摘要
采用2009—2019年中国西南地区36个气象观测站逐日降水资料,同时采用2009—2019年冬季NCEP全球逐日的2.5°×2.5°再分析资料对我国西南地区自2009年以来近10a冬季强降水过程环流形势和水汽输送进行分析。结果表明:西南地区冬季的水汽主要来自两个地区,一个是孟加拉湾地区,为主要源区;另一个水汽来源是南海西侧地区。2011年的冬季和2012年的冬季,两区域水汽充沛,它们共同作用,造成冬季强降水多发。与其相反2010年冬季西南地区的干旱特征是这两个水汽源区的水汽含量偏低,同时,相应时期的风场强度也较往年平均值低,使得近10年以来,我国西南地区冬季的水汽输送强度在时序上是先低后高,并成为该地区冬季由旱转降水偏多的重要原因。2011年冬季的异常强降水分析显示水汽通量的强度和冷空气的强弱对西南地区冬季强降水过程十分重要。
Daily precipitation data from 36 meteorological stations in southwest China from 2009 to 2019 were used.At the same time,the daily NCEP reanalysis data of 2.5°×2.5°in winter from 2009 to 2019 were used to analyze the circulation pattern and water vapor transport of heavy precipitation in winter in southwest China since 2009.The results show that the water vapor in winter mainly comes from two regions in southwest China.One is the Bay of Bengal,which is the main source region.Another source of water vapor is the western side of the South China Sea.In the winter of 2011 and 2012,water vapor was abundant in the two regions,and they worked together to produce more heavy rainfall in the winter.On the contrary,the winter drought in southwest China in 2010 was characterized by the low water vapor content in these two water vapor sources,and the wind intensity in the corresponding period was also lower than the average in previous years.In the recent 10 years,the water vapor transportation intensity in the southwest of our country was first low and then high in the sequential series,and became the important reason for the transformation from drought to precipitation in winter.The analysis of unusually heavy precipitation in winter of 2011 shows that the intensity of water vapor flux and the strength of cold air are very important to the process of heavy precipitation in winter in southwest China.
作者
廖育玲
李帮英
蔡垚
杨滨璐
LIAO Yuling;LI Bangying;CAI Yao;YANG Binlu(Congjiang Meteorological Bureau,Qiandongnan Guizhou 557400;Majiang Meteorological Bureau,Qiandongnan Guizhou 557600;Rongjiang Meteorological Bureau,Qiandongnan Guizhou 557200)
出处
《中国科技纵横》
2023年第3期132-134,共3页
China Science & Technology Overview
关键词
西南地区冬季
合成分析
强降水
西南热低压
湿热动力特征
winter in southwest china
synthetic analysis
heavy precipitation
Southwest hot low
damp-thermal dynamic characteristics
