玉溪5月旱涝分布及环流特征分析  

THE PRECIPITATION DISTRIBUTION AND CIRCULATION ANALYSIS IN MAY OF YUXI

作　　者：杨海光 李刚 解福燕 

机构地区：[1]云南省峨山县气象局,云南峨山653200 [2]云南省元江县气象局,云南元江653300 [3]云南省玉溪市气象局,云南玉溪653100

出　　处：《云南地理环境研究》2013年第3期29-33,共5页Yunnan Geographic Environment Research

基　　金：玉溪市科技局重点科研项目"初夏旱涝预测方法研究和业务系统开发应用"

摘　　要：1951—2012年玉溪5月降水极其不稳定，局部干旱、洪涝突出，其中洪涝37．8％，干旱42．2％，正常年仅有20％。影响5月洪涝的主要原因是经向环流、青藏高压、南亚高压和副热带高压偏强，极涡深厚，东亚大槽偏西偏强，南支槽频繁，海温处于冷位相，夏季风暴发偏早，冷空气和暖湿气流配合，保障了降雨所需的水汽条件。造成5月干旱的主要原因是极涡偏西，东亚高压偏强，青藏高压偏弱，极地冷空气活动弱，南亚高压和副热带高压偏南，强劲的西风带不利于北方冷空气南下和孟加拉湾水汽北上。The precipitation in May of Yuxi is extremely unstable from 1951 to 2012. Localized drought and floods are prominent, which floods account for 37.8% of years, 42. 2% were droughts, only 20% are normal. Floods in May were mainly affected by strong Meridional Circulation, Tibetan High, SAH and subtropical high pressure. Strong polar vortex, strong East Asian Trough toward the west, frequent Southern Trough, SST in the cold phase, early outbreaks of summer monsoon, cold air and warm air meet, all reasons above ensured that the required moisture conditions of rainfall. The drought in May was mainly caused by Polar Vortex toward the west, strong East High, weak Tibetan High, weak polar cold air activities, South Asia and the subtropical high pressure toward the south. Strong westerlies was not conducive to the northern cold air southward, nor conducive to the Bay of Bengal water vapor northward.

关 键 词：5月旱涝 分布特征 环流形势 玉溪市 

分 类 号：P426.6[天文地球—大气科学及气象学]