干旱地区农业研究
榦旱地區農業研究
간한지구농업연구
AGRICULTURAL RESEARCH IN THE ARID AREAS
2013年
4期
237-244,256
,共9页
川渝地区%夏季干旱%标准化降水指数%大气环流%水汽输送
川渝地區%夏季榦旱%標準化降水指數%大氣環流%水汽輸送
천투지구%하계간한%표준화강수지수%대기배류%수기수송
Sichuan-Chongqing region%summer drought%standard precipitation index%atmospheric circulation%water vapor transport
利用1979—2011年英国东英吉利大学气候研究中心(CRU)整理的地面月降水资料和日本气象厅(JMA)加工的全球高空等压面月平均气象场再分析资料,采用标准化降水指数(SPI),确定了川渝地区典型干旱年,讨论了川渝地区夏季典型干旱的气候特征及其大气环流特征。结果表明:川渝地区夏季典型干旱年具有气温高、降水少的气候特征;东亚中纬度盛行纬向气流,西风锋区偏北,冷空气多偏北东移,川渝地区及其我国北方大部分地区受大陆带状高压控制。500 hPa带状高压与100 hPa南亚高压中心位置基本一致,且500 hPa高压中心与温度场的暖中心相对应,是持续性川渝夏季干旱具有近似正压结构的典型环流特征;同时川渝地区夏季干旱年对流层低层从云贵高原到四川盆地的西南气流明显偏弱,风场距平合成表明,云贵高原到川渝地区为东北距平风,距平风场上华南地区为明显的气旋式环流;川渝地区夏季典型干旱年整层西南气流水汽输送与常年比较明显偏小。
利用1979—2011年英國東英吉利大學氣候研究中心(CRU)整理的地麵月降水資料和日本氣象廳(JMA)加工的全毬高空等壓麵月平均氣象場再分析資料,採用標準化降水指數(SPI),確定瞭川渝地區典型榦旱年,討論瞭川渝地區夏季典型榦旱的氣候特徵及其大氣環流特徵。結果錶明:川渝地區夏季典型榦旱年具有氣溫高、降水少的氣候特徵;東亞中緯度盛行緯嚮氣流,西風鋒區偏北,冷空氣多偏北東移,川渝地區及其我國北方大部分地區受大陸帶狀高壓控製。500 hPa帶狀高壓與100 hPa南亞高壓中心位置基本一緻,且500 hPa高壓中心與溫度場的暖中心相對應,是持續性川渝夏季榦旱具有近似正壓結構的典型環流特徵;同時川渝地區夏季榦旱年對流層低層從雲貴高原到四川盆地的西南氣流明顯偏弱,風場距平閤成錶明,雲貴高原到川渝地區為東北距平風,距平風場上華南地區為明顯的氣鏇式環流;川渝地區夏季典型榦旱年整層西南氣流水汽輸送與常年比較明顯偏小。
이용1979—2011년영국동영길리대학기후연구중심(CRU)정리적지면월강수자료화일본기상청(JMA)가공적전구고공등압면월평균기상장재분석자료,채용표준화강수지수(SPI),학정료천투지구전형간한년,토론료천투지구하계전형간한적기후특정급기대기배류특정。결과표명:천투지구하계전형간한년구유기온고、강수소적기후특정;동아중위도성행위향기류,서풍봉구편북,랭공기다편북동이,천투지구급기아국북방대부분지구수대륙대상고압공제。500 hPa대상고압여100 hPa남아고압중심위치기본일치,차500 hPa고압중심여온도장적난중심상대응,시지속성천투하계간한구유근사정압결구적전형배류특정;동시천투지구하계간한년대류층저층종운귀고원도사천분지적서남기류명현편약,풍장거평합성표명,운귀고원도천투지구위동북거평풍,거평풍장상화남지구위명현적기선식배류;천투지구하계전형간한년정층서남기류수기수송여상년비교명현편소。
Using the monthly precipitation data from Climate Research Unit (CRU) ,University of East Anglia in England and the global monthly mean meteorological reanalysis data at standard isobaric levels from Japan Meteorological Agency (JMA) from 1979 to 2011 ,the criterion of typical drought years in Sichuan-Chongqing region was determined with the Standardized Precipitation Index (SPI) ,and the climatological characteristics and possible causes of summer droughts in Sichuan-Chongqing region were analyzed from the aspect of atmospheric circulation .The results show that , during years with typical summer droughts ,the surface air temperature is higher and the precipitation is less than normal . The zonal circulation develops in mid-latitude regions of East Asia ,and the westerly frontal zone and the cold air mass shift northward during summer droughts .Meanwhile ,Sichuan-Chongqing region and most parts of northern China are un-der the control of mainland belt high pressure .The location of high pressure at 500 hPa field is nearly the same with the center of South Asian high pressure at 100 hPa field .Moreover ,the high pressure center at 500 hPa corresponds with the warm center in the temperature filed .This quasi -barotropic structure is the typical circulation feature of a persistent summer drought in Sichuan-Chongqing region .At the same time ,the southwesterly flow is obviously weakened from Yun-nan-Guizhou Plateau to Sichuan Basin in the low troposphere .In the anomaly wind field ,there exist northeasterly flows from Yunnan-Guizhou Plateau to Sichuan Basin ,and there is a cyclonic circulation over southern China .The entire-layer southwesterly water vapor transport in typical summer drought years is much weaker than normal in Sichuan-Chongqing re-gion .