@article{820026b3159d4e9f8d50e823e3f525ea,
title = "Chemical transport models often underestimate inorganic aerosol acidity in remote regions of the atmosphere",
abstract = "The inorganic fraction of fine particles affects numerous physicochemical processes in the atmosphere. However, there is large uncertainty in its burden and composition due to limited global measurements. Here, we present observations from eleven different aircraft campaigns from around the globe and investigate how aerosol pH and ammonium balance change from polluted to remote regions, such as over the oceans. Both parameters show increasing acidity with remoteness, at all altitudes, with pH decreasing from about 3 to about −1 and ammonium balance decreasing from almost 1 to nearly 0. We compare these observations against nine widely used chemical transport models and find that the simulations show more scatter (generally R2 < 0.50) and typically predict less acidic aerosol in the most remote regions. These differences in observations and predictions are likely to result in underestimating the model-predicted direct radiative cooling effect for sulfate, nitrate, and ammonium aerosol by 15–39%.",
author = "Nault, {Benjamin A.} and Pedro Campuzano-Jost and Day, {Douglas A.} and Jo, {Duseong S.} and Schroder, {Jason C.} and Allen, {Hannah M.} and Roya Bahreini and Huisheng Bian and Blake, {Donald R.} and Mian Chin and Clegg, {Simon L.} and Colarco, {Peter R.} and Crounse, {John D.} and Cubison, {Michael J.} and Decarlo, {Peter F.} and Dibb, {Jack E.} and Diskin, {Glenn S.} and Alma Hodzic and Weiwei Hu and Katich, {Joseph M.} and Kim, {Michelle J.} and Kodros, {John K.} and Agnieszka Kupc and Lopez-Hilfiker, {Felipe D.} and Marais, {Eloise A.} and Middlebrook, {Ann M.} and {Andrew Neuman}, J. and Nowak, {John B.} and Palm, {Brett B.} and Fabien Paulot and Pierce, {Jeffrey R.} and Schill, {Gregory P.} and Eric Scheuer and Thornton, {Joel A.} and Kostas Tsigaridis and Wennberg, {Paul O.} and Williamson, {Christina J.} and Jimenez, {Jose L.}",
note = "Funding Information: This work was supported by NASA grants NNX15AH33A, NNX15AJ23G, 80NSSC19K0124, 80NSSC18K0630, NNX15AG61A, NSF grants 1360745, 1652688, and DOE (BER/ASRprogram) DE-SC0016559. We would like to acknowledge high-performance computing support from Cheyenne (doi:10.5065/D6RX99HX) provided by NCAR{\textquoteright}s Computational and Information Systems Laboratory, sponsored by the National Sciences Foundation. ",
year = "2021",
month = may,
day = "14",
doi = "10.1038/s43247-021-00164-0",
language = "English",
volume = "2",
journal = "Communications Earth & Environment",
issn = "2662-4435",
publisher = "Nature Research",
}