Colloquium: 16 Dec 2008, EN6085A, 3:00 pm

Biomass burning is a significant source of carbonaceous aerosol in many regions of the world. When present, biomass burning particles affect the microphysical properties of clouds through their ability to function as cloud condensation nuclei or ice nuclei. My recent work has focused on methods for parameterizing aerosol hygroscopicity using simple descriptions grounded in expected thermodynamic behavior. In this talk I will present the framework and show its application to aerosol water content, cloud drop activation and homogeneous ice nucleation of biomass burning particles from laboratory-generated aerosols at the second Fire Lab At Missoula Experiment (FLAME-II). I will also discuss their condensation/immersion freezing potential at temperatures relevant to cold cumulus clouds (-30C) and will suggest that fire generated ice nuclei emissions can perturb ice nuclei concentrations on a regional scale.