Comparative evaluation of micro rain radar with ground precipitation observation instruments and its application study

The micro rain radar (MRR) inversion results can be influenced by various factors. In order to evaluate the precipitation detection capability and application effect of MRR, the rain gauge (RG) observations are used as the benchmark, the raindrop size distributions(DSD) and the corresponding inversed characteristic parameters obtained by MRR and the co-located DSG5 present weather sensor during the precipitation events from March 2022 to May 2023 at the Xiangyang National Basic Meteorological Station are implied, to evaluate the precipitation detection capability of MRR from the prospect of different heights and different rainfall types, and, the application effect of MRR by using the observations during a typical rain event on May 4th, 2023 in Xiangyang is analyzed. The results are as follows. (1) The observed hourly rainfalls of MRR and rain gauge are most consistent at the height of 100 m. (2) MRR shows the best detection performance at stratiform rain when compared to convective and light rain. (3) Compared to DSG5, the MRR observed contributions of medium and large raindrops to the rain rates during the convective rain are smaller, while the concentrations of small raindrops and their contributions to rain rates are larger. (4) Compared to MRR, the DSG5 observed average DSD for small and medium raindrops during convective and stratiform rain are smaller, and during light rain the DSG5 observed average DSD for small raindrops are also smaller, but larger for large raindrops. (5) During the typical rain event in Xiangyang, the bright band height of stratiform and light rain remain relatively stable at around 3.8 km. For the stratiform rain, the particles undergo complex phase transitions in the bright band and eventually melt into raindrops, these raindrops mainly experienced collision and evaporation of small raindrops during their descent to the ground, and, medium raindrops make the greatest contribution to the ground rain rate.