Premium
Processes controlling Southern Ocean shortwave climate feedbacks in CESM
Author(s) -
Kay J. E.,
Medeiros B.,
Hwang Y.T.,
Gettelman A.,
Perket J.,
Flanner M. G.
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2013gl058315
Subject(s) - shortwave , shortwave radiation , cloud albedo , environmental science , climatology , albedo (alchemy) , cloud forcing , atmospheric sciences , climate model , climate change , forcing (mathematics) , atmosphere (unit) , cloud feedback , cloud cover , meteorology , oceanography , geology , climate sensitivity , cloud computing , radiation , geography , radiative transfer , art , computer science , operating system , quantum mechanics , art history , physics , performance art
A climate model (Community Earth System Model with the Community Atmosphere Model version 5 (CESM‐CAM5)) is used to identify processes controlling Southern Ocean (30–70°S) absorbed shortwave radiation (ASR). In response to 21st century Representative Concentration Pathway 8.5 forcing, both sea ice loss (2.6 W m −2 ) and cloud changes (1.2 W m −2 ) enhance ASR, but their relative importance depends on location and season. Poleward of ~55°S, surface albedo reductions and increased cloud liquid water content (LWC) have competing effects on ASR changes. Equatorward of ~55°S, decreased LWC enhances ASR. The 21st century cloud LWC changes result from warming and near‐surface stability changes but appear unrelated to a small (1°) poleward shift in the eddy‐driven jet. In fact, the 21st century ASR changes are 5 times greater than ASR changes resulting from large (5°) naturally occurring jet latitude variability. More broadly, these results suggest that thermodynamics (warming and near‐surface stability), not poleward jet shifts, control 21st century Southern Ocean shortwave climate feedbacks.