Vertical profile of rain: Ka band radar observations at tropical locations

• Published in: Journal of hydrology (Amsterdam) 2016-03, Vol.534, p.31-41
• Main Authors: Das, Saurabh, Maitra, Animesh
• Format: Article
• Language: English
• Subjects: Climatology; Dominance; Drop size; Drop size distribution; Grounds; Ka band; Radar; Rain; Reflectivity; Tropical rain; Vertical profile of reflectivity; Weather
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/j.jhydrol.2015.12.053

•Ka band radar observations at three tropical locations are studied.•Large negative gradient is observed in VPR above 20mm/h rain rate.•Rain drop evolution mechanism is also studied.•Significant variations of radar VPR is observed at lower 2km height.•Results will be helpful in interpretation of GPM data over tropic. Information of vertical rain structure is important for accurate quantitative precipitation estimation from weather radars and space-borne radars. In this paper, some characteristics of the vertical rain structure observed using a Ka band Micro Rain Radar at three tropical locations in India are presented. The average vertical structure is studied in terms of drop size distribution (DSD), fall velocity, rain rate, liquid water content and radar reflectivity profile. The changes in vertical rain structure with rain rate is observed to be significant only above 20mm/h in Ahmedabad and Trivandrum, although, in Shillong, significant variation is observed starting from 2mm/h. Results show a significant negative slope of the fall velocity of rain drops and Ka band radar reflectivity up to melting layer height for rain rate above 20mm/h indicating a shift in the drop size distribution (DSD) toward lower size at all sites. The near ground measurements show strong variation of rain structure for all rain rates. The mean DSD near ground (