甘南高原秋季连阴雨的气候特征及主要环流形势  

The Climatic Characteristics of Continuous Autumn Rain in Gannan Plateau During 1981-2010 and the Main Circulation

作　　者：王建兵 安华银 汪治桂 王成福 王亚茜 陈洋 

机构地区：[1]甘肃省甘南州气象局,甘肃合作747000

出　　处：《干旱气象》2013年第1期70-77,共8页Journal of Arid Meteorology

基　　金：甘肃省气象局"甘南高原对流云的研究"课题资助

摘　　要：利用甘南州8个气象站1981～2010年的地面气象观测资料,对甘南高原秋季连阴雨的气候特征进行了分析,发现甘南秋季连阴雨在9月各旬均可出现,10月只在上、中旬出现,地理分布上秋季连阴雨出现次数自西向东减少,玛曲、碌曲最多,卓尼、临潭最少。过程降水量在15.0～50.0 mm之间的连阴雨出现次数最多,约占总次数的78.0%;持续时间出现最多的是5～10 d,约占总次数的84.4%。近30 a甘南高原秋季连阴雨出现站次呈"V"形分布,1980年代秋季连阴雨次数较多,1990年代秋季连阴雨出现站次最少,进入21世纪后连阴雨次数开始增多,秋季连阴雨次数的多少对秋季降水量有直接影响。1990年代甘南高原秋季连阴雨次数与秋季降水量的减少是由于全球变暖背景下大气环流的调整所导致的,与气候变化密切相关。个例分析表明,在副高边缘型连阴雨过程中,副高偏强,有利于副高西侧西南气流把孟加拉湾水汽经过高原输送到甘南,对连阴雨天气的形成有重要作用;巴尔喀什湖槽稳定维持,同时高原上不断有低值系统形成东移对纬向环流型连阴雨的形成有重要作用;物理量分析表明二者在水汽输送和辐合、上升运动区的位置也有明显不同。Based on the meteorological data of 8 observational stations in Gannan plateau from 1981 to 2010,the climatic characteristics of continuous autumn rain in Gannan plateau were analyzed.The results show that the continuous autumn rain occurred in September,the first and the middle ten days of October.The total occurrence times of continuous autumn rain reduced from west to east,the maximum was in the Maqu county and the Luqu county,the minimum was in the Zhuoni county and Lintan county.The cumulative precipitation of 78.0% continuous autumn rain processes was between 15.0 and 50 mm,and the lasted period of 84.4% continuous autumn rain processes ranged from five to ten days.The occurrence times of continuous autumn rain was most in the 1980s and least in the 1990s,and in the 2000s it began to increase again.The number of continuous autumn rain times had a close relationship with the precipitation of autumn.The precipitation variety in September and October was similar to the annual trend of the continuous autumn rain,and decrease of continuous autumn rain and precipitation caused by the atmospheric circulation adjust under the background of global warming,which was strongly coupled with the climate change.The large scale circulation situation of continuous autumn rain was defined as the subtropical high edge type and the zonal circulation type.For the subtropical high edge type,the subtropical high was stronger than that of average state,which would help to transport the water vapour to the Gannan plateau by the southwesterly airflow of the subtropical high edge.For the zonal circulation type,the Balkhash Lake trough was stability,at the same time,low pressure system formed over the middle of Qinghai-Xizang plateau and moved to eastward.Physical quantities analysis showed that there were different in transporting and convergence of water vapour,as well as ascending motion position for two circulation types.

关 键 词：甘南高原 秋季连阴雨 气候特征 环流形势 

分 类 号：P444[天文地球—大气科学及气象学]