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The present survey addresses the comprehensive description of geographic locations, transport ways, size, and vertical aerosol distribution during four large dust events which occurred in the Northwest China. Based on the data from 35 ground-based air quality monitoring stations and the satellite data, emission flows for dust events within the period of 2014 to 2017 have been estimated. The data show that maximum peak daily average PM10 and PM2.5 concentrations exceeded 380 and 150 μg/m3, respectively, and the PM2.5/PM10 ratio was ranging within 0.12-0.66. Both satellite data and simulation data of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) coincide with location and extension of a dust cloud. The Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) found dust at 0 to 10 km altitude which remained at this level during the most part of its trajectory. The vertical aerosol distribution at a wave of 532 nm total attenuated backscatter coefficient range of 0.0025-0.003 km−1 × sr−1. Moderate Resolution Imaging Spectroradiometer (MODIS) (Terra) Collection 6 Level-3 aerosol products data show that aerosol optical depth (AOD) at pollution epicenters exceeds 1. A comprehensive data survey thus demonstrated that the main sources of high aerosol pollutions in the territory were deserted areas of North and Northwest China as well as the most part of the Republic of Mongolia, where one of the largest deserts, Gobi, extends. [ABSTRACT FROM AUTHOR]

The present paper has used a comprehensive approach to study atmosphere pollution sources including the study of vertical distribution characteristics, the epicenters of occurrence and transport of atmospheric aerosol in North-West China under intensive dust storm registered in all cities of the region in April 2014. To achieve this goal, the remote sensing data using Moderate Resolution Imaging Spectroradiometer satellite (MODIS) as well as model-simulated data, were used, which facilitate tracking the sources, routes, and spatial extent of dust storms. The results of the study have shown strong territory pollution with aerosol during sandstorm. According to ground-based air quality monitoring stations data, concentrations of PM 10 and PM 2.5 exceeded 400 μg/m 3 and 150 μg/m 3 , respectively, the ratio PM 2.5 /PM 10 being within the range of 0.123–0.661. According to MODIS/Terra Collection 6 Level-2 aerosol products data and the Deep Blue algorithm data, the aerosol optical depth (AOD) at 550 nm in the pollution epicenter was within 0.75–1. The vertical distribution of aerosols indicates that the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) 532 nm total attenuates backscatter coefficient ranges from 0.01 to 0.0001 km −1  × sr −1 with the distribution of the main types of aerosols in the troposphere of the region within 0–12.5 km, where the most severe aerosol contamination is observed in the lower troposphere (at 3–6 km). According to satellite sounding and model-simulated data, the sources of pollution are the deserted regions of Northern and Northwestern China. [ABSTRACT FROM AUTHOR]

A dust storm that formed in the north of China and the southeastern part of Mongolia in March 2021 significantly deteriorated air quality over a large area of East Asia. According to the synoptic pattern, the cause of the dust storm was a cyclone with a significant drop in pressure leading to high winds and dry components of the soil over parts of the Gobi Desert becoming airborne. Data obtained from ground-based air quality monitoring stations show that the observed hourly PM 10 concentration greatly exceeded the recommended maximum of 150 μg/m3 with readings above 1500 μg/m3 in the cities of Tianjin, Baoding, Zhengzhou, Luoyang, Zhoukou. In Shijiazhuang, Taiyuan, Jinnan, Xining, Baotou, and Jining. In Handan, it was over 2000 μg/m3. Cities where PM 10 concentration exceeded 3900 μg/m3 included Lanzhou, Hohhot, Changzhou, Alashan, Yan'an, Yulin, Hami, Jiuquan, Heze, Hotan, and Baiyin. Concentrations exceeded 7000 μg/m3 on March 15th over parts of the provinces of Inner Mongolia, Gansu and Ningxia, in the cities of Ordos, Jinchang, Wuwei and Zhongwei. According to satellite data, the area of dust covered approximately 450,000 km2. MODIS and TROPOMI data demonstrated high aerosol optical depth (AOD) (more than 1) with a high ultraviolet aerosol index (UVAI) (more than 2), confirming the predominance of dust particles during the storm. Data from CALIPSO show the presence of a dense layer of dust extending from the earth's surface to a height of about 8 km. The Dust Regional Atmospheric Model (BSC-DREAM8b) demonstrates high synchrony with the satellite's surface dust concentration data, ranging from 640 to 1280 μg/m3, and exceeding 2650 μg/m3 in some areas. The purpose of this study is to analyze data from ground-based sensors, satellites, and atmospheric models to better understand the March 2021 dust storm event. The results may be useful for the implementation of protective and preventive measures for both the environment and human health, including air quality control. [Display omitted] • Multi-satellite observation of an intense dust event. • One of the most heavy dust storm of the last 10 years. • Spatial and temporal variations of air pollutants and aerosol properties were analyzed. • PM 10 concentration was above 1500 μg/m3 in many cities. [ABSTRACT FROM AUTHOR]