2026-09-28 愛媛大学
気候モデルでみられる海面水温の誤差
＜関連情報＞
- https://www.ehime-u.ac.jp/data_relese/pr_20260928_cmes/
- https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2026GL124012
CMIP6結合モデルの海面水温バイアスが北太平洋偏西風ジェットに及ぼす影響 Assessing the Impact of Sea Surface Temperature Biases in CMIP6 Coupled Models on the North Pacific Westerly Jet
Yusuke Ushijima, Ryo Mizuta, Shion Sekizawa, Hiroyuki Tsujino
Geophysical Research Letters Published: 28 August 2026
DOI:https://doi.org/10.1029/2026GL124012
Abstract
This study investigates the impact of sea surface temperature (SST) biases on the latitude of the climatological North Pacific westerly jet using multi-model analyses and atmospheric general circulation model (AGCM) sensitivity experiments. A comparison of atmospheric-only and coupled simulations from 35 models participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6) for 1985–2014 reveals a robust southward shift of the jet in the coupled simulations, identified in 34 models. Sensitivity experiments with an AGCM demonstrate that the jet latitude differences between atmospheric-only and coupled simulations can be reproduced by imposing annual-mean SST biases. Further analysis shows that the cold SST bias over the western North Pacific subtropical gyre dominates the jet response. Reduced atmospheric baroclinicity associated with weakened meridional temperature gradients suppresses eddy activity, favoring a southward jet shift.
