Focus on Spitsbergen data
The first meteorological station installed at Spitsbergen in 1912 was presumably the first in the arctic region north of 75ºNorth. That something has happened in the aftermath of WWI was acknowledged only 10 years later. Two expressions emerged a short time later, namely the “Greening of Greenland” and the “Warming of Europe”. The “Greening of Greenland” lasted only from ca. 1920 to 1930; the “Warming of Europe” until winter 1939/40.
One of the first to point at the extraordinary temperature development at the ‘Green Harbour’ Spitsbergen station was the Norwegian scientist B.J.Birkeland, in 1930. He was very surprised of what he discovered. He finishes his brief essay with this statement: “In conclusion I would like to stress that the mean deviation results in very high figures, probably the greatest yet known on earth”. (see: Temperatures details 1912-1926,Annex A). A couple of years later, Johannsson, Scherhag and others put Birkeland’s findings into a wider context.
(a) Johannsson (1936)
Johannsson elaborated the temperature conditions at Spitsbergen with reference to Birkeland’s research from 1930. Although Johannsson focuses his investigation on the relevance of sun-spots, some analytical consideration is nevertheless interesting, for example:
- In 1919, the statistical means crosses zero-value; or in other words, all previous years are colder; all later years are warmer (p. 86).
- The climate had become more maritime related (p. 86).
- Between 1917 and 1928 the increase during the summer season is of +0.9°C per 10 years, and in winter, of +8.3°C, in February, of +11.0°C (p. 87).
- There was a colder period from 1912 to 1917 (p. 90), which, had this not occurred, would have resulted in a 1.1°C increase at the Green Harbour Station (p. 91).
- As is known, the winters in Europe over recent decades (after 1880, even more since 1900) have become milder, the climate more maritime, the annual temperature means higher (p. 91).
- It seems that the changes are coming from the North, but this is not necessarily confirmed by temperature observations at some stations (e.g. Stockholm, Edinburgh), showing a warming from 1876-1920, but not later (p. 91).
- Temperatures in North Norway show no change between 1891 and 1905, but a +0.4°C change between 1921-30 (in Svalbard, 2.5°C), indicating that the increase in N-Norway is only delayed, and presumably also in Svalbard (p. 91f).
Johannsson’s main conclusion is that the increased air circulation (15 % higher) between 1896 and 1915 had gradually changed the current and ice conditions, thereby altering the borders between the Arctic gulf current climate and the true Arctic climate further north.
(b) Scherhag (late 1930s)
Speaking about the situation at Spitsbergen in 1919, Scherhag refers to Birkeland’s work from 1930, assuming that all warming analysis has to begin with the observation of the Spitsbergen phenomenon, because only here the increase of temperatures was measured in the winter of 1918/19 for the first time.
- There were increased Gulf Current temperatures, particularly significant in the Barents- and East Greenland Sea.
- The extraordinary increase in the winter temperatures in Greenland  was caused by a considerable retreat of the ice border and the prominent increase of the atmospheric circulation.
- The Spitsbergen winter 1936/37 was warmer than all previous winters, whereby the next winter 1937/38 broke again all records and was by mean 16ºC warmer than winter 1916/17.
- In North Europe, the southwest wind has substantially increased.
Scherhag states that a thorough research of the temperature changes over the whole northern half of the globe during the period 1921-1930 confirmed that the largest part of the region investigated had been, indeed, considerably warm during the decade 1921-1930. Scherhag stressed: “such kind of climate change as could now be observed in Spitsbergen and along the western coast of Greenland were certainly not restricted to a small region but must be global”. In his subsequent research work Scherhag pays little attention to the natural circumstances at Spitsbergen in the late 1910s, merely acknowledging that the extent of the temperature increase would be, without any doubt, the greatest in the Arctic.
(d) C.E.P. Brooks (1938)
With reference to the especially warm winter 1937/38, the author starts his paper by noting, that “in recent years attention is being directed more and more towards a problem which may possibly prove of great significance in human affairs, the rise of temperatures in the northern hemisphere, and especially in the Arctic regions”, raising other aspects as well.
- The Spitsbergen branch of the North Atlantic Current has greatly increased in strength and the surface layer of cold water in the Arctic Ocean has decreased from 200 to 100 metres in thickness.
- Attributing the recent period of warm winters to an increase in strength of atmospheric circulation (in reference to Scherhag) only pushes the problem one stage back, because one should still have to account for the change in circulation.
- It may also be objected that the atmospheric circulation depends on the difference of temperature between law and high latitudes and, hence, should be weakened instead of strengthened by a warming in the arctic.
- Regardless the mechanism, the rise of temperature did begin prematurely and had a cause, though it is conceivable that it arose spontaneously in the incessant kaleidoscope of temporary pressure distributions.
(d) Gordon Manley (1944)
- Temperature in Norway, especially in the North, has certainly risen far more in recent years than at any other time in the last two centuries. Since 1930 the retreat of Norwegian glaciers has been rapid, and the melting away of the Norwegian mountain snowfields has never since Roman times been so extensive as now.
- The general warming of the Arctic Seas since about 1921 is notably, as the diminished thickness of the surface layer of relatively fresh and easily frozen water due to less input from the Serbian rivers.
- A more vigorous atmospheric circulation in the region of the Norwegian Sea would explain the observed facts, namely the recession of the ice-limit, the increased frequency of south-westerly winds, rather than south-easterly, in N-Norway, and the consequent marked rise in winter temperatures which has attained its greatest magnitude in the north of the Scandinavian peninsula.
(e) H.W.Ahlmann (1946)
The author provides a detailed account on observed regression of glaciers and inland ice in Norway and other locations in the northern Hemisphere from 1918-1940. The retreat of sea ice in the Spitsbergen region due to ‘recent climatic improvement’ forced him to note that: “This part of the Arctic may, without exaggeration, be said to have experienced a climatic revolution”.
All papers acknowledge the suddenness of the rise in temperatures in the North Atlantic region since the early 1920s, but pay only remote attention to the location Spitsbergen. No one thought to start any investigation of the sea body off Spitsbergen. Nevertheless, the grandfathers of today’s climatologists discussed the matter very seriously and sometimes, so it seems, they might have been closer to ‘the point’ as more recent paper.
Concerning the state of art in climatology in the early 1940s it worth to mention a paper by J.N. Carruthers (1941) where he cites a paper by C.F. Brooks, with a section entitled “Surface oceanography fundamental to world meteorology”, on following subjects: x) The oceans as regulators of world weather. xx) The ocean and the planetary wind belts. xxx) Seasonal abnormalities in centres of action; and xxxx) Ocean temperatures in seasonal weather forecasting.
It seems that C.F. Brooks would presumably have sympathised with a definition saying, “Climate is the continuation of the oceans by other means”. Unfortunately, with the commencement of WWII, the discussion ceased and did not resume after the war to any acknowledgeable extent.
 Birkeland, B.J.; ‘Temperaturvariationen auf Spitzbergen’, Meteorologische Zeitschrift, Juni 1930, p. 234-236.
 Johannsson, O.V.; ‘Die Temperaturverhältnisse Spitzbergens (Svalbard)’, in: Annalen der Hydrographischen Meteorologie, Maerz 1936, pp. 81-96.
 R. Scherhag, Die Erwärmung des Polargebiets, Annalen der Hydrographie, LXVII. Jahrg.(1939), p.57-67
 R. Scherhag; ‘Eine bemerkenswerte Klimaveränderung über Nordeuropa’, in: Annalen der Hydrographischen Meteorologie, Maerz 1936, pp. 96-100.
 Scherhag, R. (Arctic); ‚Die Erwaermung der Arktis’, in: Cons. Intern. Expl. Mer. Rap. Proc.- Verb., Copenhagen, 12, 1937, p. 263-276.
 Scherhag, R. (Milderung).; ‘Die gegenwaertige Milderung der Winter und ihre Ursachen’, in: Annalen der Hydrographie und Maritimen Meteorologie, Juni 1939, pp. 292-302.
 Brooks, C.E.P; ‘The Warming Artic’, in: The Meteorological Magazine, Vol. 73, March 1938, pp. 29-31.
 Manley, Gordon; ‚Some recent contributions to the study of climatic change’, in: Quarterly Journal of Met. Soc., Vol. 73, 1944, p. 197-219.
 H.W. Ahlmann, “Researches in Snow and Ice, 1918-1940”; The Geographical Journal, 1946, Vol. 107, p. 11-25
 J.N. Carruthers, 1941, “Some Interrelationships of Meteorology and Oceanography”; Quarterly Journal of the Royal Meteorology Society, p.207-232;
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