9401672 DeHaan This award is under the International Junior Investigator and Postdoctoral Fellows Program, which enables U.S. scientists and engineers to conduct three to twelve months of research abroad at research centers of proven excellence. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twelve-month postdoctoral research visit by Dr. David DeHaan to work with Dr. Frode Storda at the Norwegian Institute for Air Research and Dr. Claus Jorgen Nielsen at the University of Oslo. This research will focus on chlorine peroxide (ClOOCl), a compound believed to be active in the destruction of ozone in the polar stratosphere but never measured in situ. Recently, it has been shown that chlorine peroxide will react with holide ions on ice surfaces. A flow-tube reactor will be interfaced to spectrophotometric detectors in order to quantitatively identify all ClOOCl reaction products and study the reaction mechanism in detail. A Knudsen cell reactor will also be used to measure the sticking coefficient of ClOOCl on ice surfaces. The newly-discovered reaction will be incorporated into state-of-the-art "air parcel" atmospheric models. In addition, Dr. DeHaan will have an opportunity to participate with scientists from all over Europe in the Second European Stratospheric Arctic and Mid-latitude Experiment (SESAME), a field measurement campaign studying the composition of stratospheric ice particles, in situ ice-surface chemistry, and chlorine partitioning. ***
