Raindrop Size Distributions and Rain Characteristics Observed by a PARSIVEL Disdrometer in Beijing, Northern China

Abstract

Fourteen-month precipitation measurements from a second-generation PARSIVEL disdrometer deployed in Beijing, northern China, were analyzed to investigate the microphysical structure of raindrop size distribution and its implications on polarimetric radar applications. Rainfall types are classified and analyzed in the domain of median volume diameter D0 and the normalized intercept parameter Nw. The separation line between convective and stratiform rain is almost equivalent to rain rate at 8.6 mm h–1 and radar reflectivity at 36.8 dBZ. Convective rain in Beijing shows distinct seasonal variations in log10Nw–D0 domain. X-band dual-polarization variables are simulated using the T-matrix method to derive radar-based quantitative precipitation estimation (QPE) estimators, and rainfall products at hourly scale are evaluated for four radar QPE estimators using collocated but independent rain gauge observations. This study also combines the advantages of individual estimators based on the thresholds on polarimetric variables. Results show that the blended QPE estimator has better performance than others. The rainfall microphysical analysis presented in this study is expected to facilitate the development of a high-resolution X-band radar network for urban QPE applications.

Statistical characteristics of raindrop size distribution during rainy seasons in the Beijing urban area and implications for radar rainfall estimation

“…The NWP systems coupled with various DSD models can capture more detailed horizontal and/or vertical rainfall information so as to improve the accuracy of precipitation predictions (Abel and Boutle, 2012;Fadnavis et al, 2014;McFarquhar et al, 2015;Saleeby and Cotton, 2004). In addition, the DSD is highly related to the kinetic energy of rainfall that has substantial impact on the soil erosions (Angulo-Martinez and Barros, 2015;Caracciolo et al, 2011;Ellison, 1945;Kinnell, 2005;Lim et al, 2015), which is critical to further understanding of the runoff processes and mitigation of subsequent flood hazards (Angulo-Martinez and Barros, 2015;Smith et al, 2009).…”

“…Ma et al: Statistical characteristics of raindrop size distribution during rainy seasons in Beijing Numerous studies have been devoted to the statistical characteristics of DSD worldwide. It is found that the DSD characteristics vary with geographical locations, climate regimes, seasons, rain types, and even diurnal cycles (Dolan et al, 2018;Ji et al, 2019;Seela et al, 2018;Tokay and Short, 1996;. Dolan et al (2018) classified the global DSD characteristics into six groups by analyzing 12 global disdrometer datasets across three latitudes using principal component analysis.…”

“…G. investigated the statistical properties of summer and winter precipitation in Beijing, including the bulk properties, raindrop fall velocity, axis ratio, and DSD, using a two-dimensional video disdrometer (2DVD) and a microrain radar (MRR). Ji et al (2019) analyzed the microphysical structure of DSD using 14-month DSD measurements from a second-generation Particle Size and Velocity (Parsivel 2 ) disdrometer in Beijing.…”

“…(a) The topography of Beijing and (b) the locations of DSD studies in the Beijing area; the red mark represents the location of the Parsivel 2 disdrometer deployed at Tsinghua University campus in this study and the green and purple makers represent locations in the studies by G. andJi et al (2019), respectively. The map data are available under the Open Database License.…”

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

“…In addition, the measured raindrop spectra can be used to explore the mechanism of precipitation erosivity. The relationship between rainfall kinetic energy (KE) and intensity (R) is a significant approach to study the impact of precipitation on soil erosion [16], and a disdrometer can be deployed to measure the rainfall kinetic energy and intensity [17]. Angulo-Martínez et al [18] measured and analyzed the uncertainty in KE-R relationships with five Parsivel disdrometers among three locations, and found that the types, accuracy and location of the disdrometers and precipitation types influence the estimation results of KE.…”