暴雨灾害 (Dec 2021)
Performance evaluation of mobile wind profiler radarin Shanghai
Abstract
Based on the data from the mobile wind profile radar (MWPR) at Baoshan of Shanghai from July 2018 to June 2019, we have evaluated and analyzed the performance of MWPR in terms of acquisition rate, horizontal wind error and the reliability of wind data under six typical weather conditions. The main results are as follow. (1) The acquisition rate is most affected by turbulence intensity, followed by atmospheric temperature and humidity. It is obviously characterized by diurnal and seasonal variations. In the boundary layer, the acquisition rate in summer and autumn is higher than that in winter and spring. It also features high acquisition rate in afternoon and low acquisition rate in late night and early morning. In free atmosphere, the acquisition rate in winter and spring is higher than that in summer and autumn. Taking the acquisition rate of 80% as the operation admittance standards, the acquisition rate of MWPR within boundary layer reaches the standard. (2) Comparing with L-band radiosonde, the horizontal wind speeds detected by MWPR in all layers are relatively low. In low mode, 34.4% of the horizontal wind speed data are in the range of 2.0 m·s-1 to 6.0 m·s-1 lower. The wind direction deviation data which exceeds ±15åccounts for 48.9% of all the horizontal wind direction data. (3) Qualitative analysis shows that the directivity of vertical velocity detected by MWPR is reasonable. During heavy rainfall, the vertical velocity detected by MWPR is actually the sum of the falling velocity of precipitation particles and atmospheric turbulence velocity. The reliability of horizontal wind data from MWPR is highin typhoon, snowy and other weather days with the characteristic of strong atmospheric homogeneity. On the whole, MWPR can basically meet the needs of daily meteorological monitoring and services in terms of detection performance, but there still lies a certain gap between its wind measurement accuracy and operation admittance standards.
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