云南2009年秋季特大旱灾大气环流特征分析-自然灾害学报.PDF

19 6 Vo.l 19 No. 6 2010 12 JOURNAL OF NATURAL DISASTERS Dec. 2010 : 1004- 45 4( 2010) 06- 0138- 09 2009 张新主, 章新平, 谢自楚 ( , 410081) : 30 1961- 2009 NCEP /NCAR, 2009 3: 2009 ; , ; 2009 9- 11, ; 2009 9- 10, 11, 00~ 500hPa; 2009 9 10, , ; 11, 1 . 5b, , 2009 : ; ; : P4261616 : A Characteristic analysis of atm ospheric circulation for extrem e heavy drought in Yunnan Province in autumn of 2009 ZHANG X in-zhu, ZHANG X in-p ing, XIE Z-i chu ( College of Resources and Environm ent, Hunan Norma lU niversity, Changsha 410081, China) Abstract: Based on monthly precipitation data of the 30 stations in ProvinceYunnan and theNCEP /NCAR reana-l ysis data from 1961 to 2009, the rainfall anomaly and the atmospheric circulation features in autumn 2009w ere an- alyzed. The atmospheric circu lation featuresw ere analyzed w ithw ater vapor flux features, W esterly w ind anomalies and subtrop ical h igh. The results show that the rainfall in Yunnan Province is reduced in autumn 2009. A t the same period, w arm moisture flux from the Bay of Bengal region and the South China Sea decreased. The interaction be- tw een coldmoisture flux from InnerMongolia andw arm moisture flux from the Bay of Bengal and North Indoch ina w asw eakened. Autumn moisture convergence reduced in Yunnan Province in 2009. Zonalw esterly circu lation en- hanced in September and October in 2009, and in November, merid ionalw esterly circulation become stronger, but the 00- 500hPa meridionalw ind vector over the w estern Inner Mongolia, N ingxia, Sichuan w eakened. Thew est