In 1926, Jacob Bjerknes was a support meteorologist when Roald Amundsen made the first crossing of the Arctic in the airship Norge. In 1931, he left his position as head of the National weather service at Bergen to become professor of meteorology at the Geophysical Institute at the University of Bergen. Jacob Bjerknes lectured at the Massachusetts Institute of Technology during the 1933-1934 school year and emigrated to the United States in 1940 where he headed a government-sponsored meteorology annex for weather forecasting, at the department of physics of the University of California, Los Angeles. During the second world war Bjerknes served the US armed forces and serving as a colonel in the US Air Force he helped find the best dates for the Atomic bombings of Hiroshima and Nagasaki.