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Decreased Aviation Leads to Increased Ice Crystal Number and a Positive Radiative Effect in Cirrus Clouds
dc.contributor.authorZhu, Jialei
dc.contributor.authorPenner, Joyce E.
dc.contributor.authorGarnier, Anne
dc.contributor.authorBoucher, Olivier
dc.contributor.authorGao, Meng
dc.contributor.authorSong, Lei
dc.contributor.authorDeng, Junjun
dc.contributor.authorLiu, Cong-Qiang
dc.contributor.authorFu, Pingqing
dc.date.accessioned2022-04-08T18:04:22Z
dc.date.available2023-05-08 14:04:17en
dc.date.available2022-04-08T18:04:22Z
dc.date.issued2022-04
dc.identifier.citationZhu, Jialei; Penner, Joyce E.; Garnier, Anne; Boucher, Olivier; Gao, Meng; Song, Lei; Deng, Junjun; Liu, Cong-Qiang ; Fu, Pingqing (2022). "Decreased Aviation Leads to Increased Ice Crystal Number and a Positive Radiative Effect in Cirrus Clouds." AGU Advances 3(2): n/a-n/a.
dc.identifier.issn2576-604X
dc.identifier.issn2576-604X
dc.identifier.urihttps://hdl.handle.net/2027.42/172020
dc.description.abstractTravel restrictions in the wake of the COVID‐19 pandemic resulted in an unprecedented decrease of 73% in global flight mileage in April–May 2020 compared to 2019. Here we examine the CALIPSO satellite observations and find a significant increase in ice crystal number concentrations (Ni) in cirrus clouds in the mid‐latitudes of the Northern Hemisphere, which we attribute to an increase in homogeneous freezing when soot from aircraft emissions is reduced. A relatively small positive global average radiative effect of 21 mW m−2 is estimated if a decrease in aircraft traffic continues, with an average of up to 64 mW m−2 over the area where aviation is most active. We infer from this analysis that the worldwide adoption of biofuel blending in aircraft fuels that lead to smaller soot emissions could lead to a significant change in the microphysical properties of cirrus clouds but a rather small positive radiative effect.Plain Language SummaryCirrus clouds play an important role in the Earth’s radiation budget. Whether soot from aircraft emissions would change the property of large‐scale cirrus clouds has been a critical question. We show that the unprecedented decrease in aircraft traffic as a result of the COVID‐19 pandemic leads to a significant increase in ice crystal number as detected by satellite. An increase in ice crystal number and positive radiative effect is estimated using a state‐of‐the‐science earth system model if the reduction in aviation activity continues for the foreseeable future. As adoption of blending biofuel in the aviation sector would lead to similar reductions (50%–70%) of aircraft soot emissions in the future, remarkable changes in the microphysical properties of large‐cirrus clouds and positive radiative effects can be expected relative to a case with no biofuel blending.Key PointsA significant increase in the number of ice crystals in cirrus clouds was found due to the decreased aircraft soot emissionThe increased ice crystal number can be explained by an enhancement of homogeneous freezing due to the decreased ice nuclei particlesWorldwide adoption of biofuel blending could lead to a significant change in the microphysical properties of cirrus clouds in the future
dc.publisherWiley Periodicals, Inc.
dc.publisherMassachusetts Institute of Technology (MIT)
dc.subject.otherradiative effects
dc.subject.othercirrus clouds
dc.subject.otheraircraft soot
dc.subject.otherCOVID‐19
dc.titleDecreased Aviation Leads to Increased Ice Crystal Number and a Positive Radiative Effect in Cirrus Clouds
dc.typeArticle
dc.rights.robotsIndexNoFollow
dc.subject.hlbsecondlevelEarth and Environmental Sciences
dc.subject.hlbtoplevelScience
dc.description.peerreviewedPeer Reviewed
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/172020/1/aga220141.pdf
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/172020/2/2021AV000546-sup-0005-First_Revision_of_Manuscript_Accepted_S04.pdf
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/172020/3/2021AV000546-sup-0004-Author_Response_to_Peer_Review_Comments_S03.pdf
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/172020/4/aga220141_am.pdf
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/172020/5/2021AV000546-sup-0003-Peer_Review_History-S02.pdf
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/172020/6/2021AV000546-sup-0002-Original_Version_of_Manuscript-S01.pdf
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/172020/7/2021AV000546-sup-0001-Supporting_Information_SI-S01.pdf
dc.identifier.doi10.1029/2021AV000546
dc.identifier.sourceAGU Advances
dc.identifier.citedreferenceSchumann, U., Poll, I., Teoh, R., Koelle, R., Spinielli, E., Molloy, J., et al. ( 2021 ). Air traffic and contrail changes over Europe during COVID‐19: A model study. Atmospheric Chemistry and Physics, 21 ( 10 ), 7429 – 7450.
dc.identifier.citedreferenceLe Quéré, C., Jackson, R. B., Jones, M. W., Smith, A. J. P., Abernethy, S., Andrew, R. M., et al. ( 2020 ). Temporary reduction in daily global CO 2 emissions during the COVID‐19 forced confinement. Nature Climate Change, 10 ( 7 ), 647 – 653. https://doi.org/10.1038/s41558-020-0797-x
dc.identifier.citedreferenceMahrt, F., Kilchhofer, K., Marcolli, C., Grönquist, P., David, R. O., Rösch, M., et al. ( 2019 ). The impact of cloud processing on the ice nucleation abilities of soot particles at cirrus temperatures. Journal of Geophysical Research: Atmospheres.
dc.identifier.citedreferenceMahrt, F., Kilchhofer, K., Marcolli, C., Grönquist, P., David, R. O., Rösch, M., et al. ( 2020 ). The impact of cloud processing on the ice nucleation abilities of soot particles at cirrus temperatures. Journal of Geophysical Research: Atmospheres, 125 ( 3 ). https://doi.org/10.1029/2019jd030922
dc.identifier.citedreferenceMitchell, D. L., Garnier, A., Pelon, J., & Erfani, E. ( 2018 ). CALIPSO (IIR‐CALIOP) retrievals of cirrus cloud ice‐particle concentrations. Atmospheric Chemistry and Physics, 18 ( 23 ), 17325 – 17354.
dc.identifier.citedreferenceMohler, O., Buttner, S., Linke, C., Schnaiter, M., Saathoff, H., Stetzer, O., et al. ( 2005 ). Effect of sulfuric acid coating on heterogeneous ice nucleation by soot aerosol particles. Journal of Geophysical Research: Atmospheres, 110 ( D11 ). https://doi.org/10.1029/2004jd005169
dc.identifier.citedreferenceMoore, R. H., Thornhill, K. L., Weinzierl, B., Sauer, D., D’Ascoli, E., Kim, J., et al. ( 2017 ). Biofuel blending reduces particle emissions from aircraft engines at cruise conditions. Nature, 543 ( 7645 ), 411 – 415. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/28300096
dc.identifier.citedreferencePenner, J. E., Zhou, C., Garnier, A., & Mitchell, D. L. ( 2018 ). Anthropogenic aerosol indirect effects in cirrus clouds. Journal of Geophysical Research: Atmospheres, 123 ( 20 ), 11652 – 11677. https://doi.org/10.1029/2018jd029204
dc.identifier.citedreferencePhillips, C. A., Caldas, A., Cleetus, R., Dahl, K. A., Declet‐Barreto, J., Licker, R., et al. ( 2020 ). Compound climate risks in the COVID‐19 pandemic. Nature Climate Change, 10 ( 7 ), 586 – 588. https://doi.org/10.1038/s41558-020-0804-2
dc.identifier.citedreferenceRichardson, M. S., DeMott, P. J., Kreidenweis, S. M., Cziczo, D. J., Dunlea, E. J., Jimenez, J. L., et al. ( 2007 ). Measurements of heterogeneous ice nuclei in the Western United States in springtime and their relation to aerosol characteristics. Journal of Geophysical Research: Atmospheres, 112 ( D2 ). https://doi.org/10.1029/2006jd007500
dc.identifier.citedreferenceSABRE. ( 2020 ). Market intelligence global demand data. Retrieved from http://www.sabreairlinesolutions.com/home/software_solutions/airports/
dc.identifier.citedreferenceSamset, B. H., Myhre, G., Herber, A., Kondo, Y., Li, S. M., Moteki, N., et al. ( 2014 ). Modelled black carbon radiative forcing and atmospheric lifetime in AeroCom Phase II constrained by aircraft observations. Atmospheric Chemistry and Physics, 14 ( 22 ), 12465 – 12477. https://doi.org/10.5194/acp-14-12465-2014
dc.identifier.citedreferenceSourdeval, O., Gryspeerdt, E., Kraemer, M., Goren, T., Delanoe, J., Afchine, A., et al. ( 2018 ). Ice crystal number concentration estimates from lidar‐radar satellite remote sensing–Part 1: Method and evaluation. Atmospheric Chemistry and Physics, 18 ( 19 ), 14327 – 14350.
dc.identifier.citedreferenceStröm, J., & Ohlsson, S. ( 1998 ). In situ measurements of enhanced crystal number densities in cirrus clouds caused by aircraft exhaust. Journal of Geophysical Research: Atmospheres, 103 ( D10 ), 11355 – 11361. https://doi.org/10.1029/98jd00807
dc.identifier.citedreferenceTesche, M., Achtert, P., Glantz, P., & Noone, K. J. ( 2016 ). Aviation effects on already‐existing cirrus clouds. Nature Communications, 7, 12016. https://doi.org/10.1038/ncomms12016
dc.identifier.citedreferenceUrbanek, B., Groß, S., Wirth, M., Rolf, C., Krämer, M., & Voigt, C. ( 2018 ). High depolarization ratios of naturally occurring cirrus clouds near air traffic regions over Europe. Geophysical Research Letters, 45 ( 23 ), 13166 – 13172. https://doi.org/10.1029/2018gl079345
dc.identifier.citedreferenceVenter, Z. S., Aunan, K., Chowdhury, S., & Lelieveld, J. ( 2020 ). COVID‐19 lockdowns cause global air pollution declines. Proceedings of the National Academy of Sciences of the United States of America, 117 ( 32 ), 18984 – 18990. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/32723816
dc.identifier.citedreferenceWang, B., Lambe, A. T., Massoli, P., Onasch, T. B., Davidovits, P., Worsnop, D. R., & Knopf, D. A. ( 2012 ). The deposition ice nucleation and immersion freezing potential of amorphous secondary organic aerosol: Pathways for ice and mixed‐phase cloud formation. Journal of Geophysical Research: Atmospheres, 117 ( D16 ). https://doi.org/10.1029/2012jd018063
dc.identifier.citedreferenceWilkerson, J. T., Jacobson, M. Z., Malwitz, A., Balasubramanian, S., Wayson, R., Fleming, G., et al. ( 2010 ). Analysis of emission data from global commercial aviation: 2004 and 2006. Atmospheric Chemistry and Physics, 10 ( 13 ), 6391 – 6408.
dc.identifier.citedreferenceWorldometers ( 2021 ). Coronavirus cases. Accessed on 25. 10. 2021. Retrieved from https://www.worldometers.info/coronavirus/
dc.identifier.citedreferenceYang, Y., Ren, L., Li, H., Wang, H., Wang, P., Chen, L., et al. ( 2020 ). Fast climate responses to aerosol emission reductions during the COVID‐19 pandemic. Geophysical Research Letters, 47 ( 19 ). https://doi.org/10.1029/2020gl089788
dc.identifier.citedreferenceZhao, B., Wang, Y., Gu, Y., Liou, K. N., Jiang, J. H., Fan, J., et al. ( 2019 ). Ice nucleation by aerosols from anthropogenic pollution. Nature Geoscience, 12, 602 – 607. https://doi.org/10.1038/s41561-019-0389-4
dc.identifier.citedreferenceZheng, B., Zhang, Q., Geng, G., Chen, C., Shi, Q., Cui, M., et al. ( 2021 ). Changes in China’s anthropogenic emissions and air quality during the COVID‐19 pandemic in 2020. Earth System Science Data, 13 ( 6 ), 2895 – 2907. https://doi.org/10.5194/essd-13-2895-2021
dc.identifier.citedreferenceZhou, C., & Penner, J. E. ( 2014 ). Aircraft soot indirect effect on large‐scale cirrus clouds: Is the indirect forcing by aircraft soot positive or negative? Journal of Geophysical Research: Atmospheres, 119 ( 19 ), 11303 – 11320.
dc.identifier.citedreferenceZhu, J., & Penner, J. E. ( 2019 ). Global modeling of secondary organic aerosol with organic nucleation. Journal of Geophysical Research: Atmospheres, 124 ( 14 ), 8260 – 8286. https://doi.org/10.1029/2019jd030414
dc.identifier.citedreferenceZhu, J., & Penner, J. E. ( 2020a ). Indirect Effects of Secondary Organic Aerosol on Cirrus Clouds. Journal of Geophysical Research: Atmospheres, 125 ( 7 ). https://doi.org/10.1029/2019jd032233
dc.identifier.citedreferenceZhu, J., & Penner, J. E. ( 2020b ). Radiative forcing of anthropogenic aerosols on cirrus clouds using a hybrid ice nucleation scheme. Atmospheric Chemistry and Physics, 20 ( 13 ), 7801 – 7827. https://doi.org/10.5194/acp-20-7801-2020
dc.identifier.citedreferenceZhu, J., Penner, J. E., Lin, G., Zhou, C., Xu, L., & Zhuang, B. ( 2017 ). Mechanism of SOA formation determines magnitude of radiative effects. Proceedings of the National Academy of Sciences of the United States of America, 114 ( 48 ), 12685 – 12690. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/29133426
dc.identifier.citedreferenceZhu, J., Penner, J. E., Yu, F., Sillman, S., Andreae, M. O., & Coe, H. ( 2019 ). Decrease in radiative forcing by organic aerosol nucleation, climate, and land use change. Nature Communications, 10 ( 1 ), 423. https://doi.org/10.1038/s41467-019-08407-7
dc.identifier.citedreferenceAdrienne, N., Budd, L., & Ison, S. ( 2020 ). Grounded aircraft: An airfield operations perspective of the challenges of resuming flights post COVID. Journal of Air Transport Management, 89, 101921. https://doi.org/10.1016/j.jairtraman.2020.101921
dc.identifier.citedreferenceAirbus ( 2019 ). Global market forecase: Cities, airports & aircraft 2019‐2038. Retrieved from https://www.airbus.com/content/dam/corporate-topics/strategy/global-market-forecast/GMF-2019-2038-Airbus-Commercial-Aircraft-book.pdf
dc.identifier.citedreferenceBarrett, S., Prather, M., Penner, J., Selkirk, H., Balasubramanian, S., Dopelheuer, A., et al. ( 2010 ). Guidance on the use of AEDT gridded aircraft emissions in atmospheric models. In A technical note submitted to the US Federal Aviation Administration. Massachusetts Institute of Technology (MIT).
dc.identifier.citedreferenceBavel, J. J. V., Baicker, K., Boggio, P. S., Capraro, V., Cichocka, A., Cikara, M., et al. ( 2020 ). Using social and behavioural science to support COVID‐19 pandemic response. Nature Human Behaviour, 4 ( 5 ), 460 – 471. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/32355299
dc.identifier.citedreferenceBickel, M., Ponater, M., Bock, L., Burkhardt, U., & Reineke, S. ( 2020 ). Estimating the effective radiative forcing of contrail cirrus. Journal of Climate, 33 ( 5 ), 1991 – 2005. https://doi.org/10.1175/jcli-d-19-0467.1
dc.identifier.citedreferenceBogoch, I. I., Watts, A., Thomas‐Bachli, A., Huber, C., Kraemer, M. U. G., & Khan, K. ( 2020a ). Pneumonia of unknown aetiology in Wuhan, China: Potential for international spread via commercial air travel. Journal of Travel Medicine, 27 ( 2 ). https://doi.org/10.1093/jtm/taaa008
dc.identifier.citedreferenceBogoch, I. I., Watts, A., Thomas‐Bachli, A., Huber, C., Kraemer, M. U. G., & Khan, K. ( 2020b ). Potential for global spread of a novel coronavirus from China. Journal of Travel Medicine, 27 ( 2 ). https://doi.org/10.1093/jtm/taaa011
dc.identifier.citedreferenceCantrell, W., & Heymsfield, A. ( 2005 ). Production of ice in tropospheric clouds: A review. Bulletin of the American Meteorological Society, 86 ( 6 ), 795 – 808. https://doi.org/10.1175/bams-86-6-795
dc.identifier.citedreferenceCziczo, D. J., Murphy, D. M., Hudson, P. K., & Thomson, D. S. ( 2004 ). Single particle measurements of the chemical composition of cirrus ice residue during CRYSTAL‐FACE. Journal of Geophysical Research: Atmospheres, 109 ( D4 ). https://doi.org/10.1029/2003jd004032
dc.identifier.citedreferenceDeMott, P., Cziczo, D., Prenni, A., Murphy, D., Kreidenweis, S., Thomson, D., et al. ( 2003 ). Measurements of the concentration and composition of nuclei for cirrus formation. Proceedings of the National Academy of Sciences, 100 ( 25 ), 14655 – 14660. https://doi.org/10.1073/pnas.2532677100
dc.identifier.citedreferenceDeMott, P. J., Chen, Y., Kreidenweis, S. M., Rogers, D. C., & Sherman, D. E. ( 1999 ). Ice formation by black carbon particles. Geophysical Research Letters, 26 ( 16 ), 2429 – 2432.
dc.identifier.citedreferenceEvangeliou, N., Platt, S. M., Eckhardt, S., Lund Myhre, C., Laj, P., Alados‐Arboledas, L., et al. ( 2021 ). Changes in black carbon emissions over Europe due to COVID‐19 lockdowns. Atmospheric Chemistry and Physics, 21 ( 4 ), 2675 – 2692. https://doi.org/10.5194/acp-21-2675-5722021
dc.identifier.citedreferenceForster, P. M., Forster, H. I., Evans, M. J., Gidden, M. J., Jones, C. D., Keller, C. A., et al. ( 2020 ). Current and future global climate impacts resulting from COVID‐19. Nature Climate Change, 10 ( 10 ), 913 – 919. https://doi.org/10.1038/s41558-020-0883-0
dc.identifier.citedreferenceGarnier, A., Pelon, J., Pascal, N., Vaughan, M. A., Dubuisson, P., Yang, P., & Mitchell, D. L. ( 2021a ). Version 4 CALIPSO Imaging Infrared Radiometer ice and liquid water cloud microphysical properties – Part I: The retrieval algorithms. Atmospheric Measurement Techniques, 14, 3253 – 3276. https://doi.org/10.5194/amt-14-3253-2021
dc.identifier.citedreferenceGarnier, A., Pelon, J., Pascal, N., Vaughan, M. A., Dubuisson, P., Yang, P., & Mitchell, D. L. ( 2021b ). Version 4 CALIPSO Imaging Infrared Radiometer ice and liquid water cloud microphysical properties – Part II: Results over oceans. Atmospheric Measurement Techniques, 14, 3277 – 3299. https://doi.org/10.5194/amt-14-3277-2021
dc.identifier.citedreferenceGasparini, B., Blossey, P. N., Hartmann, D. L., Lin, G., & Fan, J. ( 2019 ). What drives the life cycle of tropical anvil clouds? Journal of Advances in Modeling Earth Systems, 11 ( 8 ), 2586 – 2605.
dc.identifier.citedreferenceGasparini, B., Meyer, A., Neubauer, D., Munch, S., & Lohmann, U. ( 2018 ). Cirrus cloud properties as seen by the CALIPSO satellite and ECHAM‐HAM global climate model. Journal of Climate, 31 ( 5 ), 1983 – 2003.
dc.identifier.citedreferenceGryspeerdt, E., Sourdeval, O., Quaas, J., Delanoe, J., Kraemer, M., & Kuehne, P. ( 2018 ). Ice crystal number concentration estimates from lidar‐radar satellite remote sensing – Part 2: Controls on the ice crystal number concentration. Atmospheric Chemistry and Physics, 18 ( 19 ), 14351 – 14370.
dc.identifier.citedreferenceHe, G., Pan, Y., & Tanaka, T. ( 2020 ). The short‐term impacts of COVID‐19 lockdown on urban air pollution in China. Nature Sustainability, 3 ( 12 ), 1005 – 1011. https://doi.org/10.1038/s41893-020-0581-y
dc.identifier.citedreferenceHoose, C., & Möhler, O. ( 2012 ). Heterogeneous ice nucleation on atmospheric aerosols: A review of results from laboratory experiments. Atmospheric Chemistry and Physics, 12 ( 20 ), 9817 – 9854. https://doi.org/10.5194/acp-12-9817-2012
dc.identifier.citedreferenceHuang, X., Ding, A., Gao, J., Zheng, B., Zhou, D., Qi, X., et al. ( 2020 ). Enhanced secondary pollution offset reduction of primary emissions during COVID‐19 lockdown in China. National Science Review. https://doi.org/10.1093/nsr/nwaa137
dc.identifier.citedreferenceJensen, E. J., Lawson, R. P., Bergman, J. W., Pfister, L., Bui, T. P., & Schmitt, C. G. ( 2013 ). Physical processes controlling ice concentrations in synoptically forced, midlatitude cirrus. Journal of Geophysical Research: Atmospheres, 118 ( 11 ), 5348 – 5360.
dc.identifier.citedreferenceJoos, H., Spichtinger, P., Reutter, P., & Fusina, F. ( 2014 ). Influence of heterogeneous freezing on the microphysical and radiative properties of orographic cirrus clouds. Atmospheric Chemistry and Physics, 14 ( 13 ), 6835 – 6852.
dc.identifier.citedreferenceKärcher, B., Mahrt, F., & Marcolli, C. ( 2021 ). Process‐oriented analysis of aircraft soot‐cirrus interactions constrains the climate impact of aviation. Communications Earth & Environment, 2 ( 1 ), 113. https://doi.org/10.1038/s43247-021-00175-x
dc.identifier.citedreferenceKoop, T., Luo, B. P., Tsias, A., & Peter, T. ( 2000 ). Water activity as the determinant for homogeneous ice nucleation in aqueous solutions. Nature, 406 ( 6796 ), 611 – 614.
dc.identifier.citedreferenceLawson, P., Gurganus, C., Woods, S., & Bruintjes, R. ( 2017 ). Aircraft observations of cumulus microphysics ranging from the tropics to midlatitudes: Implications for a “new’’ secondary ice process. Journal of the Atmospheric Sciences, 74 ( 9 ), 2899 – 2920.
dc.identifier.citedreferenceLawson, R. P., Woods, S., & Morrison, H. ( 2015 ). The microphysics of ice and precipitation development in tropical cumulus clouds. Journal of the Atmospheric Sciences, 72 ( 6 ), 2429 – 2445.
dc.identifier.citedreferenceLee, D. S., Fahey, D. W., Skowron, A., Allen, M. R., Burkhardt, U., Chen, Q., et al. ( 2021 ). The contribution of global aviation to anthropogenic climate forcing for 2000 to 2018. Atmospheric Environment, 244, 117834. https://doi.org/10.1016/j.atmosenv.2020.117834
dc.working.doiNOen
dc.owningcollnameInterdisciplinary and Peer-Reviewed


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