The coupling of atmospheric chemistry and climate on Earth and other planets on time scales from months to billions of years is studied through aircraft, balloon, and ground-based observations, computer simulations, and laboratory experiments. Of particular interest are studies of photochemical isotope effects. These studies range from crossed beam laboratory experiments to stratospheric observations. Photochemistry and reaction dynamics experiments are aimed at understanding unusual isotope effects on the molecular scale. Global-scale field measurements and computer simulations are aimed at using stable isotopes as tracers of atmospheric chemistry and transport in today’s atmosphere and of gas exchange between the atmosphere and biosphere on annual to millennial to billion year time scales from atmospheric, ice core, and rock measurements, respectively. This insight is extended to the early Earth and other planets through laboratory investigations of photochemical haze production and other atmospheric phenomena that could serve as significant regulators of climate and habitability.

Awards and Achievements

  • National Academy of Sciences ( 2018)
  • Camile Dreyfus Teacher-Scholar Award ( 2005)