Influence of land-surface and turbulent parameterization schemes on regional-scale boundary layer characteristics over northern India

The influence of turbulent and land-surface parameterizations on regional scale boundary layer features over north India is analyzed using the Weather Research and Forecasting (WRF) modeling system during two contrasting cases of summer and winter. The model predicted surface temperatures, wind speeds, potential temperature profiles and wind speed profiles are compared with the observations from India Meteorological Department and Wyoming Weather Web data archive. The qualitative and quantitative analyses indicate that the model predictions are relatively better over three north Indian cities namely Delhi, Ahmedabad and Jodhpur when the Mellor–Yamada–Janjic boundary layer scheme along with Noah land-surface model is used. The near surface flow features during both summer and winter cases indicate the major role of land surface models (LSMs) as compared to the boundary layer parameterizations in governing the regional scale flow fields.The role of the LSMs and boundary layer parameterizations in the regional scale transport of dust particles from Thar region toward Delhi and its neighborhood depends upon their point of origin during summer. However, the flow trajectories travel in the opposite direction during the winter case because of the contrasting nature of the flow patterns and consequently, the formation of haze-like conditions over Delhi due to Thar dusts is not expected.

► Regional scale features over north India using WRF modeling system.
► Influence of planetary boundary layer (PBL) and land surface (LSM) parameterizations.
► The LSMs have greater impact on surface layer variables as compared to PBL schemes.
► The near surface flow patterns in summer case are largely sensitive to the LSMs.
► The role of LSMs and PBL schemes in dust transport depends upon its point of origin.