American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article    Cited by

GEOPHYSICAL RESEARCH LETTERS, VOL. 27, NO. 22, PAGES 3687–3690, 2000

Interdecadal Changes in Eastern Pacific ITCZ Variability and its Influence on the Atlantic ITCZ

John C. H. Chiang

Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York


Yochanan Kushnir

Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York


Stephen E. Zebiak

International Research Institute for Climate Prediction, Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York


Abstract

The eastern Pacific and Atlantic Intertropical Convergence Zones (ITCZ) exhibit the largest year-to-year variations in boreal spring. We show evidence suggesting that Atlantic ITCZ April-May variability is linked to that for the eastern Pacific through the Walker circulation as it respond to changes in equatorial Pacific convection. Analysis of ITCZ proxy indices shows the link appears to be strong in the 1980-90’s and 1920-30’s but virtually nonexistent in the 1950-60’s. We argue that this apparent nonstationarity results from the nonlinear relationship between sea surface temperature (SST) and convection in the eastern equatorial Pacific and its consequent effect on the Walker circulation and the Atlantic ITCZ. This mechanism was modulated over 1856-1998 by interdecadal changes in peak SST attained in the eastern equatorial Pacific during boreal spring.

Received 24 November 1999; accepted 22 September 2000.

Read Full Article    Cited by

Citation: Chiang, J. C. H., Y. Kushnir, and S. E. Zebiak (2000), Interdecadal Changes in Eastern Pacific ITCZ Variability and its Influence on the Atlantic ITCZ, Geophys. Res. Lett., 27(22), 3687–3690.