Variability of monsoon intracloud and intercloud microphysics over the Indian subcontinent

Abstract

Intracloud/intercloud variability ofmicrophysical quantities during different monsoon conditions has been studied for the first time over India using in situ observations of cloud microphysics collected during the Cloud-Aerosol Interaction and Precipitation Enhancement Experiment 2009. The observations for two inland locations (Hyderabad and Bareilly) for different phases ofmonsoon (preonset, onset, break, and active) have been used to investigate the entrainment and mixing processes which are defined with adiabatic fraction (ADFR)<0.4 in monsoon clouds. The variation of factor k which is the ratio of cube of cloud droplet mean volume radius (rv) to cloud droplet effective radius (re), cloud droplet number concentration (N), liquid water content (LWC), and ADFR of LWC has been used to examine the intracloud and intercloud variability of cloud microphysical properties. During the preonset (Hyderabad), clouds were undiluted ( ~ 0.59) with moderate concentration ( ~436cm-3), an average re of 8 μm, and high value of factor k (0.774 ± 0.035). During break monsoon (Bareilly), cloudswere diluted ( ≤ 0.2) having numerous ( 1000 cm-3) smaller droplets (re ≤ 6 μm) and a low value of factor k (0.678 ± 0.064). The clouds had similar characteristics ( ~ 0.4 having lesser ( ~300cm-3) droplets with re>8 μm) over both stations during onset/active monsoon conditions. The investigation of the variability of intracloud and intercloud microphysics revealed positive correlation between factor k and N and no detectable correlation between factor k and N, respectively, and are sensitive to ADFR.