Tristan L'Ecuyer is a professor of Atmospheric and Oceanic Sciences (AOS) and director of the Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin-Madison (UW-Madison). L'Ecuyer received his PhD at Colorado State University where he worked as a research scientist for 10 years prior to joining the AOS faculty at the UW-Madison in 2011.

His research leverages state-of-the-art satellite observations to address the pressing questions in climate science. L'Ecuyer's research group is pioneering new methods for measuring rain and snow from space, determining the role clouds and pollution play in shaping the Earth's climate, helping to realize the full potential of solar energy, and documenting the causes of rapid Arctic climate change. A central focus of this work is using global observations to improve the representation of clouds and atmospheric processes in climate models. L'Ecuyer also leads a NASA CubeSat mission called Polar Radian Energy in the Far-InfraRed Experiment (PREFIRE) that will measure thermal energy flows in polar regions with the goal of improving predicted rates of Arctic warming, sea ice loss, and ice sheet melt. L'Ecuyer teaches courses on global climate, radar, and satellite meteorology, and scientific programming to senior undergraduates and graduate students.