Research Summary Laser Spectroscopy, KInetics and Reaction Dynamics; Atmospheric Chemistry The Okumura Group is interested in the application of laser spectroscopy and reaction dynamics to problems in atmospheric chemistry and climate change. We study atmospheric free radicals and transient intermediates in order to understand the reactions and photochemistry that are most important in the troposphere and stratosphere, as well as in planetary atmospheres such as those of Mars and Titan. Our goal is both to determine parameters of key reactions and species in the atmosphere, and to understand the chemical physics of these processes at the most fundamental level. To achieve high sensitivities required for these experiments, we develop and apply state-of-the-art methods such as cavity-enhanced spectroscopy, frequency comb lasers, and VUV mass spectrometry using synchrotron radiation. We also apply high resolution spectroscopy for measuring spectroscopic parameters needed for the latest generation of CO2 satellites. Our group has extensive collaborations with scientists at the NASA Jet Propulsion Laboratory.