Articles | Volume 24, issue 4
https://doi.org/10.5194/acp-24-2077-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-24-2077-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
19 Feb 2024
Research article |
| 19 Feb 2024
| 19 Feb 2024
How well do Earth system models reproduce the observed aerosol response to rapid emission reductions? A COVID-19 case study
Canadian Centre for Climate Modelling and Analysis, Environment and Climate Change, Victoria, British Columbia, Canada
School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada
Nathan P. Gillett
Canadian Centre for Climate Modelling and Analysis, Environment and Climate Change, Victoria, British Columbia, Canada
Adam H. Monahan
School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada
Knut von Salzen
Canadian Centre for Climate Modelling and Analysis, Environment and Climate Change, Victoria, British Columbia, Canada
Antonis Gkikas
Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens (IAASARS/NOA), Athens, Greece
Research Centre for Atmospheric Physics and Climatology, Academy of Athens, Athens, Greece
Qianqian Song
Atmospheric and Oceanic Sciences Program, Princeton University, Princeton, NJ, USA
Zhibo Zhang
Physics Department, University of Maryland, Baltimore County, Baltimore, Maryland, USA
Goddard Earth Sciences Technology and Research II, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
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Antonis Gkikas, Anna Gialitaki, Ioannis Binietoglou, Eleni Marinou, Maria Tsichla, Nikolaos Siomos, Peristera Paschou, Anna Kampouri, Kalliopi Artemis Voudouri, Emmanouil Proestakis, Maria Mylonaki, Christina-Anna Papanikolaou, Konstantinos Michailidis, Holger Baars, Anne Grete Straume, Dimitris Balis, Alexandros Papayannis, Tomasso Parrinello, and Vassilis Amiridis
Atmos. Meas. Tech., 16, 1017–1042, https://doi.org/10.5194/amt-16-1017-2023, https://doi.org/10.5194/amt-16-1017-2023, 2023
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We perform an assessment analysis of the Aeolus Standard Correct Algorithm (SCA) backscatter coefficient retrievals against reference observations acquired at three Greek lidar stations (Athens, Thessaloniki and Antikythera) of the PANACEA network. Overall, 43 cases are analysed, whereas specific aerosol scenarios in the vicinity of Antikythera island (SW Greece) are emphasised. All key Cal/Val aspects and recommendations, and the ongoing related activities, are thoroughly discussed.
Cynthia H. Whaley, Kathy S. Law, Jens Liengaard Hjorth, Henrik Skov, Stephen R. Arnold, Joakim Langner, Jakob Boyd Pernov, Garance Bergeron, Ilann Bourgeois, Jesper H. Christensen, Rong-You Chien, Makoto Deushi, Xinyi Dong, Peter Effertz, Gregory Faluvegi, Mark Flanner, Joshua S. Fu, Michael Gauss, Greg Huey, Ulas Im, Rigel Kivi, Louis Marelle, Tatsuo Onishi, Naga Oshima, Irina Petropavlovskikh, Jeff Peischl, David A. Plummer, Luca Pozzoli, Jean-Christophe Raut, Tom Ryerson, Ragnhild Skeie, Sverre Solberg, Manu A. Thomas, Chelsea Thompson, Kostas Tsigaridis, Svetlana Tsyro, Steven T. Turnock, Knut von Salzen, and David W. Tarasick
Atmos. Chem. Phys., 23, 637–661, https://doi.org/10.5194/acp-23-637-2023, https://doi.org/10.5194/acp-23-637-2023, 2023
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Kyriakoula Papachristopoulou, Ioannis-Panagiotis Raptis, Antonis Gkikas, Ilias Fountoulakis, Akriti Masoom, and Stelios Kazadzis
Atmos. Chem. Phys., 22, 15703–15727, https://doi.org/10.5194/acp-22-15703-2022, https://doi.org/10.5194/acp-22-15703-2022, 2022
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Sjoukje Y. Philip, Sarah F. Kew, Geert Jan van Oldenborgh, Faron S. Anslow, Sonia I. Seneviratne, Robert Vautard, Dim Coumou, Kristie L. Ebi, Julie Arrighi, Roop Singh, Maarten van Aalst, Carolina Pereira Marghidan, Michael Wehner, Wenchang Yang, Sihan Li, Dominik L. Schumacher, Mathias Hauser, Rémy Bonnet, Linh N. Luu, Flavio Lehner, Nathan Gillett, Jordis S. Tradowsky, Gabriel A. Vecchi, Chris Rodell, Roland B. Stull, Rosie Howard, and Friederike E. L. Otto
Earth Syst. Dynam., 13, 1689–1713, https://doi.org/10.5194/esd-13-1689-2022, https://doi.org/10.5194/esd-13-1689-2022, 2022
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In June 2021, the Pacific Northwest of the US and Canada saw record temperatures far exceeding those previously observed. This attribution study found such a severe heat wave would have been virtually impossible without human-induced climate change. Assuming no nonlinear interactions, such events have become at least 150 times more common, are about 2 °C hotter and will become even more common as warming continues. Therefore, adaptation and mitigation are urgently needed to prepare society.
Huilin Huang, Yun Qian, Ye Liu, Cenlin He, Jianyu Zheng, Zhibo Zhang, and Antonis Gkikas
Atmos. Chem. Phys., 22, 15469–15488, https://doi.org/10.5194/acp-22-15469-2022, https://doi.org/10.5194/acp-22-15469-2022, 2022
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Using a clustering method developed in the field of artificial neural networks, we identify four typical dust transport patterns across the Sierra Nevada, associated with the mesoscale and regional-scale wind circulations. Our results highlight the connection between dust transport and dominant weather patterns, which can be used to understand dust transport in a changing climate.
Qianqian Song, Zhibo Zhang, Hongbin Yu, Jasper F. Kok, Claudia Di Biagio, Samuel Albani, Jianyu Zheng, and Jiachen Ding
Atmos. Chem. Phys., 22, 13115–13135, https://doi.org/10.5194/acp-22-13115-2022, https://doi.org/10.5194/acp-22-13115-2022, 2022
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This study developed a dataset that enables us to efficiently calculate dust direct radiative effect (DRE, i.e., cooling or warming our planet) for any given dust size distribution in addition to three sets of dust mineral components and two dust shapes. We demonstrate and validate the method of using this dataset to calculate dust DRE. Moreover, using this dataset we found that dust mineral composition is a more important factor in determining dust DRE than dust size and shape.
Eleni Drakaki, Vassilis Amiridis, Alexandra Tsekeri, Antonis Gkikas, Emmanouil Proestakis, Sotirios Mallios, Stavros Solomos, Christos Spyrou, Eleni Marinou, Claire L. Ryder, Demetri Bouris, and Petros Katsafados
Atmos. Chem. Phys., 22, 12727–12748, https://doi.org/10.5194/acp-22-12727-2022, https://doi.org/10.5194/acp-22-12727-2022, 2022
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State-of-the-art atmospheric dust models have limitations in accounting for a realistic dust size distribution (emission, transport). We modify the parameterization of the mineral dust cycle by including particles with diameter >20 μm, as indicated by observations over deserts. Moreover, we investigate the effects of reduced settling velocities of dust particles. Model results are evaluated using airborne and spaceborne dust measurements above Cabo Verde.
Cynthia H. Whaley, Rashed Mahmood, Knut von Salzen, Barbara Winter, Sabine Eckhardt, Stephen Arnold, Stephen Beagley, Silvia Becagli, Rong-You Chien, Jesper Christensen, Sujay Manish Damani, Xinyi Dong, Konstantinos Eleftheriadis, Nikolaos Evangeliou, Gregory Faluvegi, Mark Flanner, Joshua S. Fu, Michael Gauss, Fabio Giardi, Wanmin Gong, Jens Liengaard Hjorth, Lin Huang, Ulas Im, Yugo Kanaya, Srinath Krishnan, Zbigniew Klimont, Thomas Kühn, Joakim Langner, Kathy S. Law, Louis Marelle, Andreas Massling, Dirk Olivié, Tatsuo Onishi, Naga Oshima, Yiran Peng, David A. Plummer, Olga Popovicheva, Luca Pozzoli, Jean-Christophe Raut, Maria Sand, Laura N. Saunders, Julia Schmale, Sangeeta Sharma, Ragnhild Bieltvedt Skeie, Henrik Skov, Fumikazu Taketani, Manu A. Thomas, Rita Traversi, Kostas Tsigaridis, Svetlana Tsyro, Steven Turnock, Vito Vitale, Kaley A. Walker, Minqi Wang, Duncan Watson-Parris, and Tahya Weiss-Gibbons
Atmos. Chem. Phys., 22, 5775–5828, https://doi.org/10.5194/acp-22-5775-2022, https://doi.org/10.5194/acp-22-5775-2022, 2022
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Air pollutants, like ozone and soot, play a role in both global warming and air quality. Atmospheric models are often used to provide information to policy makers about current and future conditions under different emissions scenarios. In order to have confidence in those simulations, in this study we compare simulated air pollution from 18 state-of-the-art atmospheric models to measured air pollution in order to assess how well the models perform.
Hengqi Wang, Yiran Peng, Knut von Salzen, Yan Yang, Wei Zhou, and Delong Zhao
Geosci. Model Dev., 15, 2949–2971, https://doi.org/10.5194/gmd-15-2949-2022, https://doi.org/10.5194/gmd-15-2949-2022, 2022
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The aerosol activation scheme is an important part of the general circulation model, but evaluations using observed data are mostly regional. This research introduced a numerically efficient aerosol activation scheme and evaluated it by using stratus and stratocumulus cloud data sampled during multiple aircraft campaigns in Canada, Chile, Brazil, and China. The decent performance indicates that the scheme is suitable for simulations of cloud droplet number concentrations over wide conditions.
Po-Lun Ma, Bryce E. Harrop, Vincent E. Larson, Richard B. Neale, Andrew Gettelman, Hugh Morrison, Hailong Wang, Kai Zhang, Stephen A. Klein, Mark D. Zelinka, Yuying Zhang, Yun Qian, Jin-Ho Yoon, Christopher R. Jones, Meng Huang, Sheng-Lun Tai, Balwinder Singh, Peter A. Bogenschutz, Xue Zheng, Wuyin Lin, Johannes Quaas, Hélène Chepfer, Michael A. Brunke, Xubin Zeng, Johannes Mülmenstädt, Samson Hagos, Zhibo Zhang, Hua Song, Xiaohong Liu, Michael S. Pritchard, Hui Wan, Jingyu Wang, Qi Tang, Peter M. Caldwell, Jiwen Fan, Larry K. Berg, Jerome D. Fast, Mark A. Taylor, Jean-Christophe Golaz, Shaocheng Xie, Philip J. Rasch, and L. Ruby Leung
Geosci. Model Dev., 15, 2881–2916, https://doi.org/10.5194/gmd-15-2881-2022, https://doi.org/10.5194/gmd-15-2881-2022, 2022
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An alternative set of parameters for E3SM Atmospheric Model version 1 has been developed based on a tuning strategy that focuses on clouds. When clouds in every regime are improved, other aspects of the model are also improved, even though they are not the direct targets for calibration. The recalibrated model shows a lower sensitivity to anthropogenic aerosols and surface warming, suggesting potential improvements to the simulated climate in the past and future.
Antonis Gkikas, Emmanouil Proestakis, Vassilis Amiridis, Stelios Kazadzis, Enza Di Tomaso, Eleni Marinou, Nikos Hatzianastassiou, Jasper F. Kok, and Carlos Pérez García-Pando
Atmos. Chem. Phys., 22, 3553–3578, https://doi.org/10.5194/acp-22-3553-2022, https://doi.org/10.5194/acp-22-3553-2022, 2022
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We present a comprehensive climatological analysis of dust optical depth (DOD) relying on the MIDAS dataset. MIDAS provides columnar mid-visible (550 nm) DOD at fine spatial resolution (0.1° × 0.1°) over a 15-year period (2003–2017). In the current study, the analysis is performed at various spatial (from regional to global) and temporal (from months to years) scales. More specifically, focus is given to specific regions hosting the major dust sources as well as downwind areas of the planet.
Julia Schmale, Sangeeta Sharma, Stefano Decesari, Jakob Pernov, Andreas Massling, Hans-Christen Hansson, Knut von Salzen, Henrik Skov, Elisabeth Andrews, Patricia K. Quinn, Lucia M. Upchurch, Konstantinos Eleftheriadis, Rita Traversi, Stefania Gilardoni, Mauro Mazzola, James Laing, and Philip Hopke
Atmos. Chem. Phys., 22, 3067–3096, https://doi.org/10.5194/acp-22-3067-2022, https://doi.org/10.5194/acp-22-3067-2022, 2022
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Long-term data sets of Arctic aerosol properties from 10 stations across the Arctic provide evidence that anthropogenic influence on the Arctic atmospheric chemical composition has declined in winter, a season which is typically dominated by mid-latitude emissions. The number of significant trends in summer is smaller than in winter, and overall the pattern is ambiguous with some significant positive and negative trends. This reflects the mixed influence of natural and anthropogenic emissions.
Justin A. Covert, David B. Mechem, and Zhibo Zhang
Atmos. Chem. Phys., 22, 1159–1174, https://doi.org/10.5194/acp-22-1159-2022, https://doi.org/10.5194/acp-22-1159-2022, 2022
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Stratocumulus play an important role in Earth's radiative balance. The simulation of these cloud systems in climate models is difficult due to the scale at which cloud microphysical processes occur compared with model grid sizes. In this study, we use large-eddy simulation to analyze subgrid-scale variability of cloud water and its implications on a cloud water to drizzle model enhancement factor E. We find current values of E may be too large and that E should be vertically dependent in models.
Stavros-Andreas Logothetis, Vasileios Salamalikis, Antonis Gkikas, Stelios Kazadzis, Vassilis Amiridis, and Andreas Kazantzidis
Atmos. Chem. Phys., 21, 16499–16529, https://doi.org/10.5194/acp-21-16499-2021, https://doi.org/10.5194/acp-21-16499-2021, 2021
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This study investigates the temporal trends of dust optical depth (DOD; 550 nm) on global, regional and seasonal scales over a 15-year period (2003–2017) using the MIDAS (ModIs Dust AeroSol) dataset. The findings of this study revealed that the DOD was increased across the central Sahara and the Arabian Peninsula, with opposite trends over the eastern and western Sahara, the Thar and Gobi deserts, in the Bodélé Depression, and in the southern Mediterranean.
Qianqian Song, Zhibo Zhang, Hongbin Yu, Paul Ginoux, and Jerry Shen
Atmos. Chem. Phys., 21, 13369–13395, https://doi.org/10.5194/acp-21-13369-2021, https://doi.org/10.5194/acp-21-13369-2021, 2021
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We present a satellite-derived global dust climatological record over the last two decades, including the monthly mean visible dust optical depth (DAOD) and vertical distribution of dust extinction coefficient at a 2º × 5º spatial resolution derived from CALIOP and MODIS. In addition, the CALIOP climatological dataset also includes dust vertical extinction profiles. Based on these two datasets, we carried out a comprehensive comparative study of the spatial and temporal climatology of dust.
Hongbin Yu, Qian Tan, Lillian Zhou, Yaping Zhou, Huisheng Bian, Mian Chin, Claire L. Ryder, Robert C. Levy, Yaswant Pradhan, Yingxi Shi, Qianqian Song, Zhibo Zhang, Peter R. Colarco, Dongchul Kim, Lorraine A. Remer, Tianle Yuan, Olga Mayol-Bracero, and Brent N. Holben
Atmos. Chem. Phys., 21, 12359–12383, https://doi.org/10.5194/acp-21-12359-2021, https://doi.org/10.5194/acp-21-12359-2021, 2021
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This study characterizes a historic African dust intrusion into the Caribbean Basin in June 2020 using satellites and NASA GEOS. Dust emissions in West Africa were large albeit not extreme. However, a unique synoptic system accumulated the dust near the coast for about 4 d before it was ventilated. Although GEOS reproduced satellite-observed plume tracks well, it substantially underestimated dust emissions and did not lift up dust high enough for ensuing long-range transport.
Robin D. Lamboll, Chris D. Jones, Ragnhild B. Skeie, Stephanie Fiedler, Bjørn H. Samset, Nathan P. Gillett, Joeri Rogelj, and Piers M. Forster
Geosci. Model Dev., 14, 3683–3695, https://doi.org/10.5194/gmd-14-3683-2021, https://doi.org/10.5194/gmd-14-3683-2021, 2021
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Lockdowns to avoid the spread of COVID-19 have created an unprecedented reduction in human emissions. We can estimate the changes in emissions at a country level, but to make predictions about how this will affect our climate, we need more precise information about where the emissions happen. Here we combine older estimates of where emissions normally occur with very recent estimates of sector activity levels to enable different groups to make simulations of the climatic effects of lockdown.
Zhibo Zhang, Qianqian Song, David B. Mechem, Vincent E. Larson, Jian Wang, Yangang Liu, Mikael K. Witte, Xiquan Dong, and Peng Wu
Atmos. Chem. Phys., 21, 3103–3121, https://doi.org/10.5194/acp-21-3103-2021, https://doi.org/10.5194/acp-21-3103-2021, 2021
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This study investigates the small-scale variations and covariations of cloud microphysical properties, namely, cloud liquid water content and cloud droplet number concentration, in marine boundary layer clouds based on in situ observation from the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) campaign. We discuss the dependence of cloud variations on vertical location in cloud and the implications for warm-rain simulations in the global climate models.
Antonis Gkikas, Emmanouil Proestakis, Vassilis Amiridis, Stelios Kazadzis, Enza Di Tomaso, Alexandra Tsekeri, Eleni Marinou, Nikos Hatzianastassiou, and Carlos Pérez García-Pando
Atmos. Meas. Tech., 14, 309–334, https://doi.org/10.5194/amt-14-309-2021, https://doi.org/10.5194/amt-14-309-2021, 2021
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We present the development of the MIDAS (ModIs Dust AeroSol) data set, providing daily dust optical depth (DOD; 550 nm) at a global scale and fine spatial resolution (0.1° x 0.1°) over a 15-year period (2003–2017). It has been developed via the synergy of MODIS-Aqua and MERRA-2 data, while CALIOP and AERONET retrievals are used for its assessment. MIDAS upgrades existing dust observational capabilities, and it is suitable for dust climatological studies, model evaluation, and data assimilation.
Anna Gialitaki, Alexandra Tsekeri, Vassilis Amiridis, Romain Ceolato, Lucas Paulien, Anna Kampouri, Antonis Gkikas, Stavros Solomos, Eleni Marinou, Moritz Haarig, Holger Baars, Albert Ansmann, Tatyana Lapyonok, Anton Lopatin, Oleg Dubovik, Silke Groß, Martin Wirth, Maria Tsichla, Ioanna Tsikoudi, and Dimitris Balis
Atmos. Chem. Phys., 20, 14005–14021, https://doi.org/10.5194/acp-20-14005-2020, https://doi.org/10.5194/acp-20-14005-2020, 2020
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Stratospheric smoke particles are found to significantly depolarize incident light, while this effect is also accompanied by a strong spectral dependence. We utilize scattering simulations to show that this behaviour can be attributed to the near-spherical shape of the particles. We also examine whether an extension of the current AERONET scattering model to include the near-spherical shapes could be of benefit to the AERONET retrieval for stratospheric smoke associated with enhanced PLDR.
Landon A. Rieger, Jason N. S. Cole, John C. Fyfe, Stephen Po-Chedley, Philip J. Cameron-Smith, Paul J. Durack, Nathan P. Gillett, and Qi Tang
Geosci. Model Dev., 13, 4831–4843, https://doi.org/10.5194/gmd-13-4831-2020, https://doi.org/10.5194/gmd-13-4831-2020, 2020
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Recently, the stratospheric aerosol forcing dataset used as an input to the Coupled Model Intercomparison Project phase 6 was updated. This work explores the impact of those changes on the modelled historical climates in the CanESM5 and EAMv1 models. Temperature differences in the stratosphere shortly after the Pinatubo eruption are found to be significant, but surface temperatures and precipitation do not show a significant change.
Cited articles
Acharya, P., Barik, G., Gayen, B. K., Bar, S., Maiti, A., Sarkar, A., Ghosh, S., De, S. K., and Sreekesh, S.: Revisiting the Levels of Aerosol Optical Depth in South-Southeast Asia, Europe and USA amid the COVID-19 Pandemic Using Satellite Observations, Environ. Res., 193, 110514, https://doi.org/10.1016/j.envres.2020.110514, 2021. a, b
Acosta Navarro, J. C., Ekman, A. M. L., Pausata, F. S. R., Lewinschal, A., Varma, V., Seland, Ø., Gauss, M., Iversen, T., Kirkevåg, A., Riipinen, I., and Hansson, H. C.: Future Response of Temperature and Precipitation to Reduced Aerosol Emissions as Compared with Increased Greenhouse Gas Concentrations, J. Climate, 30, 939–954, https://doi.org/10.1175/JCLI-D-16-0466.1, 2017. a
Al-Abadleh, H. A., Lysy, M., Neil, L., Patel, P., Mohammed, W., and Khalaf, Y.: Rigorous Quantification of Statistical Significance of the COVID-19 Lockdown Effect on Air Quality: The Case from Ground-Based Measurements in Ontario, Canada, J. Hazard. Mat., 413, 125445, https://doi.org/10.1016/j.jhazmat.2021.125445, 2021. a
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Chang, Y., Huang, R.-J., Ge, X., Huang, X., Hu, J., Duan, Y., Zou, Z., Liu, X., and Lehmann, M. F.: Puzzling Haze Events in China During the Coronavirus (COVID-19) Shutdown, Geophys. Res. Lett., 47, e2020GL088533, https://doi.org/10.1029/2020GL088533, 2020. a, b
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Eyring, V., Gillett, N., Achuta Rao, K., Barimalala, R., Barreiro Parrillo, M., Bellouin, N., Cassou, C., Durack, P., Kosaka, Y., McGregor, S., Min, S., Morgenstern, O., and Sun, Y.: Human Influence on the Climate System, p. 423–552, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, https://doi.org/10.1017/9781009157896.005, 2021. a
Fasullo, J. T., Rosenbloom, N., Buchholz, R. R., Danabasoglu, G., Lawrence, D. M., and Lamarque, J.-F.: Coupled Climate Responses to Recent Australian Wildfire and COVID-19 Emissions Anomalies Estimated in CESM2, Geophys. Res. Lett., 48, e2021GL097420, https://doi.org/10.1029/2021GL093841, 2021. a, b
Fiedler, S., Wyser, K., Rogelj, J., and van Noije, T.: Radiative Effects of Reduced Aerosol Emissions during the COVID-19 Pandemic and the Future Recovery, Atmos. Res., 264, 105866, https://doi.org/10.1016/j.atmosres.2021.105866, 2021. a, b
Field, R. D., Hickman, J. E., Geogdzhayev, I. V., Tsigaridis, K., and Bauer, S. E.: Changes in satellite retrievals of atmospheric composition over eastern China during the 2020 COVID-19 lockdowns, Atmos. Chem. Phys., 21, 18333–18350, https://doi.org/10.5194/acp-21-18333-2021, 2021. a, b, c, d
Forster, P. M., Forster, H. I., Evans, M. J., Gidden, M. J., Jones, C. D., Keller, C. A., Lamboll, R. D., Quéré, C. L., Rogelj, J., Rosen, D., Schleussner, C.-F., Richardson, T. B., Smith, C. J., and Turnock, S. T.: Current and Future Global Climate Impacts Resulting from COVID-19, Nat. Clim. Chang., 10, 913–919, https://doi.org/10.1038/s41558-020-0883-0, 2020. a, b, c, d, e
Fyfe, J. C., Kharin, V. V., Swart, N., Flato, G. M., Sigmond, M., and Gillett, N. P.: Quantifying the Influence of Short-Term Emission Reductions on Climate, Sci. Adv., 7, eabf7133, https://doi.org/10.1126/sciadv.abf7133, 2021. a, b
Gao, J., Yang, Y., Wang, H., Wang, P., Li, H., Li, M., Ren, L., Yue, X., and Liao, H.: Fast climate responses to emission reductions in aerosol and ozone precursors in China during 2013–2017, Atmos. Chem. Phys., 22, 7131–7142, https://doi.org/10.5194/acp-22-7131-2022, 2022. a
Gaubert, B., Bouarar, I., Doumbia, T., Liu, Y., Stavrakou, T., Deroubaix, A., Darras, S., Elguindi, N., Granier, C., Lacey, F., Müller, J.-F., Shi, X., Tilmes, S., Wang, T., and Brasseur, G. P.: Global Changes in Secondary Atmospheric Pollutants During the 2020 COVID-19 Pandemic, J. Geophys. Res.-Atmos., 126, e2020JD034213, https://doi.org/10.1029/2020JD034213, 2021. a
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Gettelman, A., Chen, C.-C., and Bardeen, C. G.: The climate impact of COVID-19-induced contrail changes, Atmos. Chem. Phys., 21, 9405–9416, https://doi.org/10.5194/acp-21-9405-2021, 2021. a, b
Gkatzelis, G. I., Gilman, J. B., Brown, S. S., Eskes, H., Gomes, A. R., Lange, A. C., McDonald, B. C., Peischl, J., Petzold, A., Thompson, C. R., and Kiendler-Scharr, A.: The Global Impacts of COVID-19 Lockdowns on Urban Air Pollution, Elem. Sci. Anthr., 9, 00176, https://doi.org/10.1525/elementa.2021.00176, 2021. a, b
Gkikas, A., Proestakis, E., Amiridis, V., Kazadzis, S., Di Tomaso, E., Tsekeri, A., Marinou, E., Hatzianastassiou, N., and Pérez García-Pando, C.: ModIs Dust AeroSol (MIDAS): a global fine-resolution dust optical depth data set, Atmos. Meas. Tech., 14, 309–334, https://doi.org/10.5194/amt-14-309-2021, 2021. a, b, c, d
Goldberg, D. L., Anenberg, S. C., Griffin, D., McLinden, C. A., Lu, Z., and Streets, D. G.: Disentangling the Impact of the COVID-19 Lockdowns on Urban NO2 From Natural Variability, Geophys. Res. Lett., 47, e2020GL089269, https://doi.org/10.1029/2020GL089269, 2020. a, b
Gouda, K., Gogeri, I., and ThippaReddy, A.: Assessment of Aerosol Optical Depth over Indian Subcontinent during COVID-19 lockdown (March–May 2020), Environ. Monit. Assess., 194, 1573–2959, https://doi.org/10.1007/s10661-022-09855-3, 2022. a
Griffin, D., McLinden, C. A., Racine, J., Moran, M. D., Fioletov, V., Pavlovic, R., Mashayekhi, R., Zhao, X., and Eskes, H.: Assessing the Impact of Corona-Virus-19 on Nitrogen Dioxide Levels over Southern Ontario, Canada, Remote Sens., 12, 4112, https://doi.org/10.3390/rs12244112, 2020. a
Hajima, T., Watanabe, M., Yamamoto, A., Tatebe, H., Noguchi, M. A., Abe, M., Ohgaito, R., Ito, A., Yamazaki, D., Okajima, H., Ito, A., Takata, K., Ogochi, K., Watanabe, S., and Kawamiya, M.: Development of the MIROC-ES2L Earth system model and the evaluation of biogeochemical processes and feedbacks, Geosci. Model Dev., 13, 2197–2244, https://doi.org/10.5194/gmd-13-2197-2020, 2020. a
Hale, T., Angrist, N., Goldszmidt, R., Kria, B., Petherick, A., Phillips, T., Webster, S., Cameron-Blake, E., Hallas, L., Majumdar, S., and Tatlow, H.: A global panel database of pandemic policies (Oxford COVID-19 Government Response Tracker), Nature Human Behaviour, https://doi.org/10.1038/s41562-021-01079-8, 2021. a
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Short summary
The COVID-19 lockdowns reduced aerosol emissions. We ask whether these reductions affected regional aerosol optical depth (AOD) and compare the observed changes to predictions from Earth system models. Only India has an observed AOD reduction outside of typical variability. Models overestimate the response in some regions, but when key biases have been addressed, the agreement is improved. Our results suggest that current models can realistically predict the effects of future emission changes.
The COVID-19 lockdowns reduced aerosol emissions. We ask whether these reductions affected...
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