Premium
Meridional position biases of East Asian subtropical jet stream in CMIP5 models and their relationship with ocean model resolutions
Author(s) -
Ma Jing,
Xu Haiming,
Lin Pengfei
Publication year - 2015
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/joc.4256
Subject(s) - zonal and meridional , climatology , coupled model intercomparison project , sea surface temperature , subtropics , environmental science , geology , climate model , atmospheric sciences , oceanography , climate change , fishery , biology
The East Asian subtropical jet ( EASJ ) stream in each of the 20 models from the Coupled Model Intercomparison Project Phase 5 ( CMIP5 ) is evaluated against the ERA ‐interim product. The multi‐model ensemble mean ( MME ) simulates a reasonably realistic climatology of the EASJ ; however, the MME EASJs are shifted southward in all seasons in comparison with the observations. Upon closer inspection, it is found that only in the coupled general circulation models ( CGCMs ) with relatively coarse ocean model resolutions are the simulated EASJs shifted southward remarkably in all four seasons; for those CGCMs with relatively high ocean model resolutions, the simulated EASJs are shifted northward, indicating that the simulated meridional location of the EASJ is closely related to the horizontal resolution in the ocean model. Based on the singular value decomposition ( SVD ) and composite analyses, the simulated meridional location of the EASJ is closely associated with the sea surface temperature ( SST ) over the Kuroshio–Oyashio Extension ( KOE ) region, with southward (northward) shift of the EASJ corresponding to low (high) SSTs . The CGCMs with relatively low (high) ocean model resolutions generally simulate negative (positive) SST biases over the KOE region with an SST decrease (increase) of about −3 K (+2 K) in comparison with the MME . Through a mixed‐layer heat budget analysis, it is revealed that the SST differences between the models with coarse and fine ocean components are mainly attributed to the ocean heat transport effect.