To maintain air quality during the 31st World University Games,Chengdu employed a range of monitoring and control strategies in 2023.High-resolution regional pollutant distributions were reconstructed by integrating t...To maintain air quality during the 31st World University Games,Chengdu employed a range of monitoring and control strategies in 2023.High-resolution regional pollutant distributions were reconstructed by integrating the vertical column densities(VCDs)from mobile MAX-DOAS measurements with Gaussian process regression analysis.The correlation between the spatial distribution derived from MAX-DOAS and that of GEMS and TROPOMI satellite data exceeded 0.6.This paper explores the impact of air quality improvements during the games on the sources of HCHO and the formation process of HONO.During the control period,primary emissions and secondary formations of HCHO contributed 50.85%±24.24%and 42.81%±7.57%to the total atmospheric HCHO,respectively.The study indicates that with improved air quality,HCHO primary emissions decrease while secondary emissions and atmospheric radiation transmission intensities rise.It is found that HONO always appears under the condition of high aerosol optical depth(AOD)and NO_(2),but high NO_(2) concentration and AOD are not necessarily accompanied by high concentrations of HONO.To assess the influence of temperature and humidity on the formation of HONO from NO_(2),we calculated the emission ratesΔHONO∕ΔNO_(2) to quantify the impact of primary sources on total HONO concentrations.The analysis results show that the turning point of relative humidity is 65%(60%–70%)and the turning point of temperature is 31℃(30–32℃).Lower temperatures and higher humidity levels were found to decrease the rate of secondary HONO formation from NO_(2).展开更多
Marine vessels play a vital role in the global economy;however,their negative impact on the marine atmospheric environment is a growing concern.Quantifying marine vessel emissions is an essential prerequisite for cont...Marine vessels play a vital role in the global economy;however,their negative impact on the marine atmospheric environment is a growing concern.Quantifying marine vessel emissions is an essential prerequisite for controlling these emissions and improving the marine atmospheric environment.Optical imaging remote sensing is a vital technique for quantifying marine vessel emissions.However,the available imaging techniques have suffered from insufficient detection accuracy and inadequate spatiotemporal resolution.Herein,we propose a fast-hyperspectral imaging remote sensing technique that achieved precise imaging of nitrogen dioxide(NO_(2))and sulfur dioxide(SO_(2))from marine vessels.Several key techniques are developed,including the coaxial design of three camera systems(hyperspectral camera,visible camera,and multiwavelength filters)and a high-precision temperature control system for a spectrometer(20℃±0.5℃).Moreover,based on the variation of O_(4)within them,plumes are categorized as aerosol-present and aerosol-absent,with different air mass factor(AMF)calculation schemes developed accordingly.Multiwavelength filters combined with spectral analysis enable precise identification of the plume outline and a detailed observation of the trace gas distribution inside the plume emitted from marine vessels.In addition,we focuse on the emission characteristics of NO_(2) and SO_(2) from large ocean cargo ships and small offshore cargo ships.Although there are still many emerging issues,such as measurement of cross-sections of trace gases at different temperature,nighttime imaging,and greenhouse gas imaging,this study opens a gate for synergies in pollution and carbon reductions and the continuous improvement of the marine atmospheric environment.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFC3704200)the National Natural Science Foundation of China(Nos.42207113,42475148 and U21A2027)the Presidential Foundation of the Hefei Institutes of Physical Science,Chinese Academy Sciences(No.YZJJQY202401).
文摘To maintain air quality during the 31st World University Games,Chengdu employed a range of monitoring and control strategies in 2023.High-resolution regional pollutant distributions were reconstructed by integrating the vertical column densities(VCDs)from mobile MAX-DOAS measurements with Gaussian process regression analysis.The correlation between the spatial distribution derived from MAX-DOAS and that of GEMS and TROPOMI satellite data exceeded 0.6.This paper explores the impact of air quality improvements during the games on the sources of HCHO and the formation process of HONO.During the control period,primary emissions and secondary formations of HCHO contributed 50.85%±24.24%and 42.81%±7.57%to the total atmospheric HCHO,respectively.The study indicates that with improved air quality,HCHO primary emissions decrease while secondary emissions and atmospheric radiation transmission intensities rise.It is found that HONO always appears under the condition of high aerosol optical depth(AOD)and NO_(2),but high NO_(2) concentration and AOD are not necessarily accompanied by high concentrations of HONO.To assess the influence of temperature and humidity on the formation of HONO from NO_(2),we calculated the emission ratesΔHONO∕ΔNO_(2) to quantify the impact of primary sources on total HONO concentrations.The analysis results show that the turning point of relative humidity is 65%(60%–70%)and the turning point of temperature is 31℃(30–32℃).Lower temperatures and higher humidity levels were found to decrease the rate of secondary HONO formation from NO_(2).
基金supported by the National Natural Science Foundation of China(42475148)the National Key Research and Development Program of China(2023YFC3705400,2022YFC3704200)+1 种基金the major science and technology special project of the Xinjiang Uygur Autonomous Region(2024A03012)the President’s Foundation of Hefei Institutes of Physical Science,Chinese Academy of Sciences(YZJJQY202401,BJPY2024B09).
文摘Marine vessels play a vital role in the global economy;however,their negative impact on the marine atmospheric environment is a growing concern.Quantifying marine vessel emissions is an essential prerequisite for controlling these emissions and improving the marine atmospheric environment.Optical imaging remote sensing is a vital technique for quantifying marine vessel emissions.However,the available imaging techniques have suffered from insufficient detection accuracy and inadequate spatiotemporal resolution.Herein,we propose a fast-hyperspectral imaging remote sensing technique that achieved precise imaging of nitrogen dioxide(NO_(2))and sulfur dioxide(SO_(2))from marine vessels.Several key techniques are developed,including the coaxial design of three camera systems(hyperspectral camera,visible camera,and multiwavelength filters)and a high-precision temperature control system for a spectrometer(20℃±0.5℃).Moreover,based on the variation of O_(4)within them,plumes are categorized as aerosol-present and aerosol-absent,with different air mass factor(AMF)calculation schemes developed accordingly.Multiwavelength filters combined with spectral analysis enable precise identification of the plume outline and a detailed observation of the trace gas distribution inside the plume emitted from marine vessels.In addition,we focuse on the emission characteristics of NO_(2) and SO_(2) from large ocean cargo ships and small offshore cargo ships.Although there are still many emerging issues,such as measurement of cross-sections of trace gases at different temperature,nighttime imaging,and greenhouse gas imaging,this study opens a gate for synergies in pollution and carbon reductions and the continuous improvement of the marine atmospheric environment.
