Never has such a high sea ice extent been observed in the North Atlantic as in summer 1917 (Fig.3). This exceptional case has never been investigated. Worst! Science seems not to have taken notice of it although thorough understanding of the event could possibly answer two important questions concerning climate change:
FIRST: Contribute the late icing and subsequent melting process to the sudden extraordinary warming at Svalbard and polar region (Fig.2 & 3) since winter 1918/19?
SECOND: Contribute naval war around Great Britain since 1914 to the exceptional icing?

Fig. 1; March 1917	Fig. 2; April 1917	Fig. 3; May 1917	Fig. 4; July 1917

Although air temperatures at Svalbard fell to all time record low in winter 1917, sea ice conditions in March were usual (Fig. 1). In general annual sea ice extent is highest in April, but succeeded average already in April, Fig. 2; rising to a level by end of May, which presumably has not happen for more than 200 years or longer, Fig.3. Even in late July the sea ice remained at a unusual high level, Fig.4. This late and extensive icing process may have had a pronounced impact and ocean water structure, from sea level to may hundred meter depth, which could have influenced the most significant climatic change in the 20th Century, namely the Arctic and Northern Hemisphere warming that started 18 months later in winter 1918/19 (Fig. 5, 6 & 7)..

Fig. 5; Svalbard, T°C, seasons & annual	Fig. 6; Annual T°C north of 70°1900-2013 + Fig.15

The sudden temperature increase at Svalbard commented the Norwegian scientist B.J. Birkeland in 1930: “In conclusion I would like to stress that the mean deviation (at Svalbard, Fig. 5 & 7) results in very high figures, probably the greatest yet known on earth” . Indeed, in any way exceptional. The significance for the entire Polar region is shown in Fig. 6 (15 & 16) indicating the annual. According I. Schell (1956) such a situation may not have been duplicated earlier for 200 years and more (Fig. 8). It seems that the year 1866 is regarded as the most severe ice year (Fig. 9), but that relates to April while the case 1917 is in May/June.

Fig.7, Svalbard T°C annual means	Fig.8, I. Schell (1959) said:	Fig.9, Extreme sea ice years

What contributed naval war in Europe since August 1914? In summer 1916 the naval war machinery entered a new dimension. Sea mines, sub-marines, torpedoes, depth charges, aerial bombing, were produce an masse and used. Now almost 5-10 merchant ships sunk every day. All water from SW Wales/UK and North Sea travelled northwards with an impact on the sea surface and ocean structure down to many dozen meters, Fig. 10-13.

Fig.10	Fig.11	Fig.12	Fig.13

Exactly at the same time the summer season got a sea ice extent never observed and 1 ½ years later the biggest temperature jump in the Northern North Atlantic and adjacent sector in the Arctic ever observed (Fig.14).

1. First QUESTION: What was the role and impact of navel war on the sea ice situation in the North Atlantic in summer 1917?
2. Second QUESTION: What was the role and impact of summer sea ice on the ocean structure in the high North in winter 1918/19?
3. Third QUESTION: What was the role and impact of naval war in Northern European waters on the Norwegian and West Spitsbergen Current and subsequently ocean structure between August 1914 and November 1918?

The correlation between warming in the Arctic and naval war is evident. It seems time to investigate and prove it.

Continue reading:
http://www.seaclimate.com/i/i.html
http://www.arctic-heats-up.com/chapter_8.html

Fig. 14; Main area of warming between 1920 and 1939	Fig. 15 & Fig. 16