Cloud Microphysics and Atmospheric Structure : Application to MEGHA TROPIQUES

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Cloud Microphysics and Atmospheric Structure
Application to MEGHA TROPIQUES

• Sachchida Nand Tripathi
• snt_at_iitk.ac.in
• Department of Civil Engineering
• IIT Kanpur, INDIA

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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)
1st Stage
MT- Retrieved LWC and IW
In-situ Aircraft measurements of
Comparison with Inter-mediate Final Output
(a) T, RH, CCN IN distribution
MODEL
OUTPUT
(b) Cloud-water droplet/Ice-crystal distribution
Model validation with Initial Output
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2nd Stage
CloudSat (A-Train) satellite measures vertical
distribution of Reff for evolving cloud. This
data will be used as (a) Input in the
Microphysical model (b) for Validation of MT
data
Validation of Megha Tropiques Data product

• 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