Characteristics of Rain Integral Parameters during Tropical Convective, Transition, and Stratiform Rain at Gadanki and Its Application in Rain Retrieval

• Published in: Journal of applied meteorology and climatology 2009-06, Vol.48 (6), p.1245-1266
• Main Authors: Sharma, Sanjay, Konwar, Mahen, Sarma, Diganta Kumar, Kalapureddy, M. C. R., Jain, A. R.
• Format: Article
• Language: English
• Subjects: Atmospheric precipitations; Coefficient of variation; Coefficients; Convection clouds; Correlation coefficient; Correlation coefficients; Data analysis; Doppler effect; Earth, ocean, space; Error reduction; Exact sciences and technology; External geophysics; Meteorology; Meteors; Parameters; Precipitation; Profilers; Radar; Rain; Rain intensity; Raindrop velocity; Raindrops; Research methodology; Retrieval; Spectral reflectance; Studies; Updraft; Velocity; Velocity gradient; Velocity gradients; Water in the atmosphere (humidity, clouds, evaporation, precipitation); Wind
• ISSN: 1558-8424; 1558-8432
• DOI: 10.1175/2008jamc1948.1

In the present study the characteristics of rain integral parameters during tropical convective (C), transition (T), and stratiform (S) types of rain are studied with the help of Joss–Waldvogel disdrometer (JWD), L-band, and very-high-frequency wind profilers at Gadanki (13.5°N, 79.20°E). The classifications of three regimes are made with the help of an L-band wind profiler. For rain rateR< 10 mm h−1larger drops are found in S type of rain relative to C and T rain, and for R ≥ 10 mm h−1larger drops are found in convective rain. Empirical relations are developed for D m − R , D m − Z , N 0 * − R , Z − R , andZ/Dₘ–Rby fitting the power-law equations. Event to event, no systematic variation of the coefficients and exponents could be found forZ–RandZ/Dₘ–Rrelations during the three types of rain. Overall, the C and S events are found to be number controlled, and T events are size controlled. During C type of rain, bigger mean raindrops are found during the presence of strong updrafts. During S type of rain, bigger mean raindrops are found to be associated with the higher mean thickness of the bright band and strong velocity gradient. For each of the developed empirical relations, the correlation coefficients are found in the order of T > C > S rain. During the three types of rain, correlations are found in the order ofZ/Dₘ–R>Z–R>Dₘ–Z>Dₘ–R. Significant improvement is observed in rain retrieval by using theZ/Dₘ–Rrelation relative to the conventionalZ–Rrelation. By utilizing theZ/Dₘ–Rrelations, the root-mean-square error was reduced by 19%–46%.