Khan Rehana, Kumar Kanike Raghavendra, Zhao Tianliang
Collaborative Innovation Centre on Forecast and Evaluation of Meteorological Disasters, Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), International Joint Laboratory on Climate and Environment Change (ILCEC), Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China.
Department of Physics, Higher Education, Government of Khyber Pakhtunkhwa, Peshawar 25000, Pakistan.
Urban Clim. 2021 Jul;38:100908. doi: 10.1016/j.uclim.2021.100908. Epub 2021 Jul 7.
Quantifying the variations of atmospheric aerosols and trace gas concentrations with the impact of lockdown due to the Coronavirus disease of 2019 (COVID-19) pandemic is crucial in understanding urban air quality. For this purpose, we utilized the multi-instrumental approach of satellite remote sensing and reanalysis model data to examine the spatial and temporal patterns of major air pollutants during December 2019-June 2020 in South Asia. The lockdown has to lead to a considerable decrease in aerosol optical thickness (AOT) over South China (-18.92%) and Indo-Gangetic Plain (IGP; -24.29%) compared to its ordinary level for a couple of weeks. Noticeable reductions in tropospheric NO are observed over the Pearl River Delta (PRD; -0.3/cm) followed by Central China (CC) with -0.21/cmand IGP (-0.085/cm), and the lowest (-0.0008/cm) in the Tibetan Plateau (TP) region. The changes observed in PM and SO levels (from -58.56% to - 63.64%) are attributed to the decrease in anthropogenic emissions, vehicular exhaust, and industrial activities. However, the BC concentrations are reduced by approximately halved of its ordinary levels in the IGP (-2.28 μg/m) followed by YRD (-1.56 μg/m), CC (-1.5 μg/m), NCP (-1.29 μg/m), and PRD (-0.78 μg/m) regions. The total column O predominantly increased from 262.68 to 285.53DU, 323.00 to 343.00DU, and 245.00 to 265.00DU in the YRD, NCP, and IGP areas. This is mainly associated with solar radiation, meteorological factors, and an unprecedented reduction in NOx during the lockdown period.
量化2019年冠状病毒病（COVID-19）大流行导致封锁对大气气溶胶和痕量气体浓度变化的影响，对于理解城市空气质量至关重要。为此，我们利用卫星遥感和再分析模型数据的多仪器方法，研究了2019年12月至2020年6月南亚主要空气污染物的时空格局。与正常水平相比，封锁导致中国南方（-18.92%）和印度-恒河平原（IGP；-24.29%）的气溶胶光学厚度（AOT）在几周内大幅下降。珠江三角洲（PRD；-0.3/cm）、中国中部（CC；-0.21/cm）和IGP（-0.085/cm）地区的对流层NO明显减少，青藏高原（TP）地区最低（-0.0008/cm）。PM和SO水平的变化（从-58.56%到-63.64%）归因于人为排放、车辆尾气和工业活动的减少。然而，IGP（-2.28μg/m）、长江三角洲（YRD；-1.56μg/m）、CC（-1.5μg/m）、华北平原（NCP；-1.29μg/m）和PRD（-0.78μg/m）地区的BC浓度降至正常水平的一半左右。长江三角洲、华北平原和IGP地区的总柱O主要从262.68增加到285.53DU、从323.00增加到343.00DU、从245.00增加到265.00DU。这主要与太阳辐射、气象因素以及封锁期间NOx前所未有的减少有关。
