Aerosol-driven droplet concentrations dominate coverage and water of oceanic low-level clouds

Daniel Rosenfeld; Yannian Zhu; Minghuai Wang; Youtong Zheng; Tom Goren; Shaocai Yu

doi:10.1126/science.aav0566

Aerosol-driven droplet concentrations dominate coverage and water of oceanic low-level clouds

Science. 2019 Feb 8;363(6427):eaav0566. doi: 10.1126/science.aav0566. Epub 2019 Jan 17.

Authors

Daniel Rosenfeld^{1

2}, Yannian Zhu³, Minghuai Wang^{4

5}, Youtong Zheng⁶, Tom Goren⁷, Shaocai Yu^{8

9

10}

Affiliations

¹ Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. daniel.rosenfeld@huji.ac.il minghuai.wang@nju.edu.cn shaocaiyu@zju.edu.cn.
² School of Atmospheric Sciences, Nanjing University, China.
³ Meteorological Institute of Shaanxi Province, Xi'an, China.
⁴ School of Atmospheric Sciences, Nanjing University, China. daniel.rosenfeld@huji.ac.il minghuai.wang@nju.edu.cn shaocaiyu@zju.edu.cn.
⁵ Joint International Research Laboratory of Atmospheric and Earth System Sciences and Institute for Climate and Global Change Research, Nanjing University, China.
⁶ Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA.
⁷ University of Leipzig, Leipzig, Germany.
⁸ Research Center for Air Pollution and Health; Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, P.R. China. daniel.rosenfeld@huji.ac.il minghuai.wang@nju.edu.cn shaocaiyu@zju.edu.cn.
⁹ Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91123, USA.
¹⁰ Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, Fujian 361021, P.R. China.

PMID: 30655446
DOI: 10.1126/science.aav0566

Abstract

A lack of reliable estimates of cloud condensation nuclei (CCN) aerosols over oceans has severely limited our ability to quantify their effects on cloud properties and extent of cooling by reflecting solar radiation-a key uncertainty in anthropogenic climate forcing. We introduce a methodology for ascribing cloud properties to CCN and isolating the aerosol effects from meteorological effects. Its application showed that for a given meteorology, CCN explains three-fourths of the variability in the radiative cooling effect of clouds, mainly through affecting shallow cloud cover and water path. This reveals a much greater sensitivity of cloud radiative forcing to CCN than previously reported, which means too much cooling if incorporated into present climate models. This suggests the existence of compensating aerosol warming effects yet to be discovered, possibly through deep clouds.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.