Abstract:
The anomalous latent and sensible heat flux over the North Pacific in boreal winter and their impact on sea surface temperature (hereafter SST) anomalies are analyzed by using a longterm integration of the oceanatmosphere coupled model FGOALS_s of LASG/IAP. The relative contributions of heat flux components and oceanic dynamical terms to the SST variance are compared. The results show that the FGOALS_s can reproduce the dominant characteristics of the mean state of surface heat fluxes and the interannual variance of turbulent heat flux. In the extratropical North Pacific Ocean, significant correlation exists between anomalous latent and sensible heat flux and SST tendency anomalies in boreal winter. The turbulent heat flux is the most important factor that determine the SST variance, whereas the downward short wave flux is dominant only to the southeast of Hawaii archipelago. The model has a reasonable performance in capturing the leading mode of winter time SST tendency in the extratropical North Pacific Ocean and the corresponding pattern of sea level pressure anomalies. Analysis shows that the anomalous largescale atmospheric circulation affects the turbulent heat flux and thus plays a significant role in changing the SST anomalies. The diagnosis based on model results supports that in the boreal winter extratropical North Pacific Ocean, the atmospheric forcing is dominant in the local airsea interaction processes, and the new edition of the coupled model FGOALS_s is applicable to investigate the airsea interaction over the North Pacific in wintertime.