青藏高原热力状况异常与长江中下游地区梅雨关系的相关分析及数值试验

摘要

利用观测资料对青藏高原热力状况与长江中下游地区梅雨进行统计分析，发现两者存在一定的联系：旱、涝年青藏高原下垫面热力状况存在南北反相特征，即当青藏高原下垫面前冬南侧偏暖(冷)、北侧偏冷(暖)时，对应长江中下游地区梅雨量易偏少(多)。而且这种高原下垫面异常热力状况具有持续性，可以持续维持到夏季。在此基础上，设计了两组敏感性试验，分别改变高原下垫面热力状况，应用NCAR RegCM2区域气候模式进行数值模拟，模拟结果可以较好的验证上述统计事实。%Based on observation data, the correlation analysis of the Tibetan Plateau thermal condition and Meiyu in the Yangtze River Basin is conducted. The statistic results indicate that the surface thermal condition is correlated with the flood/drought in the Yangtze River Basin. If there exists abnormally warm thermal condition over the southern Tibet , then there will be a flooding summer in the Yangtze River Basin and vice versa. Based on such results, two sensitive experiments are designed by use of the NCAR RegCM2 model, in which the ground temperature of the northern or southern Tibetan Plateau increases or decreases respectively. The experiments simulated the features very well and validated the statistic results.