Bjerknes, Vilhelm, << bih AIRK nehs, VIHL hehlm >> (1862-1951), was a Norwegian physicist whose work led to the development of modern techniques for describing and predicting the weather. He and his students introduced the idea of the front, which is a boundary between masses of warm and cold air.
In 1898, Bjerknes used mathematical equations to describe what happens when regions of a fluid become lighter or heavier. He explained how light fluid rises and heavy fluid sinks, creating patterns of circulation. Bjerknes then applied this description to weather. In a sea breeze, for example, the circulation is the breeze, and the fluid is air. The lighter regions are masses of warm air, and the heavier regions are masses of cold air. He later used equations to predict the weather.
Bjerknes was born in Christiania (now Oslo), Norway, on March 14, 1862. He received a doctor’s degree in physics from the University of Christiania (now the University of Oslo) in 1892. Bjerknes died on April 9, 1951.
