Niels Johan Føyn Explained

Niels Johan Føyn
Birth Name:	Niels Johan Nielsen
Birth Date:	23 February 1860
Birth Place:	Slagen, Tønsberg, Norway
Nationality:	Norwegian
Occupation:	Meteorologist

Niels Johan Føyn, original surname Nielsen (February 23, 1860 – June 13, 1945) was a Norwegian meteorologist.

Føyn was born in Slagen in the municipality of Tønsberg, Norway.^{[1] [2]} He was the son of the ship operator Peder Nielsen (1818–1904) and he later adopted the surname Føyn from the oeconym of the farm where his family lived.^[2] He received his candidatus realium degree in 1886 and then worked as an assistant at the Norwegian Meteorological Institute.^[1] He received a state scholarship to study in Berlin and Vienna from 1893 to 1895.^[1] From 1903 to 1915, Føyn was the supervisor of the Bergen Meteorological Observatory,^[3] and from 1915 to 1928 he was the deputy director of the Norwegian Meteorological Institute.^[1] He was made a member of the Norwegian Academy of Science and Letters in 1904.^[1]

Legacy

In meteorology, a Köppen-like formula known as Føyn's formula is used for calculating monthly mean temperatures:^{[4] [5]}

where T_m = monthly mean temperature, T_g = monthly mean of T₁ (morning temperature) and T₃ (evening temperature), k = constant, and T₂ = midday temperature.^[6]

Selected works

• "Meteorologi" (Meteorology; as N. J. Nielsen, in Henrik Jæger (ed.), Illustreret norsk literaturhistorie, 1896)^[2]
• Wolken-Beobachtungen inn Norwegen 1896–97 (Cloud Observations in Norway 1896–97; 1900)^{[1] [7]}
• "Abhängigkeit des Barometerstandes von den Terrainverhältnissen" (Dependence of Barometer Readings on Terrain Conditions; in Meteorologische Zeitschrift, 1910)^[1]
• "Das Klima von Bergen, I. Niederschläge" (The Climate Of Bergen. Part 1: Precipitation; in Bergens Museums aarbok, 1910), "II. Lufttemperatur" (Part 2: Air Temperature; ibid., 1916)^{[1] [8]}
• "Norges Klima" (Norway's Climate; in Norge 1814–1914, 1915)^[1]
• "Klima von Nordwesteuropa und den Inseln von Island bis Franz-Josef-Land" (The Climate of Northwest Europe and the Islands from Iceland to Franz Josef Land; coauthored with Bernt Johannes Birkeland, in Handbuch der Klimatologie, vol. 3, 1932)

Notes and References

1. Book: Blangstrup . Christian . Salmonsens Konversationsleksikon, vol. 9 . 1920 . J. H. Schultz Forlagsboghandel . Copenhagen . 293 . December 2, 2018.
2. Book: Steenstrup . Hjalmar . Hvem er hvem . 1934 . H. Aschehoug & Co . Oslo . December 2, 2018.
3. Book: Bergens Museums aarbog . 1905 . Bergen . 97.
4. Book: Nordli . Øyvind . Tveito . Ole Einar . Calculation of Monthly Mean Temperature by Köppen's Formula in the Norwegian Station Network . 2008 . Norwegian Meteorological Institute . Oslo . 9 . December 2, 2018.
5. Birkeland . Bernt Johannes . Mittel und Extreme der Lufttemperatur . Geofysiske Publikasjoner . 1936 . 14 . 1.
6. Gjelten . Herdis M. . Nordli . Øyvind . Grimenes . Arne A. . Lundstad . Elin . The Ås Temperature Series in Southern Norway–Homogeneity Testing and Climate Analysis . Bulletin of Geography – Physical Geography Series . 2014 . 7 . 10 . 10.2478/bgeo-2014-0001 . 52026933 . December 2, 2018. free .
7. Book: Fortschritte der Physik . 1902 . F. Vieweg und Sohn . Braunschweig . 325.
8. Meteorologiske forhold . Statistiske Oversikter 1948 . 1948 . 16 . Statistisk sentralbyrå . Oslo.