Research Interests

I seek to understand how atmospheric gases, clouds, and aerosols regulate the planetary greenhouse effect, solar radiative heating, and climate. As a postdoctoral fellow I identified the greenhouse effect of the vibration-rotation bands of chlorofluorocarbons, which per molecule were about 10,000 times more effective than CO2 as a greenhouse gas. This surprising finding opened the door to the discovery of the greenhouse effect of numerous other trace gases and the field of trace gases-climate-chemistry interactions. Clouds were my next focus; I designed a satellite radiation budget experiment with NASA scientists and demonstrated that clouds had a net cooling effect on the planet (i.e., the reflection of solar radiation to space by clouds far exceeded their greenhouse effect). This cloud radiative-forcing data is still being used to validate climate models. My current interest is the influence of submicron engineered particles in the atmosphere. I designed (along with P. J. Crutzen) the Indian Ocean Experiment, which led to the discovery of the widespread South Asian Brown Haze, and its surprisingly large impact in reducing the solar radiation at the surface, as it not only cools the region but could also lead to global drying. This work led to a U.N. project to study the impact of such brown clouds worldwide. I am now designing an experiment using miniaturized instruments and unmanned aircraft to understand how the planet regulates its albedo.

Membership Type


Election Year


Primary Section

Section 16: Geophysics

Secondary Section

Section 63: Environmental Sciences and Ecology