关键词: 沙尘暴, 微气象学, 湍流通量, 浑善达克沙地, 观测法

Abstract: Based on data from the dust storm monitoring station over Hunshandake Desert Area, Inner Mongolia, the maximum values of micrometeorological variables, turbulent fluxes and dust concentration in the surface layer are compared for eight dust events in the spring of 2004, and the characteristics of micrometeorology and radiation components in the strongest dust storm event in March 27-28 are analyzed. The results show that temperature differences in the surface layer, net radiation and sensible heat fluxes all decrease during daytime, and the strength of temperature inversion weakens at night. When dust events occur, momentum fluxes increase. It is found that both mechanical turbulence and thermodynamic turbulence play important roles in local dust rising and vertical dust transport over source regions. During the passage of the strongest dust storm event in March 27-28, dust concentration, wind speed and vertical shear of wind velocity increase rapidly, together with changes of wind direction. At the strengthening stage of the dust storm, temperature falls by about 7℃, and there is a peak value of specific humidity. Both the net radiation and sensible heat fluxes become negative. When dust concentration reaches its maximum, the net radiation rises to zero, which reflects the heating effect of dust aerosol during nighttime.

Key words: sand-dust storm, micrometeorology, turbulent fluxes, Hunshandake desert area, observation methods