1. Cloud Microphysics and Atmospheric Structure : Application to MEGHA TROPIQUES Sachchida Nand Tripathi snt@iitk.ac.in Department of Civil Engineering IIT Kanpur, INDIA

2. Cloud Microphysical Model  Microphysical model for mixed phase clouds is being developed Inputs : T, RH, chemically-resolved CCN and Ice nuclei (IN) size distribution Processes : (a) Warm-rain: Particle activation, condensational growth, collision and coalescence, evaporation, sedimentation (b) Cold-rain: Ice particle nucleation, condensational growth, depositional growth riming, melting, evaporation and sublimation, sedimentation Outputs : (a) Initial: Cloud-water droplet/Ice-crystal distribution (b) Intermediate: Liquid water content (LWC) / Ice-water (IW) (b) Final: Rain-drop distribution (Tripathi & Harrison, Atm. Env., 2001; Tripathi & Harrison, Atm. Res., 2002; Tripathi et al., AOPP Memorandum, 2004; Modgil et al., JGR, 2005, Kanawade and Tripathi, Accepted for JGR)  Aircraft measurements of Aerosol and Black Carbon vertical profile (Tripathi et al., GRL, 2005) Application to Megha Tropiques (MT) (a) T, RH, CCN & IN distribution MODEL OUTPUT MT- Retrieved LWC and IW Comparison with Inter- mediate & Final Output 1 st Stage : In-situ Aircraft measurements of (b) Cloud-water droplet/Ice- crystal distribution Model validation with Initial Output

3.  MODIS AOD has been validated by ground based sun photometer measurements over the polluted Kanpur region (Tripathi et al., Annales Geophysicae, 23, 1093-1101, 2005)  Validation of MODIS-derived COD and Cloud effective radius is being carried out by MST Radar measurements of NMRF at Gadanki  To study changes in Total Precipitable Water and Specific Humidity Profiles over north India due to increasing level of pollution and aerosol loading, analysis of radiosonde data from 1970-2000 for New Delhi, Lucknow, Patna, Gorakhpur, Kolkata, Bhopal and Jaipur is in progress. Analysis of the Megha Tropiques data from 2009 onwards will give further idea about impacts of anthropogenic pollution on water cycle  The Rainfall and Water Vapor profile data of MT will be validated by in-situ measurements and satellite (e.g. TRMM, CloudSat) observations 2 nd Stage : Validation of Megha Tropiques Data product MT-retrieved (LWC/IW) R eff (for Cloud droplet & ice particle) Cloud Radiative Transfer Microphysical MODEL-derived (LWC/IW) Comparison Spatio-temporal domain Cloud- droplet/Ice particle distribution CloudSat (A-Train) satellite measures vertical distribution of R eff for evolving cloud. This data will be used as: (a) Input in the Microphysical model & (b) for Validation of MT data