Assessment the aging process and radiative forcing of black carbon in China, 2013-2017

Abstract:

Parameterizations that aging process of black carbon remain uncertain in regional air model. In this study, we developed and applied an aging module of black carbon (BC) to simulate the aging process and radiative impacts using a two-way coupled meteorology-chemistry model (WRF-CMAQ). In 2013, China released the Air Pollution and Control Action Plan, which set the roadmap for control actions for the period of 2013 to 2017. The decrease of BC, sulfur dioxide (SO₂), and nitrogen dioxide (NO₂) emissions with 34.9 %, 33 % and 25 %, respectively, has largely reduced national averaged PM_2.5 concentrations by 34% from 2013 to 2017, which may lead to a substantial impact of radiative forcing. We set the default model with no aerosol feedbacks (nf) scenarios (2013_nf, 2017_nf) and considered aerosol feedbacks (sf) scenarios (2013_sf, 2017_sf), respectively, to assess the change of radiative forcing. Furthermore, a BC aging module was employed in this study to assess the impact of emission reduction on BC aging. By estimating mass absorption coefficient, the quantitative evaluation of optical property was conducted. The estimation of emissions reduction and the BC aging processes could provide policy proposal for air pollution control and climate change.