Understanding the aerosol vertical characterization is of great importance to both climate and atmospheric environment. This study investigated the variations of aerosol profiles over eight regions of interest in Chin...Understanding the aerosol vertical characterization is of great importance to both climate and atmospheric environment. This study investigated the variations of aerosol profiles over eight regions of interest in China after clean air policy(2013-2019) and discussed the drivers of the vertical aerosol structure, using observations from active satellite measurements(CALIPSO). From the annual variation, the amplitude of extinction coefficient profiles showed a decreasing trend with fluctuations, and the maximum was 0.21 km-1in BeijingTianjin-Hebei(JJJ). For regions suffered from air pollution, the variation was greatest below 0.45 km, while it was between 1-1.5 km for Sichuan Basin. The correlation coefficient between the relative humidity(RH) and the extinction coefficient indicated that the increase of RH inhibited the decrease of the extinction coefficient in the Yangtze River Delta. In most regions, the main aerosol subtypes were polluted dust and polluted continental, but they were coarser in JJJ and North West. The frequency of concurrency of dust and polluted dust aerosols decreased in JJJ, but polluted continental aerosols occurred more frequently. Further, the aerosol extinction coefficient profiles under different pollution conditions showed that it changed most during heavy pollution periods in JJJ, especially in 2017, with a significant aerosol loading between700 and 1200 m. The atmospheric reanalysis data revealed that the weak convergence at low level and the divergence at high level supported the upward transport of aerosols in 2017. Overall, the differences in divergence allocation, RH, and wind filed were the main meteorological drivers.展开更多
Observations and numerical models are mainly used to investigate the spatiotemporal distribution and vertical structure characteristics of aerosols to understand aerosol pollution and its effects.However,the limitatio...Observations and numerical models are mainly used to investigate the spatiotemporal distribution and vertical structure characteristics of aerosols to understand aerosol pollution and its effects.However,the limitations of observations and the uncertainties of numerical models bias aerosol calculations and predictions.Data assimilation combines observations and numerical models to improve the accuracy of the initial,analytical fields of models and promote the development of atmospheric aerosol pollution research.Numerous studies have been conducted to integrate multi-source data,such as aerosol optical depth and aerosol extinction coefficient profile,into various chemical transport models using various data assimilation algorithms and have achieved good assimilation results.The definition of data assimilation and the main algorithms will be briefly presented,and the progress of aerosol assimilation according to two types of aerosol data,namely,aerosol optical depth and extinction coefficient,will be presented.The application of vertical aerosol data assimilation,as well as the future trends and challenges of aerosol data assimilation,will be further analysed.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDA19040203)the National research program for key issues in air pollution control (No. DQGG202106)。
文摘Understanding the aerosol vertical characterization is of great importance to both climate and atmospheric environment. This study investigated the variations of aerosol profiles over eight regions of interest in China after clean air policy(2013-2019) and discussed the drivers of the vertical aerosol structure, using observations from active satellite measurements(CALIPSO). From the annual variation, the amplitude of extinction coefficient profiles showed a decreasing trend with fluctuations, and the maximum was 0.21 km-1in BeijingTianjin-Hebei(JJJ). For regions suffered from air pollution, the variation was greatest below 0.45 km, while it was between 1-1.5 km for Sichuan Basin. The correlation coefficient between the relative humidity(RH) and the extinction coefficient indicated that the increase of RH inhibited the decrease of the extinction coefficient in the Yangtze River Delta. In most regions, the main aerosol subtypes were polluted dust and polluted continental, but they were coarser in JJJ and North West. The frequency of concurrency of dust and polluted dust aerosols decreased in JJJ, but polluted continental aerosols occurred more frequently. Further, the aerosol extinction coefficient profiles under different pollution conditions showed that it changed most during heavy pollution periods in JJJ, especially in 2017, with a significant aerosol loading between700 and 1200 m. The atmospheric reanalysis data revealed that the weak convergence at low level and the divergence at high level supported the upward transport of aerosols in 2017. Overall, the differences in divergence allocation, RH, and wind filed were the main meteorological drivers.
文摘Observations and numerical models are mainly used to investigate the spatiotemporal distribution and vertical structure characteristics of aerosols to understand aerosol pollution and its effects.However,the limitations of observations and the uncertainties of numerical models bias aerosol calculations and predictions.Data assimilation combines observations and numerical models to improve the accuracy of the initial,analytical fields of models and promote the development of atmospheric aerosol pollution research.Numerous studies have been conducted to integrate multi-source data,such as aerosol optical depth and aerosol extinction coefficient profile,into various chemical transport models using various data assimilation algorithms and have achieved good assimilation results.The definition of data assimilation and the main algorithms will be briefly presented,and the progress of aerosol assimilation according to two types of aerosol data,namely,aerosol optical depth and extinction coefficient,will be presented.The application of vertical aerosol data assimilation,as well as the future trends and challenges of aerosol data assimilation,will be further analysed.
