Abstract:

The wind fields measured from the TWP3-type wind profile radar in Shapingba and the TWP8-L(Ⅱ)-type radar in Youyang of Chongqing, were assessed and analyzed towards the ERA5 reanalysis data. The dense radiosonde observations at 13:00 from June to August of 2014-2016, which have not been assimilated by the reanalysis, are firstly used to verify the representativeness of wind data from ERA5 reanalysis in Chongqing. It shows little deviation between them two, indicating the general reliability of the ERA5 reanalysis, which could further be employed to validate the accuracy of horizontal winds from Chongqing wind profile radars. The data from wind profile radar and ERA5 reanalysis were compared and analyzed. The results indicate that the correlation coefficient of horizontal winds at lower layers is lower than that at the middle and upper layers. However, the deviations mainly range from -1 to 1 m·s^-1 at altitudes below 5000 m. With the increasing altitudes, the u-component deviations tend to increase negatively, while the v-component deviations increase positively. In the summer season with hotness and dryness, the wind field measured by wind profiles is more precise to that in winter. The accuracy of wind measurements from wind profile radars is affected by precipitation. At the lower layers, the stronger deviations of u-component from wind profiles tend to be slightly larger during precipitation processes than during non-precipitation periods. At the middle and upper layers, the accuracy of the v-component wind is significantly affected by precipitation, with its weaker deviations being slightly larger during precipitation processes than during non-precipitation periods. During squall line weather, the wind speeds detected by both datasets are relatively close, while the wind profile data show slightly larger u and v wind components at the lower layers compared to reanalysis data.

Key words: Radiosonde data, ERA5, Wind profiler radar, Wind field