In an El Nino event, positive SST anomalies usually appear in remote ocean basins such as the South China Sea, the Indian Ocean, and the tropical North Atlantic approximately 3 to 6 months after SST anomalies peak in the tropical Pacific. Ship data from 1952 to 1992 and satellite data from the 1980s both demonstrate that changes in atmospheric circulation accompanying El Nino induce changes in cloud cover and evaporation which, in turn, increase the net heat flux entering these remote oceans. It is postulated that this increased heat flux is responsible for the surface warming of these oceans. Specifically, over the eastern Indian Ocean and South China Sea, enhanced subsidence during El Nino reduces cloud cover and increases the solar radiation absorbed by the ocean, thereby leading to enhanced SSTs. In the tropical North Atlantic, a weakening of the trade winds during El Nino reduces surface evaporation and increases SSTs. These relationships fit the concept of an 'atmospheric bridge' that connects SST anomalies in the central equatorial Pacific to those in remote tropical oceans.
|Original language||English (US)|
|Number of pages||16|
|Journal||Journal of Climate|
|State||Published - Apr 1999|
All Science Journal Classification (ASJC) codes
- Atmospheric Science