Шороон шуурга болох үеийн агаар мандлын тогтворшлын параметрүүд

Abstract

Although many studies investigated the spatial distribution, duration and frequency of dust storm in Mongolia, there are a few studies were undertaken it in terms of physical process that underpinned the current study on the subject. The study examines whether it is possible to acquire the distribution of dust storms in a relatively simple way by estimating the atmospheric stability during a dust storm. In order to achieve the main purpose of the study, the atmospheric stability parameters such as Brunt-Vaisala frequency (N), Gradient Richardson Number (Ri), and Eady Growth Rate (σ_E) were evaluated on 3 different cases of heavy dust storms which are occurred from March to May 2020, covered almost all over Mongolia, using reanalysis data produced by the European Centre for Medium-Range Weather Forecasts and radiosonde data from “Dalanzadgad” an aerological station in Dalanzadgad, Umnugovi. Differential equations of N, Ri, and σ_E are solved using the finite difference method. The results of the study revealed that both Ri and σ_E stability parameters can be identified well the distribution of dust storm, while a linear relationship between a dust storm and N as well as the buoyancy component of Ri was not found. In addition, in the study, a simplified method to compute the Ri parameter based on power function was acquired by the wind shear. It was difficult to make statistical analyses in the results of the study based on few cases between March and May in 2020. Therefore, it is necessary to consider more cases in the future, to undertake statistical analysis.