Hi! I'm a PhD candidate at NASA GISS and Columbia University studying aerosols, the tiny liquid and solid particles in the atmosphere that have an outsized influence on our climate, our weather, and the air we breathe.
Outside of research, I have many interests, ranging from filmmaking and snow sculpture to long-distance walking, which occasionally, and delightfully, collide with my science.
My research interests are all things aerosols and clouds. Currently, I use satellite data from NASA's PACE mission and NASA GISS ModelE climate model simulations to study the evolution of aerosol microphysical properties, and how they influence cloud formation.
I'm advised by Dr. Susanne Bauer and Dr. Kostas Tsigaridis, and supported by a NASA FINESST Graduate Fellowship.
Before starting my PhD, I built a cloud chamber at Williams College in collaboration with Prof. Anthony Carrasquillo and Prof. Miriam Freedman to study how aerosols respond to changes in humidity. Many undergo a striking transformation, separating into two distinct liquid phases much like oil and water, with real consequences for how aerosols scatter light, facilitate cloud formation, and shape climate. I'm proud that students at Williams continue this research today.
Mutual Constraints on Global Aerosol Composition from Novel PACE Data and ModelE
In prep2024 · Highest Honors
Liquid-Liquid Phase Separation: Exploring the Effects of Hofmeister Salts and Organonitrates
B.A. Thesis · Williams College, Department of Geosciences
I believe science only matters as much as it is understood.
In 2025, I served as opening host for the 100-Hour Weather & Climate Livestream, a continuous global outreach event that reached 180,000+ live viewers and was featured in The New York Times.
This past spring, I walked 270.4 miles from New York City to Washington D.C., visiting 20 climate and weather scientists from 12 institutions along the way. I interviewed each of them about their research, then finished with a press conference on the steps of the U.S. Capitol, where I spoke to seven members of Congress about the importance of weather and climate science funding.
Music videos made with my mom in the St. Lawrence River Valley of upstate New York, the gorgeous place where I grew up.
More on the Koehler•Foisy Films page →
Paper folding videos and musical quizzes, created in between classes in undergrad!
Reach out about anything. I usually reply within a day or two. :)
