Bjørn Helland-Hansen (16 October 1877 – 7 September 1957) was a Norwegian pioneer in the field of modern oceanography. He studied the variation patterns of the weather in the northern Atlantic Ocean and of the atmosphere.
He studied both medicine and physics at the University of Christiania (now University of Oslo). He developed the “Helland-Hansen Photometer” in 1910, which was carried on board Michael Sars. It was operated for the first time close to the Azores at a depth between 500 and m. In 1915 he became Professor of oceanography at the Bergen Museum, and in 1917 director of the Geophysical Institute, University of Bergen.
In 1933 he was awarded the Alexander Agassiz Medal. From 1946 to 1948, Helland-Hansen was President of the International Union of Geodesy and Geophysics (IUGG). He was a member of the Prussian Academy of Sciences and a member of the Member of the Academy of Sciences of the German Democratic Republic (DDR).
Helland-Hansen trained Alexander Kuchin, the Russian oceanographer who went to Antarctica with Roald Amundsen. An island in the Russian Arctic, east of the Geiberg Islands, has been named Gellanda-Gansena after Helland-Hansen.
Tor Bergeron (15 August 1891 – 13 June 1977) was a Swedish meteorologist who proposed a mechanism for the formation of precipitation in clouds. In the 1930s, Bergeron and W. Findeisen developed the concept that clouds contain both supercooled water and ice crystals. According to Bergeron, most precipitation is formed as a consequence of water evaporating from small supercooled droplets and accreting onto ice crystals, which then fall as snow, or melt and fall as cold rain depending on the ambient air temperature. This process is known as the Bergeron Process, and is believed to be the primary process by which precipitation is formed.
Bergeron was one of the principal scientists in the Bergen School of Meteorology, which transformed this science by introducing a new conceptual foundation for understanding and predicting weather. While developing innovative methods of forecasting, the Bergen scientists established the notion of weather fronts and elaborated a new model of extratropical cyclones that accounted for their birth, growth, and decay. Bergeron is credited with discovering the occlusion process, which marks the final stage in the life cycle of an extratropical cyclone.
In 1949 he was awarded the Symons Gold Medal of the Royal Meteorological Society. In 1966 he was awarded the prestigious International Meteorological Organization Prize from the World Meteorological Organization.