A Norwegian geophysicist and meteorologist who was born and died in Oslo. As a student, he helped his father, who was professor of mathematics at the Christiania University (now the University of Oslo). He himself held professorships at Stockholm and Leipzig before returning to Norway in 1917 to found the Bergen Geophysical Institute (see bergen school). During the First World War, Bjerknes established a series of weather stations throughout Norway. Information from these allowed Bjerknes and his colleagues, who included his son Jakob (1897–1975) and Tor Harold Percival Bergeron (1891–1977), to develop their theory of air masses bounded by fronts.