基于拉格朗日方法的江淮梅雨水汽输送特征分析

Analysis of water vapor transport characteristics during the Vleiyu over the Yangtze-Huaihe River valley using the Lagrangian method

中文关键词:  江淮梅雨  水汽输送  拉格朗日轨迹

英文关键词:The Meiyu over the Yangtz-Huaihe River valley  Water vapor transportation  Lagrangian trajectory

中文摘要:

      利用NCEP再分析资料, 引入基于拉格朗日方法的气流轨迹模式(HYSPLITv4.9),结合用于海量轨迹分析的气块追 踪分析方法, 探讨了江淮梅雨气候平均的水汽输送特征以及梅雨异常年水汽输送的差异。结果表明, 在气候态下, 江淮梅雨 的水汽主要来自印度洋、孟加拉湾-中国南海、太平洋和欧亚大陆4 个区域, 其对江淮梅雨的水汽输送贡献分别为35%、 19%、22%和19%.其中, 印度洋、孟加拉湾-中国南海和太平洋上的输送气流主要来自850hPa以下的对流层低层, 而欧亚 大陆的输送气流主要来自600hPa左右的对流层中层。进一步对比梅雨异常年水汽输送的差异, 发现孟加拉湾-中国南海、 太平洋和印度洋的水汽输送对江淮梅雨的异常有重要影响, 梅雨偏多年来自孟加拉湾-中国南海的水汽输送较多, 其对江淮 梅雨的水汽输送贡献为24%,比梅雨偏少年约增加了13%,梅雨偏少年则是来自太平洋和印度洋的水汽输送较多, 对江淮梅 雨的水汽输送贡献分别达到了40%和30%,比梅雨偏多年约增加了5%和10%.

英文摘要:

      Using the NCEP reanalysis data and the airflow trajectory model based on the Lagrangian method(HYSPLT_4.9).the climatological characteristics of water vapor transport associated with the Meiyu and its differences in the abnormal years have been discussed in this paper. The results showed that the water vapor of the Meiyu mainly come from the Bay of Bengal-South China Sea. the Indian Ocean.the Pacific region and the Eurasian continent.accounting for 19%, 35%, 22% and 19% of the total moisture transport, respectively. Among of them, the water vapor over the Indian Ocean,the Bay of Bengal-South China Sea and the Pacific Ocean are from the lower troposphere under the 850 hPa, while the water vapor over the Eurasian continent comes from the middle troposphere. Besides, by comparing with the differences in the abnormal years, we found that water vapors from the Fray of Bengal-South China Sea, the India Ocean, and the Pacific region have import influences on the Meiyu anomalies. In wet Meiyu years, water vapor coming from the Bay of Bengal-South China Sea is more by 13% than that in dry Meiyu years, reaching to 24%, but for the areas of the Pacific and India Oceans in dry years, the contribution rates of water vapor are 40% and 30% respectively.