The relationship between the ITCZ and the Southern Hemispheric eddy-driven jet

Ceppi, P., Hwang, Y.-T., Liu, X., Frierson, D. M. W. and Hartmann, D. L. (2013) The relationship between the ITCZ and the Southern Hemispheric eddy-driven jet. Journal of Geophysical Research: Atmospheres, 118 (11). pp. 5136-5146. ISSN 2169-8996 doi: 10.1002/jgrd.50461

Abstract/Summary

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.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/46107
Item Type	Article
Refereed	Yes
Divisions	No Reading authors. Back catalogue items Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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