A large source of cloud condensation nuclei from new particle formation in the tropics

Autor(en)

Christina J. Williamson, Agnieszka Kupc, Duncan Axisa, Kelsey R. Bilsback, ThaoPaul Bui, Pedro Campuzano-Jost, Maximilian Dollner, Karl D. Froyd, Anna L. Hodshire, Jose L. Jimenez, John K. Kodros, Gan Luo, Daniel M. Murphy, Benjamin A. Nault, Eric A. Ray, Bernadett Weinzierl, James C. Wilson, Fangqun Yu, Pengfei Yu, Jeffrey R. Pierce, Charles A. Brock

Abstrakt

Cloud condensation nuclei (CCN) can affect cloud properties and therefore Earth’s radiative balance1–3. New particle formation (NPF) from condensable vapours in the free troposphere has been suggested to contribute to CCN, especially in remote, pristine atmospheric regions4, but direct evidence is sparse, and the magnitude of this contribution is uncertain5–7. Here we use in situ aircraft measurements of vertical profiles of aerosol size distributions to present a global-scale survey of NPF occurrence. We observe intense NPF at high altitudes in tropical convective regions over both Pacific and Atlantic oceans. Together with the results of chemical-transport models, our findings indicate that NPF persists at all longitudes as a global-scale band in the tropical upper troposphere, covering about 40 per cent of Earth’s surface. Furthermore, we find that this NPF in the tropical upper troposphere is a globally important source of CCN in the lower troposphere, where CCN can affect cloud properties. Our findings suggest that the production of CCN as new particles descend towards the surface is not adequately captured in global models, which tend to underestimate both the magnitude of tropical upper tropospheric NPF and the subsequent growth of new particles to CCN sizes.

Organisation(en)

Aerosolphysik und Umweltphysik

Externe Organisation(en)

University of Colorado, Boulder, National Oceanic and Atmospheric Administration, University of Denver, Droplet Measurement Technologies, Colorado State University, National Aeronautics & Space Administration (NASA), Foundation for Research and Technology—Hellas (FORTH), State University of New York, Albany, Jinan University

Journal

Nature

Band

574

Seiten

399-403

Anzahl der Seiten

5

ISSN

1476-4687

DOI

https://doi.org/10.1038/s41586-019-1638-9

Publikationsdatum

10-2019

Peer-reviewed

Ja

ÖFOS 2012

103039 Aerosolphysik, 105208 Atmosphärenchemie

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/e4edbd7a-1849-4e2a-9613-d57fcf86fcb6