Black carbon(BC)reduces the photolysis coefficient by absorbing solar radiation,thereby affecting the concentration of ozone(O_(3))near the ground.The influence of BC on O_(3)has thus received much attention.In this s...Black carbon(BC)reduces the photolysis coefficient by absorbing solar radiation,thereby affecting the concentration of ozone(O_(3))near the ground.The influence of BC on O_(3)has thus received much attention.In this study,Mie scattering and the tropospheric Ultraviolet and Visible radiation model are used to analyze the effect of BC optical properties on radiation.Combined with data of O_(3)precursors in Nanjing in 2014,an EKMA curve is drawn,and the variations in O_(3)concentration are further investigated using a zero-dimensional box mechanism model(NCAR MM).When O_(3)precursors are unchanged,radiation and O_(3)show a highly similar tendency in response to changing BC optical properties(R=0.997).With the increase of modal radius,the attenuation of fresh BC to radiation and O_(3)first trends upward before decreasing.In the mixing process,the attenuation of BC to radiation and O_(3)presents an upward tendency with the increase of relative humidity but decreases rapidly before increasing slowly with increasing thickness of coating.In addition,mass concentration is another major factor.When the BC to PM_(2.5)ratio increases to 5%in Nanjing,the radiation decreases by approximately 0.13%-3.71%while O_(3)decreases by approximately 8.13%-13.11%.The radiative effect of BC not only reduces O_(3)concentration but also changes the EKMA curve.Compared with the NO_(x)control area,radiation has a significant influence on the VOCs control area.When aerosol optical depth(AOD)increases by 17.15%,the NO_(x)to VOCs ratio decreases by 8.27%,and part of the original NO_(x)control area is transferred to the VOCs control area.展开更多
基金This work was supported by grants from the National Key Research and Development Program of China(Grant No.2017YFC0210003)the National Natural Science Foundation of China(Grant No.42075177)the Qing Lan Project.
文摘Black carbon(BC)reduces the photolysis coefficient by absorbing solar radiation,thereby affecting the concentration of ozone(O_(3))near the ground.The influence of BC on O_(3)has thus received much attention.In this study,Mie scattering and the tropospheric Ultraviolet and Visible radiation model are used to analyze the effect of BC optical properties on radiation.Combined with data of O_(3)precursors in Nanjing in 2014,an EKMA curve is drawn,and the variations in O_(3)concentration are further investigated using a zero-dimensional box mechanism model(NCAR MM).When O_(3)precursors are unchanged,radiation and O_(3)show a highly similar tendency in response to changing BC optical properties(R=0.997).With the increase of modal radius,the attenuation of fresh BC to radiation and O_(3)first trends upward before decreasing.In the mixing process,the attenuation of BC to radiation and O_(3)presents an upward tendency with the increase of relative humidity but decreases rapidly before increasing slowly with increasing thickness of coating.In addition,mass concentration is another major factor.When the BC to PM_(2.5)ratio increases to 5%in Nanjing,the radiation decreases by approximately 0.13%-3.71%while O_(3)decreases by approximately 8.13%-13.11%.The radiative effect of BC not only reduces O_(3)concentration but also changes the EKMA curve.Compared with the NO_(x)control area,radiation has a significant influence on the VOCs control area.When aerosol optical depth(AOD)increases by 17.15%,the NO_(x)to VOCs ratio decreases by 8.27%,and part of the original NO_(x)control area is transferred to the VOCs control area.
