摘要
用1951—2008年58 a 1月10日—2月2日1 000 hPa高度场逐日NCEP/NCAR再分析格点资料,求得逐日蒙古高压的强度P和中心位置λc、c指数,用其对"0801南方雪灾"期间蒙古高压的中期演变过程进行统计分析。结果表明,2008年1月10日—2月2日蒙古高压强度P和中心所在纬度φc出现了连续4次振荡,它们与我国南方降温、降水振荡过程准同步。由P、(λc,c)给出的综合动态图上蒙古高压4次活动过程也很明显地与降温、降水中期过程一一对应。分析表明2008年1月10日—2月2日蒙古高压的这一中期演变特征,是1951年以来仅有的一次。因此,可以认为,在充沛水汽供应条件下蒙古高压强而连续的爆发是导致"0801南方雪灾"产生的直接环流成因。
By using the 1 000 hPa geopotential height grid data during the 10 January—2 February in 1951—2008（from the NCEP/NCAR daily reanalysis dataset）,a set of circulation indices are calculated to statistically analyze the medium-term processes of the Mongolian high during the ＂0801 snow storm over southern China＂ period,including indices of the intensity P and centre position（λc,c） of the high.The results show that the P and c of Mongolian high had four consecutive oscillations during the period of 10 January—2 February 2008,which quasi-synchronously related to the four medium-term processes of temperature fall and precipitation over southern China.On the composite dynamic diagram of P and（λc,c）,the four active processes of Mongolian high corresponded well with four medium-term temperature fall and precipitation oscillations.This unique characteristic of the medium-term development of Mongolian high has been shown only once since 1951.Therefore,under the condition of abundant water vapor supply,it is the strong and continuous outbreaks of Mongolian high that directly caused the ＂0801 snow storm over southern China＂.
出处
《大气科学学报》
CSCD
北大核心
2009年第5期652-660,共9页
Transactions of Atmospheric Sciences
基金
国家科技支撑计划项目(2008BAC48B02-1)
关键词
“0801南方雪灾”
蒙古高压
环流指数
中期过程异常
0801 snow storm
southern China
Mongolian high
atmospheric circulation indices
anomalous medium-term process
