Impacts of initial soil moisture and vegetation on the diurnal temperature range in arid and semiarid regions in China

摘要: To assess the impacts of initial soil moisture (SMOIS) and vegetation fraction (Fg) on diurnal temperature range (DTR) in arid semiarid regions China, three simulations using weather research forecasting (WRF) model are conducted by modifying SMOIS, surface emissivity Fg. SMOIS affects daily maximum (Tmax) minimum (Tmin) altering distribution available energy between sensible latent heat fluxes during day at night. Reduced wetness can increase both Tmax Tmin, but effect DTR is determined relative strength effects Tmin. Observational data from Semi-Arid Climate Environment Observatory Lanzhou University (SACOL) Shapotou Desert Research Experimental Station (SPD) suggest that magnitude larger than In other words, has a negative DTR. Changes Fg modify radiation budget. Due to depth daytime convective boundary layer, affected less nighttime Increases decreases heating resulting increased mainly decrease thereby increasing The Tmin same, opposite.