融合“积分球光学+双波长迭代运算”技术开展民用生物质燃料的棕碳排放因子研究

大气吸光有机碳(即棕碳，BrC)是继黑碳(BC)之后，近年新认识到的吸光碳，影响地球能量收支和大气化学过程，成为环境和气候领域的新热点。生物质燃烧是主要的BrC排放源，在我国主要由民用生物质燃料主导，但由于研究领域的新颖性和独特性，尚无可靠的排放清单，不利于对其排放特征、环境气候影响的深入研究。本项目①引入近年创立、申请人完善的“积分球+迭代计算”(IS+DWIC)技术开展民用生物质燃烧BrC的排放因子测定和排放清单构建；②根据IS+DWIC技术获得的滤膜样品BrC的测试结果，探索BrC的存在和变化对传统光学法BC和热光法BC(也称EC)结果的影响关系算法；③通过测定和分化滤膜样品的逐波长吸收，结合太阳光谱能量分布，计算300-1000nm总吸收中BrC和BC的各自贡献份额。项目的完成将为完善吸光碳排放清单、提升辐射模式的准确性、支持国家的环境外交提供基础科学支撑。

Atmospheric light absorbing organic carbon (i.e. brown carbon, BrC) is a newly recognized type of light absorbing aerosol carbon. BrC has become a new hotspot in environmental and climatic research due to the unique impacts on global energy budget and atmospheric chemical processes. In China biomass burning is the main source of BrC emissions, and is dominated by residential biomass fuels. However, no reliable emission inventory is available due possibly to the novelty and uniqueness of BrC, which is not conducive to the intensive studies of emission characteristics and environmental and climate impacts of biomass fuels. ① The technology of "Integrating Sphere + Iterative Calculation (IS+DWIC)", which was established years ago and has been improved by our team, is introduced to this project for the measurement of emission factors and the construction of emission inventory of BrC for residential biomass fuels; ② beginning from the test results of on-filter BrC obtained with IS+DWIC technology, the influence of the existence and variation of BrC on the results of optical BC and thermal/optical BC (also known as EC) is investigated; ③ in consideration of the wavelength-specific energy distribution of solar spectrum, the shares of contribution of BrC and BC in total absorption with respect to λ=300-1000nm are calculated by measuring and decomposing the absorption of filter samples. The completion of the project will provide basic scientific support for improving the emission inventory of light-absorbing carbon, improving the accuracy of radiation models and supporting national environmental diplomacy.