RESPONSE OF EQUATORIAL PACIFIC UPPER OCEAN CURRENT TO WESTERLY WIND BURSTS

The characteristics of the response of equatorial Pacific upper ocean current to westerly wind bursts(WWB)were analyzed in the frequency domain by using wind and ADCP data collected by the Shiyan3 during TOGA-COARE IOP,1992-1993.The preliminary results showed that the response consistedof an eastward surface jet at shallower than 60m depth,a westward counter current centering near100m and a shear layer between them,with the variations of all three being nonlinear and nearlysynchronous.The oceanic responses in the frequency domain were characterized by occurrences of a remotely forced mixed Rossby-gravity wave with period of 8-10 days in the surface jet andcountercurrent at shallower than 110 m depth,and two locally forced waves with periods of 24 daysand 4-5 days limited in shallower than 70m depth.These fluctuations of the responses depended much more on zonal wind than meridional wind.The results also revealed that the oceanic response toWWB resulted from momentum transport and energy propagation assoc

Response of equatorial Pacific upper ocean current to westerly wind bursts

The characteristics of the response of equatorial Pacific upper ocean current to westerly wind bursts (WWB) were analyzed in the frequency domain by using wind and ADCP data collected by the Shiyan 3 during TOGA-COARE IOP, 1992-1993.The preliminary results showed that the response consisted of an eastward surface jet at shallower than 60m depth, a westward counter current centering near 100m and a shear layer between them, with the variations of all three being nonlinear and nearly synchronous. The oceanic responses in the frequency domain were characterized by occurrences of a remotely forced mixed Rossby-gravity wave with period of 8-10 days in the surface jet and countercurrent at shallower than 110 m depth. and two locally forced waves with periods of 24 days and 4-5 days limited in shallower than 70m depth. These fluctuations of the responses depended much more on zonal wind than meridional wind. The results also revealed that the oceanic response to WWB resulted from momentum transport and energy propagation associated with wave, baroclinic mode, nonlinear shear instability, and possibly other factors.