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      https://www.ias.ac.in/article/fulltext/jess/125/07/1399-1411

    • Keywords

       

      Drag coefficient; frictional velocity; latent heat flux; sensible heat flux; stability; eddy covariance

    • Abstract

       

      Surface to atmosphere exchange has received much attention in numerical weather prediction models. This exchange is defined by turbulent parameters such as frictional velocity, drag coefficient and heat fluxes, which have to be derived experimentally from high-frequency observations. High-frequency measurementsof wind speed, air temperature and water vapour mixing ratio (eddy covariance measurements), were made during the Integrated Ground Observation Campaign (IGOC) of Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) at Mahabubnagar, India (16◦44'N, 77◦59'E) in the south-west monsoon season. Using these observations, an attempt was made to investigatethe behaviour of the turbulent parameters, mentioned above, with respect to wind speed. We found that the surface layer stability derived from the Monin–Obukhov length scale, is well depicted by the magnitude of wind speed, i.e., the atmospheric boundary layer was under unstable regime for wind speeds greater than 4 m s−1; under stable regime for wind speeds less than 2 m s−1 and under neutral regime for wind speeds in the range of 2–3 m s$^{−1}$. All the three stability regimes were mixed for wind speeds 3–4 m s$^{−1}$. The drag coefficient shows scatter variation with wind speed in stable as well as unstable conditions.

    • Author Affiliations

       

      M N Patil1 R T Waghmare1 T Dharmaraj1 G R Chinthalu1 Devendraa Siingh1 G S Meena1

      1. Indian Institute of Tropical Meteorology, Dr Homi Bhabha Road, Pashan, Pune 411 008, India.
    • Dates

       
  • Journal of Earth System Science | News

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