Use of multiplatform in-situ observation to study vertical structure and microphysics of clouds during southwest monsoon over Western Ghats, India

Combination of radiosonde profiles with collocated in-situ ground and aircraft measurements is used for the first time to study the vertical structure and microphysics of clouds during southwest monsoon over the Western Ghats, India. The morphology of clouds is detailed with the help of radiosonde observations and classified as low, mid, and high-level clouds depending on the cloud base height. Radiosonde sounding profiles indicated occurrences of both single and multi-layered clouds with higher occurrences of single-layered (∼35%) clouds during monsoon transition period (June and September) and two-layered (∼42%) during core monsoon period (July and August). Dominance of low (∼30%) and high-level (∼60%) clouds were noticed compared to mid-level clouds over the observational site during the southwest monsoon. Warm cloud microphysics was investigated using collocated ground and airborne in situ measurements. Irrespective of the cloud type, the cloud liquid water content and the effective droplet diameter increased with altitude. One of the key results is the rapid broadening of the cloud droplet size distribution with height. The number concentration of droplets above 25 μm diameters showed a steep decrease at altitudes above 1800 m, suggesting active collision-coalescence. •Collocated observations of the vertical structure and microphysics of clouds over Western Ghats, India.•Cloud morphology is detailed using radiosonde observations over WG.•Warm cloud microphysics is investigated using collocated in-situ ground and airborne cloud measurements.•Rapid broadening of the cloud droplet size distribution with height was noticed.•This is the first such report over a complex terrain like Western Ghats in India.