Planetary boundary layer structure during February and May, over a semi-arid station – a numerical simulation

Abstract

Two-dimensional version of a high-resolution non-hydrostatic mesoscale model namely ARPS (advanced Regional Prediction System) was used to simulate the Intensive observational data during two different seasonal viz, winter and summer (February and May) were collected from the Land Surface Processes Exzperiment (LASPEX-97), conducted at Anand (2235'N, 72 55'E) during 1997 over Sabarmati Basin Gujarat. A comparative study of three subgrid-scale turbulence parametrization schemes was conducted to find out the most suitable scheme. The model generated vertical profiles (zonal and meridional wind components, potential temperature and specific humidity) were validated against available observations bringing out the significant characteristics of thermal structure and circulation pattern in the PBL. Diurnal variation of surface and soil temperature, net radiation, sensible, latent and soil heat flux distinguish the surface response during two different seasons. Besides, the study of temporal variation of turbulent kinetic energy (TKE) from model simulation facilitates the understanding of the characteristics of the PBL structure.