Raindrop Size Distributions of Southwest and Northeast Monsoon Heavy Precipitation Observed over Kadapa (14°4'N, 78°82'E), a Semi-Arid Region of India

Raindrop size distributions (RSD) of southwest (SW - June to September) and northeast (NE - October to December) monsoon heavy precipitation are measured with PARticle SIze and VELocity (PARSIVEL) disdrometer and Micro Rain Radar (MRR) deployed at Kadapa (14.47°N; 78.82°E), a semi-arid continental site in Andhra Pradesh, India. RSD characteristics stratified on the basis of rainrate showed that the mean values of raindrop concentration of small (medium) drops are less (more) in SW when compared with NE monsoon heavy precipitation. Gamma function applied to heavy precipitation events showed that the mean value of mass weighted mean diameter, D_m (normalized intercept parameter log₁₀ N_w) is higher (lower) in SW monsoon than NE monsoon. Stratiform and convective precipitating cloud fraction observed during SW and NE monsoons revealed that contribution of stratiform precipitation is predominant for the seasonal variation in raindrop size distribution. The coefficient and exponent values of the Z-R relations are higher in SW than NE monsoon in both stratiform and convective precipitation.