Primary marine aerosol-cloud interactions off the coast of California

Autor(en)

R. L. Modini, A. A. Frossard, L. Ahlm, L. M. Russell, C. E. Corrigan, G. C. Roberts, L. N. Hawkins, J. C. Schroder, A. K. Bertram, R. Zhao, A. K. Y. Lee, J. P. D. Abbatt, J. Lin, A. Nenes, Z. Wang, Anna Wonaschütz, A. Sorooshian, K. J. Noone, H. Jonsson, J. H. Seinfeld, D. Toom-Sauntry, A. M. Macdonald, W. R. Leaitch

Abstrakt

Primary marine aerosol (PMA)-cloud interactions off the coast of California were investigated using observations of marine aerosol, cloud condensation nuclei (CCN), and stratocumulus clouds during the Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) and the Stratocumulus Observations of Los-Angeles Emissions Derived Aerosol-Droplets (SOLEDAD) studies. Based on recently reported measurements of PMA size distributions, a constrained lognormal-mode-fitting procedure was devised to isolate PMA number size distributions from total aerosol size distributions and applied to E-PEACE measurements. During the 12 day E-PEACE cruise on the R/V Point Sur, PMA typically contributed less than 15% of total particle concentrations. PMA number concentrations averaged 12 cm(-3) during a relatively calmer period (average wind speed 12m/s(1)) lasting 8 days, and 71cm(-3) during a period of higher wind speeds (average 16m/s(1)) lasting 5 days. On average, PMA contributed less than 10% of total CCN at supersaturations up to 0.9% during the calmer period; however, during the higher wind speed period, PMA comprised 5-63% of CCN (average 16-28%) at supersaturations less than 0.3%. Sea salt was measured directly in the dried residuals of cloud droplets during the SOLEDAD study. The mass fractions of sea salt in the residuals averaged 12 to 24% during three cloud events. Comparing the marine stratocumulus clouds sampled in the two campaigns, measured peak supersaturations were 0.20.04% during E-PEACE and 0.05-0.1% during SOLEDAD. The available measurements show that cloud droplet number concentrations increased with >100 nm particles in E-PEACE but decreased in the three SOLEDAD cloud events.

Organisation(en)

Aerosolphysik und Umweltphysik

Externe Organisation(en)

University of California, San Diego, University of Arizona, Stockholm University, California Institute of Technology (Caltech), Centre National De La Recherche Scientifique (CNRS), Harvey Mudd College, University of British Columbia (UBC), University of Toronto, Georgia Institute of Technology, Center for Interdisciplinary Remotely Piloted Aircraft Studies, Environment and Climate Change Canada

Journal

Journal of Geophysical Research: Atmospheres

Band

120

Seiten

4282-4303

Anzahl der Seiten

22

ISSN

2169-897X

DOI

https://doi.org/10.1002/2014JD022963

Publikationsdatum

05-2015

Peer-reviewed

Ja

ÖFOS 2012

103039 Aerosolphysik

Schlagwörter

ASJC Scopus Sachgebiete

Forestry, Aquatic Science, Soil Science, Water Science and Technology, Earth-Surface Processes, Geochemistry and Petrology, Geophysics, Oceanography, Palaeontology, Ecology, Space and Planetary Science, Earth and Planetary Sciences (miscellaneous), Atmospheric Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/1c4baac2-9cc7-4344-aaa5-205d3fcd6785