Disdrometer

About: Disdrometer is a research topic. Over the lifetime, 930 publications have been published within this topic receiving 23092 citations.

Statistical Characteristics of Raindrop Size Distribution in Southwest Monsoon Season

Abstract: Raindrop size distribution (DSD) parameters are retrieved from dual-frequency (UHF and VHF) wind profiler measurements made at Gadanki, India, in a summer monsoon season. The convoluted UHF spectra are first corrected for vertical air motion and spectral broadening (using VHF measurements) and later are used for deriving DSD parameters. Two distinctly different case studies, a mesoscale convective system and a pure stratiform precipitation system, have been considered for a detailed study. DSD parameters obtained in these case studies reveal systematic variations of DSD from case to case and also from one rain regime to another within the same precipitating system. A statistical study has been carried out using the profiler data collected during the passage of 16 rain events. The retrieved DSD profiles are divided into separate rain regimes (stratiform and convection), based on reflectivity, to examine salient microphysical characteristics and the vertical variability of DSD in different precipit...

Investigation of Rain Attenuation in Equatorial Kuala Lumpur

Abstract: This letter investigates rain attenuation in Kuala Lumpur, Malaysia, by exploiting local drop size distribution (DSD) measurements. Coefficients for the well-established power-law model relating rain rate and specific attenuation are derived for frequencies in the Ku-, Ka-, and Q/V-bands based on three years of disdrometer data. We analyze the diurnal variation of rainfall rate for four time intervals and, moreover, we present statistics of rain attenuation for slant-path Earth-space links estimated by means of a new model (Stratiform-Convective SST) that combines the advantages of the Dual-Layer Synthetic Storm Technique (SST) and the SC EXCELL model. The predicted statistics are in good agreement with those obtained from beacon measurements (MEASAT-1 satellite at 12 GHz). Finally, the diurnal variation of the slant-path rain attenuation is presented to provide system operators and radio communication engineers with useful information on the quality of service (QoS) that can be achieved during a typical day on an Earth-space link.

Intraseasonal variation of raindrop size distribution at Koto Tabang, West Sumatra, Indonesia

Abstract: [1] Intraseasonal variation of raindrop size distribution (DSD) in response to Madden Julian Oscillation (MJO) is studied using a 2D video disdrometer (2DVD), a boundary layer radar (BLR) and the Equatorial Atmosphere Radar, operated at Koto Tabang, west Sumatra, as well as GOES-9 infra-red brightness temperature. As a parameter of DSD, ΔZMP, which is defined as the difference between a measured radar reflectivity in dB and that from the Marshall-Palmer (MP) radar reflectivity (Z) - rain rate (R) relationship, Z = 200 R1.6, is used. It is found that in non-active phase of MJO, 2DVD-derived ΔZMPs are generally positive, indicating that DSDs are broad, while they decrease toward negative values as the phase of MJO shifts to active ones. Rain-top height derived from the BLR indicates that the convective processes are more intense in the non-active MJO phase than in the active phase, which would cause the difference in DSDs.

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

Abstract: 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 rate R C > S rain. During the three types of rain, correlations are found in the order of Z/Dm–R > Z–R > Dm–Z > Dm–R. Significant improvement is observed in rain retrieval by using the Z/Dm–R relation relative to the conventional Z–R relation. By utilizing the Z/Dm–R relations, the root-mean-square error was reduced by 19%–46%.