摘要
利用NCEP 1998—2007年分析资料,分析了2007年、2005年和2003年3个淮河大洪水年7月上旬逐日各层的位势高度、温度、水汽和风场等资料。分析结果表明:这3个洪水年和近10年平均场的大尺度环流背景、高低空急流、水汽输送特征等存在显著差异。东亚夏季风异常是这3年淮河流域洪涝出现的主要原因。同时,这3年西北太平洋副热带高压均较历史同期偏强,西伸脊点偏西;华北南部到黄淮距平风场上有较常年明显的偏北气流,副热带高压西北侧850hPa低空急流较常年平均偏强6m.s-1以上,南北两支气流交汇区正好位于淮河流域;在200hPa上淮河流域处于异常的高空急流入口南侧或受较常年偏强的反气旋环流控制之下;从整层水汽通量距平分析,南海是这3个淮河洪涝年的主要水汽源地。
By using the NCEP data of the first 10 days in July from 1998 to 2007, three heavy flooding cases in 2003, 2005 and 2007 are analyzed and compared. It is found that there is an obvious difference in the atmospheric circulation background, the high/low level jets and the water vapor transportation between the flooding years and average of ten years. The abnormal feature of the East Asian summer monsoon is the main reason of the floods. During the first 10 days in July of the three flooding years, the west pacific subtropical high is stronger and its west ridge point is more western than the ten-year average. There is obviously north wind from the south of north China to the Huanghe and Huaihe basin. The low jets of 850hPa surpassed 6m/s larger than the tenear mean. The connection of the north and the south strong air current exactly lied in Huaihe River basin. At 200hPa, Huaihe River basin was under the south of the jets entrance or under the anticyclone. Through the analysis of abnormal water vapor transportation on the whole layer, it is found that the South China Sea was the main water vapor source area.
出处
《气象》
CSCD
北大核心
2008年第8期63-69,共7页
Meteorological Monthly
关键词
洪涝
环流特征
副热带高压
水汽输送
rainy season of Huaihe river basin atmospheric circulation characteristic west pacific subtropical high water vapor transportation
