Chemical transport models often underestimate inorganic aerosol acidity in remote regions of the atmosphere

Autor(en)

Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Duseong S. Jo, Jason C. Schroder, Hannah M. Allen, Roya Bahreini, Huisheng Bian, Donald R. Blake, Mian Chin, Simon L. Clegg, Peter R. Colarco, John D. Crounse, Michael J. Cubison, Peter F. DeCarlo, Jack E. Dibb, Glenn S. Diskin, Alma Hodzic, Weiwei Hu, Joseph M. Katich, Michelle J. Kim, John K. Kodros, Agnieszka Kupc, Felipe D. Lopez-Hilfiker, Eloise A. Marais, Ann M. Middlebrook, J. Andrew Neuman, John B. Nowak, Brett B. Palm, Fabien Paulot, Jeffrey R. Pierce, Gregory P. Schill, Eric Scheuer, Joel A. Thornton, Kostas Tsigaridis, Paul O. Wennberg, Christina J. Williamson, Jose L. Jimenez

Abstrakt

The acidity of inorganic aerosols in remote areas is often higher than predicted by chemical transport models, which may lead to an underestimation of direct radiative cooling, according to global aircraft observations of pH and ammonium balance in aerosols

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 R-2 < 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%.

Organisation(en)

Aerosolphysik und Umweltphysik

Externe Organisation(en)

University of Colorado, Boulder, California Institute of Technology (Caltech), University of California, Riverside, University of Maryland, Baltimore, National Aeronautics & Space Administration (NASA), University of California, Irvine, University of East Anglia, TOFWERK USA, Johns Hopkins University, University of New Hampshire, Chinese Academy of Sciences (CAS), National Oceanic and Atmospheric Administration, Tofwerk AG, University of Leicester, University of Washington, Columbia University in the City of New York, Colorado State University, National Center for Atmospheric Research (NCAR)

Journal

Communications Earth & Environment

Band

2

Anzahl der Seiten

13

ISSN

2662-4435

DOI

https://doi.org/10.1038/s43247-021-00164-0

Publikationsdatum

05-2021

Peer-reviewed

Ja

ÖFOS 2012

103037 Umweltphysik, 104023 Umweltchemie, 103039 Aerosolphysik, 105208 Atmosphärenchemie

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Umweltwissenschaft, Allgemeine Erdkunde und Planetologie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/d283aa7f-7cb2-4269-bc6f-862a9b997897