Bergeron, Tor H. P. -

(1891-1977): Swedish meteorologist. While working at the Geophysical Institute in Bergen, Norway, he conducted research on cloud formation and, in 1935, he proposed that the formation of ice crystals is crucial in producing rain in a paper entitled, "On the Physics of Clouds and Precipitation." His contributions include the theory of polar fronts (in collaboration with Jacob Bjerknes), methods of weather forecasting, and studies on the growth of ice sheets.