Vilhelm Friman Koren Bjerknes (14.03.1862—9.04.1951) — Norwegian physicist and geophysicist, a member of the Norwegian Academy of Science and Letters. The son of C. A. Bjerknes. Born in Oslo. He graduated from the university in Oslo (1888). In 1895–1907 professor at Stockholm University, in 1907–11 and 1926–32 at the university in Oslo, in 1912–17 at the University of Leipzig and director of the Geophysical Institute, and in 1917–26 director of the Geophysical Institute in Bergen.
His research was in electrodynamics, hydrodynamics, meteorology and geophysics. He extended the theory of electrical resonance and constructed resonance curves of great importance for understanding H. Hertz's experiments (1891). He worked on the theory of hydrodynamic forces and in circulation theory formulated the Bjerknes theorem. He proposed a model of the structure of cyclones and of their formation and movement, and developed the polar front theory of cyclones and a method of weather forecasting (1918). In 1900 he proposed a pulsation hypothesis of gravitation.
He founded a scientific school. A member of a number of academies of sciences.