7.4
Relationship between North Atlantic Oscillation (NAO) and North Atlantic SSTA tripole
Lin-Lin Pan, University of Hawaii, Honolulu, HI; and F. F. Jin and M. Watanabe
In this study, we explored the relationship between the atmospheric internal variability and the SST anomaly pattern in the North Atlantic region. A five-layer primitive equation model with synoptic eddy and low-frequency flow (SELF) feedback was coupled with an ocean mixed layer model to study the effect of air-sea coupling on the North Atlantic Oscillation (NAO). It is shown that the NAO-like atmospheric circulation anomalies can produce tripole-like SST anomalies in the North Atlantic region and a NAO-like dipole with an equivalent barotropic structure over the Atlantic can be excited by the North Atlantic SST tripole. The NAO-like response is primarily maintained by a positive SELF feedback that results from interactions between the heating-forced anomalous flow and the Atlantic storm track. Without SELF feedback, this covarying pattern can not exist.
Session 7, Midlatitude atmosphere–ocean interaction: Part II The North Atlantic
Thursday, 12 August 2004, 2:30 PM-5:15 PM, New Hampshire Room
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