关于El Nin ^∼o事件过程中热带MJO能量变化的SVD分析

The SVD Analysis of the Tropical MJO Energy Changes in El Nin ^∼o Event

摘要: 热带MJO垂直方向表现为斜压结构，其对流活动以上层风场辐散、下层风场辐合为标志，对流活动越强，MJO能量越强。当海表面温度(SST)升高，局地对流活动就会发展，从而对MJO能量产生积极影响。所以，理论上在El Niño事件过程中，由于SST异常变化，MJO能量也会产生波动。本文通过进行海表面温度(SST)场与MJO能量场之间的SVD分析，得出结论：当海表面温度异常(SSTA)偏高时MJO能量异常偏大；当SSTA偏低时MJO能量异常偏小，两者之间的正相关性表现良好。

Abstract: The tropical MJO behaves as a baroclinic structure in the vertical direction. The convective activity is dominated by the divergence of the upper wind field and the convergence of the lower wind field. The stronger the convective activity is, the stronger the MJO energy is. When the sea surface temperature (SST) increases, the local convection will develop. This leads some positive effects on the MJO energy. Therefore, in the El Niño event process, due to SST abnormal changes, MJO energy will also fluctuate. In this paper, the SVD analysis between SST and the energy of MJO indicates that the MJO energy is high when the sea surface temperature anomaly (SSTA) is high and the MJO energy is low when the SSTA is low. There is a significant positive correlation between the SSTA and the MJO energy.