The Influence of Madden Julian Oscillation on the Formation of the Hot Event in the Western Equatorial Pacific

Abstract

Hot event (HE) is the high SST phenomena higher than about 30C, occur in an area of more than 2×106 km2 and last for a period more than 6 days. HE develops only under the condition of high solar radiation and low wind speed. The indication of the relation between HE and MJO has been described in the previous study for one HE case. In the present study, the more case of MJO-HE relation is collected for the period of 2003-2011 and the possible mechanisms is examined. New Generation Sea Surface Temperature for Open Ocean (NGSSTO-Global-V2.0a) was used to identify HEs. Precipitation from TRMM were bandpass filtered with cut off period of 30-60 days for MJO identification. Observation data from TAO/TRITON buoy were used for investigating the possible mechanism of MJO-HE relation. Off 48 HE cases located along the equatorial band, the development of 29 HE cases was related to the suppressed phase of MJO whereas the high solar radiation occurred. High precipitation during the active phase of MJO may contribute to stabilize the upper mixed layer. The stable upper water column fasten the heating process during the suppressed phase of MJO, generating HE.