Interpreting differences in radiative feedbacks from aerosols versus greenhouse gases
Author(s)
Salvi, Pietro
Ceppi, Paulo
Gregory, Jonathan M
Type
Working Paper
Abstract
Experiments with six CMIP6 models were used to assess the climate feedback parameter for net historical, historical greenhouse gas (GHG) and anthropogenic aerosol forcings. The net radiative feedback is found to be more amplifying (higher effective climate sensitivity) for aerosol than GHG forcing, and hence also more amplifying for net historical (GHG + aerosol) than GHG only. We demonstrate that this difference is consistent with their different latitudinal distributions. Historical aerosol forcing is most pronounced in northern extratropics, where the boundary layer is decoupled from the free troposphere, so the consequent temperature change is confined to low altitude and causes low-level cloud changes. This is caused by change in stability which also affects upper-tropospheric clearsky emission, both affecting shortwave and longwave radiative feedbacks. This response is a feature of extratropical forcing generally, regardless of its sign or hemisphere.
Date Issued
2022-01-09
Citation
2022
ISSN
0094-8276
Publisher
ESSOAr
Copyright Statement
© 2022 The Author(s). This work is published under a CC BY licence.
License URL
Identifier
https://www.essoar.org/doi/10.1002/essoar.10510061.1
Subjects
Meteorology & Atmospheric Sciences
Publication Status
Published