Since the industrial revolution,enhancement of atmospheric greenhouse gas concentrations as a result of human activities has been the primary cause of global warming.The monitoring and evaluation of greenhouse gases a...Since the industrial revolution,enhancement of atmospheric greenhouse gas concentrations as a result of human activities has been the primary cause of global warming.The monitoring and evaluation of greenhouse gases are significant prerequisites for carbon emission control.Using monthly data of global atmospheric carbon dioxide(CO_(2))and methane(CH4)column concentrations(hereinafter XCO_(2) and XCH_(4),respectively)retrieved by the Greenhouse Gas Observation Satellite(GOSAT),we analyzed the variations in XCO_(2)and XCH_(4)in China during 2010-2022 after confirming the reliability of the data.Then,the influence of a strong El Niño event in 2015-2016 on XCO_(2) and XCH_(4) variations in China was further studied.The results show that the retrieved XCO_(2) and XCH_(4) from GOSAT have similar temporal variation trends and significant correlations with the ground observation and emission inventory data of an atmospheric background station,which could be used to assess the variations in XCO_(2) and XCH_(4) in China.XCO_(2) is high in spring and winter while XCH_(4) is high in autumn.Both XCO_(2) and XCH_(4) gradually declined from Southeast China to Northwest and Northeast China,with variation ranges of 401-406 and 1.81-1.88 ppmv,respectively;and the high value areas are located in the middle-lower Yangtze River basin.XCO_(2) and XCH_(4) in China increased as a whole during 2010-2022,with rapid enhancement and high levels of XCO_(2) and XCH_(4) in several areas.The significant increases in XCO_(2) and XCH_(4) over China in 2016 might be closely related to the strong El Niño-Southern Oscillation(ENSO)event during 2015-2016.Under a global warming background in 2015,XCO_(2) and XCH_(4) increased by 0.768%and 0.657%in 2016 in China.Data analysis reveals that both the XCO_(2) and XCH_(4) variations might reflect the significant impact of the ENSO event on glacier melting in the Tibetan Plateau.展开更多
To better understand the characteristics and transformation mechanisms of secondary inorganic aerosols,hourly mass concentrations of water-soluble inorganic ions(WSIIs)in PM_(2.5)and their gaseous precursors were meas...To better understand the characteristics and transformation mechanisms of secondary inorganic aerosols,hourly mass concentrations of water-soluble inorganic ions(WSIIs)in PM_(2.5)and their gaseous precursors were measured online from 2016 to 2018 at an urban site in Beijing.Seasonal and diurnal variations in water-soluble ions and gaseous precursors were discussed and their gas-particle conversion and partitioning were also examined,some related parameters were characterized.The(TNH_(3))Rich was also defined to describe the variations of the excess NH_(3)in different seasons.In addition,a sensitivity test was carried out by using ISORROPIA II to outline the driving factors of gas-particle partitioning.In Beijing,the relative contribution of nitrate to PM_(2.5)has increased markedly in recent years,especially under polluted conditions.In the four seasons,only a small portion of NO_(2)in the atmosphere was converted into total nitrate(TNO_(3)),and more than 80%of TNO_(3)occurred in the form of nitrate due to the abundant ammonia.The concentration of total ammonia(TNH_(3))was much higher than that required to neutralize acid gases,and most of the TNH_(3)occurred as gaseous NH_(3).The nitrous acid(HONO)concentration was highly correlated with NH_(3)concentration and had increased significantly in Beijing compared with previous studies.The total chloride(TCl)was the highest in winter,andε(Cl^(-))was more sensitive to variations in the ambient temperature(T)and relative humidity(RH)thanε(NO_(3)^(-)).展开更多
With the intensification of pollution and urbanization, the aerosol radiation effect continues to play an important role in the urban boundary layer. In this paper, a winter pollution process in Beijing has been taken...With the intensification of pollution and urbanization, the aerosol radiation effect continues to play an important role in the urban boundary layer. In this paper, a winter pollution process in Beijing has been taken as an example, and a new aerosol vertical profile in the radiative parameterization scheme within the Weather Forecast Research and Forecasting(WRF) model has been updated to study the effect of aerosols on radiation and the boundary layer. Furthermore, the interactions among aerosols,urbanization, and planetary boundary layer(PBL) meteorology were discussed through a series of numerical experiments. The results show the following:(1) The optimization improves the performance of the model in simulating the distribution features of air temperature, humidity, and wind in Beijing.(2) The aerosols reduce the surface temperature by reducing solar radiation and increasing the temperature in the upper layer by absorbing or backscattering solar radiation. The changes in the PBL temperature lead to more stable atmospheric stratification, reducing the energy transfer from the surface and the height of the boundary layer.(3) With the increase in the aerosol optical depth, the atmospheric stratification most likely becomes stable over rural areas, most likely becomes stable over suburb areas, and has great difficultly becoming stable over urban areas. Aerosol radiative forcing,underlying urban surfaces, and the interaction between them are the main factors that affect the changes in the meteorological elements in the PBL.展开更多
基金Supported by the Natural Science Foundation of Liaoning Province(2022-MS-098)Joint Open Fund of the Institute of Atmospheric Environment,China Meteorological Administration,Shenyang and Key Laboratory of Agro-Meteorological Disasters of Liaoning Province(2024SYIAEKFZD05 and 2023SYIAEKFZD06)+3 种基金Open Research Project of Shangdianzi Atmospheric Background Station(SDZ20220912)Joint Research Project for Meteorological Capacity Improvement(23NLTSZ006)Applied Basic Research Program of Liaoning Province(2022JH2/101300193)National Natural Science Foundation of China(42105159 and 42005040).
文摘Since the industrial revolution,enhancement of atmospheric greenhouse gas concentrations as a result of human activities has been the primary cause of global warming.The monitoring and evaluation of greenhouse gases are significant prerequisites for carbon emission control.Using monthly data of global atmospheric carbon dioxide(CO_(2))and methane(CH4)column concentrations(hereinafter XCO_(2) and XCH_(4),respectively)retrieved by the Greenhouse Gas Observation Satellite(GOSAT),we analyzed the variations in XCO_(2)and XCH_(4)in China during 2010-2022 after confirming the reliability of the data.Then,the influence of a strong El Niño event in 2015-2016 on XCO_(2) and XCH_(4) variations in China was further studied.The results show that the retrieved XCO_(2) and XCH_(4) from GOSAT have similar temporal variation trends and significant correlations with the ground observation and emission inventory data of an atmospheric background station,which could be used to assess the variations in XCO_(2) and XCH_(4) in China.XCO_(2) is high in spring and winter while XCH_(4) is high in autumn.Both XCO_(2) and XCH_(4) gradually declined from Southeast China to Northwest and Northeast China,with variation ranges of 401-406 and 1.81-1.88 ppmv,respectively;and the high value areas are located in the middle-lower Yangtze River basin.XCO_(2) and XCH_(4) in China increased as a whole during 2010-2022,with rapid enhancement and high levels of XCO_(2) and XCH_(4) in several areas.The significant increases in XCO_(2) and XCH_(4) over China in 2016 might be closely related to the strong El Niño-Southern Oscillation(ENSO)event during 2015-2016.Under a global warming background in 2015,XCO_(2) and XCH_(4) increased by 0.768%and 0.657%in 2016 in China.Data analysis reveals that both the XCO_(2) and XCH_(4) variations might reflect the significant impact of the ENSO event on glacier melting in the Tibetan Plateau.
基金supported by the National Natural Science Foundation of China(No.42005079,41675131)the Beijing Natural Science Foundation(No.8131003)the Beijing Talents Fund(No.2014000021223ZK49)。
文摘To better understand the characteristics and transformation mechanisms of secondary inorganic aerosols,hourly mass concentrations of water-soluble inorganic ions(WSIIs)in PM_(2.5)and their gaseous precursors were measured online from 2016 to 2018 at an urban site in Beijing.Seasonal and diurnal variations in water-soluble ions and gaseous precursors were discussed and their gas-particle conversion and partitioning were also examined,some related parameters were characterized.The(TNH_(3))Rich was also defined to describe the variations of the excess NH_(3)in different seasons.In addition,a sensitivity test was carried out by using ISORROPIA II to outline the driving factors of gas-particle partitioning.In Beijing,the relative contribution of nitrate to PM_(2.5)has increased markedly in recent years,especially under polluted conditions.In the four seasons,only a small portion of NO_(2)in the atmosphere was converted into total nitrate(TNO_(3)),and more than 80%of TNO_(3)occurred in the form of nitrate due to the abundant ammonia.The concentration of total ammonia(TNH_(3))was much higher than that required to neutralize acid gases,and most of the TNH_(3)occurred as gaseous NH_(3).The nitrous acid(HONO)concentration was highly correlated with NH_(3)concentration and had increased significantly in Beijing compared with previous studies.The total chloride(TCl)was the highest in winter,andε(Cl^(-))was more sensitive to variations in the ambient temperature(T)and relative humidity(RH)thanε(NO_(3)^(-)).
基金supported by the Ministry of Science and Technology of China (Grant No. 2015DFA20870)the Beijing Municipal Science and Technology Commission (Grant Nos. D171100000717003, Z161100001116065 & Z151100002115045)
文摘With the intensification of pollution and urbanization, the aerosol radiation effect continues to play an important role in the urban boundary layer. In this paper, a winter pollution process in Beijing has been taken as an example, and a new aerosol vertical profile in the radiative parameterization scheme within the Weather Forecast Research and Forecasting(WRF) model has been updated to study the effect of aerosols on radiation and the boundary layer. Furthermore, the interactions among aerosols,urbanization, and planetary boundary layer(PBL) meteorology were discussed through a series of numerical experiments. The results show the following:(1) The optimization improves the performance of the model in simulating the distribution features of air temperature, humidity, and wind in Beijing.(2) The aerosols reduce the surface temperature by reducing solar radiation and increasing the temperature in the upper layer by absorbing or backscattering solar radiation. The changes in the PBL temperature lead to more stable atmospheric stratification, reducing the energy transfer from the surface and the height of the boundary layer.(3) With the increase in the aerosol optical depth, the atmospheric stratification most likely becomes stable over rural areas, most likely becomes stable over suburb areas, and has great difficultly becoming stable over urban areas. Aerosol radiative forcing,underlying urban surfaces, and the interaction between them are the main factors that affect the changes in the meteorological elements in the PBL.
