摘要
利用NCEP/NCAR再分析资料、地面站点资料,引入拉格朗日方法的轨迹模式,定量分析洞庭湖地区2014—2017年夏半年水汽输送来源特征,对比2017年“6·22”极端降水2个时段的水汽输送来源差异,得到以下结论:洞庭湖地区夏半年的主要输送源地为太平洋(32.3%,水汽输送贡献),孟加拉湾—南海(28.3%),印度洋(26.6%),中国东部水汽输送相对较少,但不可忽视。各源地各月水汽输送具有较大差异,其中4、5月以太平洋和孟加拉湾—南海水汽输送为主,6、7月以印度洋水汽输送为主,太平洋、孟加拉湾—南海次之。“6·22”极端降水环流背景:中低纬西太平洋副热带高压稳定维持,洞庭湖地区处于副热带高压西侧的强水汽输送带中,有利于水汽不断往暴雨区输送。极端降水期间,印度洋水汽输送异常偏多,太平洋水汽输送异常偏少。第一个时段的水汽源地主要为印度洋,其次为孟加拉湾—南海,其它源地水汽输送贡献较小,欧亚大陆为干冷空气输入。第二时段中国东部和欧亚大陆无水汽来源,中低层无干冷空气侵入,印度洋、孟加拉湾—南海水汽输送仍占主导地位,太平洋水汽输送明显增多。
In this study,based on the NCEP reanalysis data,precipitation of meteorological stations and employed the Lagrange trajectory model(HYSPLIT),the characteristics of water vapor transport sources in summer half year from 2014 to 2017 in the Dongting Lake region was quantitatively analyzed and the differences of water vapor transport sources in the two periods of“6·22”extreme precipitation in 2017 were compared.Major conclusions are as follows:In the summer half-year of the Dongting Lake,the primary transport sources are the Pacific Ocean(32.3%,water vapor transmission contribution),the Bay of Bengal-South China Sea(28.3%),and the Indian Ocean(26.6%).The Eastern China water vapor transport is relatively small,but it is still a part that cannot be ignored.The moisture transport from different sources shows differently in each month.In April and May,the Pacific Ocean and Bay of Bengal-South China Sea are the initial vapor transport sources.In June and July,water vapor transport in the Indian Ocean was the main one,followed by the Pacific Ocean,Bay of Bengal-South China Sea.The background of“6·22”extreme precipitation circulation shows that the subtropical high in the Western Pacific at medium and low latitudes remains stable,and Dongting Lake region is located in the strong moisture conveyor belt on the west side of the subtropical high,which is conducive to the continuous water vapor transport to the rainstorm region.During extreme precipitation,the water vapor transport in the Indian Ocean is abnormal more,while that in the Pacific Ocean is abnormal less.In the first period of extreme precipitation,the primary water vapor source is from the Indian Ocean,then followed by the Bay of Bengal-South China Sea,and the other water vapor sources contributed less.The dry cold air imported from Eurasia.There was no water vapor transport from Eastern China and Eurasia in the second period,and no dry cold air intruded into the middle and lower layers.The water vapor transport from the Indian Ocean and Bay of Bengal-sou
作者
蒋帅
尹依雯
陈世文
彭洁
朱浩
陈太龙
JIANG Shuai;YIN Yiwen;CHEN Shiwen;PENG Jie;ZHU Hao;CHEN Tailong(Key Laboratory of Preventing and Reducing Meteorological Disaster of Hunan,Changsha 410118,China;Yueyang Meteorological Bureau,Yueyang 414000,China)
出处
《沙漠与绿洲气象》
2021年第5期55-63,共9页
Desert and Oasis Meteorology
基金
2019年度中国气象局气候变化专项(CCSF201946)
2017年湖南省气象局预报员专项(XQKJ17C007)
2018年湖南省气象局预报员专项(XQKJ19C008)
2021年湖南省气象局短平快项目(XQKJ21B020)。
