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CSIRO Marine and Atmospheric Research
Past Seminars

Seminar Abstract

Could El Nino be triggered from the South China Sea?

Predicting the genesis of an imminent El Niño remains a difficult and uncertain task, despite great advances in observation and forecasting. A consistent triggering theory is presented, in which warm water from a pool in the eastern South China Sea suddenly overflows into the Pacific through the Luzon Strait. The warm pool is accumulated during the summer over several years by the southwest monsoon through Ekman drift and leans against the coasts of Borneo and the Philippines. When the pool has become deep enough, a geostrophic northeastward current will develop at its western boundary and lead to the overflow into the Pacific. The intruding warm water to the left of the Kuroshio destroys its geostrophic balance and thereby disrupts it, leaving part of the North Equatorial Current stranded east of the Philippines. The locally disrupted subtropical gyre recovers through the removal of the stranded warm waters towards the southeast, initiating a new El Niño event.

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CSIRO = Marine Laboratories Auditorium, Castray Esplanade, Hobart

For further information, or to schedule a seminar, contact:
Peter Oke, (Oceanographic seminars) CSIRO Marine Research (03) 6232 5387
Keith Hayes, (Biological seminars) CSIRO Marine Research (03) 6232 5298
Katrina Nitschke, Antarctic Climate and Ecosystems CRC (03) 6226 2265 & IASOS, University of Tasmania (03) 6226 2509