The International Arctic Research Center at the University of Alaska Fairbanks is a think-tank on Arctic matters primarily due to Syun-Ichi Akasofu (see recent Hot Topic) and Igor V. Polyakov.  In 2003 he and his colleagues emphasized that the period between 1918 and 1922 displayed an exceptional rapid winter warming in the Arctic[1]. Although this warming event had been as significant as the recent climatic change, little efforts has been made to learn from the past, instead the issue has been pushed aside by such remarks as e.g. “natural variability”(see: HERE).  Already 70 years ago the American scientist C.E.P. Brooks noted:  “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 temperature in the northern hemisphere, and especially in the Arctic regions.”[2]

The sudden warming of the Arctic in the early 20th Century is presumably not as puzzling as assumed[3] if investigated on three parameters, namely winter temperature observation in the region, the prevailing sea ice conditions, and the impact the sea has on air temperatures at high latitudes during the sunless winter season. Who else than the ocean can influence the air temperatures at high latitude in winter. That is particular significant if the ocean space is free of sea ice and is supplied with warm water from elsewhere. In the Northern Hemisphere there is only one location where it happen, the West Spitsbergen Current, which supplies warm and saline water via the Fram Strait to the Arctic Ocean. (Discussed: Here)

Winter temperature deviation 1921-30, with 3°+ only at Spitsbergen and West Greenland
Extract from original R. Scherhag Fig., 1936	Winter deviation, 1933-35	Full year deviation – Nov.1936 to Oct. 1938

The starting point is the extreme warming at Spitsbergen in winter 1918/19. The winter temperatures exploded (see Fig. above) only here. The warming was sustained and remained for two decades, showing up in the Kara Sea and eastwards only after 1920. That is an evident aspect that the warming started at Spitsbergen.  When Syun-Ichi Akasofu[4] recently acknowledged  that: “The recent rapid retreat of sea ice in the Arctic Ocean, particularly in 2007, is partly caused by the inflow of warm North Atlantic (Karcher et al., 2003; Polyakov, 2006)“, it would be the same situation as during the Arctic warming 90 years ago. An earlier paper by Polyakov et al.[5] expressed it in this way:
„This study was motivated by a strong warming signal seen in mooring-based and oceanographic survey data collected in 2004 in the Eurasian Basin of the Arctic Ocean. The source of this and earlier Arctic Ocean changes lies in interactions between polar and sub-polar basins. Evidence suggests such changes are abrupt, or pulse-like, taking the form of propagating anomalies that can be traced to higher-latitudes. For example, an anomaly found in 2004 in the eastern Eurasian Basin took 1.5 years to propagate from the Norwegian Sea to the Fram Strait region, and additional 4.5–5 years to reach the Laptev Sea slope.“
Indeed, at first there is the Spitsbergen Current, and some time later, since the mid 1920s the region eastward from Spitsbergen generated a warming impulse on its own during the winter season (see Fig.-Box).  A thorough historical research of the early warming from app. 1919- 1939 would presumably have lead to a similar conclusion since long.
A detailed assessment on the early Arctic warming is  HERE