Statistical characteristics of raindrop size distribution over the Western Ghats of India: wet versus dry spells of the Indian summer monsoon

Abstract. The nature of raindrop size distribution (DSD) is analyzed for wet and dry spells the Indian summer monsoon (ISM) in Western Ghats (WG) region using Joss–Waldvogel disdrometer (JWD) measurements during ISM period (June–September) 2012–2015. observed DSDs are fitted with a gamma distribution. Observations show higher number smaller drops more midsize large spells. DSD spectra distinct diurnal variation exhibit strong cycle two peaks, while not very prominent Results reveal microphysical characteristics warm rain both periods. However, underlying dynamical parameters, such as moisture availability vertical wind, cause differences characteristics. winds can provide sufficient time raindrops to grow bigger spells, whereas temperature may lead evaporation drop breakup processes In addition, different rates also observed. further by separating them into stratiform convective types. Finally, an empirical relationship between slope parameter λ shape μ derived fitting quadratic polynomial well types rain. μ–λ relations obtained this work slightly compared previous studies. These could be related microphysics collision–coalescence breakup.