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An oceanic teleconnection between the equatorial and southern Indian Ocean
Author(s) -
Schouten M. W.,
de Ruijter W. P. M.,
van Leeuwen P. J.,
Dijkstra H. A.
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2001gl014542
Subject(s) - kelvin wave , teleconnection , rossby wave , indian ocean dipole , geology , oceanography , indian ocean , sea surface height , climatology , ocean surface topography , monsoon , equatorial waves , altimeter , sea surface temperature , latitude , el niño southern oscillation , equator , geodesy
Sequences of Kelvin and Rossby waves are found to rapidly carry sea surface height anomalies across the Indian Ocean, and have an impact on Indian to Atlantic interocean exchange. Satellite altimeter data reveal an oceanic teleconnection between equatorial winds and variability of the interocean exchange. Four times per year, we observe an equatorial Kelvin wave to hit Indonesia, forced by monsoon variability. The signal then propagates southward along the Indonesian coast and triggers Rossby waves that propagate westward across the subtropical Indian Ocean. On reaching the Madagascar and Mozambique Channel regions, large rings form at the same four per year frequency. These drift towards the Agulhas retroflection where they control the shedding of Agulhas rings. Disturbances of this pin‐ball‐like propagating signal can be traced from Indian Ocean Dipole/El Niño events in 1994 and 1997/1998, to decreases of Indian‐Atlantic ocean exchange by Agulhas rings over two years later.