【摘要】 利用ECMWF 2.5°×2.5°的再分析资料,用大尺度水汽通量流函数和速度势以及水汽收支对台风Dan(9914)在形成、加强和减弱过程中的水汽输送和收支进行了诊断分析。结果表明:台风Dan西行期的水汽主要从西边界和东边界流入台风,水汽主要是来自于副热带高压南侧偏东气流对水汽的输送;转向北移后则以西边界流入的水汽占主导作用,水汽主要是来自南海。台风Dan的水汽输送主要集中在对流层中低层,一般在925 hPa有最大的水汽总收支。在Dan发生发展的不同时期,由大尺度水汽通量流函数和速度势表示的水汽通量输送和辐合也有明显的变化,表明水汽输送和辐合在Dan的发生发展及消亡过程中有一定作用。更多还原

【Abstract】 In this paper it is indicated that the vapor flux plays a very important role in the genesis,development and dissipation of Typhoon Dan through the calculation of stream function,velocity potential and vapor budget in the large-scale background around it.It is shown that when Dan moved westward,the water vapor mainly came from the eastern and western boundaries,and the most of vapor were transferred from the Pacific Ocean;after Dan swerved northward,the water vapor mainly came from western boundary of the typhoon,and the vapor came from the South China Sea and the Indian Ocean together.The transfer of water vapor was mainly concentrated on the lower levels of the troposphere,especially in the 925 hPa,where the most intensive transfer belt located.During different periods of Dan,there was great water vapor change as indicated by stream function,velocity potential and vapor budget,which showed the importance of water vapor in the development of typhoon Dan.更多还原