Characteristics Of MJO In The South China Sea And The Western Pacific And Its Impact On The Drought/Flood Of China

Use on the data of OLR, SST and air-sea latent heat flux to analyze the oscillation of 10-20d and 30-60d in the atmosphere, ocean and air-sea system in the South China Sea-west Pacific region; As an example, the El Nino of 1982/1983 is used to study the low frequency characteristics of SST; Lastly, we chose the South China Sea, using the QuikSCAT data of 2001 and 2003, to analyze the variation characteristics of South China Sea summer monsoon and the relationship between its LFO components and the rainfall in Yangtze River-Huaihe River basin, in drought/flood years of Yangtze River-Huaihe River basin. The result showed that:(1)In South China Sea-western Pacific region, the MJO’s seasonal characteristics of OLR, SST and air-sea latent heat flux is different. On the whole, the low frequency oscillation of OLR in 10-20d and 30-60d showed the same point, namely, the low frequency oscillation is strong in summer and weak in winter; The oscillation energy of 10-20d is stronger than that of 30-60d. The oscillation’s seasonal feature of 10-20d and 30-60d about SST is that spring and summer are relatively active season; The intensity and distribution of 30-60d oscillation are stronger and larger than which of 10-20d oscillation; During the developing and declining phase of El Nino, the low frequency energy of SST is mainly distributed in the western Pacific region, However, during the mature stage, the area of ENSO3.4 is the energy’s main active region; In addition, the activity of low frequency oscillation about SST existed all year in South China Sea. The seasonal features of air-sea latent heat flux, which is associative with the oscillation energy of 10-20d and 30-60d, is that it is strong in winter, and on the energy intensity, the oscillation energy of 10-20d is much stronger than which of 30-60d.(2)The relatively active region’s distribution of MJO for OLR, SST and air-sea latent heat flux are different. The relatively active region of OLR 10-20d oscillation is two north-south symmetry active belt in all year. The relatively active region of 30-60d oscillation performance for along the meridional distribution of Australian monsoon region in summer half year, which showed a thin strip from the South China Sea to east in winter half year. The variance contribution of 30-60d oscillation is less than variance contribution of 10-20d oscillation. SSTs relatively active region of 10-20d oscillation is a northwest to southeast ribbon that started at ENSO3.4 area and ended in the Philippine islands. There are multiple relatively active center and variance contribution is 35%. The South China Sea is the mainly area of SSTs 30-60d oscillation. The relatively active region of oscillation of 10-20d about air-sea latent heat flux is showed two active belts in all year; The relatively active region of 30-60d oscillation about air-sea latent heat flux is obvious in summer half year, only for strip along 10°N.(3)Choosing the South China Sea, the variation characteristics of South China Sea summer monsoon and the relationship between its LFO components and the rainfall in Yangtze River-Huaihe River basin are analyzed, in drought/flood years of Yangtze River-Huaihe River basin. The results showed that:in 2001 and 2003, the onset of South China Sea monsoon is nearly in the same time, but the monsoon appeared interrupt in the middle of June,2003. In addition, the monsoon northward advances and its center rapidly moves from 8°N to the northern part of the South China Sea, and the same period in 2003,the monsoon was wandering about the central south of the South China Sea.(4)During the study of South China Sea summer monsoon’s low frequency process, We found that, in the two years, there are three pairs of oscillation centers which propagated northward significantly and displayed almost opposite LFO phase in the low frequency wind field, but in terms of intensity and duration, the intensity and duration of 2001 are stronger and longer than that of 2003. The IM-scs and IN-SCS are defined,according to the location of the low-frequency wind’s strong center regions, and finding the correlation between the indexes and the rainfall of June and July in the Yangtze River-Huaihe River basin and in the middle and east parts of Tibetan Plateau and is a pronounced, time-delayed negatively correlation. However, the relationship between the low frequency monsoon index and the rain of the middle and west parts of Yunnan Province and some of region in North China show us a pronounced, time-delayed correlation.