I'm interested in planetary atmospheres. I use spacecraft observations, numerical modeling and theoretical calculation to infer the climate of a planet. My research topics include atmospheric photochemistry, radiaiton and dynamics. Planets are also natural laboratories for studying fundamental atmospheric dynamics and chemistry. Although Earth has the most abundant observations, the possible range of Earth's climate only occupies a niche of the parameter space of all planetary atmospheres that have been observed in the universe. By studying planets, and exercising our knowledge on them, we may find out what we have overlooked in studying our own Earth.