Fig. 9: Schematic highlighting various cloud microphysical and precipitation processes in a cold-based convective storm.

a The schematic describes the control simulation of cold-based mesoscale system as in STEPS case (cloud base at ~1 °C). Two pie charts at the bottom are shown for warm-rain and ice-crystal processes governing surface precipitation over stratiform and convective regions. In the control run, ice crystal process primarily contributes to the ground precipitation over both these regions. b Same as (a) but for lowered cloud base and CCN (Low CB/CCN) sensitivity simulations for STEPS. In this sensitivity simulation, the schematic shows that the majority of the ground precipitation has now been switched to the warm-rain process. The warm-rain process (e.g., melting of warm-graupel) is indicated by solid red dot. Similarly, the ice crystal process (e.g., melting of cold-graupel and snow) is depicted by solid blue dot.