Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing 210044, China; Precision Regional Earth Modeling and Information Center, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing 210044, China; Precision Regional Earth Modeling and Information Center, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Sci Total Environ. 2022 Feb 10;807(Pt 2):151490. doi: 10.1016/j.scitotenv.2021.151490. Epub 2021 Nov 5.
Long-term variations in aerosol optical properties, types, and radiative forcing over the Sichuan Basin (SCB) and surrounding regions in Southwest China were investigated based on two-decade data (2001-2020) from the Moderate Resolution Imaging Spectroradiometer, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation, and the Santa Barbara DISORT Atmospheric Radiative Transfer model. The results showed that the aerosol optical depth (AOD) in the SCB, a major polluted region in Southwest China, experienced an increasing tendency at a rate of +0.052 yr during 2001-2006; thereafter, it decreased speedy up from -0.020 to -0.058 yr over recent years, whereas the interannual variation in Ångström exponent (AE) presented a persistently increasing trend during 2001-2020, with a rate of +0.014 yr. An improved atmospheric environment but an enhanced fine particle contribution to regional aerosols in the SCB was observed. Over the polluted SCB region, the dominant aerosol types were biomass burning/urban industrial and mixed-type aerosols with the proportions of 80.7%-87.5% in regional aerosols, with a higher frequency of clean aerosols in recent years, reflecting an effect of controlling anthropogenic emission in the SCB owing to governmental regulation. By contrast, few changes were observed in the aerosol types and amounts in the eastern Tibetan Plateau (ETP), where clean continental aerosols dominate with high proportion of 93.7% in the clean atmospheric environment. A significant decline in polluted anthropogenic aerosols was observed below 3 km over the SCB, resulting in the regional aerosol extinction coefficients at 532 nm (EC) were declined by -0.22 km from 2013 to 2020. Notably, the decreases in aerosol radiative forcing within the atmosphere were found in the SCB and the adjacent northern Yunnan-Guizhou Plateau (NYGP) and ETP, with -41.6%, -33.7%, and -13.6%, respectively during 2013-2020. This indicates that such an attenuated aerosol heating rate in the atmosphere, caused by aerosol variation, could alter the atmospheric thermal structure over the SCB and surrounding areas for regional changes of environment and climate in recent years.
基于 Moderate Resolution Imaging Spectroradiometer、Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation 以及 Santa Barbara DISORT Atmospheric Radiative Transfer 模型二十年（2001-2020 年）的数据，研究了中国西南部四川盆地（SCB）及其周边地区气溶胶光学特性、类型和辐射强迫的长期变化。结果表明，作为中国西南部主要污染区的 SCB 地区气溶胶光学厚度（AOD）在 2001-2006 年期间呈上升趋势，增长率为+0.052 yr；此后，近年来迅速下降至-0.020 至-0.058 yr，而 2001-2020 年期间 Ångström 指数（AE）的年际变化呈持续上升趋势，增长率为+0.014 yr。观察到 SCB 地区大气环境改善，但细颗粒对区域气溶胶的贡献增强。在污染严重的 SCB 地区，主要气溶胶类型为生物质燃烧/城市工业和混合气溶胶，占区域气溶胶的 80.7%-87.5%，近年来清洁气溶胶的频率较高，反映了由于政府法规，SCB 地区人为排放控制的效果。相比之下，在大气环境清洁的东部青藏高原（ETP）地区，气溶胶类型和数量几乎没有变化，清洁大陆气溶胶占主导地位，比例高达 93.7%。在 SCB 地区 3 公里以下，污染人为气溶胶显著减少，导致 2013 年至 2020 年期间 532nm 处的区域气溶胶消光系数（EC）下降了-0.22km。值得注意的是，在 2013-2020 年期间，SCB 及其周边的北部云南-贵州高原（NYGP）和 ETP 地区的气溶胶辐射强迫在大气中都有所减少，分别为-41.6%、-33.7%和-13.6%。这表明，由于气溶胶变化导致的大气中气溶胶加热率的这种衰减，可能会改变 SCB 及周边地区的大气热力结构，从而导致近年来环境和气候的区域变化。
