Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049 China; Department of Environmental Science, International Islamic University, Islamabad, Pakistan; The Abdus Salam International Centre for Theoretical Physics, Trieste, Italy.
Department of Environmental Science, International Islamic University, Islamabad, Pakistan.
J Environ Sci (China). 2021 Jan;99:28-39. doi: 10.1016/j.jes.2020.04.045. Epub 2020 Jun 28.
This study finds out seasonal and monthly variations in Aerosol Optical Depth (AOD) over eastern and western routes of China Pakistan Economic Corridor (CPEC) and the relationship between AOD and meteorological parameters (i.e., temperature, rainfall and wind speed). The Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR) data was used from the terra satellite for the period of 2000-2016. This study aims to overtake the conventional view of the purpose of using the satellite datasets. This study takes on to the concept that validated satellite data sets rather should be used for the analysis instead of just validation specifically for our study region. Hence, after comparing MODIS AOD with MISR AOD, only MISR AOD dataset is used for further analysis. The results show a decreasing trend of AOD in summer season, a positive relationship between temperature and AOD during winter and spring seasons whereas a positive relationship between wind speed and AOD in winter and spring seasons over eastern and western routes. Periodic analysis of MODIS AOD and MISR AOD depicts May-Aug as the peak period of aerosol concentration over central Pakistan. The inter-annual analysis shows the aerosol trend remained higher during summer season however rainfall shows the washout effect. Eastern route has higher standard deviation and larger values for aerosol prevalence as compared to western route. The trajectory analysis using the HYSPLIT model suggests the bias of air mass trajectory caused deviation in the aerosol trend in the year 2014.
本研究发现了中国-巴基斯坦经济走廊（CPEC）东、西通道气溶胶光学厚度（AOD）的季节性和月度变化，以及 AOD 与气象参数（即温度、降雨量和风速）之间的关系。本研究使用 Terra 卫星上的中分辨率成像光谱仪（MODIS）和多角度成像光谱仪（MISR）数据，时间跨度为 2000 年至 2016 年。本研究旨在超越使用卫星数据集的传统观点。本研究采用了这样一种概念，即经过验证的卫星数据集应该被用于分析，而不仅仅是针对我们研究区域的验证。因此，在比较 MODIS AOD 与 MISR AOD 后，仅使用 MISR AOD 数据集进行进一步分析。结果表明，AOD 在夏季呈下降趋势，冬季和春季温度与 AOD 呈正相关，而冬季和春季风速与 AOD 呈正相关。MODIS AOD 和 MISR AOD 的定期分析表明，5 月至 8 月是巴基斯坦中部气溶胶浓度的高峰期。年际分析表明，气溶胶趋势在夏季仍然较高，而降雨量则有冲刷作用。与西部通道相比，东部通道的气溶胶出现率具有更高的标准差和更大的值。使用 HYSPLIT 模型进行的轨迹分析表明，空气团轨迹的偏差导致了 2014 年气溶胶趋势的偏差。
