Contribution of Pacific wind stress to multi-decadal variations in upper-ocean heat content and sea level in the tropical south Indian Ocean
Article first published online: 18 JUN 2011
Copyright 2011 by the American Geophysical Union.
Geophysical Research Letters
Volume 38, Issue 12, June 2011
How to Cite
2011), Contribution of Pacific wind stress to multi-decadal variations in upper-ocean heat content and sea level in the tropical south Indian Ocean, Geophys. Res. Lett., 38, L12602, doi:10.1029/2011GL047651., and (
- Issue published online: 18 JUN 2011
- Article first published online: 18 JUN 2011
- Manuscript Accepted: 9 MAY 2011
- Manuscript Revised: 6 MAY 2011
- Manuscript Received: 4 APR 2011
- Indian Ocean;
- heat content;
- sea level
 Reconstructions of the spatial pattern of recent multi-decadal sea level trends in the Indian Ocean (IO) indicate a zonally-extended band in the southern tropics where sea level has substantially fallen between the 1960s and 1990s; the decline is consistent with the observed subsurface cooling associated with a shoaling thermocline in this region. Here the origin and spatio-temporal characteristics of these trends are elucidated by a sequence of ocean model simulations. Whereas interannual variability in the southwestern tropical IO appears mainly governed by IO atmospheric forcing, longer term changes in the south tropical IO involve a strong contribution from the western Pacific via wave transmission of thermocline anomalies through the Indonesian Archipelago, and their subsequent westward propagation by baroclinic Rossby waves. The late 20th-century IO subsurface cooling trend reversed in the 1990s, reflecting the major regime shift in the tropical Pacific easterlies associated with the Pacific Decadal Oscillation.