大气科学2011，Vol.35Issue(5)：982-992,11.
南海地区大气30～60天低频振荡及其对南海夏季风的可能影响
Tropical Low Frequency Oscillations with 30- 60 Day Period and Its Possible Influence on the South China Sea Summer Monsoon
摘要
Abstract
The tropical low frequency oscillation and its possible influence on the South China Sea (SCS) summer monsoon are studied by using the daily NCEP/NCAR-2 (National Centers for Environmental Prediction and National Center for Atmospheric Research) reanalysis data and the outgoing long-wave radiation (OLR) data from NOAA(National Oceanic and Atmospheric Administration) for the time period of 1979 - 2008, and the CPC Merged Analysis of Precipitation (CMAP) data for the time period of 1979 - 2007. Results reveal that there are significant low frequency oscillations with 30 - 60 day period over the SCS region. When the 30 - 60 day oscillation is in an active state, the low frequency components of southwesterly prevail over the SCS and the cyclonic circulation appears in northern SCS. Hence, in the active state the low frequency oscillation tends to strengthen the South China Sea summer monsoon (SCSSM) trough and the SCS summer monsoon. In the inactive state of the low frequency oscillation, the situation tends to be opposite. Further researches indicate that the spatial pattern for the variability of the low frequency oscillation is analogous to that for the interannual variations of the SCS summer monsoon. Particularly the variance of low frequency oscillation activity in the SCS region can account for nearly half of that for the interannual variations of the SCS summer monsoon. The comparison between strong and weak SCS summer monsoon years presents that the occurrence probability of active state is higher than that of inactive state for the low frequency oscillation in strong monsoon years. However, in weak monsoon years the occurrence probability of inactive state is higher than that of active state. Therefore, the low frequency oscillation with 30 - 60 day period likely has an important influence on the SCS summer monsoon. When the active state is dominant for the low frequency oscillation, the SCS summer monsoon tends to be strong. ()n the contrary, the SCS summer monsoon tends to be weak when the inactive state is dominant for the low frequency oscillation.关键词
30～60天低频振荡/南海夏季风/活跃状态/不活跃状态Key words
low frequency oscillation with 30 - 60 day period, the South China Sea summer monsoon, active state, inactive state分类
天文与地球科学引用本文复制引用
陈尚锋,温之平,陈文..南海地区大气30～60天低频振荡及其对南海夏季风的可能影响[J].大气科学,2011,35(5):982-992,11.基金项目
国家重点基础研究发展规划项目2009CB421405,国家自然科学基金资助项目41025017、40921160379 （）
