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

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.

Large-Scale Saharan Dust Episode in April 2019: Study of Desert Aerosol Loads over Sofia, Bulgaria, Using Remote Sensing, In Situ, and Modeling Resources

“…This means that the height profiles of aerosol backscatter and extinction likely have nearly the same shape, one that follows the shape of the aerosol mass concentration (MC) profile. Thus, an opportunity is opened up for height profiling of the aerosol MC, using appropriate calibration [95], directly from the aerosol BSC profiles, without the need for intermediate determination of the aerosol extinction profiles. Here, this possibility is realized by using the vertical aerosol BSC profiles presented in Figures 9a,d,g and 10, together with data from parallel in situ measurements of the aerosol PM 10 concentration in the respective time intervals by the elevated rural Kopitoto AMS, shown in Figure 11a.…”

Evolution of turbulent kinetic energy during the entire sandstorm process

“…Sandstorms are devastating natural hazards and one of the main global environmental problems which accelerate the expansion of desertification (Hu et al, 2017;Gu et al, 2021;Yang et al, 2021). Analyzing the temporal and spatial characteristics and the causes of sandstorms can help us better understand their occurrence and development, improving the level of sandstorm forecasting and reducing disaster impact and loss (Gasch et al, 2017;Li, 2020;Zhang and Zhou, 2020;Xu et al, 2020;Miri et al, 2021;Hamzeh et al, 2021).…”

“…However, wind, as a driving force, is the energy source of wind-blown sand movement. The structural characteristics of the flow field directly affect the surface sand emission and vertical transport (Zheng et al, 2013;Martin and Kok, 2017;Zhan et al, 2017). Wind velocity has been proven to have a more significant impact on sandstorms than other meteorological elements (Li, 2020).…”

Relationships between Near-Surface Horizontal Dust Fluxes and Dust Depositions at the Centre and Edge of the Taklamakan Desert

“…Regarding the variation in horizontal dust flux with height, many researchers found that the transport flux declined sharply with increased height and proposed various distribution equations for dust flux versus height, which were primarily exponential functions [26][27][28][29][30] and power functions [31][32]. The latest research results of horizontal dust flux also include methods and verifications of empirical formulas with new data, and effects of weather and climate; experiments [33][34][35][36][37][38], such as the method of estimating low-frequency variations in the density of turbulent dust-aerosol fluxes over hyper-arid, arid, semi-arid and lake dried beds, have been proposed based on measurement data on aerosol-particle concentrations and the vertical wind velocity component [33]. Zhang et al [34] studied the distribution of biological soil crust in sand and dust storm source areas of Central and East Asia using moderate resolution imaging spectroradiometer satellite (MODIS) surface reflectance data collected in 2000-2019 to determine its potential impact on dust emission according to two empirical schemes.…”