Interpreting the dependence of cloud‐radiative adjustment on forcing agent
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Published version
Author(s)
Salvi, Pietro
Ceppi, Paulo
Gregory, Jonathan M
Type
Journal Article
Abstract
Effective radiative forcing includes a contribution by rapid adjustments, that is, changes in temperature, water vapor, and clouds that modify the energy budget. Cloud adjustments in particular have been shown to depend strongly on forcing agent. We perform idealized atmospheric heating experiments to demonstrate a relationship between cloud adjustment and the vertical profile of imposed radiative heating: boundary-layer heating causes a positive cloud adjustment (a net downward radiative anomaly), while free-tropospheric heating yields a negative adjustment. This dependence is dominated by the shortwave effect of changes in low clouds. Much of the variation in cloud adjustment among common forcing agents such as CO2, CH4, solar forcing, and black carbon is explained by the “characteristic altitude” (i.e., the vertical center-of-mass) of their heating profiles, through its effect on tropospheric stability.
Date Issued
2021-09-20
Date Acceptance
2021-08-24
Citation
Geophysical Research Letters, 2021, 48 (18)
ISSN
0094-8276
Publisher
American Geophysical Union (AGU)
Journal / Book Title
Geophysical Research Letters
Volume
48
Issue
18
Copyright Statement
© 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Sponsor
Natural Environment Research Council (NERC)
Natural Environment Research Council (NERC)
Grant Number
NE/T006250/1
NCR10284 - NE/T007788/1
Subjects
Meteorology & Atmospheric Sciences
Publication Status
Published
Article Number
ARTN e2021GL093616
Date Publish Online
2021-08-29