AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Spectral Dependence of Black Carbon Aerosol Optical Properties and Implications for Direct Radiative Forcing
RAJAN CHAKRABARTY, Yu Yang, Ian Arnold, Apoorva Pandey, William Heinson, Washington University in St Louis
Abstract Number: 585 Working Group: Aerosols, Clouds, and Climate
Abstract The radiative properties of black carbon (BC) aerosols have been implicated in rapid global warming, accelerated melting of glaciers, changing monsoon patterns, and degradation of human health and the environment. Their poor parameterization in climate models and satellite retrieval algorithms have contributed to large uncertainties in current estimates of climate forcing. To address this issue, researchers have made thorough efforts in recent years to characterize the wavelength-dependent absorption and scattering properties of BC emitted from both small-scale, controlled combustion systems (e.g. prescribed/slash burns and cook stoves) and large-scale wildfires as a function of various process parameters such as fuel type, fire phase, environmental conditions driving the combustion process, and interrelationships of these parameters. In this talk, I will present our recent experimental and theoretical findings on the wavelength dependence of mass absorption and scattering cross-sections, single scattering albedo, and upscatter fraction of BC aerosols in the UV-Vis-IR solar spectra. Angstrom exponent analyses of these optical parameters will be presented, which provide a way for ground-based instruments and satellites to distinguish between BC emissions from a small-scale versus large-scale combustion source. I will end my talk with a discussion on the implications of our findings on the direct radiative forcing by BC.