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Syl Foisy

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 to snow sculpture, which occasionally, and delightfully, collide with my science.

Syl Foisy

Animation I made of aerosol composition across the globe for one week in April 2024, as simulated by NASA GISS ModelE. Each column of atmosphere is colored by its volume-dominant aerosol species.

I research the sky

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.

Columbia DEES profile

I love trying new things

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.

Aerosol microscopy images

Images I took of super-coarse aerosol droplets undergoing liquid-liquid phase separation in the new cloud chamber.

News

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Blog

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Publications & Presentations

Mutual Constraints on Global Aerosol Composition from Novel PACE Data and ModelE

Foisy, S., Bauer, S., Tsigaridis, K., Hasekamp, O., Fu, G.

Submitted

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Break

Science Communication

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 250 miles from NYC to DC, visiting 20 climate and weather scientists from 12 institutions along the way. Learn more here!

Syl speaking at the Capitol podium

Speaking at the U.S. Capitol press conference in June 2026!

Music making

Viva La Vida · ColdplayThe Munter Trail, Potsdam, NY
Good to Be Alive · Andy GrammerFeaturing the murals of Potsdam, NY

More on the Koehler•Foisy Films page

TikTok · @syl_foisy

TikTok: guess the song
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TikTok: how to make the best airplane
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TikTok: how to make a flying paper butterfly
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Photo Gallery

Let's chat!

Reach out about anything. I usually reply within a day or two. :)