内蒙古西部一次沙尘暴贴地层物理通量研究

Study on Physical Flux of a Sandstorm Near Stratum in Western Inner Mongolia

2022年4月20—21日,内蒙古西部地区出现了沙尘暴天气,此次沙尘暴爆发性强,范围大,强度弱,短时沙尘暴多发。文章利用地面10 min常规观测资料,研究沙尘暴发生时的感热通量、潜热通量、动量通量的特征及其与水平能见度之间的关系。结果表明:沙尘暴期间的感热通量、潜热通量分时段存在正值、负值和0值,其会在0值附近波动振荡;夜间的动量通量小于白天的动量通量;空气温度和地表温度的昼夜变化引起感热通量和潜热通量对沙尘暴的反馈机制;感热通量对沙尘暴的作用远大于潜热通量对沙尘暴的作用,相对于感热加热,潜热加热在夜间对沙尘暴的加热作用比白天更小;在感热通量和潜热通量0值附近,感热通量的最大波动振幅大于潜热通量的最大波动振幅,水平能见度与感热通量绝对值、潜热通量绝对值呈正相关,其随着感热通量绝对值、潜热通量绝对值增加而增大或减少而减小。

From April 20 to 21, 2022, there will be a sandstorm weather in the western part of Inner Mongolia. This sandstorm was explosive, large in scope, weak in intensity,and frequent in a short time. In this paper,the characteristics of sensible heat flux,latent heat flux, momentum flux and their relationship with horizontal visibility during sandstorms were studied by using 10 minute conventional observation data on the ground.The results show that there are positive,negative and zero values of sensible heat flux and latent heat flux during dust storms,which fluctuate around zero. The momentum flux at night was smaller than that at daytime.The diurnal variation of air temperature and surface temperature causes the feedback mechanism of sensible heat flux and latent heat flux to dust storms. The effect of sensible heat flux on sandstorm was far greater than that of latent heat flux on sandstorm. Compared with sensible heat heating, the heating effect of latent heat heating on sandstorm at night was smaller than that at daytime. Near the 0 value of sensible heat flux and latent heat flux, the maximum fluctuation amplitude of the sensible heat flux was greater than that of the latent heat flux. The horizontal visibility was positively correlated with the absolute value of the sensible heat flux and the absolute value of the latent heat flux, and it increases or decreases with the increase of the absolute value of the sensible heat flux and the absolute value of the latent heat flux.