1897-1975

Norwegian-American meteorologist who developed the extratropical cyclone model (1919) of modern meteorology while conducting research on weather systems and forecasting techniques with his father Vilhelm Bjerknes and others at Bergen, Norway. Bjerknes and collaborator Halvor Solberg went on to develop frontal theory in terms of warm and cold fronts defined by airmass temperature boundaries. Bjerknes also identified the upper atmospheric wave that generated the surface extratropical cyclone/frontal dynamics. He founded the UCLA department of meteorology and was an early pioneer defining the El Niño mechanism.