Statistical Characteristics of Raindrop Size Distribution in the Monsoon Season Observed in Southern China

Abstract

This study investigates the statistical characteristics of raindrop size distributions (DSDs) in monsoon season with observations collected by the second-generation Particle Size and Velocity (Parsivel2) disdrometer located in Zhuhai, southern China. The characteristics are quantified based on convective and stratiform precipitation classified using the rainfall intensity and total number of drops. On average of the whole dataset, the DSD characteristic in southern China consists of a higher number concentration of relatively small-sized drops when compare with eastern China and northern China, respectively. In the meanwhile, the Dm and log10Nw scatter plots prove that the convective rain in monsoon season can be identified as maritime-like cluster. The DSD is in good agreement with a three-parameter gamma distribution, especially for the medium to large raindrop size. Using filtered data observed by Parsivel2 disdrometer, a new Z–R relationship, Z = 498R1.3, is derived for convective rain in monsoon season in southern China. These results offer insights of the microphysical nature of precipitation in Zhuhai during monsoon season, and provide essential information that may be useful for precipitation retrievals based on weather radar observations.

Microphysical Characteristics of Winter Precipitation in Eastern China from 2014 to 2019

“…The PSD data used in this study were measured by a PARSIVEL disdrometer. This instrument is widely used in the study of worldwide precipitation microphysical characteristics because of its high-cost performance and portability [29]. It was originally primarily developed as a PSD measurement of rainfall and can be used as a weather sensor to distinguish precipitation types [27].…”

“…There are other instruments that can be used to observe precipitation microphysical characteristics, but they also have their own shortcomings. For example, 2DVD can obtain the two-dimensional contour of precipitation particles, but it will underestimate the number of precipitation particles with diameters of less than 0.3 mm [29]; snowflake video imager (SVI) can record the image of snowflakes, but not their fall speeds [22]. To obtain more accurate measurement results, researchers are committed to developing new measurement methods and instruments, such as multiangle snow imager (MASC) [62], and precipitation microphysical characteristics sensor (PMCS) [63].…”

“…The output data of the instrument is a matrix of 32 by 32: 32 bins with sizes ranging from 0.062 to 24.5 mm and 32 bins with speeds ranging from 0.05 to 20.5 m/s [26,27]. Because of its good cost performance, the instrument is widely used in the QPE of radar, soil erosion and weather modification [13,28,29]. However, due to the limitations of the device performance and built-in algorithm, quality control is required to obtain the best possible measurement results.…”

“…However, it has been proven that µ is highly variable, and it is heavily influenced by the microphysical characteristics of precipitation [27,51]. Thus, a localized µ-Λ relationship is proposed to reduce the number of required inversion parameters [29,44,52,53]. Figure 5 shows the µ-Λ scatters of the four types of precipitation and their fitting curves obtained by the least square method.…”

Seasonal Characteristics of Disdrometer-Observed Raindrop Size Distributions and Their Applications on Radar Calibration and Erosion Mechanism in a Semi-Arid Area of China

“…Liu et al [9] measured the precipitation in Nanjing, China and compared four different methods of rainfall to conclude that the disdrometer and other methods are consistent within the range of medium particle size. However, Zhang et al [10] used three different methods to analyze the DSD characteristics in Zhuhai, China and found that the disdrometer had limitations in measuring small raindrops when compared to other methods. Raupach et al [11] used a 2DVD device to correct the DSDs measured by three disdrometers and the correction showed its general applicability under different climate types.…”