Fig. \ref{fig:TsMon} also shows the historical$-$AMIP surface wind difference. In general, the winds blow from the north to the south, due to the large-scale thermal contrast of cool north and warm south and the consequent pressure gradient bias. The pattern of the surface wind biases implies that the Asian monsoon circulation is strengthened in winter but weakened in summer, suggesting that there might be a strong connection between the bias in East Africa and that in the large-scale Asian monsoon. The  winds over the equatorial Indian Ocean are dominated by easterlies during the latter half year, which contributes  to the maintenance of the warm SST bias over the western Indian Ocean (near the coast of East Africa).