Study of relationship between wave transport and sea surface temperature anomaly (SSTA) in the tropical Pacific

摘要

Large-scale water transport is one of the key factors that affect sea surface temperature anomaly (SSTA) in the eastern equatorial Pacific (EEP). The relationship between the wave transport in the tropical Pacific and the SSTA in the EEP is examined by different methods, including band-pass filtering, period analysis, correlation analysis, significant analysis, and empirical orthogonal function (EOF) analysis. We have found that the eastward shift of the wave transport anomaly in the tropical Pacific, with a period of 2 a and enhancing the transport of warm waters from the western Pacific warm pool, precedes the increase of sea surface temperature (SST) in the EEP. The wave transport and the SSTA in the EEP have a maximum correlation of 0.65 with a time-lag of 6 months (transport variation precedes the temperature). The major periods (3.7 a and 2.45 a) of the wave transport variability, as revealed by the EOF analysis, appear to be consistent with the SSTA oscillation cycle in the EEP. Based on the first occurrence of a significant SSTA in the Niño 3 region (5°S–5°N, 90°–150°W), two types of warm events are defined. The wave transport anomalies in two types present predominantly the west anomaly in the tropical Pacific, it is that the wave transport continues transport warm water from west to east before the onset of the warm event. The impact of wave-induced water transport on the SSTA in the EEP is confirmed by the heat flux of the wave transport. The wave transport exerts significant effect on the SSTA variability in the EEP and thus is not neglectable in the further studies.