Title: Examination of the link between aerosol properties and cloud droplet activation efficiency

Don CollinsAssociate ProfessorDept. of Atmospheric SciencesTexas A & M UniversityAbstract:Among the factors contributing to the overall uncertainty in the indirect effect of aerosols on climate is the still inadequately understood relationship between particle size, composition, and critical supersaturation. Applying the results of laboratory studies of the activation efficiency of relatively simplistic aerosols to predict CCN concentration for an ambient aerosol for which only an incomplete description of its size distribution and composition is available is undoubtedly challenging, as is reflected in the varied success of several recent CCN closure efforts. Whereas an understanding of the link between composition and critical supersaturation is ultimately needed, insight into the factors controlling activation can be gained through an improved understanding of the relationship between hygroscopic growth under subsaturated conditions and cloud droplet formation under supersaturated conditions.
I will describe both our recent efforts aimed at quantifying the link between critical supersaturation and hygroscopicity, and our recent development and use of an instrument that permits quantification of the link between critical supersaturation and composition.

Location: Stauffer Science Lecture Hall, Rm 102

Audiences: Everyone Is Invited

Contact: April Mundy