Gps Precipitable Water Vapor Data Assimilation Analysis On The 2009 Typhoon Morakot

• Main Authors: Hsin-WeiFeng, 馮信瑋
• Other Authors: Ruey-Juin Rau
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/t5b79n

碩士 === 國立成功大學 === 地球科學系 === 106 === Within the past 20 years, GPS satellite observation has been widely used, which is free from the constraint of space and time, overcome the thickness of the cloud as well as the severe weather. This thesis will take the 2009 typhoon Morakot as the object for research, taking the NCEP analysis field data (FNL), global observation data (OBS), GPS PWV precipitation observation data during the typhoon period; by the mesoscale numerical weather prediction model (WRF). Three-dimensional variational data assimilation (3DVAR) program for numerical simulation is used for analysis. Experimental methods will be separated into 3 models: simple WRF simulation, WRF with OBS data for assimilating simulation, as well as the WRF with OBS and PWV with precipitation data for assimilating simulation. The difference is to verify the improvement regarding the precipitation data to the numerical weather predicting model. The simulation analysis of the precipitation of the station is compared with the data of the assimilation of the data, and the predicted precipitation is corrected on a time-by-time basis, which is closer to the real case. With the increase of the simulation time, the improvement effect of the M-PWV group is more significant. The station assimilation data correction effect, the GPS PWV precipitation signal can be added during the data assimilation process, and the correction effect of the 9.5% error can be reduced at the Hengchun station, the Yongkang station is reduced by 8.6%, and the Yushan station is reduced by 58.2%. Therefore, GPS PWV can be used to add precipitation signals during data assimilation. In the station precipitation forecast, the error correction can be used to a certain extent.