DETECTION OF AN ANNUAL WESTWARD PROPAGATING SIGNAL IN THE MERIDIONAL WIND COMPONENT ALONG 8-DEGREES-N IN THE PACIFIC

A westward propagating signal with the annual period is detected in an omalies of the zonally averaged meridional wind component along 8 degr ees N across the Pacific Ocean. The propagating signal in the ''eddy'' (defined as the departure from the zonally averaged) meridional wind has approximately the same propagation speed as the well-known propaga ting signal in the zonal wind component along the equator, and the for mer has larger amplitude than the latter. The eddy SST gradient betwee n the equator and 10 degrees N exhibits a similar westward propagation and is in phase with the eddy meridional wind; the northward eddy win d is accompanied by the warmer eddy SST to the north. The propagating features in both the eddy meridional wind and the SST gradient are qui te regular from year to year, except for El Nino years. In the El Nino periods, the regular features are disturbed in the western Pacific, b ut the in-phase relationship between these two parameters still holds. These relationships indicate that the boundary-layer mechanism is mos t likely to be of primary importance in the response of the eddy merid ional wind to the SST variations.