大气科学学报
大氣科學學報
대기과학학보
JOURNAL OF NANJING INSTITUTE OF METEOROLOGY
2009年
5期
686-694
,共9页
川渝地区%干旱%大气环流异常%热源
川渝地區%榦旱%大氣環流異常%熱源
천투지구%간한%대기배류이상%열원
Sichuan-Chongqing region%drought%atmospheric circulation anomaly%heat source
利用NCEP/NCAR再分析月平均资料、全国160站降水资料、向外长波辐射OLR(outgoing longwave radiation)资料和所计算的热源资料,分析了2006年夏季东亚大气环流的异常特征,并研究了热力异常与川渝地区夏季降水的关系.结果表明,2006年夏季由南向北的水汽输送较常年偏弱;西太洋副热带高压较常年异常偏强,脊线位置明显偏北,川渝地区受高压系统影响盛行下沉气流.中高纬环流场则表现为乌拉尔山地区和东北亚区域无明显阻塞高压形势,冷空气活动比常年弱:南亚高压比常年偏北偏强,持续控制川渝地区;2006年夏季青藏高原热源偏弱,热带西太平洋暖池区热源偏强,是引起西太平洋副热带高压偏北偏强的重要原因之一.川渝地区夏季降水与西太平洋副热带高压的异常变化有密切关系,川渝地区夏季干旱年,西太平洋副热带高压偏北,并且引起西太平洋副热带高压偏北的原因与2006年类似.
利用NCEP/NCAR再分析月平均資料、全國160站降水資料、嚮外長波輻射OLR(outgoing longwave radiation)資料和所計算的熱源資料,分析瞭2006年夏季東亞大氣環流的異常特徵,併研究瞭熱力異常與川渝地區夏季降水的關繫.結果錶明,2006年夏季由南嚮北的水汽輸送較常年偏弱;西太洋副熱帶高壓較常年異常偏彊,脊線位置明顯偏北,川渝地區受高壓繫統影響盛行下沉氣流.中高緯環流場則錶現為烏拉爾山地區和東北亞區域無明顯阻塞高壓形勢,冷空氣活動比常年弱:南亞高壓比常年偏北偏彊,持續控製川渝地區;2006年夏季青藏高原熱源偏弱,熱帶西太平洋暖池區熱源偏彊,是引起西太平洋副熱帶高壓偏北偏彊的重要原因之一.川渝地區夏季降水與西太平洋副熱帶高壓的異常變化有密切關繫,川渝地區夏季榦旱年,西太平洋副熱帶高壓偏北,併且引起西太平洋副熱帶高壓偏北的原因與2006年類似.
이용NCEP/NCAR재분석월평균자료、전국160참강수자료、향외장파복사OLR(outgoing longwave radiation)자료화소계산적열원자료,분석료2006년하계동아대기배류적이상특정,병연구료열력이상여천투지구하계강수적관계.결과표명,2006년하계유남향북적수기수송교상년편약;서태양부열대고압교상년이상편강,척선위치명현편북,천투지구수고압계통영향성행하침기류.중고위배류장칙표현위오랍이산지구화동북아구역무명현조새고압형세,랭공기활동비상년약:남아고압비상년편북편강,지속공제천투지구;2006년하계청장고원열원편약,열대서태평양난지구열원편강,시인기서태평양부열대고압편북편강적중요원인지일.천투지구하계강수여서태평양부열대고압적이상변화유밀절관계,천투지구하계간한년,서태평양부열대고압편북,병차인기서태평양부열대고압편북적원인여2006년유사.
Based on the NCEP/NCAR reanalysis monthly mean data,the 160 stations rainfall data in China,the OLR(outgoing longwave radiation)data and the calculated heat source data,the anomalies of atmospheric circulation in summer 2006 have been analyzed,and the relation between heat source a-nomalies and summer precipitation in the Sichuan-Chongqing region has been investigated.It is shown that the vertically integrated moisture transport from south to north in summer 2006 was weaker than normal.The western Pacific subtropical high(WPSH) was stronger and shifted northwestward and the subsidence flow prevailed over the Sichuan-Chongqing region.There was no blocking high over the U-ral Mountains and Northeast Asia,and the cold air activities were weaker than normal.The South Asia high Was also stronger than normal,and controlled persistently the area over eastem Sichuan and Chongqing.One reason that the WPSH Was stronger and shifted northwestward,is that the heat sources over the Tibetan Plateau were weaker while the western Pacific warm pool Was stronger.The summer rainfall over Sichuan-Chongqing has a close relation with the WPSH;in the summer drought years of Sichuan-Chongqing,the WPSH shifts northwards.The reason for that is the same for the summer case of 2006.