An overview of the land surface processes experiment (LASPEX) over a semi-arid region of India

To understand and quantify the land-surface-vegetation interaction with the atmospheric boundary layer, and validate or improve upon the existing surface flux parameterization schemes in various weather forecast models, a LAnd Surface Processes EXperiment ( LASPEX), was designed and executed in the semi-arid region of Gujarat, India during January 1997-December 1998. Micrometeorological tower observations, soil and vegetation parameters, radiation, turbulence and upper air observations were taken continuously for two years at five sites, separated by about 60-100 km from each other. Towers of 9 m height with instruments at four levels were installed at sites that are agricultural fields and characterized with a variety of soil properties, vegetation and diverse crops. An overview of the experiment is presented. Some results, such as the seasonal variation of surface energy balance and turbulence statistics, are discussed.