初夏孟加拉湾风暴对藏东雨季开始期的影响

Influence of The Bay of Bengal Storm on The Beginning of Rainy Season in the Eastern Tibet in Early Summer

利用2000—2020年降水资料,联合台风警报中心(JTWC)孟加拉湾风暴资料,在计算藏东12个站点的雨季开始期的基础上,分析孟湾风暴的活动特征以及对雨季开始期关系、对初夏孟湾风暴造成高原降水的环流进行分型、分析初夏孟湾风暴影响下的藏东雨季水汽轨迹。结果表明:初夏孟加拉湾热带气旋移动方向、路径特征可以将风暴分为北上、西北移、东北移、转向4种类型;影响藏东雨季开始期的初夏孟加拉湾风暴源地大致位置为4°N~18°N、81°E~94°E,环流形势以切变线与孟湾低值系统相结合型为主;孟湾风暴影响下的强降水过程水汽轨迹以偏南方向为主,水汽主要来源于印度洋、孟加拉湾、阿拉伯海。

Based on the precipitation data from 2000 to 2020 and the Joint Typhoon Warning Center storm data(JTWC) of Bay of Bengal, the onset of the rainy season at 12stations in eastern Tibet is calculated, the characteristics of the storm activity in the Bay of Bengal and the relationship between the onset of the rainy season, the circulation patterns of the precipitation in the plateau caused by the storm in the early summer, and the vapor track in the rainy season in eastern Tibet under the influence of the storm in the early summer are analyzed. The results show that the direction and path of tropical cyclone over Bay of Bengal in early summer can be divided into northward, northwest, northeast and turning types The sources of the Bay of Bengal storm in the early summer affecting the onset of the eastern Tibetan rainy season are generally between 4°and 18°N, and between 81°and 94°E. the circulation pattern is mainly the combination of the shear line and the low value system of the Bay of Bengal. The vapor track of the heavy precipitation process in the Bay of Bengal is mainly southward,and the vapor mainly comes from the Indian Ocean, the Bay of Bengal Ocean and the Arabian Sea.