Microphysical explanation of the RH-dependent water affinity of biogenic organic aerosol and its importance for climate
Acosta Navarro, JC
Geophysical Research Letters
American Geophysical Union (AGU)
©2017. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
A large fraction of atmospheric organic aerosol (OA) originates from natural emissions that are oxidized in the atmosphere to form secondary organic aerosol (SOA). Isoprene (IP) and monoterpenes (MT) are the most important precursors of SOA originating from forests. The climate impacts from OA are currently estimated through parameterizations of water uptake that drastically simplify the complexity of OA. We combine laboratory experiments, thermodynamic modeling, field observations, and climate modeling to (1) explain the molecular mechanisms behind RH-dependent SOA water-uptake with solubility and phase separation; (2) show that laboratory data on IP- and MT-SOA hygroscopicity are representative of ambient data with corresponding OA source profiles; and (3) demonstrate the sensitivity of the modeled aerosol climate effect to assumed OA water affinity. We conclude that the commonly used single-parameter hygroscopicity framework can introduce significant error when quantifying the climate effects of organic aerosol. The results highlight the need for better constraints on the overall global OA mass loadings and its molecular composition, including currently underexplored anthropogenic and marine OA sources.
The data presented in the paper will be available through the Bolin Centre database (http://bolin.su.se/data/). The EC H2020 European Research Council ERC (ERC-StGATMOGAIN-278277 and ERC-StG-QAPPA-335478) and integrated project 641816 CRESCENDO Svenska Forskningsrådet Formas (Swedish Research Council Formas) (2015-749), Knut och Alice Wallenbergs Stiftelse (Knut and Alice Wallenberg Foundation Wallenberg Fellowship AtmoRemove), Academy of Finland (grants 272041 and 259005), Natural Environment Research Council (NERC grants NE/M003531/1 and NE/J02175X/1), Norwegian Research Council (EVA grant 229771), Natural Sciences and Engineering Research Council of Canada (NSERC, grant RGPIN/04315-2014), National Science Foundation (NSF, grants ATM-1242258, AGS-1242932, and AGS-1360834), U.S. Environmental Protection Agency (EPA, STAR grant R835410), National Oceanic and Atmospheric Administration (NOAA, CPO award 538NA10OAR4310102), Electric Power Research Institute (EPRI, grant 10004734), U.S. Department of Energy (DOE, grants BER/ASR DE-SC0016559 and DE-SC0012792), Georgia Institute of Technology, and NordForsk (Nordic Centre of Excellence eSTICC) are gratefully acknowledged for funding. The climate model simulations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC) at the National Supercomputing Centre. Benjamin Murphy is acknowledged for useful discussions.
This is the final version of the article. Available from American Geophysical Union via the DOI in this record.
Vol. 44 (10), pp. 5167 - 5177
Showing items related by title, author, creator and subject.
New trajectory-driven aerosol and chemical process model Chemical and Aerosol Lagrangian Model (CALM) Tunved, P; Partridge, DG; Korhonen, H (European Geosciences Union (EGU) / Copernicus Publications, 2010-11-01)A new Chemical and Aerosol Lagrangian Model (CALM) has been developed and tested. The model incorporates all central aerosol dynamical processes, from nucleation, condensation, coagulation and deposition to cloud formation ...
HST hot-Jupiter transmission spectral survey: Evidence for aerosols and lack of TiO in the atmosphere of WASP-12b Sing, David K.; Lecavelier des Etangs, A.; Fortney, J.J.; Burrows, A.S.; Pont, F.; Wakeford, H.R.; Ballester, G.; Nikolov, N.; Henry, G.; Aigrain, Suzanne; Deming, D.; Evans, T.M.; Gibson, N.; Huitson, Catherine M.; Knutson, H.; Showman, A.P.; Vidal-Madjar, A.; Wilson, Paul A.; Williamson, M.H.; Zahnle, K. (Oxford University Press on behalf of the Royal Astronomical Society, 2013)We present Hubble Space Telescope (HST) optical transmission spectra of the transiting hot-Jupiter WASP-12b, taken with the Space Telescope Imaging Spectrograph instrument. The resulting spectra cover the range 2900–10 300 Å ...
Osborne, Joe M.; Lambert, F. Hugo (Nature Publishing Group, 2014)Regional temperature change over the twentieth century has been strongly influenced by aerosol forcing [1, 2]. The aerosol effect is also expected to be pronounced on regional precipitation change . Changes in historical ...