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Atmospheric Chemistry and Physics
An interactive open-access journal of the European Geosciences Union
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- About
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IF 5.414
5.958CiteScore
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index 191h5-index 89
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Abstracted/indexed
ACP | Articles | Volume 20, issue 4
Atmos. Chem. Phys., 20, 2341–2351, 2020
https://doi.org/10.5194/acp-20-2341-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-20-2341-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
Special issue: New observations and related modelling studies of the aerosol–cloud–climate...
Atmos. Chem. Phys., 20, 2341–2351, 2020
https://doi.org/10.5194/acp-20-2341-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-20-2341-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article 27 Feb 2020
Research article | 27 Feb 2020
Ultra-clean and smoky marine boundary layers frequently occur in the same season over the southeast Atlantic
Sam Pennypacker et al.
Related authors
Sam Pennypacker and Allison L. Steiner
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2016-289, https://doi.org/10.5194/acp-2016-289, 2016
Revised manuscript has not been submitted
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We examine aerosol-cloud interactions detected in springtime cloud statistics over the Southern Great Plains of the United States in the context of cloud phase, measurement uncertainty and regional meteorology. Satellite retrievals of cloud properties are collocated with surface aerosol measurements over five years. The goal is to frame and motivate further work in what could cause deviations from the traditional theory of aerosol-cloud interactions over a given region.
Francesca Gallo, Janek Uin, Stephen Springston, Jian Wang, Guangjie Zheng, Chongai Kuang, Robert Wood, Eduardo B. Azevedo, Allison McComiskey, Fan Mei, Adam Theisen, Jenni Kyrouac, and Allison C. Aiken
Atmos. Chem. Phys., 20, 7553–7573, https://doi.org/10.5194/acp-20-7553-2020, https://doi.org/10.5194/acp-20-7553-2020, 2020
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Continuous high-time-resolution ambient data can include periods when aerosol properties do not represent regional aerosol processes due to high-concentration local events. We develop a novel aerosol mask at the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) facility in the eastern North Atlantic (ENA). We use two ground sites to validate the mask, include a comparison with aircraft overflights, and provide guidance to increase data quality at ENA and other locations.
Jens Redemann, Robert Wood, Paquita Zuidema, Sarah J. Doherty, Bernadette Luna, Samuel E. LeBlanc, Michael S. Diamond, Yohei Shinozuka, Ian Y. Chang, Rei Ueyama, Leonhard Pfister, Ju-me Ryoo, Amie N. Dobracki, Arlindo M. da Silva, Karla M. Longo, Meloë S. Kacenelenbogen, Connor J. Flynn, Kristina Pistone, Nichola M. Knox, Stuart J. Piketh, James M. Haywood, Paola Formenti, Marc Mallet, Philip Stier, Andrew S. Ackerman, Susanne E. Bauer, Ann M. Fridlind, Gregory R. Carmichael, Pablo E. Saide, Gonzalo A. Ferrada, Steven G. Howell, Steffen Freitag, Brian Cairns, Brent N. Holben, Kirk D. Knobelspiesse, Simone Tanelli, Tristan S. L'Ecuyer, Andrew M. Dzambo, Ousmane O. Sy, Greg M. McFarquhar, Michael R. Poellot, Siddhant Gupta, Joseph R. O'Brien, Athanasios Nenes, Mary E. Kacarab, Jenny P. S. Wong, Jennifer D. Small-Griswold, Kenneth L. Thornhill, David Noone, James R. Podolske, K. Sebastian Schmidt, Peter Pilewskie, Hong Chen, Sabrina P. Cochrane, Arthur J. Sedlacek, Timothy J. Lang, Eric Stith, Michal Segal-Rozenhaimer, Richard A. Ferrare, Sharon P. Burton, Chris A. Hostetler, David J. Diner, Steven E. Platnick, Jeffrey S. Myers, Kerry G. Meyer, Douglas A. Spangenberg, Hal Maring, and Lan Gao
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-449, https://doi.org/10.5194/acp-2020-449, 2020
Preprint under review for ACP
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Southern Africa produces significant biomass burning emissions whose impacts on regional and global climate are poorly understood. ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) is a five-year NASA investigation designed to study the key processes that determine these climate impacts. The main purpose of this paper is to familiarize the broader scientific community with the ORACLES project, the data set it produced, and the most important initial findings.
Tianle Yuan, Hua Song, Robert Wood, Johannes Mohrmann, Kerry Meyer, Lazaros Oreopoulos, and Steven Platnick
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-61, https://doi.org/10.5194/amt-2020-61, 2020
Revised manuscript under review for AMT
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We use deep transfer learning techniques to classify satellite cloud images into different morphology types. It achieves the state-of-the-art results and can automatically process large amount of satellite data. The algorithm will help low cloud researchers to better understand their mesoscale organiizations.
Mary Kacarab, K. Lee Thornhill, Amie Dobracki, Steven G. Howell, Joseph R. O'Brien, Steffen Freitag, Michael R. Poellot, Robert Wood, Paquita Zuidema, Jens Redemann, and Athanasios Nenes
Atmos. Chem. Phys., 20, 3029–3040, https://doi.org/10.5194/acp-20-3029-2020, https://doi.org/10.5194/acp-20-3029-2020, 2020
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We find that extensive biomass burning aerosol plumes from southern Africa can profoundly influence clouds in the southeastern Atlantic. Concurrent variations in vertical velocity, however, are found to magnify the relationship between boundary layer aerosol and the cloud droplet number. Neglecting these covariances may strongly bias the sign and magnitude of aerosol impacts on the cloud droplet number.
Samuel E. LeBlanc, Jens Redemann, Connor Flynn, Kristina Pistone, Meloë Kacenelenbogen, Michal Segal-Rosenheimer, Yohei Shinozuka, Stephen Dunagan, Robert P. Dahlgren, Kerry Meyer, James Podolske, Steven G. Howell, Steffen Freitag, Jennifer Small-Griswold, Brent Holben, Michael Diamond, Robert Wood, Paola Formenti, Stuart Piketh, Gillian Maggs-Kölling, Monja Gerber, and Andreas Namwoonde
Atmos. Chem. Phys., 20, 1565–1590, https://doi.org/10.5194/acp-20-1565-2020, https://doi.org/10.5194/acp-20-1565-2020, 2020
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The southeast Atlantic during August–October experiences layers of smoke from biomass burning over marine stratocumulus clouds. Here we present the light attenuation of the smoke and its dependence in the spatial, vertical, and spectral domain through direct measurements from an airborne platform during September 2016. From our observations of this climatically important smoke, we found an average aerosol optical depth of 0.32 at 500 nm, slightly lower than comparative satellite measurements.
Yohei Shinozuka, Pablo E. Saide, Gonzalo A. Ferrada, Sharon P. Burton, Richard Ferrare, Sarah J. Doherty, Hamish Gordon, Karla Longo, Marc Mallet, Yan Feng, Qiaoqiao Wang, Yafang Cheng, Amie Dobracki, Steffen Freitag, Steven G. Howell, Samuel LeBlanc, Connor Flynn, Michal Segal-Rosenhaimer, Kristina Pistone, James R. Podolske, Eric J. Stith, Joseph Ryan Bennett, Gregory R. Carmichael, Arlindo da Silva, Ravi Govindaraju, Ruby Leung, Yang Zhang, Leonhard Pfister, Ju-Mee Ryoo, Jens Redemann, Robert Wood, and Paquita Zuidema
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2019-678, https://doi.org/10.5194/acp-2019-678, 2019
Revised manuscript accepted for ACP
Marc Mallet, Pierre Nabat, Paquita Zuidema, Jens Redemann, Andrew Mark Sayer, Martin Stengel, Sebastian Schmidt, Sabrina Cochrane, Sharon Burton, Richard Ferrare, Kerry Meyer, Pablo Saide, Hiren Jethva, Omar Torres, Robert Wood, David Saint Martin, Romain Roehrig, Christina Hsu, and Paola Formenti
Atmos. Chem. Phys., 19, 4963–4990, https://doi.org/10.5194/acp-19-4963-2019, https://doi.org/10.5194/acp-19-4963-2019, 2019
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The model is able to represent LWP but not the LCF. AOD is consistent over the continent but also over ocean (ACAOD). Differences are observed in SSA due to the absence of internal mixing in ALADIN-Climate. A significant regional gradient of the forcing at TOA is observed. An intense positive forcing is simulated over Gabon. Results highlight the significant effect of enhanced moisture on BBA extinction. The surface dimming modifies the energy budget.
Guangjie Zheng, Yang Wang, Allison C. Aiken, Francesca Gallo, Michael P. Jensen, Pavlos Kollias, Chongai Kuang, Edward Luke, Stephen Springston, Janek Uin, Robert Wood, and Jian Wang
Atmos. Chem. Phys., 18, 17615–17635, https://doi.org/10.5194/acp-18-17615-2018, https://doi.org/10.5194/acp-18-17615-2018, 2018
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Here, we elucidate the key processes that drive marine boundary layer (MBL) aerosol size distribution in the eastern North Atlantic (ENA) using long-term measurements. The governing equations of particle concentration are established for different modes. Particles entrained from the free troposphere represent the major source of MBL cloud condensation nuclei (CCN), contributing both directly to CCN population and indirectly by supplying Aitken-mode particles that grow to CCN in the MBL.
Anna Possner, Hailong Wang, Robert Wood, Ken Caldeira, and Thomas P. Ackerman
Atmos. Chem. Phys., 18, 17475–17488, https://doi.org/10.5194/acp-18-17475-2018, https://doi.org/10.5194/acp-18-17475-2018, 2018
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We quantify aerosol–cloud radiative interactions in a regime of deep open-cell stratocumuli (boundary layer depth 1.5 km), a regime which remains largely unexplored within this context and yet is more dominant than cases of shallow stratocumuli previously studied. We simulate substantial increases in albedo in a regime where ship tracks are not found and argue that such changes may escape detection and attribution through remote sensing due to the large natural variability in the system.
Michael S. Diamond, Amie Dobracki, Steffen Freitag, Jennifer D. Small Griswold, Ashley Heikkila, Steven G. Howell, Mary E. Kacarab, James R. Podolske, Pablo E. Saide, and Robert Wood
Atmos. Chem. Phys., 18, 14623–14636, https://doi.org/10.5194/acp-18-14623-2018, https://doi.org/10.5194/acp-18-14623-2018, 2018
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Smoke from Africa can mix into clouds over the southeast Atlantic and create new droplets, which brightens the clouds, reflects more sunlight, and thus cools the region. Using aircraft data from a NASA field campaign, we find that cloud properties are correlated with smoke as expected when the smoke is below the clouds but not when smoke is above the clouds because it takes several days for clouds to mix smoke downward. We recommend methods that can track clouds as they move for future studies.
Daniel P. Grosvenor, Odran Sourdeval, and Robert Wood
Atmos. Meas. Tech., 11, 4273–4289, https://doi.org/10.5194/amt-11-4273-2018, https://doi.org/10.5194/amt-11-4273-2018, 2018
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We provide a parameterized correction to the retrieval of cloud effective radius from satellite instruments to account for the assumption that the retrieved value is representative of that at cloud top, whereas in reality it is representative of that lower down. The error leads to errors (which we quantify) in the retrieved cloud droplet concentrations of up to 38 % for stratocumulus regions and also to liquid water path errors, both of which can be corrected using our parameterizations.
Daniel T. McCoy, Frida A.-M. Bender, Daniel P. Grosvenor, Johannes K. Mohrmann, Dennis L. Hartmann, Robert Wood, and Paul R. Field
Atmos. Chem. Phys., 18, 2035–2047, https://doi.org/10.5194/acp-18-2035-2018, https://doi.org/10.5194/acp-18-2035-2018, 2018
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The interaction between clouds and aerosols represents the largest source of uncertainty in the anthropogenic radiative forcing. Cloud droplet number concentration (CDNC) is the state variable that moderates the interaction between aerosol and clouds. Here we show that CDNC decreases off the coasts of East Asia and North America due to controls on emissions. We support this analysis through an examination of volcanism in Hawaii and Vanuatu.
Xiaoli Zhou, Andrew S. Ackerman, Ann M. Fridlind, Robert Wood, and Pavlos Kollias
Atmos. Chem. Phys., 17, 12725–12742, https://doi.org/10.5194/acp-17-12725-2017, https://doi.org/10.5194/acp-17-12725-2017, 2017
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Shallow maritime clouds make a well-known transition from stratocumulus to trade cumulus with flow from the subtropics equatorward. Three-day large-eddy simulations that investigate the potential influence of overlying African biomass burning plumes during that transition indicate that cloud-related impacts are likely substantially cooling to negligible at the top of the atmosphere, with magnitude sensitive to background and perturbation aerosol and cloud properties.
Kuan-Ting O and Robert Wood
Atmos. Chem. Phys., 16, 7239–7249, https://doi.org/10.5194/acp-16-7239-2016, https://doi.org/10.5194/acp-16-7239-2016, 2016
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In this work, based on the well-known formulae of classical nucleation theory (CNT), the temperature at which the mean number of critical embryos inside a droplet is unity is derived from the Boltzmann distribution function and explored as a new simplified approximation for homogeneous freezing temperature. It thus appears that the simplicity of this approximation makes it potentially useful for predicting homogeneous freezing temperatures of water droplets in the atmosphere.
Sam Pennypacker and Allison L. Steiner
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2016-289, https://doi.org/10.5194/acp-2016-289, 2016
Revised manuscript has not been submitted
Short summary
Short summary
We examine aerosol-cloud interactions detected in springtime cloud statistics over the Southern Great Plains of the United States in the context of cloud phase, measurement uncertainty and regional meteorology. Satellite retrievals of cloud properties are collocated with surface aerosol measurements over five years. The goal is to frame and motivate further work in what could cause deviations from the traditional theory of aerosol-cloud interactions over a given region.
C. R. Terai, C. S. Bretherton, R. Wood, and G. Painter
Atmos. Chem. Phys., 14, 8071–8088, https://doi.org/10.5194/acp-14-8071-2014, https://doi.org/10.5194/acp-14-8071-2014, 2014
D. P. Grosvenor and R. Wood
Atmos. Chem. Phys., 14, 7291–7321, https://doi.org/10.5194/acp-14-7291-2014, https://doi.org/10.5194/acp-14-7291-2014, 2014
A. Muhlbauer, I. L. McCoy, and R. Wood
Atmos. Chem. Phys., 14, 6695–6716, https://doi.org/10.5194/acp-14-6695-2014, https://doi.org/10.5194/acp-14-6695-2014, 2014
A. H. Berner, C. S. Bretherton, R. Wood, and A. Muhlbauer
Atmos. Chem. Phys., 13, 12549–12572, https://doi.org/10.5194/acp-13-12549-2013, https://doi.org/10.5194/acp-13-12549-2013, 2013
C. R. Terai and R. Wood
Atmos. Chem. Phys., 13, 9899–9914, https://doi.org/10.5194/acp-13-9899-2013, https://doi.org/10.5194/acp-13-9899-2013, 2013
A. Gettelman, H. Morrison, C. R. Terai, and R. Wood
Atmos. Chem. Phys., 13, 9855–9867, https://doi.org/10.5194/acp-13-9855-2013, https://doi.org/10.5194/acp-13-9855-2013, 2013
R. C. George, R. Wood, C. S. Bretherton, and G. Painter
Atmos. Chem. Phys., 13, 6305–6328, https://doi.org/10.5194/acp-13-6305-2013, https://doi.org/10.5194/acp-13-6305-2013, 2013
C. H. Twohy, J. R. Anderson, D. W. Toohey, M. Andrejczuk, A. Adams, M. Lytle, R. C. George, R. Wood, P. Saide, S. Spak, P. Zuidema, and D. Leon
Atmos. Chem. Phys., 13, 2541–2562, https://doi.org/10.5194/acp-13-2541-2013, https://doi.org/10.5194/acp-13-2541-2013, 2013
Related subject area
Subject: Aerosols | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
Effects of continental emissions on cloud condensation nuclei (CCN) activity in the northern South China Sea during summertime 2018
Multidecadal trend analysis of in situ aerosol radiative properties around the world
Particle number concentrations and size distribution in a polluted megacity: the Delhi Aerosol Supersite study
Airborne in situ measurements of aerosol size distributions and black carbon across the Indo-Gangetic Plain during SWAAMI–RAWEX
Predictions of the glass transition temperature and viscosity of organic aerosols from volatility distributions
Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols
The vertical variability of black carbon observed in the atmospheric boundary layer during DACCIWA
Effects of atmospheric circulations on the interannual variation in PM2.5 concentrations over the Beijing–Tianjin–Hebei region in 2013–2018
On the relationship between cloud water composition and cloud droplet number concentration
Identifying a regional aerosol baseline in the eastern North Atlantic using collocated measurements and a mathematical algorithm to mask high-submicron-number-concentration aerosol events
Cloud condensation nuclei characteristics during the Indian summer monsoon over a rain-shadow region
Heavy air pollution with a unique “non-stagnant” atmospheric boundary layer in the Yangtze River middle basin aggravated by regional transport of PM2.5 over China
Decreasing trends of particle number and black carbon mass concentrations at 16 observational sites in Germany from 2009 to 2018
Condensation/immersion mode ice-nucleating particles in a boreal environment
Rapid reduction in black carbon emissions from China: evidence from 2009–2019 observations on Fukue Island, Japan
Variability in lidar-derived particle properties over West Africa due to changes in absorption: towards an understanding
Hygroscopic properties and cloud condensation nuclei activity of atmospheric aerosols under the influences of Asian continental outflow and new particle formation at a coastal site in eastern Asia
Mixing characteristics of refractory black carbon aerosols at an urban site in Beijing
Shipborne observations reveal contrasting Arctic marine, Arctic terrestrial and Pacific marine aerosol properties
New particle formation and sub-10 nm size distribution measurements during the A-LIFE field experiment in Paphos, Cyprus
Influx of African biomass burning aerosol during the Amazonian dry season through layered transatlantic transport of black carbon-rich smoke
Large-scale ion generation for precipitation of atmospheric aerosols
Overview of aerosol optical properties over southern West Africa from DACCIWA aircraft measurements
Haze pollution under a high atmospheric oxidization capacity in summer in Beijing: insights into formation mechanism of atmospheric physicochemical processes
On the annual variability of Antarctic aerosol size distributions at Halley Research Station
Absorption closure in highly aged biomass burning smoke
Seasonal contrast in size distributions and mixing state of black carbon and its association with PM1.0 chemical composition from the eastern coast of India
Vertical profiles of submicron aerosol single scattering albedo over the Indian region immediately before monsoon onset and during its development: research from the SWAAMI field campaign
Vertical characteristics of aerosol hygroscopicity and impacts on optical properties over the North China Plain during winter
The significant impact of aerosol vertical structure on lower atmosphere stability and its critical role in aerosol–planetary boundary layer (PBL) interactions
Characterising mass-resolved mixing state of black carbon in Beijing using a morphology-independent measurement method
Contrasting impacts of two types of El Niño events on winter haze days in China's Jing-Jin-Ji region
Cloud condensation nuclei properties of South Asian outflow over the northern Indian Ocean during winter
Apparent dust size discrepancy in aerosol reanalysis in north African dust after long-range transport
In situ vertical characteristics of optical properties and heating rates of aerosol over Beijing
Amplification of black carbon light absorption induced by atmospheric aging: temporal variation at seasonal and diel scales in urban Guangzhou
Aerosol immission maps and trends over Germany with hourly data at four rural background stations from 2009 to 2018
A transition of atmospheric emissions of particles and gases from on-road heavy-duty trucks
Above-cloud aerosol optical depth from airborne observations in the southeast Atlantic
Characterization of aerosol particles at Cabo Verde close to sea level and at the cloud level – Part 1: Particle number size distribution, cloud condensation nuclei and their origins
Variation of size-segregated particle number concentrations in wintertime Beijing
Significant contribution of organics to aerosol liquid water content in winter in Beijing, China
Distinct diurnal variation in organic aerosol hygroscopicity and its relationship with oxygenated organic aerosol
Evidence for impacts on surface-level air quality in the northeastern US from long-distance transport of smoke from North American fires during the Long Island Sound Tropospheric Ozone Study (LISTOS) 2018
Altitude profiles of cloud condensation nuclei characteristics across the Indo-Gangetic Plain prior to the onset of the Indian summer monsoon
Daytime aerosol optical depth above low-level clouds is similar to that in adjacent clear skies at the same heights: airborne observation above the southeast Atlantic
Rapid formation of intense haze episodes via aerosol–boundary layer feedback in Beijing
Traffic-originated nanocluster emission exceeds H2SO4-driven photochemical new particle formation in an urban area
Multi-method determination of the below-cloud wet scavenging coefficients of aerosols in Beijing, China
Estimating cloud condensation nuclei number concentrations using aerosol optical properties: role of particle number size distribution and parameterization
Mingfu Cai, Baoling Liang, Qibin Sun, Shengzhen Zhou, Xiaoyang Chen, Bin Yuan, Min Shao, Haobo Tan, and Jun Zhao
Atmos. Chem. Phys., 20, 9153–9167, https://doi.org/10.5194/acp-20-9153-2020, https://doi.org/10.5194/acp-20-9153-2020, 2020
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Cloud condensation nuclei activity in marine atmosphere affects cloud formation and the solar radiation balance over ocean. We employed advanced instruments to measure aerosol hygroscopicity and chemical composition in the northern South China Sea. Our results show that marine aerosols can be affected by local emissions or pollutants from long-range transport. Our study highlights dynamical variations in particle properties and the impact of long-range transport on this region during summertime.
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
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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.
Shahzad Gani, Sahil Bhandari, Kanan Patel, Sarah Seraj, Prashant Soni, Zainab Arub, Gazala Habib, Lea Hildebrandt Ruiz, and Joshua S. Apte
Atmos. Chem. Phys., 20, 8533–8549, https://doi.org/10.5194/acp-20-8533-2020, https://doi.org/10.5194/acp-20-8533-2020, 2020
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Delhi, India, has had the highest fine particle mass (PM2.5; diameter < 2.5 µm) concentrations of any megacity on the planet in recent years. Here, we undertook a year of detailed measurements of particle size distributions. We observed that the number count of ultrafine particles (diameter < 100 nm) – unlike PM2.5 – is not dramatically elevated in Delhi. Using observations and a simple model, we illustrate how the high amount of PM2.5 in Delhi may suppress ultrafine particle concentrations.
Mukunda Madhab Gogoi, Venugopalan Nair Jayachandran, Aditya Vaishya, Surendran Nair Suresh Babu, Sreedharan Krishnakumari Satheesh, and Krishnaswamy Krishna Moorthy
Atmos. Chem. Phys., 20, 8593–8610, https://doi.org/10.5194/acp-20-8593-2020, https://doi.org/10.5194/acp-20-8593-2020, 2020
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Extensive airborne measurements of aerosol number–size distribution and black carbon (BC) profiles are carried out for the first time across the IGP prior to the onset of the Indian summer monsoon. These measurements, combined with spaceborne sensors and model results, provided an east–west transect of the role of mineral dust (local and transported) in the aerosol loading across the IGP, with an increase in coarse mode concentration and coarse mode mass fraction with altitude.
Ying Li, Douglas A. Day, Harald Stark, Jose L. Jimenez, and Manabu Shiraiwa
Atmos. Chem. Phys., 20, 8103–8122, https://doi.org/10.5194/acp-20-8103-2020, https://doi.org/10.5194/acp-20-8103-2020, 2020
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Viscosity is an important property of organic aerosols, but viscosity measurements of ambient organic aerosols are scarce. We developed a method to predict glass transition temperatures using volatility and the atomic oxygen-to-carbon ratio. The method was applied to field observations of volatility distributions to predict viscosity of ambient organic aerosols, yielding consistent results with ambient particle phase-state measurements and global simulations.
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
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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.
Barbara Altstädter, Konrad Deetz, Bernhard Vogel, Karmen Babić, Cheikh Dione, Federica Pacifico, Corinne Jambert, Friederike Ebus, Konrad Bärfuss, Falk Pätzold, Astrid Lampert, Bianca Adler, Norbert Kalthoff, and Fabienne Lohou
Atmos. Chem. Phys., 20, 7911–7928, https://doi.org/10.5194/acp-20-7911-2020, https://doi.org/10.5194/acp-20-7911-2020, 2020
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We present the high vertical variability of the black carbon (BC) mass concentration measured with the unmanned aerial system ALADINA during the field experiment of DACCIWA. The COSMO-ART model output was applied for the campaign period and is compared with the observational BC data during a case study on 14–15 July 2016. Enhanced BC concentrations were related to transport processes to the measurement site by maritime inflow and not to local emissions as initially expected.
Xiaoyan Wang and Renhe Zhang
Atmos. Chem. Phys., 20, 7667–7682, https://doi.org/10.5194/acp-20-7667-2020, https://doi.org/10.5194/acp-20-7667-2020, 2020
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This study investigated the effects of meteorological elements on the interannual variation in air quality. It shows consistent variations of PM2.5 concentrations and the occurrence of unfavorable circulation types. The favorable meteorological conditions in 2017 contribute to 59.9 % of the interannual decrease in PM2.5 concentrations, which highlights the importance of atmospheric conditions when evaluating the interannual variations in local air quality.
Alexander B. MacDonald, Ali Hossein Mardi, Hossein Dadashazar, Mojtaba Azadi Aghdam, Ewan Crosbie, Haflidi H. Jonsson, Richard C. Flagan, John H. Seinfeld, and Armin Sorooshian
Atmos. Chem. Phys., 20, 7645–7665, https://doi.org/10.5194/acp-20-7645-2020, https://doi.org/10.5194/acp-20-7645-2020, 2020
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Understanding how humans affect Earth's climate requires understanding of how particles in the air affect the number concentration of droplets in a cloud (Nd). We use the air-equivalent mass concentration of different chemical species contained in cloud water to predict Nd. In this study we found that the prediction of Nd is (1) best described by total sulfate; (2) improved when considering up to five species; and (3) dependent on factors like turbulence, smoke presence, and in-cloud height.
Francesca Gallo, Janek Uin, Stephen Springston, Jian Wang, Guangjie Zheng, Chongai Kuang, Robert Wood, Eduardo B. Azevedo, Allison McComiskey, Fan Mei, Adam Theisen, Jenni Kyrouac, and Allison C. Aiken
Atmos. Chem. Phys., 20, 7553–7573, https://doi.org/10.5194/acp-20-7553-2020, https://doi.org/10.5194/acp-20-7553-2020, 2020
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Continuous high-time-resolution ambient data can include periods when aerosol properties do not represent regional aerosol processes due to high-concentration local events. We develop a novel aerosol mask at the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) facility in the eastern North Atlantic (ENA). We use two ground sites to validate the mask, include a comparison with aircraft overflights, and provide guidance to increase data quality at ENA and other locations.
Venugopalan Nair Jayachandran, Mercy Varghese, Palani Murugavel, Kiran S. Todekar, Shivdas P. Bankar, Neelam Malap, Gurnule Dinesh, Pramod D. Safai, Jaya Rao, Mahen Konwar, Shivsai Dixit, and Thara V. Prabha
Atmos. Chem. Phys., 20, 7307–7334, https://doi.org/10.5194/acp-20-7307-2020, https://doi.org/10.5194/acp-20-7307-2020, 2020
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Continuous aerosol and cloud condensation nuclei (CCN) measurements carried out at the ground observational facility of a CAIPEEX campaign, situated in the rain-shadow region of the Indian subcontinent, are illustrated. The variations in CCN characteristics within the monsoon period are investigated along with the aerosol physical and optical properties. The change in the dependency of CCN activity on aerosol size and composition due to the variations in air mass and meteorology is brought out.
Chao Yu, Tianliang Zhao, Yongqing Bai, Lei Zhang, Shaofei Kong, Xingna Yu, Jinhai He, Chunguang Cui, Jie Yang, Yinchang You, Guoxu Ma, Ming Wu, and Jiacheng Chang
Atmos. Chem. Phys., 20, 7217–7230, https://doi.org/10.5194/acp-20-7217-2020, https://doi.org/10.5194/acp-20-7217-2020, 2020
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This study investigated the ambient PM2.5 variations over Wuhan, a typical urban Yangtze River middle basin (YRMB) region in central eastern China in January 2016. Through an analysis of observational data of the environment and meteorology, as well as via a FLEXPART-WRF simulation, it heavy air pollution is revealed with the unique “non-stagnant” atmospheric boundary layer in the YRMB region aggravated by regional transport of PM2.5 over central and eastern China.
Jia Sun, Wolfram Birmili, Markus Hermann, Thomas Tuch, Kay Weinhold, Maik Merkel, Fabian Rasch, Thomas Müller, Alexander Schladitz, Susanne Bastian, Gunter Löschau, Josef Cyrys, Jianwei Gu, Harald Flentje, Björn Briel, Christoph Asbach, Heinz Kaminski, Ludwig Ries, Ralf Sohmer, Holger Gerwig, Klaus Wirtz, Frank Meinhardt, Andreas Schwerin, Olaf Bath, Nan Ma, and Alfred Wiedensohler
Atmos. Chem. Phys., 20, 7049–7068, https://doi.org/10.5194/acp-20-7049-2020, https://doi.org/10.5194/acp-20-7049-2020, 2020
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To evaluate the effectiveness of emission mitigation policies, we evaluated the trends of the size-resolved particle number concentrations and equivalent black carbon mass concentration at 16 observational sites for various environments in Germany (2009–2018). Overall, significant decrease trends are found for most of the parameters and sites. This study suggests that a combination of emission mitigation policies can effectively improve the air quality on large spatial scales such as in Germany.
Mikhail Paramonov, Saskia Drossaart van Dusseldorp, Ellen Gute, Jonathan P. D. Abbatt, Paavo Heikkilä, Jorma Keskinen, Xuemeng Chen, Krista Luoma, Liine Heikkinen, Liqing Hao, Tuukka Petäjä, and Zamin A. Kanji
Atmos. Chem. Phys., 20, 6687–6706, https://doi.org/10.5194/acp-20-6687-2020, https://doi.org/10.5194/acp-20-6687-2020, 2020
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Ice-nucleating particle (INP) measurements were performed in the boreal environment of southern Finland in the winter–spring of 2018. It was found that no single parameter could be used to predict the INP number concentration at the measurement location during the examined time period. It was also not possible to identify physical and chemical properties of ambient INPs despite the complexity of the instrumental set-up. Therefore, this paper addresses the necessity for future INP measurements.
Yugo Kanaya, Kazuyo Yamaji, Takuma Miyakawa, Fumikazu Taketani, Chunmao Zhu, Yongjoo Choi, Yuichi Komazaki, Kohei Ikeda, Yutaka Kondo, and Zbigniew Klimont
Atmos. Chem. Phys., 20, 6339–6356, https://doi.org/10.5194/acp-20-6339-2020, https://doi.org/10.5194/acp-20-6339-2020, 2020
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Fundamental disagreements among bottom-up emission inventories exist about the sign of the black carbon emissions trend from China over the past decade. Our decadal observations on Fukue Island clearly indicate its rapid reduction, after correcting for interannual meteorological variability, which supports inventories reflecting governmental clean air actions after 2010. The reduction pace surpasses those of SSP1 scenarios for 2015–2030, suggesting highly successful emission control policies.
Igor Veselovskii, Qiaoyun Hu, Philippe Goloub, Thierry Podvin, Mikhail Korenskiy, Yevgeny Derimian, Michel Legrand, and Patricia Castellanos
Atmos. Chem. Phys., 20, 6563–6581, https://doi.org/10.5194/acp-20-6563-2020, https://doi.org/10.5194/acp-20-6563-2020, 2020
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Atmospheric dust has a significant impact on the Earth's climate system, and this impact remains highly uncertain. The desert dust is always a mixture of various minerals, and the imaginary part of the complex refractive index often exhibits an increase in UV for dust containing iron oxides. Our results demonstrate that multiwavelength Raman lidar measurements allow for the characterization of the spectral dependence of the imaginary part of dust.
Hing Cho Cheung, Charles Chung-Kuang Chou, Celine Siu Lan Lee, Wei-Chen Kuo, and Shuenn-Chin Chang
Atmos. Chem. Phys., 20, 5911–5922, https://doi.org/10.5194/acp-20-5911-2020, https://doi.org/10.5194/acp-20-5911-2020, 2020
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Air pollution can result in changes to the amount and properties of aerosols, which in turn could influence climate by acting as cloud condensation nuclei (CCN). This study investigated the composition and hygroscopicity of aerosols (PM2.5) at a station under influences of eastern Asian (EA) outflows and local air mass during respective seasons. The results show that the EA aerosols were more hygroscopic, whereas new particle formation and coagulation could also influence local CCN activity.
Hang Liu, Xiaole Pan, Dantong Liu, Xiaoyong Liu, Xueshun Chen, Yu Tian, Yele Sun, Pingqing Fu, and Zifa Wang
Atmos. Chem. Phys., 20, 5771–5785, https://doi.org/10.5194/acp-20-5771-2020, https://doi.org/10.5194/acp-20-5771-2020, 2020
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The bare black carbon (BC) was in a fractal structure. With coating thickness increasing, BC changed from a fractal structure to a core–shell structure. In the ambient atmosphere, plenty of BC particles were not in a perfect core–shell structure. This study brought attention to the combined effects of morphology and coating thickness on the absorption enhancement of BC-containing particles, which is helpful for determining the climatic effects of BC.
Jiyeon Park, Manuel Dall'Osto, Kihong Park, Yeontae Gim, Hyo Jin Kang, Eunho Jang, Ki-Tae Park, Minsu Park, Seong Soo Yum, Jinyoung Jung, Bang Yong Lee, and Young Jun Yoon
Atmos. Chem. Phys., 20, 5573–5590, https://doi.org/10.5194/acp-20-5573-2020, https://doi.org/10.5194/acp-20-5573-2020, 2020
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The physical properties of aerosol particles throughout the Arctic Ocean and Pacific Ocean were measured aboard the Korean icebreaker R/V Araon during the summer of 2017. A number of new particle formation (NPF) events and growth were frequently observed in both Arctic terrestrial and Arctic marine air masses. This suggests that terrestrial ecosystems – including river outflows and tundra – strongly affect aerosol emissions in the Arctic coastal areas, affecting
radiative forcing.
Sophia Brilke, Nikolaus Fölker, Thomas Müller, Konrad Kandler, Xianda Gong, Jeff Peischl, Bernadett Weinzierl, and Paul M. Winkler
Atmos. Chem. Phys., 20, 5645–5656, https://doi.org/10.5194/acp-20-5645-2020, https://doi.org/10.5194/acp-20-5645-2020, 2020
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Atmospheric particle size distributions with the focus on freshly nucleated particles were measured during the A-LIFE field experiment in Cyprus. A DMA-train was set up for the first time in an atmospheric environment and captures the sub-10 nm particle dynamics. Several new particle formation (NPF) events are studied in detail, of which some did not show particle growth beyond 10 nm indicating that NPF may occur more frequently than estimated when the sub-10 nm size range is not covered.
Bruna A. Holanda, Mira L. Pöhlker, David Walter, Jorge Saturno, Matthias Sörgel, Jeannine Ditas, Florian Ditas, Christiane Schulz, Marco Aurélio Franco, Qiaoqiao Wang, Tobias Donth, Paulo Artaxo, Henrique M. J. Barbosa, Stephan Borrmann, Ramon Braga, Joel Brito, Yafang Cheng, Maximilian Dollner, Johannes W. Kaiser, Thomas Klimach, Christoph Knote, Ovid O. Krüger, Daniel Fütterer, Jošt V. Lavrič, Nan Ma, Luiz A. T. Machado, Jing Ming, Fernando G. Morais, Hauke Paulsen, Daniel Sauer, Hans Schlager, Johannes Schneider, Hang Su, Bernadett Weinzierl, Adrian Walser, Manfred Wendisch, Helmut Ziereis, Martin Zöger, Ulrich Pöschl, Meinrat O. Andreae, and Christopher Pöhlker
Atmos. Chem. Phys., 20, 4757–4785, https://doi.org/10.5194/acp-20-4757-2020, https://doi.org/10.5194/acp-20-4757-2020, 2020
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Biomass burning smoke from African savanna and grassland is transported across the South Atlantic Ocean in defined layers within the free troposphere. The combination of in situ aircraft and ground-based measurements aided by satellite observations showed that these layers are transported into the Amazon Basin during the early dry season. The influx of aged smoke, enriched in black carbon and cloud condensation nuclei, has important implications for the Amazonian aerosol and cloud cycling.
Shaoxiang Ma, He Cheng, Jiacheng Li, Maoyuan Xu, Dawei Liu, and Kostya Ostrikov
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-23, https://doi.org/10.5194/acp-2020-23, 2020
Revised manuscript accepted for ACP
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Our work suggests that the large corona discharge system is an efficient and possibly economically sustainable way to increase the ion density in the open air and control precipitation of atmospheric aerosols. Once the system is installed on the mountain top, it will generate lots of charged nuclei, which may trigger water precipitation or fog elimination within a certain region in the downwind directions.
Cyrielle Denjean, Thierry Bourrianne, Frederic Burnet, Marc Mallet, Nicolas Maury, Aurélie Colomb, Pamela Dominutti, Joel Brito, Régis Dupuy, Karine Sellegri, Alfons Schwarzenboeck, Cyrille Flamant, and Peter Knippertz
Atmos. Chem. Phys., 20, 4735–4756, https://doi.org/10.5194/acp-20-4735-2020, https://doi.org/10.5194/acp-20-4735-2020, 2020
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This paper presents aircraft measurements of aerosol optical properties over southern West Africa. We show that aerosol optical properties in the boundary layer were dominated by a persistent biomass burning loading from the Southern Hemisphere. Biomass burning aerosols were more light absorbing that those previously measured in other areas (Amazonia, North America). Our study suggests that lens-coated black carbon particles were the dominant absorber for these biomass burning aerosols.
Dandan Zhao, Guangjing Liu, Jinyuan Xin, Jiannong Quan, Yuesi Wang, Xin Wang, Lindong Dai, Wenkang Gao, Guiqian Tang, Bo Hu, Yongxiang Ma, Xiaoyan Wu, Lili Wang, Zirui Liu, and Fangkun Wu
Atmos. Chem. Phys., 20, 4575–4592, https://doi.org/10.5194/acp-20-4575-2020, https://doi.org/10.5194/acp-20-4575-2020, 2020
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Under strong atmospheric oxidization capacity, haze pollution in the summer in Beijing was the result of the synergistic effect of the physicochemical process in the atmospheric boundary layer (ABL). With the premise of an extremely stable ABL structure, the formation of secondary aerosols dominated by nitrate was quite intense, driving the outbreak of haze pollution.
Thomas Lachlan-Cope, David C. S. Beddows, Neil Brough, Anna E. Jones, Roy M. Harrison, Angelo Lupi, Young Jun Yoon, Aki Virkkula, and Manuel Dall'Osto
Atmos. Chem. Phys., 20, 4461–4476, https://doi.org/10.5194/acp-20-4461-2020, https://doi.org/10.5194/acp-20-4461-2020, 2020
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We present a statistical cluster analysis of the physical characteristics of particle size distributions collected at Halley (Antarctica) for the year 2015. Complex interactions between multiple ecosystems, coupled with different atmospheric circulation, result in very different aerosol size distributions populating the Southern Hemisphere.
Jonathan W. Taylor, Huihui Wu, Kate Szpek, Keith Bower, Ian Crawford, Michael J. Flynn, Paul I. Williams, James Dorsey, Justin M. Langridge, Michael I. Cotterell, Cathryn Fox, Nicholas W. Davies, Jim M. Haywood, and Hugh Coe
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-333, https://doi.org/10.5194/acp-2020-333, 2020
Revised manuscript accepted for ACP
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Every year, huge plumes of smoke hundreds of miles wide travel over the south Atlantic Ocean from fires in central and southern Africa. These plumes absorb the sun’s energy and warm the climate. We measured the properties of the smoke using instruments on board an aircraft, to work out how absorbing the smoke is, and which components of the smoke warm the air the most. We also tested different ways of simulating these properties that could be used in a climate model.
Sobhan Kumar Kompalli, Surendran Nair Suresh Babu, Sreedharan Krishnakumari Satheesh, Krishnaswamy Krishna Moorthy, Trupti Das, Ramasamy Boopathy, Dantong Liu, Eoghan Darbyshire, James D. Allan, James Brooks, Michael J. Flynn, and Hugh Coe
Atmos. Chem. Phys., 20, 3965–3985, https://doi.org/10.5194/acp-20-3965-2020, https://doi.org/10.5194/acp-20-3965-2020, 2020
Mohanan R. Manoj, Sreedharan K. Satheesh, Krishnaswamy K. Moorthy, and Hugh Coe
Atmos. Chem. Phys., 20, 4031–4046, https://doi.org/10.5194/acp-20-4031-2020, https://doi.org/10.5194/acp-20-4031-2020, 2020
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The study reports the observation of highly absorbing aerosol layers at high altitudes (1–2.5 km) prior to monsoon and during its development over the Indian region and quantifies its climate impacts. The absorption of solar radiation in these layers perturbs the onset of monsoon through the impact on the atmospheric stability. When height-resolved values of single scattering albedo (SSA) are used in a radiative transfer model, a maximum heating ~1 K d (~twice that using SSA) is obtained.
Quan Liu, Dantong Liu, Qian Gao, Ping Tian, Fei Wang, Delong Zhao, Kai Bi, Yangzhou Wu, Shuo Ding, Kang Hu, Jiale Zhang, Deping Ding, and Chunsheng Zhao
Atmos. Chem. Phys., 20, 3931–3944, https://doi.org/10.5194/acp-20-3931-2020, https://doi.org/10.5194/acp-20-3931-2020, 2020
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We present a series of aircraft-based in situ measurements of aerosol chemical components and size distributions over the North China Plain, and the hygroscopicity is derived from aerosol chemical composition. These results reveal the vertical characteristics of aerosol hygroscopicity, and we investigated their impacts on optical properties and activation under different moisture and pollution conditions over this polluted region.
Tianning Su, Zhanqing Li, Chengcai Li, Jing Li, Wenchao Han, Chuanyang Shen, Wangshu Tan, Jing Wei, and Jianping Guo
Atmos. Chem. Phys., 20, 3713–3724, https://doi.org/10.5194/acp-20-3713-2020, https://doi.org/10.5194/acp-20-3713-2020, 2020
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We study the role of aerosol vertical distribution in thermodynamic stability and PBL development. Under different aerosol vertical structures, the diurnal cycles of PBLH and PM2.5 show distinct characteristics. Large differences in the heating rate affect atmospheric buoyancy and stability differently under different aerosol structures. As a result, the aerosol–PBL interaction can be strengthened by the inverse aerosol structure and potentially neutralized by the decreasing structure.
Chenjie Yu, Dantong Liu, Kurtis Broda, Rutambhara Joshi, Jason Olfert, Yele Sun, Pingqing Fu, Hugh Coe, and James D. Allan
Atmos. Chem. Phys., 20, 3645–3661, https://doi.org/10.5194/acp-20-3645-2020, https://doi.org/10.5194/acp-20-3645-2020, 2020
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This study presents the first atmospheric application of a new morphology-independent measurement for the quantification of the mixing state of rBC-containing particles in urban Beijing as part of the UK–China APHH campaign. An inversion method has been applied for better quantification of rBC mixing state. The mass-resolved rBC mixing state information presented here has implications for detailed models of BC, its optical properties and its atmospheric life cycle.
Xiaochao Yu, Zhili Wang, Hua Zhang, Jianjun He, and Ying Li
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2019-1215, https://doi.org/10.5194/acp-2019-1215, 2020
Revised manuscript accepted for ACP
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There are statistically significant positive and negative correlations, respectively, between winter haze days (WHD) in China's Jing-Jin-Ji region and Eastern Pacific and Central Pacific El Niño events. These opposite changes in WHD are attributable to the anomalies of both large-scale circulation and local synoptic condition corresponding to two types of El Niño. Our study highlights the importance of distinguishing the impacts of two types of El Niño on winter haze pollution in this region.
Vijayakumar S. Nair, Venugopalan Nair Jayachandran, Sobhan Kumar Kompalli, Mukunda M. Gogoi, and S. Suresh Babu
Atmos. Chem. Phys., 20, 3135–3149, https://doi.org/10.5194/acp-20-3135-2020, https://doi.org/10.5194/acp-20-3135-2020, 2020
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Extensive measurements of the aerosol and cloud condensation nuclei (CCN) properties in South Asian outflow to the northern Indian Ocean were carried out as a part of the ICARB-2018 experiment during winter. At high supersaturations, most of the aerosols in the South Asian outflow become activated as CCN, whereas the aerosol system over the equatorial Indian Ocean is less CCN efficient even at higher supersaturations.
Samantha J. Kramer, Claudia Alvarez, Anne Barkley, Peter R. Colarco, Lillian Custals, Rodrigo Delgadillo, Cassandra Gaston, Ravi Govindaraju, and Paquita Zuidema
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1, https://doi.org/10.5194/acp-2020-1, 2020
Revised manuscript accepted for ACP
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Comparisons of sea salt and size-resolved dust mass concentration measurements over southeast Florida to those from the MERRA2/GEOS-5 FP aerosol reanalysis indicate the reanalysis depicts excessive sea salt and puts too much dust in larger intermediate sizes, than do the measurements. The dust vertical profile is approximately correct. The incorrect reanalysis aerosol speciation and dust sizes has implications for the modeling of their transport, deposition, and radiative impact.
Ping Tian, Dantong Liu, Delong Zhao, Chenjie Yu, Quan Liu, Mengyu Huang, Zhaoze Deng, Liang Ran, Yunfei Wu, Shuo Ding, Kang Hu, Gang Zhao, Chunsheng Zhao, and Deping Ding
Atmos. Chem. Phys., 20, 2603–2622, https://doi.org/10.5194/acp-20-2603-2020, https://doi.org/10.5194/acp-20-2603-2020, 2020
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This study paints a full picture of the evolution of vertical characteristics of aerosol optical properties and shortwave heating impacts of carbonaceous aerosols during different stages of pollution events over the Beijing region and highlights the increased contribution of brown carbon absorption, especially at higher levels, during pollution.
Jia Yin Sun, Cheng Wu, Dui Wu, Chunlei Cheng, Mei Li, Lei Li, Tao Deng, Jian Zhen Yu, Yong Jie Li, Qianni Zhou, Yue Liang, Tianlin Sun, Lang Song, Peng Cheng, Wenda Yang, Chenglei Pei, Yanning Chen, Yanxiang Cen, Huiqing Nian, and Zhen Zhou
Atmos. Chem. Phys., 20, 2445–2470, https://doi.org/10.5194/acp-20-2445-2020, https://doi.org/10.5194/acp-20-2445-2020, 2020
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Atmospheric aging processes (AAPs) can lead to black carbon (BC) light absorption enhancement (Eabs), which remained poorly characterized at a long timescale. By applying a newly developed approach, the minimum R squared method (MRS), this study investigated the temporal variations of BC Eabs at both seasonal and diel scales in an urban environment. Factors affecting the temporal variability of BC Eabs were also analyzed, including variability in emission sources and various types of AAPs.
Jost Heintzenberg, Wolfram Birmili, Bryan Hellack, Maik Merkel, Gerald Spindler, Thomas Tuch, Kay Weinhold, and Alfred Wiedensohler
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2019-1098, https://doi.org/10.5194/acp-2019-1098, 2020
Revised manuscript accepted for ACP
Liyuan Zhou, Åsa M. Hallquist, Mattias Hallquist, Christian M. Salvador, Samuel M. Gaita, Åke Sjödin, Martin Jerksjö, Håkan Salberg, Ingvar Wängberg, Johan Mellqvist, Qianyun Liu, Berto P. Lee, and Chak K. Chan
Atmos. Chem. Phys., 20, 1701–1722, https://doi.org/10.5194/acp-20-1701-2020, https://doi.org/10.5194/acp-20-1701-2020, 2020
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The study reports the transition in the atmospheric emission of particles and gases from on-road heavy-duty trucks (HDTs) caused by the modernisation of the fleet. We measured particle number (PN), particle mass (PM), black carbon (BC), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbon (HC), particle size distributions, and volatility in the plumes of 556 individual HDTs. Significant but different changes in emissions were evident for various pollutants with respect to emission standards.
Samuel E. LeBlanc, Jens Redemann, Connor Flynn, Kristina Pistone, Meloë Kacenelenbogen, Michal Segal-Rosenheimer, Yohei Shinozuka, Stephen Dunagan, Robert P. Dahlgren, Kerry Meyer, James Podolske, Steven G. Howell, Steffen Freitag, Jennifer Small-Griswold, Brent Holben, Michael Diamond, Robert Wood, Paola Formenti, Stuart Piketh, Gillian Maggs-Kölling, Monja Gerber, and Andreas Namwoonde
Atmos. Chem. Phys., 20, 1565–1590, https://doi.org/10.5194/acp-20-1565-2020, https://doi.org/10.5194/acp-20-1565-2020, 2020
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The southeast Atlantic during August–October experiences layers of smoke from biomass burning over marine stratocumulus clouds. Here we present the light attenuation of the smoke and its dependence in the spatial, vertical, and spectral domain through direct measurements from an airborne platform during September 2016. From our observations of this climatically important smoke, we found an average aerosol optical depth of 0.32 at 500 nm, slightly lower than comparative satellite measurements.
Xianda Gong, Heike Wex, Jens Voigtländer, Khanneh Wadinga Fomba, Kay Weinhold, Manuela van Pinxteren, Silvia Henning, Thomas Müller, Hartmut Herrmann, and Frank Stratmann
Atmos. Chem. Phys., 20, 1431–1449, https://doi.org/10.5194/acp-20-1431-2020, https://doi.org/10.5194/acp-20-1431-2020, 2020
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We characterized the aerosol particles in Cabo Verde at sea and cloud levels. We found four well-separable types of PNSDs, with the strongest differences between air masses coming from the ocean compared to from the African continent. During the strongest observed dust periods, CCN concentrations were 2.5 higher than during clean marine periods. The hygroscopicity of the particles did not vary much between different periods. Aerosol at sea level and on the mountaintop was well in agreement.
Ying Zhou, Lubna Dada, Yiliang Liu, Yueyun Fu, Juha Kangasluoma, Tommy Chan, Chao Yan, Biwu Chu, Kaspar R. Daellenbach, Federico Bianchi, Tom V. Kokkonen, Yongchun Liu, Joni Kujansuu, Veli-Matti Kerminen, Tuukka Petäjä, Lin Wang, Jingkun Jiang, and Markku Kulmala
Atmos. Chem. Phys., 20, 1201–1216, https://doi.org/10.5194/acp-20-1201-2020, https://doi.org/10.5194/acp-20-1201-2020, 2020
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In this study, we focus on explaining the concentration variations in the observed particle modes, by relating them to the potential aerosol sources and sinks, and on understanding the connections between these modes. Interestingly, even in the atmospheric cocktail in urban Beijing, secondary new particle formation (NPF) drives the particle number concentration, especially in the sub-3 nm range. We found that the total number concentration is ~ 4 times higher on NPF days than on haze days.
Xiaoai Jin, Yuying Wang, Zhanqing Li, Fang Zhang, Weiqi Xu, Yele Sun, Xinxin Fan, Guangyu Chen, Hao Wu, Jingye Ren, Qiuyan Wang, and Maureen Cribb
Atmos. Chem. Phys., 20, 901–914, https://doi.org/10.5194/acp-20-901-2020, https://doi.org/10.5194/acp-20-901-2020, 2020
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In this study the aerosol liquid water content (ALWC) is determined from aerosol hygroscopic growth factor (GF) measurement (ALWCHTDMA) and also simulated by the ISORROPIA II thermodynamic model (ALWCISO). We found that ALWC contributed by organics (ALWCOrg) accounts for 30 % ± 22 % of the total ALWC in winter in Beijing. A case study reveals that ALWCOrg plays an important role in the formation of secondary aerosols through multiphase reactions at the initial stage of a heavy-haze episode.
Ye Kuang, Yao He, Wanyun Xu, Pusheng Zhao, Yafang Cheng, Gang Zhao, Jiangchuan Tao, Nan Ma, Hang Su, Yanyan Zhang, Jiayin Sun, Peng Cheng, Wenda Yang, Shaobin Zhang, Cheng Wu, Yele Sun, and Chunsheng Zhao
Atmos. Chem. Phys., 20, 865–880, https://doi.org/10.5194/acp-20-865-2020, https://doi.org/10.5194/acp-20-865-2020, 2020
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A new method was developed to calculate hygroscopicity parameter κ of organic aerosols (κOA) based on aerosol light-scattering measurements and bulk aerosol chemical-composition measurements. Derived high-time-resolution κOA varied in a wide range (near 0 to 0.25), and the organic aerosol oxidation degree significantly impacts variations in κOA. Distinct diurnal variation in κOA is found, and its relationship with oxygenated organic aerosol is discussed.
Haley M. Rogers, Jenna C. Ditto, and Drew R. Gentner
Atmos. Chem. Phys., 20, 671–682, https://doi.org/10.5194/acp-20-671-2020, https://doi.org/10.5194/acp-20-671-2020, 2020
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This study combines surface-level air quality measurements with satellite imagery and back-trajectory modeling to investigate the long-distance transport of these emissions to the New York City metropolitan area and the northeastern US. Two events in August 2018 were traced to biomass burning on the western coast of Canada and from the southeastern US, highlighting the importance of understanding long-distance transport of fire emissions in air quality planning.
Venugopalan Nair Jayachandran, Surendran Nair Suresh Babu, Aditya Vaishya, Mukunda M. Gogoi, Vijayakumar S. Nair, Sreedharan Krishnakumari Satheesh, and Krishnaswamy Krishna Moorthy
Atmos. Chem. Phys., 20, 561–576, https://doi.org/10.5194/acp-20-561-2020, https://doi.org/10.5194/acp-20-561-2020, 2020
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Concurrent measurements of the altitude profiles of the concentration of cloud condensation nuclei (CCNs), as a function of supersaturation (ranging from 0.2 % to 1.0 %), and aerosol optical properties were carried out aboard an instrumented aircraft across the Indo-Gangetic Plain (IGP) just prior to the onset of the 2016 Indian summer monsoon (ISM). A high CCN concentration is observed up to 2.5 km across the IGP, indicating the significant possibility of aerosol indirect effects.
Yohei Shinozuka, Meloë S. Kacenelenbogen, Sharon P. Burton, Steven G. Howell, Paquita Zuidema, Richard A. Ferrare, Samuel E. LeBlanc, Kristina Pistone, Stephen Broccardo, Jens Redemann, K. Sebastian Schmidt, Sabrina P. Cochrane, Marta Fenn, Steffen Freitag, Amie Dobracki, Michal Segal-Rosenheimer, and Connor J. Flynn
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2019-1007, https://doi.org/10.5194/acp-2019-1007, 2020
Revised manuscript accepted for ACP
Yonghong Wang, Miao Yu, Yuesi Wang, Guiqian Tang, Tao Song, Putian Zhou, Zirui Liu, Bo Hu, Dongsheng Ji, Lili Wang, Xiaowan Zhu, Chao Yan, Mikael Ehn, Wenkang Gao, Yuepeng Pan, Jinyuan Xin, Yang Sun, Veli-Matti Kerminen, Markku Kulmala, and Tuukka Petäjä
Atmos. Chem. Phys., 20, 45–53, https://doi.org/10.5194/acp-20-45-2020, https://doi.org/10.5194/acp-20-45-2020, 2020
Short summary
Short summary
We found a positive particle matter-mixing layer height feedback at three observation platforms at the 325 m Beijing meteorology tower, which is characterized by a shallower mixing layer height and a higher particle matter concentration. Measurements of solar radiation, aerosol chemical composition, meteorology parameters, trace gases and turbulent kinetic energy (TKE) could explain the feedback mechanism to some extent.
Miska Olin, Heino Kuuluvainen, Minna Aurela, Joni Kalliokoski, Niina Kuittinen, Mia Isotalo, Hilkka J. Timonen, Jarkko V. Niemi, Topi Rönkkö, and Miikka Dal Maso
Atmos. Chem. Phys., 20, 1–13, https://doi.org/10.5194/acp-20-1-2020, https://doi.org/10.5194/acp-20-1-2020, 2020
Short summary
Short summary
Photochemically formed sulfuric acid is generally considered the main source for new particle formation in the atmosphere. Contrary to current understanding, our measurements of nanoclusters and gaseous sulfuric acid performed in an urban area imply that traffic contributes to sulfuric acid concentration and that even for the smallest particles, the traffic-emitted fraction mostly exceeds the photochemistry-driven regional new particle formation.
Danhui Xu, Baozhu Ge, Xueshun Chen, Yele Sun, Nianliang Cheng, Mei Li, Xiaole Pan, Zhiqiang Ma, Yuepeng Pan, and Zifa Wang
Atmos. Chem. Phys., 19, 15569–15581, https://doi.org/10.5194/acp-19-15569-2019, https://doi.org/10.5194/acp-19-15569-2019, 2019
Short summary
Short summary
Wet deposition is one of the most important and efficient removal mechanisms in the evolution of the air pollution. Due to the lack of a localized parameterization scheme and some mechanisms being neglected in theoretical estimations and modeling calculations, below-cloud wet scavenging coefficients (BWSC) have large uncertainties. We compare the BWSCs under the same conditions to perform a multi-method evaluation in order to describe their characteristics.
Yicheng Shen, Aki Virkkula, Aijun Ding, Krista Luoma, Helmi Keskinen, Pasi P. Aalto, Xuguang Chi, Ximeng Qi, Wei Nie, Xin Huang, Tuukka Petäjä, Markku Kulmala, and Veli-Matti Kerminen
Atmos. Chem. Phys., 19, 15483–15502, https://doi.org/10.5194/acp-19-15483-2019, https://doi.org/10.5194/acp-19-15483-2019, 2019
Short summary
Short summary
Long-term cloud condensation nuclei (CCN) number concentration (NCCN) data are scarce; there are a lot more data on aerosol optical properties (AOPs). It is therefore valuable to derive parameterizations for estimating NCCN from AOP measurements. With the new parameterization NCCN can be estimated from backscatter fraction, scattering Ångström exponent, and total light-scattering coefficient. The NCCN–AOP relationships depend on the geometric mean diameter and the width of the size distribution.
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Search articles
Short summary
Using observations from instruments deployed to a small island in the southeast Atlantic, we study days when the atmospheric concentrations of particles near the surface are exceptionally low. Interestingly, these ultra-clean boundary layers occur in the same months as the smokiest boundary layers associated with biomass burning in Africa. We find evidence that enhancements in drizzle scavenging, on top of a seasonal maximum in cloudiness and precipitation, likely drive these conditions.
Using observations from instruments deployed to a small island in the southeast Atlantic, we...
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