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      https://www.ias.ac.in/article/fulltext/jess/129/0065

    • Keywords

       

      Mesoscale convective systems; cloud to ground lightning; isentropic sloping; wind profiler; microwave radiometer; doppler weather radar

    • Abstract

       

      To enhance the knowledge of various physical mechanisms related to the evolution of Tropical Mesoscale Convective Systems (MCSs), detailed analysis has been performed using suite of observations (weather radar, electric field mill, surface weather station, flux tower, microwave radiometer and wind profilers) available at Gadanki ($13.5^{0}\rm{N}/79.2^{0}\rm{E}$), located over southeast India. Analysis suggests that these systems developed in warm, moist environment associated with large scale low level convergence. Significant variations in cloud to ground (CG) lightning activity indicate the storm electrification. Deep (shallow) vertical extents with high (low) reflectivity and cloud liquid water; dominant upward (downward) motionreveals variant distribution in convective (stratiform) portions. Existence of both +CG and –CG Cashes in convective regions, dominant –CG in stratiform regions explains the relation between lightning polarity and rain and cloud type. Sharp changes in surface meteorological variables and variations in surface fluxes are noticed in connection to cold pool of the system. Increase (decrease) in temperature, moisture and equivalent potential temperature ($\theta$e) within the boundary layer in convective (stratiform) regions associated with latent heat warming (cooling) of air parcel are apparent. Presence of updrafts and downdrafts in convective region and dominant downdrafts in stratiform regions are evident from vertical velocity measurements. Isentropic upgliding (downgliding) illustrate the existence of isentropic ascents (descent) of air parcels in the storm vicinity. Veering (backing) of wind due to warm (cold) and moist (dry) air advections demonstrated the formation of $\theta$e ridge in storm environment. Blend of observations provided considerable insight of electrical, microphysical, thermodynamic, dynamic and kinematic features of MCS.

    • Author Affiliations

       

      A MADHULATHA1 2 M RAJEEVAN3 T S MOHAN4 S B THAMPI5

      1. National Atmospheric Research Laboratory, Gadanki 517 502, India.
      2. Present address: Korea Institute of Atmospheric Prediction Systems, Seoul, South Korea.
      3. Ministry of Earth Sciences, New Delhi, India.
      4. Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates.
      5. Doppler Weather Radar Division, India Meteorological Department, Chennai, India.
    • Dates

       
  • Journal of Earth System Science | News

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