Ka-band radar observations of tropical rain features

Radar remote sensing of precipitation is important for disaster management and early warning systems. Interpretation of radar reflectivity to derive rain information is, however, not straight forward due to presence of various drop size distributions and rain structure. Information of vertical rain structure is important for accurate quantitative precipitation estimation from space-borne radar since the radar measures rain aloft ground level. In this paper, some characteristics of the vertical rain structure observed using Ka band radar (Micro Rain Radar) at a tropical location, are presented. Study show vertical profiles of radar reflectivity and rain rate are relatively uniform only upto 2 mm/h rain rate. Considerable negative gradient of radar reflectivity and fall velocity with height is observed for rain rate above 2 mm/h. Results indicate the presence of small drops at higher heights and large drops at ground in convective rain implying drop coalescence is the dominant mechanism in convective rain.