李天浩2006-07-252018-07-092006-07-252018-07-092001http://ntur.lib.ntu.edu.tw//handle/246246/2760本研究嘗試利用GBVTD (Ground-Based Velocity Track Display, Lee et al., 1999 and 2000)法分析五分山雷達之都卜 勒風速觀測資料，未來擬作為初始化中尺度 （meso-á）數值模式颱風渦旋的同化方法， 以期改進極短時(3-12)定量降水的預報。在都 卜勒風場資料的分析上，首先應用軸對稱颱 風環流概念，發展一套颱風環流之都卜勒風 速摺疊校正（dealiasing）法，以此都卜勒風 速摺疊校正法，處理中央氣象局五分山雷達 之都卜勒風速觀測資料。其次利用GBVTD 法解析颱風渦旋動力最強的核心部分的分層 水平風場。第三步驟將分析得到的颱風渦旋 植入MM5 的6.67 公里解析度風場數值解 中，先以九點移動平均的方式內插平滑化植 入颱風風場和模式風場解之間的差異；再採 用斜壓方程式演算使風場達到質量平衡。未 來計畫再將植入MM5 之颱風渦旋以反覆迭 代的方式，產生動力平衡的初始場，之後再 進行3~6 小時的定量降雨預報，期望透過雷 達資料同化改進數值模式之初始場，增進數 值模式預報3~6 小時颱風定量降雨分佈的能 力。The concept of typhoon circulation is applied to develop an automatic Doppler velocity dealiasing algorithm. And the algorithm was tested with the Doppler velocity data of Wu-Feng-Shan (WFS) radar during Typhoon Herb. Then, the GBVTD technique is applied to deduce the layered horizontal wind field of typhoon vortex. The analyzed layered wind-field of typhoon vortex is inserted into the numerical model output wind-field by the PSU-NCAR Mesoscale Model version 5 (MM5) with a 6.67 km horizontal resolution. The 2-D wind field layers are smoothed with the nine-point moving average filter to remove the discontinuities at the interface. Then, each of these 2-D wind fields at different altitude is processed using the scaled isobaric primitive equation and hydrostatic equation to derive the corresponding balanced mass field, geo-potential field and temperature field. In the future, it is planed to apply an iterative method using MM5 model to further process the wind field to obtain a dynamically balanced initial condition . It is hoped that the radar data assimilation processing can improve the NWP model’s typhoon vortex initialization in order to enhance the three- to twelve-hour quantitative precipitation forecast (QPF).application/pdf1278846 bytesapplication/pdfzh-TW國立臺灣大學土木工程學系暨研究所徑向速度反摺疊GBVTD 法及雷達反演颱風渦旋之初始化radial velocity dealiasingthe GBVTD techniquethe initialization method of the typhoon vortex retrieved by radar datareporthttp://ntur.lib.ntu.edu.tw/bitstream/246246/2760/1/892625Z002046.pdf