Detection of a Dust Storm in 2020 by a Multi-Observation Platform over the Northwest China

Lili Yang,Zhiyuan Hu,Huijie Tao,Zhongwei Huang,Jing Wang,Lina Wang,Wenyu Han,Yanping Yang

doi:10.3390/rs13061056

Abstract

Dust storms have occurred frequently in northwest China and can dramatically reduce visibility and exacerbate air quality in downwind regions through long-range transport. In order to study the distribution characteristics of dust particles sizes, structures and concentrations in the process of dust storm, especially for the vertical distributions, the multi-observation platform composed of six Lidars and nine aerosol analytical instruments is first used to detect a severe dust storm event, which occurred in Northwest China on 3 May 2020. As a strong weather system process, the dust storm has achieved high intensity and wide range. When the intensity of a dust storm is at its strongest, the ratios of PM2.5 (particulate matter with diameter < 2.5 µm) and PM10 (particulate matter with diameter < 10 µm) (PM2.5/PM10) in cities examined were less than 0.2 and the extinction coefficients became greater than 1 km−1 based on Lidar observations. In addition, the growth rates of PM2.5 were higher than that of PM10. The dust particles mainly concentrated at heights of 2 km, after being transported about 200–300 km, vertical height increased by 1–2 km. Meanwhile, the dust concentration decreased markedly. Furthermore, the depolarization ratio showed that dust in the Tengger Desert was dominated by spherical particles. The linear relationships between 532 nm extinction coefficient and the concentration of PM2.5 and PM10 were found firstly and their R2 were 0.706 to 0.987. Our results could give more information for the physical schemes to simulate dust storms in specific models, which could improve the forecast of dust storms.

Highlights

In recent decades, dust storms have occurred frequently, along with climate change, on a global scale [1,2]
Used linear and exponential models to retrieve PM2.5 concentration based on extinction coefficient from 355 nm Lidar, and the results showed that the PM2.5 concentration and the measured values of the two models had a strong correlation coefficient
Mass distribution was obtained by synergy usage of satellite and Lidar measurements [37], and the results showed that the correlation coefficients between the estimated aerosol extinction coefficients and the surface PM mass were 0.57–0.86 for PM2.5 and 0.59–0.78 for most of the above studies were based on a single Lidar, and a single Lidar is difficult to reveal the source, transmission and development trend of sand and dust

Summary

Introduction

Dust storms have occurred frequently, along with climate change, on a global scale [1,2]. Dust event monitoring is providing great help for dust forecast, early warning and ecological environment impact assessment, and has a profound and lasting impact on global climate change and human life [13]. As advanced aerosol monitoring equipment, satellite remote sensing can provide monitoring results in regional and global scales, and these datasets are widely used in meteorology [18], environmental [19], hydrology [20], agriculture [21].

Methods

Results

Conclusion