When
Monday, November 2, 2026, at 10:00 a.m.
Tim Garrett
Professor of Atmospheric Sciences
University of Utah
"How Big is a Cloud? Can We Know?"
Harshbarger 118A-A1
ABSTRACT
Perhaps the most seemingly objective of questions when it comes to characterizing clouds using satellite data is “how big is that cloud?” It is also a question of central interest to studies of climate change — any change of cloud area with increasing carbon dioxide levels is a primary control of how rapidly surface temperatures rise. I will discuss whether the very simple measurement question of cloud size is fundamentally ill-posed. Such factors as satellite resolution, sensor sensitivity, imaging domain, and even whether or not clouds have holes turn out to have remarkably large impacts on how we define cloud. Some solutions will be suggested, including describing clouds as part of a spectrum rather than discrete "things". A new spectral model will be shown that reproduces cloud fields and physics (without AI) with very high realism that is 100,000 to 1,000,000 times faster than existing LES models.
ABOUT THE SPEAKER
Tim Garrett is a professor of atmospheric sciences at the University of Utah, where he explores simple thermodynamic frameworks for understanding the dynamics of complex systems, with a focus on clouds and precipitation. Clouds display an extraordinarily wide range of interactive physical processes, from the atomic to planetary scales. Understanding these processes is critical for improving weather and climate forecasts. Garrett's research aims to show that such complexity emerges from underlying simplicity
Garrett also develops simple physical models for describing and predicting global economic growth and collapse. While clouds and the economy may seem disconnected, both are complex systems that share principles such as competition for resources and growth through increasing resource access. His work demonstrates that the fields of economics and physics can be linked in a robust fashion, enabling constrained predictions of where humanity is headed this century.
Garrett works closely with Particle Flux Analytics Inc., a start-up company he founded in 2016. In close collaboration between the company and a team of faculty, postdocs and students in mechanical engineering and atmospheric sciences at the University of Utah, the group designs, builds and commercializes new meteorological sensors. The company has received several Small Business Innovation Research awards, including more than $2 million from the Department of Energy, to develop two new sensor designs that are now deployed by the Utah Department of Transportation along Interstate 80 and in Little Cottonwood Canyon for the measurement of precipitation rate and snow density.