Yi completed his PhD in 2003 and is now a research scientist at NOAA GFDL in New Jersey. Her research work focused on the thermodynamics of aerosol particles with an emphasis on modeling the organic compounds present in aerosols. He studied the hygroscopic growth behaviors of aerosol particles with the Princeton Organic-Electrolyte Model (POEM) jointly developed with Prof. Russell. This model helped him to understand the radiative properties of aerosols in the global climate model.