关键词: 巴丹吉林沙漠, 大气边界层, 变化

Abstract: The characteristics of daily potential temperature, specific humidity, wind speed and direction of the boundary layer in summer was analyzed based on the observed data from July to September of 2009. The result showed that: (1) Surface daily temperature range was high, the variation of specific humidity was the opposite of temperature, and wind speed changed obviously at the daytime. (2) When energy imbalance item R_d>0, Monin-Obukhov Length L<0, the atmospheric stratification was unstable, and vice versa. The most of net radiation was transformed to sensible heat flux at the daytime, providing thermal condition for boundary layer development. (3) Stable Boundary Layer (SBL) experiences from rebuilt to disappearance, Residual Layer (RL) over SBL was thicker before noon; Mixed Layer (ML) got through the RL and develops swiftly, super-adiabatic lapse phenomenon appears at the near-surface in the afternoon; in the nighttime, SBL develops rapidly, and the maximum thickness reached 900 m, ML changed into RL. (4)To the whole atmospheric layer, five-layer boundary structure turned into three-layer structure in the afternoon, SBL disappears, ML develops and the maximum value was about 3 000 m. the thickness of entrainment zone(EZ) achieves 1 500 m and super-adiabatic layer height reaches about 200 m.

Key words: Badain Jaran Desert, atmospheric boundary layer, variation