Methane is the second largest anthropogenic greenhouse gas,and changes in atmospheric methane concentrations can reflect the dynamic balance between its emissions and sinks.Therefore,the monitoring of CH_(4)concentrat...Methane is the second largest anthropogenic greenhouse gas,and changes in atmospheric methane concentrations can reflect the dynamic balance between its emissions and sinks.Therefore,the monitoring of CH_(4)concentration changes and the assessment of underlying driving factors can provide scientific basis for the government’s policy making and evaluation.China is the world’s largest emitter of anthropogenic methane.However,due to the lack of ground-based observation sites,little work has been done on the spatial-temporal variations for the past decades and influencing factors in China,especially for areas with high anthropogenic emissions as Central and Eastern China.Here to quantify atmospheric CH_(4)enhancements trends and its driving factors in Central and Eastern China,we combined the most up-to-date TROPOMI satellite-based column CH_(4)(xCH_(4))concentration from 2018 to 2022,anthropogenic and natural emissions,and a random forest-based machine learning approach,to simulate atmospheric xCH_(4)enhancements from 2001 to 2018.The results showed that(1)the random forest model was able to accurately establish the relationship between emission sources and xCH_(4)enhancement with a correlation coefficient(R^(2))of 0.89 and a root mean-square error(RMSE)of 11.98 ppb;(2)The xCH_(4)enhancement only increased from 48.21±2.02 ppb to 49.79±1.87 ppb from the year of 2001 to 2018,with a relative change of 3.27%±0.13%;(3)The simulation results showed that the energy activities and waste treatment were the main contributors to the increase in xCH_(4)enhancement,contributing 68.00%and 31.21%,respectively,and the decrease of animal ruminants contributed-6.70%of its enhancement trend.展开更多
Strict air pollution control measures were conducted during the Youth Olympic Games(YOG)period at Nanjing city and surrounding areas in August 2014.This event provides a unique chance to evaluate the effect of governm...Strict air pollution control measures were conducted during the Youth Olympic Games(YOG)period at Nanjing city and surrounding areas in August 2014.This event provides a unique chance to evaluate the effect of government control measures on regional atmospheric pollution and greenhouse gas emissions.Many previous studies have observed significant reductions of atmospheric pollution species and improvement in air quality,while no study has quantified its synergism on anthropogenic CO_(2)emissions,which can be coreduced with air pollutants.To better understand to what extent these pollution control measures have reduced anthropogenic CO_(2)emissions,we conducted atmospheric CO_(2)measurements at the suburban site in Nanjing city from 1^(st) July to 30^(th) September 2014 and 1^(st) August to 31^(st) August 2015,obvious decrease in atmospheric CO_(2)was observed between YOG and the rest period.By coupling the a prioriemission inventory with atmospheric transport model,we applied the scale factor Bayesian inversion approach to derive the posteriori CO_(2)emissions in YOG period and regular period.Results indicate CO_(2)emissions from power industry decreased by 45%,and other categories also decreased by 16%for manufacturing combusting,and 37%for non-metallic mineral production.Monthly total anthropogenic CO_(2)emissions were 9.8(±3.6)×10^(9) kg/month CO_(2) for regular period and decreased to 6.2(±1.9)×10^(9) kg/month during the YOG period in Nanjing city,with a 36.7%reduction.When scaling up to whole Jiangsu Province,anthropogenic CO_(2)emissions were 7.1(±2.4)×10^(10) kg/month CO_(2)for regular period and decreased to 4.4(±1.2)×10^(10)kg/month CO_(2) during the YOG period,yielding a 38.0%reduction.展开更多
基金supported by the National Natural Science foundation of China(No.42105117)the Natural Science Foundation of Jiangsu Province(No.BK20200802)supported by the National Key R&D Program of China(Nos.2020YFA0607501 and 2019YFA0607202)。
文摘Methane is the second largest anthropogenic greenhouse gas,and changes in atmospheric methane concentrations can reflect the dynamic balance between its emissions and sinks.Therefore,the monitoring of CH_(4)concentration changes and the assessment of underlying driving factors can provide scientific basis for the government’s policy making and evaluation.China is the world’s largest emitter of anthropogenic methane.However,due to the lack of ground-based observation sites,little work has been done on the spatial-temporal variations for the past decades and influencing factors in China,especially for areas with high anthropogenic emissions as Central and Eastern China.Here to quantify atmospheric CH_(4)enhancements trends and its driving factors in Central and Eastern China,we combined the most up-to-date TROPOMI satellite-based column CH_(4)(xCH_(4))concentration from 2018 to 2022,anthropogenic and natural emissions,and a random forest-based machine learning approach,to simulate atmospheric xCH_(4)enhancements from 2001 to 2018.The results showed that(1)the random forest model was able to accurately establish the relationship between emission sources and xCH_(4)enhancement with a correlation coefficient(R^(2))of 0.89 and a root mean-square error(RMSE)of 11.98 ppb;(2)The xCH_(4)enhancement only increased from 48.21±2.02 ppb to 49.79±1.87 ppb from the year of 2001 to 2018,with a relative change of 3.27%±0.13%;(3)The simulation results showed that the energy activities and waste treatment were the main contributors to the increase in xCH_(4)enhancement,contributing 68.00%and 31.21%,respectively,and the decrease of animal ruminants contributed-6.70%of its enhancement trend.
基金supported by the Natural Science Foundation of Jiangsu Province (No.BK20200802 to Cheng Hu)the National Key R&D Program of China (No.2020YFA0607501&2019YFA0607202 to WX)+4 种基金The National Natural Science Foundation of China (No.42021004)support by Technology Foundation for Selected Overseas Chinese Scholar,Nanjing (no.013108039)the Open Research Project of Shangdianzi National Atmospheric Background Station (SDZ2020617)start-up foundation from Nanjing Forestry Universitysupport from the Jiangxi Provincial Natural Science Foundation (No.20202BAB213019).
文摘Strict air pollution control measures were conducted during the Youth Olympic Games(YOG)period at Nanjing city and surrounding areas in August 2014.This event provides a unique chance to evaluate the effect of government control measures on regional atmospheric pollution and greenhouse gas emissions.Many previous studies have observed significant reductions of atmospheric pollution species and improvement in air quality,while no study has quantified its synergism on anthropogenic CO_(2)emissions,which can be coreduced with air pollutants.To better understand to what extent these pollution control measures have reduced anthropogenic CO_(2)emissions,we conducted atmospheric CO_(2)measurements at the suburban site in Nanjing city from 1^(st) July to 30^(th) September 2014 and 1^(st) August to 31^(st) August 2015,obvious decrease in atmospheric CO_(2)was observed between YOG and the rest period.By coupling the a prioriemission inventory with atmospheric transport model,we applied the scale factor Bayesian inversion approach to derive the posteriori CO_(2)emissions in YOG period and regular period.Results indicate CO_(2)emissions from power industry decreased by 45%,and other categories also decreased by 16%for manufacturing combusting,and 37%for non-metallic mineral production.Monthly total anthropogenic CO_(2)emissions were 9.8(±3.6)×10^(9) kg/month CO_(2) for regular period and decreased to 6.2(±1.9)×10^(9) kg/month during the YOG period in Nanjing city,with a 36.7%reduction.When scaling up to whole Jiangsu Province,anthropogenic CO_(2)emissions were 7.1(±2.4)×10^(10) kg/month CO_(2)for regular period and decreased to 4.4(±1.2)×10^(10)kg/month CO_(2) during the YOG period,yielding a 38.0%reduction.
