Verification of multiple-Doppler-radar derived vertical velocity using profiler data and high resolution examination over complex terrain

• Main Authors: Yi-An Chen, 陳奕安
• Other Authors: Yu-Chieng Liou
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/y9kz9c

碩士 === 國立中央大學 === 大氣科學學系 === 107 === The retrieval of vertical velocity using Doppler radar data always contains large uncertainty. In this study the quality of the vertical velocity retrieved by a 3DVar-based multiple-Doppler wind analysis system named WISSDOM (WInd Synthesis System using DOppler Measurement) is investigated. Data from one S-band (RCWF) radar and two C-band radars (RCTP and NCU) in northern Taiwan are utilized. The accuracy of the vertical velocity from WISSDOM is examined using two profilers (L-band and UHF) observations. The inter-comparison shows that WISSDOM-derived vertical velocity agrees reasonably well with the profiler data. The highest correlation and the smallest RMSD (Root-Mean-Square Deviation) take place when comparing against the L-band profiler data obtained under vertical beam scanning mode. The WISSDOM-derived results are generally better than those reported in a previous study using ARM scanning radar network in Oklahoma. The winds from the L-band profiler are also merged into WISSDOM, resulting in an overall improvement of the three-dimension wind field at low levels. UHF and RCTP are applied to verify the accuracy of the method. It is shown that WISSDOM assimilating the L-band can reduce RMSD and enhance correlation with UHF and RCTP. The result suggests that the method can get better three-dimension wind field. Finally, WISSDOM retrieved wind field in different terrain with high resolution (100m) is tested. A true wind field is simulated by WRF and two virtual radars are put outside the domain in an OSSE experiment. Both the domain set in a plain and in a mountain show that WISSDOM can retrieve a well-organized wind field.