Tracking the Influence of Irrigation on Land Surface Fluxes and Boundary Layer Climatology

Abstract

When the land surface is altered as a first order change in the climate system, it affects the latent heat flux and evaporative cooling, thereby altering the surface temperature and boundary layer development. Modeling the processes associated with land surface alteration requires an interdisciplinary approach in which the hydrologic processes such as evapotranspiration and soil moisture influenced by human‐induced changes are connected to the atmospheric system. The Noah Land Surface Model (LSM) coupled with the Weather Research and Forecasting (WRF) model was modified to represent irrigation in the Snake River basin. By simulating the surface energy balance components and the boundary layer in the growing season, we compared the differences between irrigation and no‐irrigation (control) simulations to assess the differences in climatology attributed to irrigation‐induced cooling. Differences such as increased latent heat flux from the irrigated areas and decreased potential temperature, wind speed, and planetary boundary layer height were evident. This study reiterates the importance of the anthropogenic processes defining the nexus between the land and atmosphere on the local and regional weather and climate.