Characteristics and Numerical Simulations of Atmospheric boundary layer heights in the arid regions of Northwest China

Over the arid regions in the Northwest of China, the height of atmospheric boundary layer can be extremely high during late spring to summer time. For instance, the depth of observed convective boundary layer can exceed 3000 m of height or even up to 4000 m at some stations. In order to characterize the atmospheric boundary layer conditions and thermal driven mesoscale circulations during this extreme event and also understand the mechanisms that cause the event, in this study we use an advanced research version of community weather research and forecasting model (WRF) to simulate a observed event in May of 2000. The ability of WRF model in simulating the atmospheric boundary layer height over the arid areas is evaluated. Sensitivity experiments are also performed to identify the key parameters that contribute to the extreme high boundary layer height.