Future changes in the Great Plains Low-Level Jet governed by seasonally dependent pattern changes in the North Atlantic Subtropical High

• Published in: Geophysical Research Letters
• Main Authors: Zhou, Wenyu, Leung, Lai-Yung, Song, Fengfei, Lu, Jian
• Language: unknown
• Published: 2021
• Subjects: 58 GEOSCIENCES; Nash; North Atlantic
• Online Access: http://www.osti.gov/servlets/purl/1778788; https://www.osti.gov/biblio/1778788; https://doi.org/10.1029/2020GL090356

The southerly Great Plains low-level jet (GPLLJ) plays an important role in the Central US hydroclimate, but our understanding of its response to global warming remains elusive. Here we show that the GPLLJ will intensify and intrude deeper under warming in both spring and autumn but change marginally in summer. This response is governed by seasonally dependent pattern changes of the North-Atlantic subtropical high (NASH). In spring and autumn, with a substantial poleward shift in the North America westerly jet, the NASH expands poleward notably. The anomalous surface high poleward of the NASH enhances the southerly GPLLJ to its west. In summer, however, the poleward westerly-jet shift is weak and changes in the NASH manifest a westward extension, which only marginally affects the GPLLJ. Among models, the NASH expansion and GPLLJ enhancement are correlated with the poleward jet shift, highlighting its critical role in regulating the future NASH and GPLLJ changes.