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Winter Precipitation Changes in California Under Global Warming: Contributions of CO 2 , Uniform SST Warming, and SST Change Patterns
Author(s) -
Dong Lu,
Leung L. Ruby
Publication year - 2021
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 - 10.1029/2020gl091736
Subject(s) - climatology , teleconnection , environmental science , global warming , sea surface temperature , precipitation , atmospheric sciences , radiative forcing , forcing (mathematics) , climate model , climate change , troposphere , coupled model intercomparison project , geology , meteorology , oceanography , geography , el niño southern oscillation
Climate models project a wetting winter over California, distinct from the drying in all other Mediterranean climate regions under warming. Dynamic effect via an eastward extension of the westerly jet stream over the North Pacific is the root cause for the wetting California. Utilizing four sets of prescribed‐SST (sea surface temperature) simulations, the relative effects of direct CO 2 radiative forcing, uniform SST warming, and SST change patterns are investigated. The wetting winter is dominated by uniform SST warming mainly through its effect on the jet extension. As a fundamental response to the enhanced upper‐tropospheric warming in the tropics, the jet extension in coupled simulations is well reproduced under uniform SST warming and robust among models. An El Niño‐like SST warming pattern has a secondary contribution to the jet extension via atmospheric teleconnection, but with large inter‐model spread. Relative to the SST forcing, the direct CO 2 radiative effect is negligible.