Tim VanReken

	Tim VanReken

Tim VanReken (ACD), has been working on several experimental and modeling studies during the past year, exploring different ways that atmospheric aerosols interact with their surroundings. In the laboratory, Tim has continued his studies of new particle formation from biogenic sources. Working with several collaborators in ACD, he has demonstrated that particle can in fact form directly from the oxidation of biogenic emissions at concentrations similar to those found in the ambient atmosphere. Tim also participated in the MIRAGE-Mex field campaign, a large multi-agency multi-platform campaign whose primary goal was to study the impact of the Mexico City pollution plume on regional and global climate. During the study, Tim was based at a ground site outside of Mexico City , where he was responsible for measurements of nanoparticle composition (along with Jim Smith and Matt Dunn of ACD) and ammonia concentration (in collaboration with Marc Fischer of Lawrence Berkeley National Laboratory). Analyses of these field data are ongoing.

In addition to his experimental work, Tim's research includes two modeling projects focusing on very different aspects of cloud development. One project, nearing completion, involves using a cloud parcel model to explore how the addition of water vapor could negatively impact the performance of a proposed solar chimney power facility; this work is in collaboration with Athanasios Nenes of the Georgia Institute of Technology. The other modeling project examines the effect of inclusion morphology on droplet freezing at the molecular level, using advanced Monte Carlo sampling techniques. It is hypothesized that surface defects add stability to the molecular clusters that lead to the liquid-ice transition, and this study will estimate the magnitude of these effects. This final project is ongoing, in collaboration with Bernhardt Trout of MIT.

Funding Sources

This research is supported by the National Science Foundation.