中文摘要：

使用三波长光声黑碳光度计(PASS-3)和气溶胶质谱仪(AMS),于2011年秋季在浙江城市点金华和2014年夏季河北区域点望都进行了大气在线观测,采用改进的光吸收Angstrom指数(AAE)的方法统计外推黑碳AAE值,估算这2个典型地区PM2.5中棕色碳的吸光贡献.结果表明:经统计外推获得的金华和望都的黑碳AAE在405nm下的基准值分别是1.12和0.77,532nm下的基准值分别是0.87和0.63;进而估算金华和望都PM2.5中的棕色碳在405nm下的吸光贡献分别为9.8%和22.3%;532nm下的吸光贡献分别为5.9%和15.2%,表明我国大气中气溶胶棕色碳在短波段下的吸光贡献和辐射强迫影响不可忽视.

英文摘要：

Two field campaigns were conducted using a three-wavelength photo-acoustic soot spectrometer(PASS-3)andaerosol mass spectrometers(AMS),including urban site Jinhua during autumn2011and rural site Wangdu during summer2014in this study.Light absorption of brown carbon with improved Absorption Angstrom Exponent(AAE)method wasevaluated by extrapolating the more realistic AAE by“pure”BC(AAE_BC).The AAE_BC were found to be1.12,0.77between405nm and781nm,and0.87,0.63between532nm and781nm in the campaign of Jinhua and Wangdu,respectively.The contributions of BrC aerosol light absorption of PM2.5at405nm were9.8%and22.3%,and5.9%and15.2%at532nm in Jinhua and Wangdu,respectively.The results indicate that the contribution of brown carbon to theaerosol light absorption at shorter wavelength is not negligible in China.