A field observational study of electrification within a dust storm in Minqin, China

Abstract

Previous studies have confirmed the existence of vertical electric fields generated within windblown sand and dust storms. The magnitude of the vertical electric field is generally hundreds of times or even thousand times that of the fair weather value. However, studies of the horizontal electric field and relation between the electric field and other physical quantities, such as wind velocity, wind-blown sand flux, humidity and temperature, are still limited. In this paper, we present simultaneous field observations of the electric field and other physical quantities within a dust storm in Minqin, China. These observations revealed that the horizontal and upward-pointing electric fields coexist in the dust storm, where the direction of horizontal electric field point along with the wind direction and the magnitude is greater than that of the vertical electric field. The average and standard deviation of the horizontal and vertical electric fields are linearly related to the velocity in the increasing and decreasing stage of dust storm. In addition, the magnitude of the horizontal and vertical electric fields may be related to the atmospheric temperature or humidity. The average and standard deviation of the electric field at one height is linearly related to that at another height, and they first increase and then decrease with the height. The probability density function of the electric field follows a Gaussian distribution with a magnitude greater than the average electric field itself.