The role of the stratospheric polar vortex for the austral jet response to greenhouse gas forcing
File(s)
Published version
OA Location
Author(s)
Ceppi, P
Shepherd, TG
Type
Journal Article
Abstract
Future shifts of the austral midlatitude jet are subject to large uncertainties in climate model projections. Here we show that, in addition to other previously identified sources of intermodel uncertainty, changes in the timing of the stratospheric polar vortex breakdown modulate the austral jet response to greenhouse gas forcing during summertime (December–February). The relationship is such that a larger delay in vortex breakdown favors a more poleward jet shift, with an estimated 0.7–0.8° increase in jet shift per 10-day delay in vortex breakdown. The causality of the link between the timing of the vortex breakdown and the tropospheric jet response is demonstrated through climate modeling experiments with imposed changes in the seasonality of the stratospheric polar vortex. The vortex response is estimated to account for about 30% of the intermodel variance in the shift of the summertime austral jet and about 45% of the mean jet shift.
Date Issued
2019-06-28
Date Acceptance
2019-05-03
Citation
Geophysical Research Letters, 2019, 46 (12), pp.6972-6979
ISSN
0094-8276
Publisher
Wiley
Start Page
6972
End Page
6979
Journal / Book Title
Geophysical Research Letters
Volume
46
Issue
12
Copyright Statement
©2019. The Authors.This is an open access article under theterms of the Creative CommonsAttribution-NonCommercial-NoDerivsLicense, which permits use anddistribution in any medium, providedthe original work is properly cited, theuse is non-commercial and nomodifications or adaptations are made
Identifier
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL082883
Subjects
Science & Technology
Physical Sciences
Geosciences, Multidisciplinary
Geology
jet stream
stratospheric polar vortex
climate change
CIRCULATION RESPONSE
CLIMATE-CHANGE
SOUTHERN
VARIABILITY
PERSISTENCE
BREAKDOWN
Meteorology & Atmospheric Sciences
Publication Status
Published
Date Publish Online
2019-05-09