Jacob (Aall Bonnevie) Bjerknes

Meteorologist, born in Stockholm, Sweden. The son of the famous Norwegian meteorologist Vilhelm Bjerknes, he was instrumental in the development of weather prediction in the USA. With his father he established weather observation stations in Norway during World War 1, and developed the famous Bergen Institute in Norway. He was visiting the University of California, Los Angeles (UCLA) in 1940 when Hitler invaded Norway, preventing his return home. He joined the faculty of UCLA and became a naturalized citizen in 1946. He was instrumental in introducing the concept of weather fronts to US forecasters, and with phenomenal insight he was able to describe cyclones and the development and dissipation of warm and cold fronts, thus laying the foundation necessary for accurate weather prediction. In the 1950s his research turned to the ocean. He described the ‘Niño’ effect from the Pacific Ocean and persuaded scientists of the importance of studying the ocean and atmosphere as a single, highly interactive system.

Jacob Aall Bonnevie Bjerknes (November 2, 1897, Stockholm, Sweden – July 7, 1975, Los Angeles, California) was a Norwegian-American meteorologist.

He was part of a group of meteorologists led by Vilhelm Bjerknes developed the model that explains the generation, intensification and ultimate decay (the life cycle) of midlatitude cyclones, introducing the idea of fronts, that is, sharply defined boundaries between air masses.

Bjerknes was a support meteorologist when Roald Amundsen made the first crossing of the Arctic in the airship Norge in 1926.