Parameterization of land surface processes to study boundary layer characteristics over a semiarid region in Northwest India

Abstract

The atmospheric boundary layer and land surface processes play a crucial role and affect large-scale phenomena such as monsoons. A comprehensive soil-vegetation parameterization scheme has been developed to understand the complex interaction of the transfer processes, such as heat and moisture within the atmospheric surface layer and the active land layer. In this scheme, attention is given to the accurate representation of soil heat and moisture by considering all three states of water and their phase transitions. This scheme is incorporated in a one-dimensional multilevel boundary layer model for accurate representation of energy exchange processes to study the boundary layer characteristics. Numerical experiments are carried out with this model using special datasets obtained from the Land Surface Processes Experiment (LASPEX-97) at Anand (22.4°N, 72.6°E), a semiarid region of the state of Gujarat in northwest India. For this study, a dry simulation in February 1997 and a wet situation in July 1997 are considered. The model-simulated temporal variation of the fluxes of sensible heat, latent heat, and net radiation and soil temperatures are compared with the available observations. The results suggest that this model is suitable for better representation of land surface processes and the PBL in large-scale atmospheric models.