The effect of the equatorial Pacific cold SST bias on simulated ENSO teleconnections to the North Pacific and California
Details
Serval ID
serval:BIB_F962B89E0230
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The effect of the equatorial Pacific cold SST bias on simulated ENSO teleconnections to the North Pacific and California
Journal
Climate Dynamics
ISSN
0930-7575
1432-0894
1432-0894
Publication state
Published
Issued date
10/2019
Peer-reviewed
Oui
Volume
53
Number
7-8
Pages
3771-3789
Language
english
Abstract
Precipitation in California is modulated by variability in the tropical Pacific associated with El Niño/Southern Oscillation (ENSO): more rainfall is expected during El Niño episodes, and reduced rainfall during La Niña. It has been suggested that besides the shape and location of the sea surface temperature (SST) anomaly this remote connection depends on the strength and location of the atmospheric convection response in the tropical Pacific. Here we show in a perturbed physics ensemble of the Kiel Climate Model and CMIP5 models that due to a cold equatorial SST bias many climate models are in a La Niña-like mean state, resulting in a too westward position of the rising branch of the Pacific Walker Circulation. This in turn results in a convective response along the equator during ENSO events that is too far west in comparison to observations. This effect of the equatorial cold SST bias is not restricted to the tropics, moreover it leads to a too westward SLP response in the North Pacific and too westward precipitation response that does not reach California. Further we show that climate models with a reduced equatorial cold SST bias have a more realistic representation of the spatial asymmetry of the teleconnections between El Niño and La Niña.
Keywords
El Niño/Southern Oscillation, Sea surface temperature bias, North Pacific teleconnections, Rainfall over California, Perturbed physics ensemble, CMIP5
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Create date
08/03/2022 14:13
Last modification date
11/07/2024 9:54