【摘要】 应用NCEP/NCAR的再分析资料,对云南5月降水异常的1997年和1999年进行对比分析,发现孟加拉湾水汽输送发生异常对云南5月降水有重要影响。结果表明:在5月少雨年,孟加拉湾、中南半岛及云南OLR场呈正距平分布,200hPa南亚高压和850hPa孟加拉湾低压偏弱,孟加拉湾南支槽偏弱,此时孟加拉湾水汽输送偏弱;在5月多雨年,孟加拉湾、中南半岛及云南OLR场呈负距平分布,200hPa南亚高压和850hPa孟加拉湾低压偏强,孟加拉湾南支槽偏强,此时孟加拉湾水汽输送偏强。并且孟加拉湾水汽输送异常与ElNino事件或LaNina事件密切相关。更多还原

【Abstract】 By using NCEP/NCAR reanalysis data had analyzed to contrast the abnormal precipitation of Yunnan in May on the year of1997and1999,and found out that the abnormal moisture transport on the Bay of Bengal was very important to the rainfall of Yunnan in May.The results had shown that the seldom rainfall year in May was simultaneously emerged with positive anomalies distribution of OLR fields on the Bay of Bengal,Indochina and Yunnan,weaker of South Asia high on200hPa and the Bay of Bengal low on850hPa,flat India trough on the Bay of Bengal and lack moisture transport on the Bay of Bengal;on the other hand,the abundantly rainfall year in May was corresponding with negative anomalies distribution of OLR fields on the Bay of Bengal,Indochina and Yunnan,stronger of South Asia high on200hPa and the Bay of Bengal low on850hPa,deep India trough on the Bay of Bengal and rich moisture transport on the Bay of Bengal.It was also shown that the abnormal moisture transport on the Bay of Bengal had closely correlated with El Nino events or La Nino events.更多还原