Characteristics of Precipitation Parameters Reflected by Ground Laser Raindrop Disdrometer
Adopting the precipitation data of 100 days in Henan Province from 2016 to 2017, this paper comparatively analyzed the difference between raindrop size distribution inversion echo and radar echo, and the difference between raindrop size distribution inversion precipitation intensity and rain gauge observation precipitation intensity. Gamma fitting of raindrop size distribution was conducted to explore raindrop size distribution and precipitation cloud types in Henan Province. Z-I fitting was done to explore relationship between precipitation echo and precipitation intensity in Henan Province. The results are as follows. (1) The variation trends of raindrop size distribution inversion echo and radar echo have good consistency. The former is generally smaller than the latter, and the possible causes are that there was a certain height difference between the radar echo above ground raindrop disdrometer that observed through the lowest elevation angle and the ground raindrop disdrometer, and that the evaporation process, when raindrops fell, could reduce the diameter of raindrops that reached the surface. (2) There is a certain difference between raindrop size distribution inversion precipitation intensity and rain gauge observation precipitation intensity, but there is no obviously large or small regularity. (3) The widths of raindrop size distribution of convective cloud and stratocumulus mixed cloud are wider than that of stratiform cloud, the density of medium-scale raindrops is larger. The density of small droplets in stratiform cloud is larger. Most precipitation processes in Henan Province are stratiform precipitations with narrower raindrop size distribution. (4) The fitting formula of precipitation echo and precipitation intensity in Henan Province is Z=262I1.34, the fitting formula of laminar cloud is Z=219I1.30 and the fitting formula of convective cloud is Z=307I1.38. (5) The raindrop concentrations in June and July are higher (about 1500 m-3), the precipitation intensity between August and October are higher (>60 mm·h-1), the maximum diameters of raindrops between April and August are higher (4.3-4.8 mm), the mean diameters of raindrops between March and April are higher (approximately 3 mm). There is no consistency in the monthly feature changes of four precipitation microphysical quantities.