The Agricultural & Applied Economics Association ( AAEA) is a not - for - profit association serving the professional interests of members working in agricultural and broadly related fields of applied economics. M...The Agricultural & Applied Economics Association ( AAEA) is a not - for - profit association serving the professional interests of members working in agricultural and broadly related fields of applied economics. Members of the AAEA are employed by aca-展开更多
Black carbon(BC)aerosol can lead to adverse health effects and drive climate change;therefore,the characteristic research and identification of BC sources are essential for lowering emissions.In this study,equivalent ...Black carbon(BC)aerosol can lead to adverse health effects and drive climate change;therefore,the characteristic research and identification of BC sources are essential for lowering emissions.In this study,equivalent black carbon(eBC)measurement was performed using a seven-wavelength Aethalometer(AE33)at an urban site in a typical industrial city(Zibo)of Northern China for the first time.The monitoring was performed from February 2021 to January 2022.The mass absorption cross-section(MAC)of AE33 was optimised using the online elemental carbon(EC)data,and eBC was corrected using the MAC.The corrected annual BC concentration was 1.72±1.18μg/m^(3).The diurnal variation of BC depicted a bimodal distribution.Furthermore,the BC concentration on weekends was 18%lower than on weekdays.The diurnal variation and weekend effect reflect the critical contributions of traffic emission to BC concentration.The source apportionment of BC was calculated by a constraining Aethalometer model,which restricted theÅngstrom exponent using the online potassium ions.The results revealed that BC was not significantly affected by biomass burning(BC_(bb))in Zibo.The relative contribution of BC_(bb)was higher in winter than in other seasons.The daily morning peak of BC was primarily influenced by traffic sources,whereas the contribution of biomass burning increased after 17:00 in the evening peak.Our findings suggest that it is more important to control fossil fuel sources for BC emission reduction in Zibo,while it is necessary to strengthen the control of biomass combustion sources in winter.展开更多
In this study,the black carbon (BC) measurements in the atmosphere of Nanjing,China were continuously conducted from 2015 to 2018 using a Model AE-33 aethalometer.By combining dataset of PM_(2.5),PM_(10),CO,NO_2,SO_2,...In this study,the black carbon (BC) measurements in the atmosphere of Nanjing,China were continuously conducted from 2015 to 2018 using a Model AE-33 aethalometer.By combining dataset of PM_(2.5),PM_(10),CO,NO_2,SO_2,O_3 and meteorological parameters,the temporal variations and the source apportionment of BC were given in this study.The results showed that the PM_(2.5) mass concentrations decreased in Nanjing,with an average annual rate of variation of 6.50μg/(m^3·year).Differently,the annual average concentrations of BC increased with an average annual variation rate of 214.71 ng/(m^3·year).The seasonal variations showed the pattern of BC mass concentrations in winter>autumn>spring>summer.The diurnal variations of BC mass concentrations showed a double-peak in all four seasons.The first peak occurred at approximately 7:00 in spring,summer and autumn and around 8:00 in winter.The second peak took place after 18:00.The average AAE (absorption ?ngstr?m exponent) was 1.26 with a maximum of 1.35 during wintertime and the lowest(1.12) during summertime.In addition,the AAE was smaller in the daytime than that at night,with a minimum occurring between 13:00 and 14:00.BC and visibility show a good power-function relationship at different humidity levels.The average values of the visibility thresholds of the BC mass concentrations in spring,summer,autumn and winter were 1.326,5.522,1.340 and 0.708μg/m^3,respectively.The greater the relative humidity,the smaller the visibility threshold for the BC mass concentrations was.展开更多
文摘The Agricultural & Applied Economics Association ( AAEA) is a not - for - profit association serving the professional interests of members working in agricultural and broadly related fields of applied economics. Members of the AAEA are employed by aca-
基金supported by the National Key Research and Development Program of China(Nos.2017YFC0212501 and 2017YFC0212503).
文摘Black carbon(BC)aerosol can lead to adverse health effects and drive climate change;therefore,the characteristic research and identification of BC sources are essential for lowering emissions.In this study,equivalent black carbon(eBC)measurement was performed using a seven-wavelength Aethalometer(AE33)at an urban site in a typical industrial city(Zibo)of Northern China for the first time.The monitoring was performed from February 2021 to January 2022.The mass absorption cross-section(MAC)of AE33 was optimised using the online elemental carbon(EC)data,and eBC was corrected using the MAC.The corrected annual BC concentration was 1.72±1.18μg/m^(3).The diurnal variation of BC depicted a bimodal distribution.Furthermore,the BC concentration on weekends was 18%lower than on weekdays.The diurnal variation and weekend effect reflect the critical contributions of traffic emission to BC concentration.The source apportionment of BC was calculated by a constraining Aethalometer model,which restricted theÅngstrom exponent using the online potassium ions.The results revealed that BC was not significantly affected by biomass burning(BC_(bb))in Zibo.The relative contribution of BC_(bb)was higher in winter than in other seasons.The daily morning peak of BC was primarily influenced by traffic sources,whereas the contribution of biomass burning increased after 17:00 in the evening peak.Our findings suggest that it is more important to control fossil fuel sources for BC emission reduction in Zibo,while it is necessary to strengthen the control of biomass combustion sources in winter.
基金supported by the National Natural Science Foundation of China (Nos.91644224 and 41805096)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control (No.19K03ESPCP)+1 种基金the Natural Science Foundation of Jiangsu Province (No.BK20180801)the Natural Science Research Project for Universities of Jiangsu Province,China (No.18KJB170011)。
文摘In this study,the black carbon (BC) measurements in the atmosphere of Nanjing,China were continuously conducted from 2015 to 2018 using a Model AE-33 aethalometer.By combining dataset of PM_(2.5),PM_(10),CO,NO_2,SO_2,O_3 and meteorological parameters,the temporal variations and the source apportionment of BC were given in this study.The results showed that the PM_(2.5) mass concentrations decreased in Nanjing,with an average annual rate of variation of 6.50μg/(m^3·year).Differently,the annual average concentrations of BC increased with an average annual variation rate of 214.71 ng/(m^3·year).The seasonal variations showed the pattern of BC mass concentrations in winter>autumn>spring>summer.The diurnal variations of BC mass concentrations showed a double-peak in all four seasons.The first peak occurred at approximately 7:00 in spring,summer and autumn and around 8:00 in winter.The second peak took place after 18:00.The average AAE (absorption ?ngstr?m exponent) was 1.26 with a maximum of 1.35 during wintertime and the lowest(1.12) during summertime.In addition,the AAE was smaller in the daytime than that at night,with a minimum occurring between 13:00 and 14:00.BC and visibility show a good power-function relationship at different humidity levels.The average values of the visibility thresholds of the BC mass concentrations in spring,summer,autumn and winter were 1.326,5.522,1.340 and 0.708μg/m^3,respectively.The greater the relative humidity,the smaller the visibility threshold for the BC mass concentrations was.
