The relationship between the ITCZ and the Southern Hemispheric eddy-driven jet
File(s)
Author(s)
Ceppi, Paulo
Hwang, Yen-Ting
Liu, Xiaojuan
Frierson, Dargan MW
Hartmann, Dennis L
Type
Journal Article
Abstract
[1] We study the effect of a thermal forcing confined to the midlatitudes of one hemisphere on the eddy‐driven jet in the opposite hemisphere. We demonstrate the existence of an “interhemispheric teleconnection,” whereby warming (cooling) the Northern Hemisphere causes both the intertropical convergence zone (ITCZ) and the Southern Hemispheric midlatitude jet to shift northward (southward). The interhemispheric teleconnection is effected by a change in the asymmetry of the Hadley cells: as the ITCZ shifts away from the Equator, the cross‐equatorial Hadley cell intensifies, fluxing more momentum toward the subtropics and sustaining a stronger subtropical jet. Changes in subtropical jet strength, in turn, alter the propagation of extratropical waves into the tropics, affecting eddy momentum fluxes and the eddy‐driven westerlies. The relevance of this mechanism is demonstrated in the context of future climate change simulations, where shifts of the ITCZ are significantly related to shifts of the Southern Hemispheric eddy‐driven jet in austral winter. The possible relevance of the proposed mechanism to paleoclimates is discussed, particularly with regard to theories of ice age terminations.
Date Issued
2013-06-16
Date Acceptance
2013-05-02
Citation
Journal of Geophysical Research: Atmospheres, 2013, 118 (11), pp.5136-5146
ISSN
2169-897X
Publisher
American Geophysical Union
Start Page
5136
End Page
5146
Journal / Book Title
Journal of Geophysical Research: Atmospheres
Volume
118
Issue
11
Copyright Statement
©2013. American Geophysical Union. All Rights Reserved.
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000325212600007&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Physical Sciences
Meteorology & Atmospheric Sciences
ITCZ
Hadley cells
Jet streams
Teleconnections
ATMOSPHERIC CIRCULATION
HADLEY CIRCULATIONS
STORM-TRACK
CLIMATE
MODEL
SPEED
OCEAN
Publication Status
Published
Date Publish Online
2013-05-04