Surface roughness length for heat (m) in the Control (a, b) and MODIFIED (c, d) simulations during the pre-monsoon (a, c) and monsoon (b, d) seasons.

SEASONAL DIFFERENCES IN THE LAND-ATMOSPHERE COUPLING OVER SOUTH ASIA SIMULATED USING A REGIONAL CLIMATE MODEL

Main Findings (Rakesh and Takahashi 2020, Geographical Reports of Tokyo Metropolitan University)

1. Default WRF coupled with NOAH land surface model configuration overestimated the roughness length for heat over short vegetation and underestimated the same metric over tall vegetation, leading to a larger sensible heat flux over South Asia.
   
2. A modified NOAH LSM reduced the over-estimation of roughness length for heat, and thus reduced the sensible heat flux.
   
3. A dry precipitation bias during the onset phase of the Indian summer monsoon over central India was found to be effectively reduced in the modified NOAH land surface model.