Microphysical features of typhoon and non-typhoon rainfall observed in Taiwan, an island in the northwestern Pacific

Abstract

Abstract. Information about the raindrop size distribution (RSD) is vital for comprehending the precipitation microphysics, improving the rainfall estimation algorithms, and appraising the rainfall erosivity. Previous research has revealed that the RSD exhibits diversity with geographical location and weather type, which leads to the assessment of the region and weather-specific RSDs. Based on long-term (2004 to 2016) disdrometer measurements in northern Taiwan, this study attempts to demonstrate the RSD aspects of summer seasons that were bifurcated into two weather conditions, namely typhoon (TY) and non-typhoon (NTY) rainfall. The results show a higher concentration of small drops and a lower concentration of large-sized drops in TY compared to NTY rainfall, and this behavior persisted even after characterizing the RSDs into different rainfall rate classes. RSDs expressed in gamma parameters show higher mass-weighted mean diameter (Dm) and lower normalized intercept parameter (Nw) values in NTY than TY rainfall. Moreover, sorting these two weather conditions (TY and NTY rainfall) into stratiform and convective regimes revealed a larger Dm in NTY than in TY rainfall. The RSD empirical relations used in the valuation of rainfall rate (Z–R, Dm–R, and Nw–R) and rainfall kinetic energy (KE–R and KE–Dm) were enumerated for TY and NTY rainfall, and they exhibited profound diversity between these two weather conditions. Attributions of RSD variability between the TY and NTY rainfall to the thermodynamical and microphysical processes are elucidated with the aid of reanalysis, remote sensing, and ground-based data sets.

Raindrop Size Distributions of North Indian Ocean Tropical Cyclones Observed at the Coastal and Inland Stations in South India

“…For the locations where there is no availability of RSD information, the KE and the rainfall erosivity factor can be estimated using the empirical relations between rainfall KE and rainfall intensity (KE-R relations) [3,59]. These relations showed diversity with the geographical location and weather systems [3,21,60,61], which requires one to deduce region-specific relations. Moreover, in India, due to the lack of indigenous KE relations, previous studies adopted the relations of other areas [62], which can result in overestimation or underestimation of KE.…”

“…In terms of understanding the microphysical features of TCs, globally, there has been increasing interest in TC RSD studies. There have been attempts in understanding TCs' RSD features over the Atlantic Ocean [17], Northwest Pacific Ocean [18][19][20][21], and South Indian Ocean [22] using ground-based disdrometers, and these studies were conducted using Joss-Waldvogel disdrometer [17,22], 2-Dimensional video disdrometer [20], and Parsivel disdrometer [18,19,23] measurements. Furthermore, over the North Indian Ocean (NIO), the disparities in the RSDs of TC rainfall to the monsoon rainfall, one TC to another TC, as well as between their pre-and post-landfall were well documented [8,9,24,25].…”

A Comparative Study on the Vertical Structures and Microphysical Properties of Stratiform Precipitation over South China and the Tibetan Plateau

“…The ground disdrometer used is a second-generation Parsivel disdrometer (disdrometer), which has also been used in many previous studies [39][40][41][42][43][44]. The disdrometer is an optical-based disdrometer that transmits a 54-cm 2 (18-cm long, 3-cm wide) horizontal laser beam, and can simultaneously measure the diameter and falling velocity of passing raindrops according to the attenuation and duration of received signals.…”

Raindrop Size Distribution Characteristics of the Western Pacific Tropical Cyclones Measured in the Palau Islands

“…Raindrop size distribution (RSD) is one of the essential parameters of precipitation, offering investigation into cloud and rain microphysics [1]. RSD information can improve cloud modeling parametrization, rain retrieval algorithms of the global precipitation measurement dual-frequency precipitation radar (GPM DPR), and assess rainfall kinetic energy relations [2][3][4][5][6]. RSDs substantially vary with changes in formation and the evolution of precipitation, and show considerable variations with the seasons, different geographical regions, weather conditions, and precipitation types [1,3,[7][8][9][10][11][12].…”

“…RSD information can improve cloud modeling parametrization, rain retrieval algorithms of the global precipitation measurement dual-frequency precipitation radar (GPM DPR), and assess rainfall kinetic energy relations [2][3][4][5][6]. RSDs substantially vary with changes in formation and the evolution of precipitation, and show considerable variations with the seasons, different geographical regions, weather conditions, and precipitation types [1,3,[7][8][9][10][11][12]. For instance, the RSD measurements in Taiwan showed a greater concentration of large-sized drops in the summer than in the winter seasons [11].…”