Variability of Summer Atmospheric Moisture Flux and Its Effect on Precipitation over East China
Using the in-situ precipitation and NCEP/NCAR daily reanalysis data, we found by studies of change of moisture flux and its effect that the northward water vapor transport represented by moisture flux in East China tends to retreat southward, and the eastward water vapor transport tends to weaken with weakening of the intensity of moisture flux. The north boundary of meridional moisture flux (50 kg m-1s-1) retreats 2.8 degrees in latitude per decade during 1968-2003. The weakening of water vapor transport implies the weakening and southward retreat of East Asian monsoon, which leads to the tendency of decrease in moisture flux convergence over North China and the middle and lower reaches of the Yellow River, and the tendency of decrease in precipitation over those regions, but on the contrary the enhanced water vapor transport convergence over the middle and lower reaches of the Yangtze River implies the tendency of increase in precipitation to some extent. Indeed the long-term variability of precipitation in East China has a close relation with that of atmospheric moisture flux.
作 者： JIANG Ying ZHAI ranmao WANG Qiyi 作者单位： Laboratory for Climate Studies of China Meteorological Administration, National Climate Center, Beijing 100081 刊 名： 气象学报（英文版） SCI 英文刊名： ACTA METEOROLOGICA SINICA 年，卷(期)： 2005 19(4) 分类号： P4 关键词： moisture flux (water vapor flux) precipitation change tendency