Multi-temporal Scale Characteristics and Its Causes of Intraseasonal Oscillation of Sea Surface Temperature in the Pacific

摘要

In the context of daily NMC sea surface temperature (SST), 10-m winds (Vμ) and monthly mixed layer depth ( mld ) data, the climatic and anomaly characteristics are researched, with investigating the maintaining mechanisms of SST intraseasonal oscillation ( SST ) on the different time scales. The results show that 1) there are three high SST intensity areas in the Pacific, which are the tropical eastern Pacific existing for the whole year，the northwest Pacific for the boreal spring, summer and autumn, and the southwest Pacific for the austral summer half year; They all appear in the smallest areas and the seasons of mixed layer depth ( mld ). 2) The interannual anomaly of SST over the above areas shows marked negative correlation relationship with that of mld physically, which is more direct than that with SST anomaly. 3) The basal coupled pattern of May-September Vφand SST for the North Pacific, which is obtained by time -lagged Singular Value Decomposition (SVD), disclose a negative feedback process considering drift and sensible heat as power. This process existing in the smallest mld areas is the maintaining mechanism of strong SST.