His expertise is in large-scale air-sea interaction and atmospheric dynamics in the tropics. His special research interests include the subseasonal variability (the Madden-Julian Oscillation), its interaction with El Nino, and African and American monsoons, and using uncrewed systems (saildrones, ocean gliders) to observe hurricanes. He is a Fellow of the American Geophysical Union and a Fellow of the American Meteorology Society. He serves as a co-chair of the Science Steering Committee of the international program Years of the Maritime Continent (YMC) and the Chair of US Clivar Science Steering Committee.