E. Galbally, Alex B. Guenther, Clare Paton-Walsh, Elise-Andree Guerette, Martin E. Cope, Melita D. Keywood, Sarah J. Lawson, Suzie B. Molloy, Erin Dunne, Marcus Thatcher, Thomas Karl, and Simin D. Maleknia
Atmos. Chem. Phys., 16, 6997–7011, https://doi.org/10.5194/acp-16-6997-2016, https://doi.org/10.5194/acp-16-6997-2016, 2016
Short summary
Short summary
We have tested how a model using a global inventory of plant-based emissions compares with four sets of measurements made in southeast Australia. This region is known for its eucalypt species, which dominate the summertime global inventory. The Australian part of the inventory has been produced using measurements made on eucalypt saplings. The model could not match the measurements, and the inventory needs to be improved by taking measurements of a wider range of Australian plant types and ages.
Holly Winton, Andrew Bowie, Melita Keywood, Pier van der Merwe, and Ross Edwards
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2016-12, https://doi.org/10.5194/amt-2016-12, 2016
Revised manuscript not accepted
Short summary
Short summary
Aerosols containing iron have been investigated over the remote Southern Ocean to constrain iron budgets in surface waters and related biological production. Protocols for the sampling of ambient air were used to assess the suitability of high-volume aerosol samplers for aerosol iron studies in pristine air masses. Significant evidence of airborne insect and local soil contamination was detected in exposure blank filters. Suggestions for future aerosol iron sampling in clean air are provided.
Kane A. Stone, Olaf Morgenstern, David J. Karoly, Andrew R. Klekociuk, W. John French, N. Luke Abraham, and Robyn Schofield
Atmos. Chem. Phys., 16, 2401–2415, https://doi.org/10.5194/acp-16-2401-2016, https://doi.org/10.5194/acp-16-2401-2016, 2016
Short summary
Short summary
This paper describes the set-up and evaluation of the Australian Community Climate and Earth System Simulator – chemistry-climate model.
Emphasis is placed on the Antarctic ozone hole, which is very important considering its role modulating Southern Hemisphere surface climate. While the model simulates the global distribution of ozone well, there is a disparity in the vertical location of springtime ozone depletion over Antarctica, highlighting important areas for future development.
Emphasis is placed on the Antarctic ozone hole, which is very important considering its role modulating Southern Hemisphere surface climate. While the model simulates the global distribution of ozone well, there is a disparity in the vertical location of springtime ozone depletion over Antarctica, highlighting important areas for future development.
C. S. M. Turney, C. J. Fogwill, A. R. Klekociuk, T. D. van Ommen, M. A. J. Curran, A. D. Moy, and J. G. Palmer
The Cryosphere, 9, 2405–2415, https://doi.org/10.5194/tc-9-2405-2015, https://doi.org/10.5194/tc-9-2405-2015, 2015
Short summary
Short summary
Recent trends in ocean circulation, sea ice and climate over the Southern Ocean and Antarctica are highly complex. Here we report a new snow core from the South Pole alongside reanalysis of 20th century global atmospheric circulation. We demonstrate for the first time that atmospheric pressure anomalies in the mid-latitudes act as "gatekeepers" to meridional exchange over continental Antarctica, modulated by the tropical Pacific, with potentially significant impacts on surface mass balance.
S. J. Lawson, M. D. Keywood, I. E. Galbally, J. L. Gras, J. M. Cainey, M. E. Cope, P. B. Krummel, P. J. Fraser, L. P. Steele, S. T. Bentley, C. P. Meyer, Z. Ristovski, and A. H. Goldstein
Atmos. Chem. Phys., 15, 13393–13411, https://doi.org/10.5194/acp-15-13393-2015, https://doi.org/10.5194/acp-15-13393-2015, 2015
Short summary
Short summary
Biomass burning (BB) plumes were opportunistically measured at the Cape Grim Baseline Station in Tasmania, Australia. We provide a unique set of trace gas and particle emission factors for temperate Australian coastal heathland fires, and attribute a major short-lived enhancement in emission ratios to a minor rainfall event. The ability of BB particles to act as cloud condensation nuclei, and the contribution of BB emissions to observed particle growth and ozone enhancements are discussed.
R. S. Humphries, R. Schofield, M. D. Keywood, J. Ward, J. R. Pierce, C. M. Gionfriddo, M. T. Tate, D. P. Krabbenhoft, I. E. Galbally, S. B. Molloy, A. R. Klekociuk, P. V. Johnston, K. Kreher, A. J. Thomas, A. D. Robinson, N. R. P. Harris, R. Johnson, and S. R. Wilson
Atmos. Chem. Phys., 15, 13339–13364, https://doi.org/10.5194/acp-15-13339-2015, https://doi.org/10.5194/acp-15-13339-2015, 2015
Short summary
Short summary
An atmospheric new particle formation event that was observed in the pristine East Antarctic pack ice during a springtime voyage in 2012 is characterised in terms of formation and growth rates. Known nucleation mechanisms (e.g. those involving sulfate, iodine and organics) were unable to explain observations; however, correlations with total gaseous mercury were found, leading to the suggestion of a possible mercury-driven nucleation mechanism not previously described.
S. R. Wilson
Atmos. Chem. Phys., 15, 7337–7349, https://doi.org/10.5194/acp-15-7337-2015, https://doi.org/10.5194/acp-15-7337-2015, 2015
Short summary
Short summary
Measurements of the photolysis rates which drive production of OH from ozone are reported for Cape Grim, a "clean-air" site in the southern midlatitudes. This remote maritime site sits in the Southern Ocean, a region of the globe which is little studied. From the 6 years of data the dependence of this photolysis on solar zenith angle and stratospheric ozone is determined. Included with the reported values is an estimate of the uncertainties in these measurements.
W. Frey, R. Schofield, P. Hoor, D. Kunkel, F. Ravegnani, A. Ulanovsky, S. Viciani, F. D'Amato, and T. P. Lane
Atmos. Chem. Phys., 15, 6467–6486, https://doi.org/10.5194/acp-15-6467-2015, https://doi.org/10.5194/acp-15-6467-2015, 2015
Short summary
Short summary
This study examines the simulated downward transport and mixing of stratospheric air into the upper tropical troposphere as observed on a research flight during the SCOUT-O3 campaign in connection with a deep convective system, using the WRF model. Passive tracers are initialised to study the impact of the deep convection on the tracers and water vapour. We use the model to explain the processes causing the transport and also expose areas of inconsistencies between the model and observations.
J. A. Fisher, S. R. Wilson, G. Zeng, J. E. Williams, L. K. Emmons, R. L. Langenfelds, P. B. Krummel, and L. P. Steele
Atmos. Chem. Phys., 15, 3217–3239, https://doi.org/10.5194/acp-15-3217-2015, https://doi.org/10.5194/acp-15-3217-2015, 2015
Short summary
Short summary
The Southern Hemisphere (SH) serves as an important test bed for evaluating our understanding of the processes that drive the composition of the clean background atmosphere. Using data from two aircraft campaigns, combined with four atmospheric chemistry models, we find a large sensitivity in the remote SH to biogenic emissions and their subsequent chemistry and transport. Future model evaluation and measurement campaigns should prioritize reducing uncertainties in these processes.
F. Slemr, H. Angot, A. Dommergue, O. Magand, M. Barret, A. Weigelt, R. Ebinghaus, E.-G. Brunke, K. A. Pfaffhuber, G. Edwards, D. Howard, J. Powell, M. Keywood, and F. Wang
Atmos. Chem. Phys., 15, 3125–3133, https://doi.org/10.5194/acp-15-3125-2015, https://doi.org/10.5194/acp-15-3125-2015, 2015
Short summary
Short summary
• Longer-term mercury measurement in the Southern Hemisphere is compared.
• Mercury, in terms of monthly and annual medians and averages, is more evenly distributed than hitherto believed.
• Consequently, trends observed at one or a few sites are likely to be representative of the whole hemisphere, and smaller trends can be detected in shorter time periods.
• We report a change in the trend sign at Cape Point from decreasing mercury concentrations in 1996-2004 to increasing ones since 2007.
R. Schofield, L. M. Avallone, L. E. Kalnajs, A. Hertzog, I. Wohltmann, and M. Rex
Atmos. Chem. Phys., 15, 2463–2472, https://doi.org/10.5194/acp-15-2463-2015, https://doi.org/10.5194/acp-15-2463-2015, 2015
Short summary
Short summary
Ozone measurements onboard three Concordiasi balloons flown in the stratosphere in
the Antarctic spring of 2010 are presented. These measurements are the first long-duration in situ measurements of Antarctic springtime stratospheric ozone. By matching air parcels, ozone loss rates where derived. Downwind of the Antarctic Peninsula, very large ozone losses of up to 230 ppb per day or 16 ppbv per sunlit hour were observed. These high rates are consistent with almost complete chlorine activation.
K. Stone, M. B. Tully, S. K. Rhodes, and R. Schofield
Atmos. Meas. Tech., 8, 1043–1053, https://doi.org/10.5194/amt-8-1043-2015, https://doi.org/10.5194/amt-8-1043-2015, 2015
S. J. Lawson, P. W. Selleck, I. E. Galbally, M. D. Keywood, M. J. Harvey, C. Lerot, D. Helmig, and Z. Ristovski
Atmos. Chem. Phys., 15, 223–240, https://doi.org/10.5194/acp-15-223-2015, https://doi.org/10.5194/acp-15-223-2015, 2015
Short summary
Short summary
Glyoxal and methylglyoxal are short-lived organic trace gases and important precursors of secondary organic aerosol. Measurements over oceans are sparse. We present the first in situ glyoxal and methylglyoxal observations over remote temperate oceans, alongside observations of precursor gases. Precursor gases cannot explain observed mixing ratios, highlighting an unknown source. We show a large discrepancy between calculated vertical column densities of glyoxal and those retrieved by satellite.
J. M. Siddaway, S. V. Petelina, D. J. Karoly, A. R. Klekociuk, and R. J. Dargaville
Atmos. Chem. Phys., 13, 4413–4427, https://doi.org/10.5194/acp-13-4413-2013, https://doi.org/10.5194/acp-13-4413-2013, 2013
S. P. Alexander, D. J. Murphy, and A. R. Klekociuk
Atmos. Chem. Phys., 13, 3121–3132, https://doi.org/10.5194/acp-13-3121-2013, https://doi.org/10.5194/acp-13-3121-2013, 2013
Related subject area
Subject: Aerosols | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
Measurement report: Long-term assessment of primary and secondary organic aerosols in the Shanghai megacity throughout China's Clean Air actions since 2010
The evolution of aerosol mixing state derived from a field campaign in Beijing: implications for particle aging timescales in urban atmospheres
Measurement report: Size-resolved particle effective density measured by an AAC-SMPS and implications for chemical composition
Measurement report: Aircraft observations of aerosol and microphysical quantities of stratocumulus in autumn over Guangxi Province, China – daylight variation, vertical distribution, and aerosol–cloud interactions
Hygroscopic aerosols amplify longwave downward radiation in the Arctic
Measurement report: Optical and structural properties of atmospheric water-soluble organic carbon in China – insights from multi-site spectroscopic measurements
Measurement report: The variation properties of aerosol hygroscopic growth related to chemical composition during new particle formation days in a coastal city of Southeast China
In situ vertical observations of the layered structure of air pollution in a continental high-latitude urban boundary layer during winter
Size-resolved hygroscopicity and volatility properties of ambient urban aerosol particles measured by a volatility hygroscopicity tandem differential mobility analyzer system in Beijing
Terrestrial runoff is an important source of biological ice-nucleating particles in Arctic marine systems
Characterization of aerosol over the eastern Mediterranean by polarization-sensitive Raman lidar measurements during A-LIFE – aerosol type classification and type separation
Aerosol spectral optical properties in the Paris urban area and its peri-urban and forested surroundings during summer 2022 from ACROSS surface observations
Measurement report: An investigation of the spatiotemporal variability in aerosols in the mountainous terrain of the upper Colorado River basin using SAIL-Net
Contributions of the synoptic meteorology to the seasonal cloud condensation nuclei cycle over the Southern Ocean
Measurement report: Cloud condensation nuclei (CCN) activity in the South China Sea from shipborne observations during the summer and winter of 2021 – seasonal variation and anthropogenic influence
Source-Dependent Optical Properties and Molecular Characteristics of Atmospheric Brown Carbon
On-road vehicle emission measurements show a significant reduction of black carbon and nitrogen oxides emissions in Euro6c and 6d diesel-powered cars
Measurement report: A comparative analysis of an intensive incursion of fluorescing African dust particles over Puerto Rico and another over Spain
Measurement report: Analysis of aerosol optical depth variation at Zhongshan Station in Antarctica
External particle mixing influences hygroscopicity in a sub-urban area
Long-term observations of black carbon and carbon monoxide in the Poker Flat Research Range, central Alaska, with a focus on forest wildfire emissions
High ice-nucleating particle concentrations associated with Arctic haze in springtime cold-air outbreaks
CCN estimations at a high-altitude remote site: role of organic aerosol variability and hygroscopicity
Aerosol hygroscopicity over the southeast Atlantic Ocean during the biomass burning season – Part 1: From the perspective of scattering enhancement
Spatial, temporal, and meteorological impact of the 26 February 2023 dust storm: increase in particulate matter concentrations across New Mexico and West Texas
Large spatiotemporal variability in aerosol properties over central Argentina during the CACTI field campaign
Microphysical properties of refractory black carbon aerosols for different air masses at a central European background site
Quantification and characterization of primary biological aerosol particles and microbes aerosolized from Baltic seawater
Brownness of organics in anthropogenic biomass burning aerosols over South Asia
Multi-year black carbon observations and modeling close to the largest gas flaring and wildfire regions (Western Siberian Arctic)
Source apportionment of particle number size distribution at the street canyon and urban background sites
Long-range transport of coarse mineral dust: an evaluation of the Met Office Unified Model against aircraft observations
Extreme Saharan dust events expand northward over the Atlantic and Europe, prompting record-breaking PM10 and PM2.5 episodes
Atmospheric black carbon in the metropolitan area of La Paz and El Alto, Bolivia: concentration levels and emission sources
Changing optical properties of black carbon and brown carbon aerosols during long-range transport from the Indo-Gangetic Plain to the equatorial Indian Ocean
Aerosol size distribution properties associated with cold-air outbreaks in the Norwegian Arctic
Ice-nucleating particles active below −24 °C in a Finnish boreal forest and their relationship to bioaerosols
Measurement report: The influence of particle number size distribution and hygroscopicity on the microphysical properties of cloud droplets at a mountain site
Measurements of particle emissions of an A350-941 burning 100 % sustainable aviation fuels in cruise
Vertical distribution of ice nucleating particles over the boreal forest of Hyytiälä, Finland
Multi-year gradient measurements of sea spray fluxes over the Baltic Sea and the North Atlantic Ocean
Measurement report: In situ vertical profiles of below-cloud aerosol over the central Greenland Ice Sheet
Occurrence, abundance, and formation of atmospheric tarballs from a wide range of wildfires in the western US
Measurement report: Contribution of atmospheric new particle formation to ultrafine particle concentration, cloud condensation nuclei, and radiative forcing – results from 5-year observations in central Europe
Simulated contrail-processed aviation soot aerosols are poor ice-nucleating particles at cirrus temperatures
Biological and dust aerosols as sources of ice-nucleating particles in the eastern Mediterranean: source apportionment, atmospheric processing and parameterization
Quantifying the dust direct radiative effect in the southwestern United States: findings from multiyear measurements
How horizontal transport and turbulent mixing impact aerosol particle and precursor concentrations at a background site in the UAE
Markedly different impacts of primary emissions and secondary aerosol formation on aerosol mixing states revealed by simultaneous measurements of CCNC, H(/V)TDMA, and SP2
Phase matrix characterization of long-range transported Saharan dust using multiwavelength polarized polar imaging nephelometry
Haifeng Yu, Yunhua Chang, Lin Cheng, Yusen Duan, and Jianlin Hu
Atmos. Chem. Phys., 25, 5355–5369, https://doi.org/10.5194/acp-25-5355-2025, https://doi.org/10.5194/acp-25-5355-2025, 2025
Short summary
Short summary
This study presents long-term measurements and comprehensive analysis of carbonaceous aerosols in fine particles in Shanghai. We further estimated primary and secondary carbon levels, examining their temporal variations on interannual, monthly, seasonal, and diurnal scales. Through rigorous statistical analysis and correlation studies with meteorological parameters and pollutant concentrations, the origins, formation mechanisms, and spatial distribution patterns of secondary organic carbon were elucidated.
Jieyao Liu, Fang Zhang, Jingye Ren, Lu Chen, Anran Zhang, Zhe Wang, Songjian Zou, Honghao Xu, and Xingyan Yue
Atmos. Chem. Phys., 25, 5075–5086, https://doi.org/10.5194/acp-25-5075-2025, https://doi.org/10.5194/acp-25-5075-2025, 2025
Short summary
Short summary
Particle mixing states and aging timescales are important for the evaluation of aerosol climate effects, but they are poorly parameterized in current models. We unravel the evolution of real-time mixing states and the aging timescale of size-resolved particles based on field measurements in urban Beijing. This study provides an observational basis for accurately parameterizing the aging timescale of aerosol particles in climate models.
Yao Song, Jing Wei, Wenlong Zhao, Jinmei Ding, Xiangyu Pei, Fei Zhang, Zhengning Xu, Ruifang Shi, Ya Wei, Lu Zhang, Lingling Jin, and Zhibin Wang
Atmos. Chem. Phys., 25, 4755–4766, https://doi.org/10.5194/acp-25-4755-2025, https://doi.org/10.5194/acp-25-4755-2025, 2025
Short summary
Short summary
This study investigates the size-resolved effective density (ρeff) of aerosol particles in Hangzhou using a tandem aerodynamic aerosol classifier and scanning mobility particle sizer system. The ρeff values ranged from 1.47 to 1.63 g cm-3, increasing with particle diameter. The relationship between ρeff and the particle diameter varies due to differences in the chemical composition of the particles. A new method to derive the size-resolved chemical composition of particles from ρeff is proposed.
Sihan Liu, Honglei Wang, Delong Zhao, Wei Zhou, Yuanmou Du, Zhengguo Zhang, Peng Cheng, Tianliang Zhao, Yue Ke, Zihao Wu, and Mengyu Huang
Atmos. Chem. Phys., 25, 4151–4165, https://doi.org/10.5194/acp-25-4151-2025, https://doi.org/10.5194/acp-25-4151-2025, 2025
Short summary
Short summary
To understand the effect of aerosols on the vertical distribution of stratocumulus microphysical quantities in southwest China, the daily variation characteristics and formation mechanism of the vertical profiles of stratocumulus microphysical characteristics in this region were described using the data of nine cloud-crossing aircraft observations over Guangxi from 10 October to 3 November 2020.
Denghui Ji, Mathias Palm, Matthias Buschmann, Kerstin Ebell, Marion Maturilli, Xiaoyu Sun, and Justus Notholt
Atmos. Chem. Phys., 25, 3889–3904, https://doi.org/10.5194/acp-25-3889-2025, https://doi.org/10.5194/acp-25-3889-2025, 2025
Short summary
Short summary
Our study explores how certain aerosols, like sea salt, affect infrared heat radiation in the Arctic, potentially speeding up warming. We used advanced technology to measure aerosol composition and found that these particles grow with humidity, significantly increasing their heat-trapping effect in the infrared region, especially in winter. Our findings suggest these aerosols could be a key factor in Arctic warming, emphasizing the importance of understanding aerosols for climate prediction.
Haibiao Chen, Caiqing Yan, Liubin Huang, Lin Du, Yang Yue, Xinfeng Wang, Qingcai Chen, Mingjie Xie, Junwen Liu, Fengwen Wang, Shuhong Fang, Qiaoyun Yang, Hongya Niu, Mei Zheng, Yan Wu, and Likun Xue
Atmos. Chem. Phys., 25, 3647–3667, https://doi.org/10.5194/acp-25-3647-2025, https://doi.org/10.5194/acp-25-3647-2025, 2025
Short summary
Short summary
A comprehensive understanding of the optical properties of brown carbon (BrC) is essential to accurately assess its climatic effects. Based on multi-site spectroscopic measurements, this study demonstrated the significant spatial heterogeneity in the optical and structural properties of water-soluble organic carbon (WSOC) in different regions of China and revealed factors affecting WSOC light absorption and the relationship between fluorophores and light absorption of WSOC.
Lingjun Li, Mengren Li, Xiaolong Fan, Yuping Chen, Ziyi Lin, Anqi Hou, Siqing Zhang, Ronghua Zheng, and Jinsheng Chen
Atmos. Chem. Phys., 25, 3669–3685, https://doi.org/10.5194/acp-25-3669-2025, https://doi.org/10.5194/acp-25-3669-2025, 2025
Short summary
Short summary
Here, we show differences and variations in the aerosol scattering hygroscopic growth factor (f(RH)) between new particle formation (NPF) and non-NPF days and the effect of aerosol chemical compositions on f(RH) in Xiamen with in situ observations. The findings are helpful for the further understanding of aerosol hygroscopicity in a coastal city and the use of hygroscopic growth factors in models of air quality and climate change.
Roman Pohorsky, Andrea Baccarini, Natalie Brett, Brice Barret, Slimane Bekki, Gianluca Pappaccogli, Elsa Dieudonné, Brice Temime-Roussel, Barbara D'Anna, Meeta Cesler-Maloney, Antonio Donateo, Stefano Decesari, Kathy S. Law, William R. Simpson, Javier Fochesatto, Steve R. Arnold, and Julia Schmale
Atmos. Chem. Phys., 25, 3687–3715, https://doi.org/10.5194/acp-25-3687-2025, https://doi.org/10.5194/acp-25-3687-2025, 2025
Short summary
Short summary
This study presents an analysis of vertical measurements of pollution in an Alaskan city during winter. It investigates the relationship between the atmospheric structure and the layering of aerosols and trace gases. Results indicate an overall very shallow surface mixing layer. The height of this layer is strongly influenced by a local shallow wind. The study also provides information on the pollution chemical composition at different altitudes, including pollution signatures from power plants.
Aoyuan Yu, Xiaojing Shen, Qianli Ma, Jiayuan Lu, Xinyao Hu, Yangmei Zhang, Quan Liu, Linlin Liang, Lei Liu, Shuo Liu, Hongfei Tong, Huizheng Che, Xiaoye Zhang, and Junying Sun
Atmos. Chem. Phys., 25, 3389–3412, https://doi.org/10.5194/acp-25-3389-2025, https://doi.org/10.5194/acp-25-3389-2025, 2025
Short summary
Short summary
In this work, we utilized a volatility hygroscopicity tandem differential mobility analyzer (VH-TDMA) to investigate, for the first time, the hygroscopicity and volatility of submicron aerosols, as well as their hygroscopicity after heating, in urban Beijing during the autumn of 2023. We analyzed the size-resolved characteristics of hygroscopicity and volatility, the relationship between hygroscopic and volatile properties, and the hygroscopicity of heated submicron aerosols.
Corina Wieber, Lasse Z. Jensen, Leendert Vergeynst, Lorenz Meire, Thomas Juul-Pedersen, Kai Finster, and Tina Šantl-Temkiv
Atmos. Chem. Phys., 25, 3327–3346, https://doi.org/10.5194/acp-25-3327-2025, https://doi.org/10.5194/acp-25-3327-2025, 2025
Short summary
Short summary
The Arctic region is subject to profound changes due to a warming climate. Ice-nucleating particles (INPs) in the seawater can get transported to the atmosphere and impact cloud formation. However, the sources of characteristics of INPs in the marine areas are poorly understood. We investigated the INPs in seawater from Greenlandic fjords and identified a seasonal variability, with highly active INPs originating from terrestrial sources such as glacial and soil runoff.
Silke Groß, Volker Freudenthaler, Moritz Haarig, Albert Ansmann, Carlos Toledano, David Mateos, Petra Seibert, Rodanthi-Elisavet Mamouri, Argyro Nisantzi, Josef Gasteiger, Maximilian Dollner, Anne Tipka, Manuel Schöberl, Marilena Teri, and Bernadett Weinzierl
Atmos. Chem. Phys., 25, 3191–3211, https://doi.org/10.5194/acp-25-3191-2025, https://doi.org/10.5194/acp-25-3191-2025, 2025
Short summary
Short summary
Aerosols contribute to the largest uncertainties in climate change predictions. The eastern Mediterranean is a hotspot for aerosols with natural and anthropogenic contributions. We present lidar measurements performed during A-LIFE (Absorbing aerosol layers in a changing climate: aging, lifetime and dynamics) to characterize aerosols and aerosol mixtures. We extend current lidar classification and separation schemes and compare them to classification schemes using different methods.
Ludovico Di Antonio, Claudia Di Biagio, Paola Formenti, Aline Gratien, Vincent Michoud, Christopher Cantrell, Astrid Bauville, Antonin Bergé, Mathieu Cazaunau, Servanne Chevaillier, Manuela Cirtog, Patrice Coll, Barbara D'Anna, Joel F. de Brito, David O. De Haan, Juliette R. Dignum, Shravan Deshmukh, Olivier Favez, Pierre-Marie Flaud, Cecile Gaimoz, Lelia N. Hawkins, Julien Kammer, Brigitte Language, Franck Maisonneuve, Griša Močnik, Emilie Perraudin, Jean-Eudes Petit, Prodip Acharja, Laurent Poulain, Pauline Pouyes, Eva Drew Pronovost, Véronique Riffault, Kanuri I. Roundtree, Marwa Shahin, Guillaume Siour, Eric Villenave, Pascal Zapf, Gilles Foret, Jean-François Doussin, and Matthias Beekmann
Atmos. Chem. Phys., 25, 3161–3189, https://doi.org/10.5194/acp-25-3161-2025, https://doi.org/10.5194/acp-25-3161-2025, 2025
Short summary
Short summary
The spectral complex refractive index (CRI) and single scattering albedo were retrieved from submicron aerosol measurements at three sites within the greater Paris area during the ACROSS field campaign (June–July 2022). Measurements revealed urban emission impact on surrounding areas. CRI full period averages at 520 nm were 1.41 – 0.037i (urban), 1.52 – 0.038i (peri-urban), and 1.50 – 0.025i (rural). Organic aerosols dominated the aerosol mass and contributed up to 22 % of absorption at 370 nm.
Leah D. Gibson, Ezra J. T. Levin, Ethan Emerson, Nick Good, Anna Hodshire, Gavin McMeeking, Kate Patterson, Bryan Rainwater, Tom Ramin, and Ben Swanson
Atmos. Chem. Phys., 25, 2745–2762, https://doi.org/10.5194/acp-25-2745-2025, https://doi.org/10.5194/acp-25-2745-2025, 2025
Short summary
Short summary
From fall 2021 to summer 2023, SAIL-Net, a network of six aerosol measurement nodes, was deployed in the East River watershed (Colorado, USA) to study aerosol variability across space and time in mountainous terrain. We found that aerosol variability is influenced by elevation differences, with the most representative site in the region changing seasonally, suggesting aerosol spatial variability also varies seasonally. This work offers a blueprint for future studies in other mountainous regions.
Tahereh Alinejadtabrizi, Yi Huang, Francisco Lang, Steven Siems, Michael Manton, Luis Ackermann, Melita Keywood, Ruhi Humphries, Paul Krummel, Alastair Williams, and Greg Ayers
Atmos. Chem. Phys., 25, 2631–2648, https://doi.org/10.5194/acp-25-2631-2025, https://doi.org/10.5194/acp-25-2631-2025, 2025
Short summary
Short summary
Clouds over the Southern Ocean are crucial to Earth's energy balance, but understanding the factors that control them is complex. Our research examines how weather patterns affect tiny particles called cloud condensation nuclei (CCN), which influence cloud properties. Using data from Kennaook / Cape Grim, we found that winter air from Antarctica brings cleaner conditions with lower CCN, while summer patterns from Australia transport more particles. Precipitation also helps reduce CCN in winter.
Hengjia Ou, Mingfu Cai, Yongyun Zhang, Xue Ni, Baoling Liang, Qibin Sun, Shixin Mai, Cuizhi Sun, Shengzhen Zhou, Haichao Wang, Jiaren Sun, and Jun Zhao
Atmos. Chem. Phys., 25, 2495–2513, https://doi.org/10.5194/acp-25-2495-2025, https://doi.org/10.5194/acp-25-2495-2025, 2025
Short summary
Short summary
Two shipborne observations in the South China Sea (SCS) in summer and winter 2021 were conducted. Our study found aerosol hygroscopicity is higher in the SCS in summer than winter, with significant influences from various terrestrial air masses. Aerosol size distribution had a stronger effect on activation ratio than aerosol hygroscopicity in summer and vice versa in winter. Our study provides valuable information to enhance our understanding of cloud condensation nuclei activities in the SCS.
Jinghao Zhai, Yin Zhang, Pengfei Liu, Yujie Zhang, Antai Zhang, Yaling Zeng, Baohua Cai, Jingyi Zhang, Chunbo Xing, Honglong Yang, Xiaofei Wang, Jianhuai Ye, Chen Wang, Tzung-May Fu, Lei Zhu, Huizhong Shen, Shu Tao, and Xin Yang
EGUsphere, https://doi.org/10.5194/egusphere-2025-463, https://doi.org/10.5194/egusphere-2025-463, 2025
Short summary
Short summary
Our findings show that BrC's optical properties vary by source. Secondary BrC from ozone pollution had the lowest absorption but highest wavelength dependence, while BrC from biomass combustion had the highest absorption with the lowest wavelength dependence. Molecular analysis indicated that CHON species from biomass burning had the strongest light absorption. These insights enhance the accuracy of climate models by highlighting source-specific optical properties of BrC.
Irena Ježek Brecelj, Asta Gregorič, Lucijan Zgonik, Tjaša Rutar, Matic Ivančič, Balint Alfoldy, Griša Močnik, and Martin Rigler
EGUsphere, https://doi.org/10.5194/egusphere-2024-3553, https://doi.org/10.5194/egusphere-2024-3553, 2025
Short summary
Short summary
Following a major car industry scandal involving diesel emissions tests, Europe introduced new testing procedures. However, concerns remained about their effectiveness. Our independent study examined real-world vehicle emissions and revealed encouraging findings: modern diesel cars perform as well as, or even better than, gasoline cars in terms of nitrogen oxides emissions. We found the same pattern for soot particles, challenging common perceptions about diesel's environmental impact.
Bighnaraj Sarangi, Darrel Baumgardner, Ana Isabel Calvo, Benjamin Bolaños-Rosero, Roberto Fraile, Alberto Rodríguez-Fernández, Delia Fernández-González, Carlos Blanco-Alegre, Cátia Gonçalves, Estela D. Vicente, and Olga L. Mayol-Bracero
Atmos. Chem. Phys., 25, 843–865, https://doi.org/10.5194/acp-25-843-2025, https://doi.org/10.5194/acp-25-843-2025, 2025
Short summary
Short summary
Measurements of fluorescing aerosol particle properties have been made during two major African dust events, one over the island of Puerto Rico and the other over the city of León, Spain. The measurements were made with two wideband integrated bioaerosol spectrometers. A significant change in the background aerosol properties, at both locations, is observed when the dust is in the respective regions.
Lijing Chen, Lei Zhang, Yong She, Zhaoliang Zeng, Yu Zheng, Biao Tian, Wenqian Zhang, Zhaohui Liu, Huizheng Che, and Minghu Ding
Atmos. Chem. Phys., 25, 727–739, https://doi.org/10.5194/acp-25-727-2025, https://doi.org/10.5194/acp-25-727-2025, 2025
Short summary
Short summary
Aerosol optical depth (AOD) at Zhongshan Station varies seasonally, with lower values in summer and higher values in winter. Winter and spring AOD increases due to reduced fine-mode particles, while summer and autumn increases are linked to particle growth. Diurnal AOD variation correlates positively with temperature but negatively with wind speed and humidity. Backward trajectories show that aerosols on high-AOD (low-AOD) days primarily originate from the ocean (interior Antarctica).
Shravan Deshmukh, Laurent Poulain, Birgit Wehner, Silvia Henning, Jean-Eudes Petit, Pauline Fombelle, Olivier Favez, Hartmut Herrmann, and Mira Pöhlker
Atmos. Chem. Phys., 25, 741–758, https://doi.org/10.5194/acp-25-741-2025, https://doi.org/10.5194/acp-25-741-2025, 2025
Short summary
Short summary
Aerosol hygroscopicity has been investigated at a sub-urban site in Paris; analysis shows the sub-saturated regime's measured hygroscopicity and the chemically derived hygroscopic growth, shedding light on the large effect of external particle mixing and its influence on predicting hygroscopicity.
Takeshi Kinase, Fumikazu Taketani, Masayuki Takigawa, Chunmao Zhu, Yongwon Kim, Petr Mordovskoi, and Yugo Kanaya
Atmos. Chem. Phys., 25, 143–156, https://doi.org/10.5194/acp-25-143-2025, https://doi.org/10.5194/acp-25-143-2025, 2025
Short summary
Short summary
Boreal forest wildfires in interior Alaska represent an important black carbon (BC) source for the Arctic and surrounding regions. We observed BC and carbon monoxide (CO) concentrations in the Poker Flat Research Range since 2016 and found a positive correlation between the observed BC / ∆CO ratio and fire radiative power (FRP) observed in Alaska and Canada. Our finding suggests the BC emission factor and/or inventory could be potentially improved by using FRP.
Erin N. Raif, Sarah L. Barr, Mark D. Tarn, James B. McQuaid, Martin I. Daily, Steven J. Abel, Paul A. Barrett, Keith N. Bower, Paul R. Field, Kenneth S. Carslaw, and Benjamin J. Murray
Atmos. Chem. Phys., 24, 14045–14072, https://doi.org/10.5194/acp-24-14045-2024, https://doi.org/10.5194/acp-24-14045-2024, 2024
Short summary
Short summary
Ice-nucleating particles (INPs) allow ice to form in clouds at temperatures warmer than −35°C. We measured INP concentrations over the Norwegian and Barents seas in weather events where cold air is ejected from the Arctic. These concentrations were among the highest measured in the Arctic. It is likely that the INPs were transported to the Arctic from distant regions. These results show it is important to consider hemispheric-scale INP processes to understand INP concentrations in the Arctic.
Fernando Rejano, Andrea Casans, Marta Via, Juan Andrés Casquero-Vera, Sonia Castillo, Hassan Lyamani, Alberto Cazorla, Elisabeth Andrews, Daniel Pérez-Ramírez, Andrés Alastuey, Francisco Javier Gómez-Moreno, Lucas Alados-Arboledas, Francisco José Olmo, and Gloria Titos
Atmos. Chem. Phys., 24, 13865–13888, https://doi.org/10.5194/acp-24-13865-2024, https://doi.org/10.5194/acp-24-13865-2024, 2024
Short summary
Short summary
This study provides valuable insights to improve cloud condensation nuclei (CCN) estimations at a high-altitude remote site which is influenced by nearby urban pollution. Understanding the factors that affect CCN estimations is essential to improve the CCN data coverage worldwide and assess aerosol–cloud interactions on a global scale. This is crucial for improving climate models, since aerosol–cloud interactions are the most important source of uncertainty in climate projections.
Lu Zhang, Michal Segal-Rozenhaimer, Haochi Che, Caroline Dang, Junying Sun, Ye Kuang, Paola Formenti, and Steven G. Howell
Atmos. Chem. Phys., 24, 13849–13864, https://doi.org/10.5194/acp-24-13849-2024, https://doi.org/10.5194/acp-24-13849-2024, 2024
Short summary
Short summary
Using airborne measurements over the southeast Atlantic Ocean, we examined how much moisture aerosols take up during Africa’s biomass burning season. Our study revealed the important role of organic aerosols and introduced a predictive model for moisture uptake, accounting for organics, sulfate, and black carbon, summarizing results from various campaigns. These findings improve our understanding of aerosol–moisture interactions and their radiative effects in this climatically critical region.
Mary C. Robinson, Kaitlin Schueth, and Karin Ardon-Dryer
Atmos. Chem. Phys., 24, 13733–13750, https://doi.org/10.5194/acp-24-13733-2024, https://doi.org/10.5194/acp-24-13733-2024, 2024
Short summary
Short summary
On 26 February 2023, New Mexico and West Texas were impacted by a severe dust storm. To analyze this storm, 28 meteorological stations and 19 PM2.5 and PM10 stations were used. Dust particles were in the air for 16 h, and dust storm conditions lasted for up to 120 min. Hourly PM2.5 and PM10 concentrations were up to 518 and 9983 µg m−3, respectively. For Lubbock, Texas, the maximum PM2.5 concentrations were the highest ever recorded.
Jerome D. Fast, Adam C. Varble, Fan Mei, Mikhail Pekour, Jason Tomlinson, Alla Zelenyuk, Art J. Sedlacek III, Maria Zawadowicz, and Louisa Emmons
Atmos. Chem. Phys., 24, 13477–13502, https://doi.org/10.5194/acp-24-13477-2024, https://doi.org/10.5194/acp-24-13477-2024, 2024
Short summary
Short summary
Aerosol property measurements recently collected on the ground and by a research aircraft in central Argentina during the Cloud, Aerosol, and Complex Terrain Interactions (CACTI) campaign exhibit large spatial and temporal variability. These measurements coupled with coincident meteorological information provide a valuable data set needed to evaluate and improve model predictions of aerosols in a traditionally data-sparse region of South America.
Yifan Yang, Thomas Müller, Laurent Poulain, Samira Atabakhsh, Bruna A. Holanda, Jens Voigtländer, Shubhi Arora, and Mira L. Pöhlker
EGUsphere, https://doi.org/10.5194/egusphere-2024-3539, https://doi.org/10.5194/egusphere-2024-3539, 2024
Short summary
Short summary
Black carbon (BC) is the major atmospheric aerosol that can absorb light and influence climate. We measured the physical properties of BC at a background site in Germany. In summer, BC particles were smaller and the mixture with other atmospheric components occurred during the daytime. In winter, emissions from residential heating significantly influenced BC's properties. Understanding these characteristics of BC can help improve aerosol optics simulation accuracy.
Julika Zinke, Gabriel Pereira Freitas, Rachel Ann Foster, Paul Zieger, Ernst Douglas Nilsson, Piotr Markuszewski, and Matthew Edward Salter
Atmos. Chem. Phys., 24, 13413–13428, https://doi.org/10.5194/acp-24-13413-2024, https://doi.org/10.5194/acp-24-13413-2024, 2024
Short summary
Short summary
Bioaerosols, which can influence climate and human health, were studied in the Baltic Sea. In May and August 2021, we used a sea spray simulation chamber during two ship-based campaigns to collect and measure these aerosols. We found that microbes were enriched in air compared to seawater. Bacterial diversity was analysed using DNA sequencing. Our methods provided consistent estimates of microbial emission fluxes, aligning with previous studies.
Chimurkar Navinya, Taveen Singh Kapoor, Gupta Anurag, Chandra Venkataraman, Harish C. Phuleria, and Rajan K. Chakrabarty
Atmos. Chem. Phys., 24, 13285–13297, https://doi.org/10.5194/acp-24-13285-2024, https://doi.org/10.5194/acp-24-13285-2024, 2024
Short summary
Short summary
Brown carbon (BrC) aerosols show an order-of-magnitude variation in their light absorption strength. Our understanding of BrC from real-world biomass burning remains limited, complicating the determination of its radiative impact. Our study reports absorption properties of BrC emitted from four major biomass burning sources using field measurements in India. It develops an absorption parameterization for BrC and examines the spatial variability in BrC's absorption strength across India.
Olga B. Popovicheva, Marina A. Chichaeva, Nikolaos Evangeliou, Sabine Eckhardt, Evangelia Diapouli, and Nikolay S. Kasimov
EGUsphere, https://doi.org/10.5194/egusphere-2024-3124, https://doi.org/10.5194/egusphere-2024-3124, 2024
Short summary
Short summary
High-quality measurements of light-absorbing carbon were performed at the polar aerosol station "Island Bely” (Western Siberian Arctic) from 2019 to 2022. The maximum light absorption coefficients were seen in summer due to gas flaring contribution, which is the most significant source in the region. However, the increasing Siberian wildfires had a special share in carbon contribution to this high Arctic station with a persistent smoke layer extending over the whole troposphere in summer.
Sami D. Harni, Minna Aurela, Sanna Saarikoski, Jarkko V. Niemi, Harri Portin, Hanna Manninen, Ville Leinonen, Pasi Aalto, Phil K. Hopke, Tuukka Petäjä, Topi Rönkkö, and Hilkka Timonen
Atmos. Chem. Phys., 24, 12143–12160, https://doi.org/10.5194/acp-24-12143-2024, https://doi.org/10.5194/acp-24-12143-2024, 2024
Short summary
Short summary
In this study, particle number size distribution data were used in a novel way in positive matrix factorization analysis to find aerosol source profiles in the area. Measurements were made in Helsinki at a street canyon and urban background sites between February 2015 and June 2019. Five different aerosol sources were identified. These sources underline the significance of traffic-related emissions in urban environments despite recent improvements in emission reduction technologies.
Natalie G. Ratcliffe, Claire L. Ryder, Nicolas Bellouin, Stephanie Woodward, Anthony Jones, Ben Johnson, Lisa-Maria Wieland, Maximilian Dollner, Josef Gasteiger, and Bernadett Weinzierl
Atmos. Chem. Phys., 24, 12161–12181, https://doi.org/10.5194/acp-24-12161-2024, https://doi.org/10.5194/acp-24-12161-2024, 2024
Short summary
Short summary
Large mineral dust particles are more abundant in the atmosphere than expected and have different impacts on the environment than small particles, which are better represented in climate models. We use aircraft measurements to assess a climate model representation of large-dust transport. We find that the model underestimates the amount of large dust at all stages of transport and that fast removal of the large particles increases this underestimation with distance from the Sahara.
Sergio Rodríguez and Jessica López-Darias
Atmos. Chem. Phys., 24, 12031–12053, https://doi.org/10.5194/acp-24-12031-2024, https://doi.org/10.5194/acp-24-12031-2024, 2024
Short summary
Short summary
Extreme Saharan dust events expanded northward to the Atlantic and Europe, prompting record-breaking PM10 and PM2.5 events. These episodes are caused by low-to-high dipole meteorology during hemispheric anomalies characterized by subtropical anticyclones shifting to higher latitudes, anomalous low pressures beyond the tropics and amplified Rossby waves. Extreme dust events occur in a paradoxical context of a multidecadal decrease in dust emissions, a topic that requires further investigation.
Valeria Mardoñez-Balderrama, Griša Močnik, Marco Pandolfi, Robin L. Modini, Fernando Velarde, Laura Renzi, Angela Marinoni, Jean-Luc Jaffrezo, Isabel Moreno R., Diego Aliaga, Federico Bianchi, Claudia Mohr, Martin Gysel-Beer, Patrick Ginot, Radovan Krejci, Alfred Wiedensohler, Gaëlle Uzu, Marcos Andrade, and Paolo Laj
Atmos. Chem. Phys., 24, 12055–12077, https://doi.org/10.5194/acp-24-12055-2024, https://doi.org/10.5194/acp-24-12055-2024, 2024
Short summary
Short summary
Levels of black carbon (BC) are scarcely reported in the Southern Hemisphere, especially in high-altitude conditions. This study provides insight into the concentration level, variability, and optical properties of BC in La Paz and El Alto and at the Chacaltaya Global Atmosphere Watch Station. Two methods of source apportionment of absorption were tested and compared showing traffic as the main contributor to absorption in the urban area, in addition to biomass and open waste burning.
Krishnakant Budhavant, Mohanan Remani Manoj, Hari Ram Chandrika Rajendran Nair, Samuel Mwaniki Gaita, Henry Holmstrand, Abdus Salam, Ahmed Muslim, Sreedharan Krishnakumari Satheesh, and Örjan Gustafsson
Atmos. Chem. Phys., 24, 11911–11925, https://doi.org/10.5194/acp-24-11911-2024, https://doi.org/10.5194/acp-24-11911-2024, 2024
Short summary
Short summary
The South Asian Pollution Experiment 2018 used access to three strategically located receptor observatories. Observational constraints revealed opposing trends in the mass absorption cross sections of black carbon (BC MAC) and brown carbon (BrC MAC) during long-range transport. Models estimating the climate effects of BC aerosols may have underestimated the ambient BC MAC over distant receptor areas, leading to discrepancies in aerosol absorption predicted by observation-constrained models.
Abigail S. Williams, Jeramy L. Dedrick, Lynn M. Russell, Florian Tornow, Israel Silber, Ann M. Fridlind, Benjamin Swanson, Paul J. DeMott, Paul Zieger, and Radovan Krejci
Atmos. Chem. Phys., 24, 11791–11805, https://doi.org/10.5194/acp-24-11791-2024, https://doi.org/10.5194/acp-24-11791-2024, 2024
Short summary
Short summary
The measured aerosol size distribution modes reveal distinct properties characteristic of cold-air outbreaks in the Norwegian Arctic. We find higher sea spray number concentrations, smaller Hoppel minima, lower effective supersaturations, and accumulation-mode particle scavenging during cold-air outbreaks. These results advance our understanding of cold-air outbreak aerosol–cloud interactions in order to improve their accurate representation in models.
Franziska Vogel, Michael P. Adams, Larissa Lacher, Polly B. Foster, Grace C. E. Porter, Barbara Bertozzi, Kristina Höhler, Julia Schneider, Tobias Schorr, Nsikanabasi S. Umo, Jens Nadolny, Zoé Brasseur, Paavo Heikkilä, Erik S. Thomson, Nicole Büttner, Martin I. Daily, Romy Fösig, Alexander D. Harrison, Jorma Keskinen, Ulrike Proske, Jonathan Duplissy, Markku Kulmala, Tuukka Petäjä, Ottmar Möhler, and Benjamin J. Murray
Atmos. Chem. Phys., 24, 11737–11757, https://doi.org/10.5194/acp-24-11737-2024, https://doi.org/10.5194/acp-24-11737-2024, 2024
Short summary
Short summary
Primary ice formation in clouds strongly influences their properties; hence, it is important to understand the sources of ice-nucleating particles (INPs) and their variability. We present 2 months of INP measurements in a Finnish boreal forest using a new semi-autonomous INP counting device based on gas expansion. These results show strong variability in INP concentrations, and we present a case that the INPs we observe are, at least some of the time, of biological origin.
Xiaojing Shen, Quan Liu, Junying Sun, Wanlin Kong, Qianli Ma, Bing Qi, Lujie Han, Yangmei Zhang, Linlin Liang, Lei Liu, Shuo Liu, Xinyao Hu, Jiayuan Lu, Aoyuan Yu, Huizheng Che, and Xiaoye Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2024-2850, https://doi.org/10.5194/egusphere-2024-2850, 2024
Short summary
Short summary
In this work, an automatic switched inlet system was developed and employed to investigate the aerosols and cloud droplets at a mountain site with frequent cloud processes. It showed different characteristics of cloud residual and interstitial particles. Stronger particle hygroscopicity reduced liquid water content and smaller cloud droplet diameters. This investigation contributes to understanding aerosol-cloud interactions by assessing the impact of aerosol particles on cloud microphysics.
Rebecca Dischl, Daniel Sauer, Christiane Voigt, Theresa Harlaß, Felicitas Sakellariou, Raphael Märkl, Ulrich Schumann, Monika Scheibe, Stefan Kaufmann, Anke Roiger, Andreas Dörnbrack, Charles Renard, Maxime Gauthier, Peter Swann, Paul Madden, Darren Luff, Mark Johnson, Denise Ahrens, Reetu Sallinen, Tobias Schripp, Georg Eckel, Uwe Bauder, and Patrick Le Clercq
Atmos. Chem. Phys., 24, 11255–11273, https://doi.org/10.5194/acp-24-11255-2024, https://doi.org/10.5194/acp-24-11255-2024, 2024
Short summary
Short summary
In-flight measurements of aircraft emissions burning 100 % sustainable aviation fuel (SAF) show reduced particle number concentrations up to 41 % compared to conventional jet fuel. Particle emissions are dependent on engine power setting, flight altitude, and fuel composition. Engine models show a good correlation with measurement results. Future increased prevalence of SAF can positively influence the climate impact of aviation.
Zoé Brasseur, Julia Schneider, Janne Lampilahti, Ville Vakkari, Victoria A. Sinclair, Christina J. Williamson, Carlton Xavier, Dmitri Moisseev, Markus Hartmann, Pyry Poutanen, Markus Lampimäki, Markku Kulmala, Tuukka Petäjä, Katrianne Lehtipalo, Erik S. Thomson, Kristina Höhler, Ottmar Möhler, and Jonathan Duplissy
Atmos. Chem. Phys., 24, 11305–11332, https://doi.org/10.5194/acp-24-11305-2024, https://doi.org/10.5194/acp-24-11305-2024, 2024
Short summary
Short summary
Ice-nucleating particles (INPs) strongly influence the formation of clouds by initiating the formation of ice crystals. However, very little is known about the vertical distribution of INPs in the atmosphere. Here, we present aircraft measurements of INP concentrations above the Finnish boreal forest. Results show that near-surface INPs are efficiently transported and mixed within the boundary layer and occasionally reach the free troposphere.
Piotr Markuszewski, E. Douglas Nilsson, Julika Zinke, E. Monica Mårtensson, Matthew Salter, Przemysław Makuch, Małgorzata Kitowska, Iwona Niedźwiecka-Wróbel, Violetta Drozdowska, Dominik Lis, Tomasz Petelski, Luca Ferrero, and Jacek Piskozub
Atmos. Chem. Phys., 24, 11227–11253, https://doi.org/10.5194/acp-24-11227-2024, https://doi.org/10.5194/acp-24-11227-2024, 2024
Short summary
Short summary
Our research provides new insights into the study of sea spray aerosol (SSA) emissions in the Baltic Sea and North Atlantic. We observed that SSA flux is suppressed during increased marine biological activity in the Baltic Sea. At the same time, the influence of wave age showed higher SSA emissions in the Baltic Sea for younger waves compared to the Atlantic Ocean. These insights underscore the complex interplay between biological activity and physical dynamics in regulating SSA emissions.
Heather Guy, Andrew S. Martin, Erik Olson, Ian M. Brooks, and Ryan R. Neely III
Atmos. Chem. Phys., 24, 11103–11114, https://doi.org/10.5194/acp-24-11103-2024, https://doi.org/10.5194/acp-24-11103-2024, 2024
Short summary
Short summary
Aerosol particles impact cloud properties which influence Greenland Ice Sheet melt. Understanding the aerosol population that interacts with clouds is important for constraining future melt. Measurements of aerosols at cloud height over Greenland are rare, and surface measurements are often used to investigate cloud–aerosol interactions. We use a tethered balloon to measure aerosols up to cloud base and show that surface measurements are often not equivalent to those just below the cloud.
Kouji Adachi, Jack E. Dibb, Joseph M. Katich, Joshua P. Schwarz, Hongyu Guo, Pedro Campuzano-Jost, Jose L. Jimenez, Jeff Peischl, Christopher D. Holmes, and James Crawford
Atmos. Chem. Phys., 24, 10985–11004, https://doi.org/10.5194/acp-24-10985-2024, https://doi.org/10.5194/acp-24-10985-2024, 2024
Short summary
Short summary
We examined aerosol particles from wildfires and identified tarballs (TBs) from the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign. This study reveals the compositions, abundance, sizes, and mixing states of TBs and shows that TBs formed as the smoke aged for up to 5 h. This study provides measurements of TBs from various biomass-burning events and ages, enhancing our knowledge of TB emissions and our understanding of their climate impact.
Jia Sun, Markus Hermann, Kay Weinhold, Maik Merkel, Wolfram Birmili, Yifan Yang, Thomas Tuch, Harald Flentje, Björn Briel, Ludwig Ries, Cedric Couret, Michael Elsasser, Ralf Sohmer, Klaus Wirtz, Frank Meinhardt, Maik Schütze, Olaf Bath, Bryan Hellack, Veli-Matti Kerminen, Markku Kulmala, Nan Ma, and Alfred Wiedensohler
Atmos. Chem. Phys., 24, 10667–10687, https://doi.org/10.5194/acp-24-10667-2024, https://doi.org/10.5194/acp-24-10667-2024, 2024
Short summary
Short summary
We investigated the characteristics of new particle formation (NPF) for various environments from urban background to high Alpine and the impacts of NPF on cloud condensation nuclei and aerosol radiative forcing. NPF features differ between site categories, implying the crucial role of local environmental factors such as the degree of emissions and meteorological conditions. The results also underscore the importance of local environments when assessing the impact of NPF on climate in models.
Baptiste Testa, Lukas Durdina, Jacinta Edebeli, Curdin Spirig, and Zamin A. Kanji
Atmos. Chem. Phys., 24, 10409–10424, https://doi.org/10.5194/acp-24-10409-2024, https://doi.org/10.5194/acp-24-10409-2024, 2024
Short summary
Short summary
Aviation soot residuals released from contrails can become compacted upon sublimation of the ice crystals, generating new voids in the aggregates where ice nucleation can occur. Here we show that contrail-processed soot is highly compact but that it remains unable to form ice at a relative humidity different from that required for the formation of background cirrus from the more ubiquitous aqueous solution droplets, suggesting that it will not perturb cirrus cloud formation via ice nucleation.
Kunfeng Gao, Franziska Vogel, Romanos Foskinis, Stergios Vratolis, Maria I. Gini, Konstantinos Granakis, Anne-Claire Billault-Roux, Paraskevi Georgakaki, Olga Zografou, Prodromos Fetfatzis, Alexis Berne, Alexandros Papayannis, Konstantinos Eleftheridadis, Ottmar Möhler, and Athanasios Nenes
Atmos. Chem. Phys., 24, 9939–9974, https://doi.org/10.5194/acp-24-9939-2024, https://doi.org/10.5194/acp-24-9939-2024, 2024
Short summary
Short summary
Ice nucleating particle (INP) concentrations are required for correct predictions of clouds and precipitation in a changing climate, but they are poorly constrained in climate models. We unravel source contributions to INPs in the eastern Mediterranean and find that biological particles are important, regardless of their origin. The parameterizations developed exhibit superior performance and enable models to consider biological-particle effects on INPs.
Alexandra Kuwano, Amato T. Evan, Blake Walkowiak, and Robert Frouin
Atmos. Chem. Phys., 24, 9843–9868, https://doi.org/10.5194/acp-24-9843-2024, https://doi.org/10.5194/acp-24-9843-2024, 2024
Short summary
Short summary
The dust direct radiative effect is highly uncertain. Here we used new measurements collected over 3 years and during dust storms at a field site in a desert region in the southwestern United States to estimate the regional dust direct radiative effect. We also used novel soil mineralogy retrieved from an airborne spectrometer to estimate this parameter with model output. We find that, in this region, dust has a minimal net cooling effect on this region's climate.
Jutta Kesti, Ewan J. O'Connor, Anne Hirsikko, John Backman, Maria Filioglou, Anu-Maija Sundström, Juha Tonttila, Heikki Lihavainen, Hannele Korhonen, and Eija Asmi
Atmos. Chem. Phys., 24, 9369–9386, https://doi.org/10.5194/acp-24-9369-2024, https://doi.org/10.5194/acp-24-9369-2024, 2024
Short summary
Short summary
The study combines aerosol particle measurements at the surface and vertical profiling of the atmosphere with a scanning Doppler lidar to investigate how particle transportation together with boundary layer evolution can affect particle and SO2 concentrations at the surface in the Arabian Peninsula region. The instrumentation enabled us to see elevated nucleation mode particle and SO2 concentrations at the surface when air masses transported from polluted areas are mixed in the boundary layer.
Jiangchuan Tao, Biao Luo, Weiqi Xu, Gang Zhao, Hanbin Xu, Biao Xue, Miaomiao Zhai, Wanyun Xu, Huarong Zhao, Sanxue Ren, Guangsheng Zhou, Li Liu, Ye Kuang, and Yele Sun
Atmos. Chem. Phys., 24, 9131–9154, https://doi.org/10.5194/acp-24-9131-2024, https://doi.org/10.5194/acp-24-9131-2024, 2024
Short summary
Short summary
Using simultaneous measurements of DMA–CCNC, H(/V)TDMA, and DMA–SP2, impacts of primary emissions and secondary aerosol formations on changes in aerosol physicochemical properties were comprehensively investigated. It was found that intercomparisons among aerosol mixing-state parameters derived from different techniques can help us gain more insight into aerosol physical properties which, in turn, will aid the investigation of emission characteristics and secondary aerosol formation pathways.
Elena Bazo, Daniel Perez-Ramirez, Antonio Valenzuela, Vanderlei Martins, Gloria Titos, Alberto Cazorla, Fernando Rejano, Diego Patrón, Arlett Diaz-Zurita, Francisco Jose Garcia-Izquierdo, David Fuertes, Lucas Alados-Arboledas, and Francisco Jose Olmo
EGUsphere, https://doi.org/10.5194/egusphere-2024-2080, https://doi.org/10.5194/egusphere-2024-2080, 2024
Short summary
Short summary
This works analyses aerosol scattering phase function for transported Saharan dust to the city of Granada – located in southwestern Europe. We use the novel technique polar imaging nephelometry that helps to determine the phase functions using a CCD camara. The capability of measuring with polarized light helps to inferr new properties about the mixture of Saharan dust particles with other of anthropogenic origin.
Cited articles
Allan, J. D., Williams, P. I., Najera, J., Whitehead, J. D., Flynn, M. J.,
Taylor, J. W., Liu, D., Darbyshire, E., Carpenter, L. J., Chance, R.,
Andrews, S. J., Hackenberg, S. C., and McFiggans, G.: Iodine observed in new
particle formation events in the Arctic atmosphere during ACCACIA, Atmos.
Chem. Phys., 15, 5599–5609, https://doi.org/10.5194/acp-15-5599-2015, 2015.
Asmi, E., Frey, A., Virkkula, A., Ehn, M., Manninen, H. E., Timonen, H.,
Tolonen-Kivimäki, O., Aurela, M., Hillamo, R., and Kulmala, M.:
Hygroscopicity and chemical composition of Antarctic sub-micrometre aerosol
particles and observations of new particle formation, Atmos. Chem. Phys., 10,
4253–4271, https://doi.org/10.5194/acp-10-4253-2010, 2010.
Atkinson, H. M., Huang, R.-J., Chance, R., Roscoe, H. K., Hughes, C.,
Davison, B., Schönhardt, A., Mahajan, A. S., Saiz-Lopez, A., Hoffmann,
T., and Liss, P. S.: Iodine emissions from the sea ice of the Weddell Sea,
Atmos. Chem. Phys., 12, 11229–11244, https://doi.org/10.5194/acp-12-11229-2012, 2012.
Bates, T. S., Lamb, B. K., Guenther, A., Dignon, J., and Stoiber, R. E.:
Sulfur emissions to the atmosphere from natural sources, J. Atmos. Chem.,
14, 315–337,
https://doi.org/10.1007/bf00115242, 1992.
Bates, T. S., Huebert, B. J., Gras, J. L., Griffiths, F. B., and Durkee, P. A.:
International Global Atmospheric Chemistry (IGAC) project's first Aerosol Characterization Experiment (ACE 1): overview, J. Geophys. Res., 103, 16297,
https://doi.org/10.1029/97JD03741, 1998.
Belosi, F., Contini, D., Donateo, A., Santachiara, G., and Prodi, F.: Aerosol size
distribution at Nansen Ice Sheet Antarctica, Atmos. Res., 107, 42–50, 2012.
Bigg, E. K., Gras, J. L., and Evans, C.: Origin of aitken particles in remote
regions of the Southern Hemisphere, J. Atmos. Chem., 1, 203–214, 1983.
Brechtel, F. J., Kreidenweis, S. M., and Swan, H. B.: Air mass characteristics,
aerosol particle number concentrations, and number size distributions at
Macquarie Island during the First Aerosol Characterization Experiment (ACE 1),
J. Geophys. Res.-Atmos., 103, 16351–16367,
https://doi.org/10.1029/97jd03014, 1998.
Carslaw, K. S., Lee, L. A., Reddington, C. L., Pringle, K. J., Rap, A.,
Forster, P. M., Mann, G. W., Spracklen, D. V., Woodhouse, M. T.,
Regayre, L. A., and Pierce, J. R.: Large contribution of natural aerosols to
uncertainty in indirect forcing, Nature, 503, 67–71,
https://doi.org/10.1038/nature12674, 2013.
Choi, J., Son, S.-W., Lu, J., and Min, S.-K.: Further observational evidence
of Hadley cell widening in the Southern Hemisphere, Geophys. Res. Lett., 41,
2590–2597,
https://doi.org/10.1002/2014GL059426,
2014.
Davis, S. M. and Rosenlof, K. H.: A multidiagnostic intercomparison of
tropical-width time series using reanalyses and satellite observations, J.
Climate, 25, 1061–1078,
https://doi.org/10.1175/JCLI-D-11-00127.1,
2012.
Davison, B., Hewitt, C. N., O'Dowd, C. D., Lowe, J. A., Smith, M. H.,
Schwikowski, M., Baltensperger, U., and Harrison, R. M.: Dimethyl sulfide,
methane sulfonic acid and physicochemical aerosol properties in Atlantic air
from the United Kingdom to Halley Bay, J. Geophys. Res., 101, 22855–22867,
https://doi.org/10.1029/96jd01166, 1996.
Dee, D. P., Uppala, S. M., Simmons, A. J., Berrisford, P., Poli, P.,
Kobayashi, S., Andrae, U., Balmaseda, M. A., Balsamo, G., Bauer, P.,
Bechtold, P., Beljaars, A. C. M., van de Berg, L., Bidlot, J., Bormann, N.,
Delsol, C., Dragani, R., Fuentes, M., Geer, A. J., Haimberger, L.,
Healy, S. B., Hersbach, H., Hólm, E. V., Isaksen, L., Kållberg, P.,
Köhler, M., Matricardi, M., McNally, A. P., Monge-Sanz, B. M.,
Morcrette, J.-J., Park, B.-K., Peubey, C., de Rosnay, P., Tavolato, C.,
Thépaut, J.-N., and Vitart, F.: The ERA-Interim reanalysis:
configuration and performance of the data assimilation system, Q. J. Roy.
Meteor. Soc., 137, 553–597,
https://doi.org/10.1002/qj.828, 2011.
Dong, S., Sprintall, J., and Gille, S. T.: Location of the Antarctic polar
front from AMSR-E satellite sea surface temperature measurements, J. Phys.
Oceanogr., 36, 2075–2089,
https://doi.org/10.1175/JPO2973.1, 2006.
Draxler, R. R. and Hess, G. D.: An overview of the HYSPLIT_4 modelling
system for trajectories, dispersion, and deposition, Aust. Meteorol. Mag.,
47, 295–308, 1998.
Frieß, U., Wagner, T., Pundt, I., Pfeilsticker, K., and Platt, U.:
Spectroscopic measurements of tropospheric iodine oxide at Neumayer Station,
Antarctica, Geophys. Res. Lett., 28, 1941–1944,
https://doi.org/10.1029/2000gl012784,
2001.
Frieß, U., Deutschmann, T., Gilfedder, B. S., Weller, R., and Platt, U.:
Iodine monoxide in the Antarctic snowpack, Atmos. Chem. Phys., 10,
2439–2456, https://doi.org/10.5194/acp-10-2439-2010, 2010.
Fyfe, J. C.: Extratropical Southern Hemisphere cyclones: harbingers of
climate change?, J. Climate, 16, 2802–2805,
https://doi.org/10.1175/1520-0442(2003)016<2802:ESHCHO>2.0.CO;2,
2003.
Ghan, S. J., Smith, S. J., Wang, M., Zhang, K., Pringle, K., Carslaw, K.,
Pierce, J., Bauer, S., and Adams, P.: A simple model of global aerosol
indirect effects, J. Geophys. Res.-Atmos., 118, 6688–6707,
https://doi.org/10.1002/jgrd.50567, 2013.
Gras, J. L., Jimi, S. I., Siems, S. T., and Krummel, P. B.: Postfrontal
nanoparticles at Cape Grim: observations, Environ. Chem., 6, 508–514,
https://doi.org/10.1071/EN09075, 2009.
Hansen, G., Aspmo, K., Berg, T., Edvardsen, K. R., Fiebig, M.,
Kallenborn, R., Krognes, T., Lunder, C., Stebel, K., Schmidbauer, N.,
Solberg, S., and Yttri, K. E.: Atmospheric monitoring at the Norwegian
Antarctic station Troll: measurement programme and first results, Polar
Res., 28, 353–363,
https://doi.org/10.3402/polar.v28i3.6142,
2009.
Hara, K.: Chemistry of sea-salt particles and inorganic halogen species in
Antarctic regions: compositional differences between coastal and inland
stations, J. Geophys. Res., 109, D20208,
https://doi.org/10.1029/2004JD004713,
2004.
Hara, K., Iwasaka, Y., Wada, M., Ihara, T., Shiba, H., Osada, K., and
Yamanouchi, T.: Aerosol constituents and their spatial distribution in the
free troposphere of coastal Antarctic regions, J. Geophys. Res., 111, D15216,
https://doi.org/10.1029/2005JD006591,
2006.
Hara, K., Osada, K., Nishita-Hara, C., Yabuki, M., Hayashi, M., Yamanouchi,
T., Wada, M., and Shiobara, M.: Seasonal features of ultrafine particle
volatility in the coastal Antarctic troposphere, Atmos. Chem. Phys., 11,
9803–9812, https://doi.org/10.5194/acp-11-9803-2011, 2011a.
Hara, K., Osada, K., Nishita-Hara, C., and Yamanouchi, T.: Seasonal
variations and vertical features of aerosol particles in the Antarctic
troposphere, Atmos. Chem. Phys., 11, 5471–5484,
https://doi.org/10.5194/acp-11-5471-2011, 2011b.
Helsen, M. M., van de Wal, R. S. W., van den Broeke, M. R.,
Masson-Delmotte, V., Meijer, H. A. J., Scheele, M. P., and Werner, M.:
Modeling the isotopic composition of Antarctic snow using backward
trajectories: simulation of snow pit records, J. Geophys. Res., 111, D15109,
https://doi.org/10.1029/2005JD006524,
2006.
Humphries, R.: Aerosol formation in the Antarctic Sea-Ice Region, Doctor of
Philosophy thesis, School of Chemistry, University of Wollongong, available
at: http://ro.uow.edu.au/theses/4536/ (last access: 31 January 2015),
2015.
Humphries, R., Wilson, S., Keywood, M., Ward, J., and Schofield, R.: In-situ
total aerosol number using condensation particle counters as observed during
the SIPEX II voyage of the Aurora Australis, 2012,
https://doi.org/10.4225/15/5342423241BE4,
2014.
Humphries, R. S., Schofield, R., Keywood, M. D., Ward, J., Pierce, J. R.,
Gionfriddo, C. M., Tate, M. T., Krabbenhoft, D. P., Galbally, I. E., Molloy,
S. B., Klekociuk, A. R., Johnston, P. V., Kreher, K., Thomas, A. J.,
Robinson, A. D., Harris, N. R. P., Johnson, R., and Wilson, S. R.: Boundary
layer new particle formation over East Antarctic sea ice – possible
Hg-driven nucleation?, Atmos. Chem. Phys., 15, 13339–13364,
https://doi.org/10.5194/acp-15-13339-2015, 2015.
Humphries, R., Klekociuk, A., Schofield, R., Alexander, S. P., Keywood, M.,
and Wilson, S.: Characterising atmospheric transport in Antarctica and the
Southern Ocean using HYSPLIT, in preparation, 2016.
IPCC: Climate Change 2013: The Physical Science Basis, Contribution
of Working Group I to the Fifth Assessment Report of the
Intergovernmental Panel on Climate Change, Cambridge University
Press, Cambridge, UK, New York, NY, USA,
https://doi.org/10.1017/CBO9781107415324,
2013.
Ito, T.: Antarctic submicron aerosols and long-range transport of pollutants, Ambio, 18, 34–41, 1989.
Ito, T.: Size distribution of Antarctic submicron aerosols, Tellus B, 45, 145–159, 1993.
Ito, T.: Nature and origin of Antarctic submicron aerosols, NATO Asi. Ser. Ser. I, 30, 23–38, 1995.
Ito, T., Morita, Y., and Iwasaka, Y.: Balloon observation of aerosols in the antarctic troposphere and stratosphere, Tellus B, 38, 214–222,
https://doi.org/10.3402/tellusb.v38i3-4.15130, 1986.
Iwasaka, Y., Okada, K., and Ono, A.: Individual aerosol particles in the
Antarctic uper troposphere, in: Memoirs of National Institute of Polar
Research, 39, 17–29, available at:
http://ci.nii.ac.jp/naid/110000010056/en/ (last access:
22 October 2015), 1985.
Järvinen, E., Virkkula, A., Nieminen, T., Aalto, P. P., Asmi, E.,
Lanconelli, C., Busetto, M., Lupi, A., Schioppo, R., Vitale, V., Mazzola, M.,
Petäjä, T., Kerminen, V.-M., and Kulmala, M.: Seasonal cycle and
modal structure of particle number size distribution at Dome C, Antarctica,
Atmos. Chem. Phys., 13, 7473–7487, https://doi.org/10.5194/acp-13-7473-2013, 2013.
Jimi, S. I., Gras, J., Siems, S. T., and Krummel, P. B.: A short climatology
of nanoparticles at the Cape Grim Baseline Air Pollution Station, Tasmania,
Environ. Chem., 4, 301–309,
2007.
Kanamitsu, M.: Description of the NMC Global Data Assimilation and Forecast System, Weather Forecast., 4, 335–342,
https://doi.org/10.1175/1520-0434(1989)004<0335:DOTNGD>2.0.CO;2, 1989.
Kistler, R., Kalnay, E., Collins, W., Saha, S., White, G., Woollen, J.,
Chelliah, M., Ebisuzaki, W., Kanamitsu, M., Kousky, V., van den Dool, H.,
Jenne, R., and Fiorino, M.: The NCEP–NCAR 50-year reanalysis: monthly means
CD-ROM and documentation, B. Am. Meteorol. Soc., 82, 247–267, 2001.
Koponen, I. K., Virkkula, A., Hillamo, R., and Kerminen, V.-M.: Number size
distributions and concentrations of marine aerosols: Observations during a
cruise between the English Channel and the coast of Antarctica, J. Geophys.
Res.-Atmos., 107, 4753,
https://doi.org/10.1029/2002JD002533,
2002
Koponen, I. K., Virkkula, A., Hillamo, R., Kerminen, V.-M., and Kulmala, M.:
Number size distributions and concentrations of the continental summer
aerosols in Queen Maud Land, Antarctica, J. Geophys. Res.-Atmos., 108, 4587,
https://doi.org/10.1029/2003jd003614,
2003.
Kottmeier, C. and Fay, B.: Trajectories in the Antarctic lower troposphere, J. Geophys. Res., 103, 10947,
https://doi.org/10.1029/97JD00768, 1998.
Kulmala, M., Petäjä, T., Nieminen, T., Sipilä, M.,
Manninen, H. E., Lehtipalo, K., Dal Maso, M., Aalto, P. P., Junninen, H.,
Paasonen, P., Riipinen, I., Lehtinen, K. E. J., Laaksonen, A., and
Kerminen, V.-M.: Measurement of the nucleation of atmospheric aerosol
particles, Nat. Protoc., 7, 1651–1667,
https://doi.org/10.1038/nprot.2012.091,
2012.
Kyrö, E.-M., Kerminen, V.-M., Virkkula, A., Dal Maso, M., Parshintsev,
J., Ruíz-Jimenez, J., Forsström, L., Manninen, H. E., Riekkola,
M.-L., Heinonen, P., and Kulmala, M.: Antarctic new particle formation from
continental biogenic precursors, Atmos. Chem. Phys., 13, 3527–3546,
https://doi.org/10.5194/acp-13-3527-2013, 2013.
Lana, A., Bell, T. G., Simó, R., Vallina, S. M., Ballabrera-Poy, J.,
Kettle, A. J., Dachs, J., Bopp, L., Saltzman, E. S., Stefels, J.,
Johnson, J. E., and Liss, P. S.: An updated climatology of surface
dimethlysulfide concentrations and emission fluxes in the global ocean,
Global Biogeochem. Cy., 25, GB1004,
https://doi.org/10.1029/2010gb003850,
2011.
Levasseur, M.: Ocean science: if Gaia could talk, Nat. Geosci., 4, 351–352,
https://doi.org/10.1038/ngeo1175, 2011.
Lim, E.-P. and Simmonds, I.: Southern Hemisphere winter extratropical
cyclone characteristics and vertical organization observed with the ERA-40
Data in 1979–2001, J. Climate, 20, 2675–2690,
https://doi.org/10.1175/JCLI4135.1, 2007.
Lucas, C., Timbal, B., and Nguyen, H.: The expanding tropics: a critical
assessment of the observational and modeling studies, Wiley
Interdisciplinary Reviews: Climate Change, 5, 89–112,
https://doi.org/10.1002/wcc.251, 2014.
Mason, S., Jakob, C., Protat, A., and Delanoë, J.: Characterizing
observed midtopped cloud regimes associated with Southern Ocean shortwave
radiation biases, J. Climate, 27, 6189–6203,
https://doi.org/10.1175/JCLI-D-14-00139.1,
2014.
Meskhidze, N. and Nenes, A.: Phytoplankton and cloudiness in the Southern
Ocean, Science, 314, 1419–1423,
https://doi.org/10.1126/science.1131779,
2006.
Moore, J. K. and Abbott, M. R.: Phytoplankton chlorophyll distributions and primary production in the Southern Ocean, J. Geophys. Res.-Oceans, 105, 28709–28722,
https://doi.org/10.1029/1999jc000043, 2000.
O'Dowd, C. D., Lowe, J. A., Smith, M. H., Davison, B., Hewitt, C. N., and
Harrison, R. M.: Biogenic sulphur emissions and inferred
non-sea-salt-sulphate cloud condensation nuclei in and around Antarctica, J.
Geophys. Res.-Atmos., 102, 12839–12854,
https://doi.org/10.1029/96jd02749, 1997.
O'Dowd, C. D., Geever, M., Hill, M. K., Smith, M. H., and Jennings, S. G.:
New particle formation: Nucleation rates and spatial scales in the clean
marine coastal environment, Geophys. Res. Lett., 25, 1661–1664,
https://doi.org/10.1029/98GL01005, 1998.
Osada, K., Hara, K., Wada, M., Yamanouchi, T., and Matsunaga, K.: Lower
tropospheric vertical distribution of aerosol particles over Syowa Station,
Antarctica from spring to summer 2004, Polar Meteorology and Glaciology, 20,
16–27, 2006.
Park, J., Sakurai, H., Vollmers, K., and McMurry, P. H.: Aerosol size
distributions measured at the South Pole during ISCAT, Atmos. Environ., 38,
5493–5500, 2004.
Pierce, J. R. and Adams, P. J.: Global evaluation of CCN formation by direct
emission of sea salt and growth of ultrafine sea salt, J. Geophys. Res.,
111, D06203,
https://doi.org/10.1029/2005JD006186,
2006.
Quinn, P. K., Coffman, D. J., Kapustin, V. N., Bates, T. S., and
Covert, D. S.: Aerosol optical properties in the marine boundary layer
during the First Aerosol Characterization Experiment (ACE 1) and the
underlying chemical and physical aerosol properties, J. Geophys. Res., 103,
16547, https://doi.org/10.1029/97JD02345,
1998.
Reeve, J.: Aurora Australis Voyage VMS 2012/13 Track and Underway Data
(SIPEX II), Australian Antarctic Data Centre,
https://doi.org/10.4225/15/546580A408D97,
2013.
Roscoe, H. K., Jones, A. E., Brough, N., Weller, R., Saiz-Lopez, A.,
Mahajan, A. S., Schoenhardt, A., Burrows, J. P., and Fleming, Z. L.:
Particles and iodine compounds in coastal Antarctica, J. Geophys.
Res.-Atmos., 120, 7144–7156,
https://doi.org/10.1002/2015JD023301,
2015.
Saiz-Lopez, A., Chance, K., Liu, X., Kurosu, T. P., and Sander, S. P.: First
observations of iodine oxide from space, Geophys. Res. Lett., 34, L12812,
https://doi.org/10.1029/2007gl030111,
2007a.
Saiz-Lopez, A., Mahajan, A. S., Salmon, R. A., Bauguitte, S. J. B.,
Jones, A. E., Roscoe, H. K., and Plane, J. M. C.: Boundary layer halogens in
coastal Antarctica, Science, 317, 348–351,
https://doi.org/10.1126/science.1141408,
2007b.
Schofield, R. and Klekociuk, A.: Hysplit atmospheric
back-trajectories at 10 m, 500 m, 1000 m,
1500 m, 2000 m, 2500 m, 3000 m,
3500 m, 4000 m collected during the SIPEX II voyage
of the Aurora Australis, 2012,
https://doi.org/10.4225/15/532F83302FF88, 2014.
Schofield, R., Klekociuk, A., Galbally, I., Molloy, S., and Humphries, R.:
In-situ atmospheric ozone measurements observed during
the SIPEX II voyage of the Aurora Australis, 2012,
https://doi.org/10.4225/15/53266BE438281, 2014.
Schönhardt, A., Richter, A., Wittrock, F., Kirk, H., Oetjen, H., Roscoe,
H. K., and Burrows, J. P.: Observations of iodine monoxide columns from
satellite, Atmos. Chem. Phys., 8, 637–653, https://doi.org/10.5194/acp-8-637-2008, 2008.
Schönhardt, A., Begoin, M., Richter, A., Wittrock, F., Kaleschke, L.,
Gómez Martín, J. C., and Burrows, J. P.: Simultaneous satellite
observations of IO and BrO over Antarctica, Atmos. Chem. Phys., 12,
6565–6580, https://doi.org/10.5194/acp-12-6565-2012, 2012.
Seidel, D. J., Fu, Q., Randel, W. J., and Reichler, T. J.: Widening of the
tropical belt in a changing climate, Nat. Geosci., 1, 21–24,
https://doi.org/10.1038/ngeo.2007.38,
2008.
Shindell, D. T., Lamarque, J.-F., Schulz, M., Flanner, M., Jiao, C., Chin,
M., Young, P. J., Lee, Y. H., Rotstayn, L., Mahowald, N., Milly, G.,
Faluvegi, G., Balkanski, Y., Collins, W. J., Conley, A. J., Dalsoren, S.,
Easter, R., Ghan, S., Horowitz, L., Liu, X., Myhre, G., Nagashima, T., Naik,
V., Rumbold, S. T., Skeie, R., Sudo, K., Szopa, S., Takemura, T.,
Voulgarakis, A., Yoon, J.-H., and Lo, F.: Radiative forcing in the ACCMIP
historical and future climate simulations, Atmos. Chem. Phys., 13,
2939–2974, https://doi.org/10.5194/acp-13-2939-2013, 2013.
Simmonds, I. and Keay, K.: Mean Southern Hemisphere extratropical cyclone
behavior in the 40-year NCEP–NCAR reanalysis, J. Climate, 13, 873–885,
https://doi.org/10.1175/1520-0442(2000)013<0873:MSHECB>2.0.CO;2,
2000a.
Simmonds, I. and Keay, K.: Variability of Southern Hemisphere extratropical
cyclone behavior, 1958–97, J. Climate, 13, 550–561,
https://doi.org/10.1175/1520-0442(2000)013<0550:VOSHEC>2.0.CO;2,
2000b.
Six, K. D., Kloster, S., Ilyina, T., Archer, S. D., Zhang, K., and Maier-Reimer, E.:
Global warming amplified by reduced sulphur fluxes as a result of ocean acidification,
Nature Clim. Change,, 3, 975–978,
https://doi.org/10.1038/nclimate1981, 2013.
Stohl, A. and Sodemann, H.: Characteristics of atmospheric transport into
the Antarctic troposphere, J. Geophys. Res., 115, D02305,
https://doi.org/10.1029/2009jd012536,
2010.
Thompson, D. W. J., Solomon, S., Kushner, P. J., England, M. H., Grise, K. M.,
and Karoly, D. J.: Signatures of the Antarctic ozone hole in Southern Hemisphere surface climate change, Nat. Geosci., 4, 741–749,
https://doi.org/10.1038/ngeo1296, 2011.
Trenberth, K. E. and Fasullo, J. T.: Simulation of present-day and twenty-first-century
energy budgets of the southern oceans, J. Climate, 23, 440–454,
https://doi.org/10.1175/2009JCLI3152.1, 2010.
Virkkula, A., Teinilä, K., Hillamo, R., Kerminen, V.-M., Saarikoski, S., Aurela, M.,
Koponen, I. K., and Kulmala, M.: Chemical size distributions of boundary layer
aerosol over the Atlantic Ocean and at an Antarctic site, J. Geophys. Res., 111, D05306,
https://doi.org/10.1029/2004JD004958, 2006.
Virkkula, A., Asmi, E., Teinilä, K., Frey, A., Aurela, M., Timonen, H.,
Mäkelä, T., Samuli, A., Hillamo, R., Aalto, P. P., Kirkwood, S., and
Kulmala, M.: Review of aerosol research at the Finnish Antarctic Research
Station Aboa and its surroundings in Queen Maud Land, Antarctica,
Geophysica, 45, 163–181, 2009.
von der Weiden, S.-L., Drewnick, F., and Borrmann, S.: Particle Loss
Calculator – a new software tool for the assessment of the performance of
aerosol inlet systems, Atmos. Meas. Tech., 2, 479–494,
https://doi.org/10.5194/amt-2-479-2009, 2009.
Warren, D. R. and Seinfeld, J. H.: Prediction of aerosol concentrations resulting from a burst of nucleation, J. Colloid Interf. Sci., 105, 136–142,
https://doi.org/10.1016/0021-9797(85)90356-X, 1985.
Weber, R. J., McMurry, P. H., Bates, T. S., Clarke, A. D., Covert, D. S.,
Brechtel, F. J., and Kok, G. L.: Intercomparison of airborne and
surface-based measurements of condensation nuclei in the remote marine
troposphere during ACE 1, J. Geophys. Res.-Atmos., 104, 21673–21683,
https://doi.org/10.1029/1998jd100103,
1999.
Weller, R., Minikin, A., Wagenbach, D., and Dreiling, V.: Characterization of
the inter-annual, seasonal, and diurnal variations of condensation particle
concentrations at Neumayer, Antarctica, Atmos. Chem. Phys., 11, 13243–13257,
https://doi.org/10.5194/acp-11-13243-2011, 2011.
Wiedensohlet, A., Orsini, D., Covert, D. S., Coffmann, D., Cantrell, W.,
Havlicek, M., Brechtel, F. J., Russell, L. M., Weber, R. J., Gras, J.,
Hudson, J. G., and Litchy, M.: Intercomparison study of the size-dependent
counting efficiency of 26 condensation particle counters, Aerosol Sci.
Tech., 27, 224–242,
https://doi.org/10.1080/02786829708965469,
1997.
WMO (World Meteorological Organization): Scientific Assessment of Ozone
Depletion: 2014, Tech. rep., Geneva, Switzerland, 2014.
Short summary
This work represents the first observational study of atmospheric sub-micron aerosols in the East Antarctic pack ice region and found springtime aerosol concentrations were higher than any observed elsewhere in the Antarctic and Southern Ocean region. Further analysis suggested these aerosols formed in the Antarctic free troposphere. Their subsequent transport to the Southern Ocean, as suggest by trajectory analyses, could help to reduce the discrepancy in the radiative budget in the region.
This work represents the first observational study of atmospheric sub-micron aerosols in the...
Altmetrics
Final-revised paper
Preprint