I stumbled upon this website from the Norwegian Polar Institute today which gives the user the ability to plot sea ice edge around the general Svalbard area, from a selection of specific dates starting at 1553 up to 1917.
https://geodata.npolar.no/arcgis/rest/services/Temadata/I_Havis_Historiske_isgrenser_Svalbard/MapServerI used the ArcGIS online viewer at the top of the page to plot the data.
I don't have much information on the source of the data. However I am aware that researchers such as Degroot have researched whaling activity in the area, going back centuries.
Smeerenburg located at the very NW tip of Spitzbergen was ice free many times during the early 17th century. It was founded by the Danish and Dutch in 1619 as one of Europe's northernmost outposts. With the local bowhead whale population soon decimated and whaling developed into a pelagic industry, Smeerenburg was abandoned around 1660.
The menu on the left of the ArcGIS viewer gives a selection of dates. To make the plot, ensure first two indents are ticked, then tick the particular year and then then month date (if available for that year).
There are options also to change the plot lines & colour schemes.
I have made 3 plots (attached)
15th July 1596 : The ice edge is at the NW tip of Spitzbergen
1st July 1900 : The west coast of Spitzbergen is ice free.
1st July 1917 : Ice extends far further south from Svalbard and over much of the Barents Sea and almost at the entrance of the White Sea in Russia.
Note : The legend attached to these plots refers to "Ice Cond." These are attributed a scale of 1 to 10. I do not know what exactly these numbers relate to but I imagine from the plots that the high numbers refer to low ice condition and low numbers refer to close drift ice ?
Shortly after 1917 there was a rapid reduction of sea ice around Svalbard & Barents Sea and
this article outlines the effects this reduction had on the much of the Arctic - initiating the rapid Arctic warming of the 20th century.
"The Arctic 1920–40 warming is one of the most puzzling climate anomalies of the twentieth century. Over a period of some 15 yr the Arctic warmed by 1.7°C and remained warm for more than a decade. This is a warming in the region comparable in magnitude to what is to be expected as a consequence of anthropogenic climate change in the next several decades. A gradual cooling commenced in the late 1940s bringing the temperature back to much lower values although not as cold as before the warming started. Here, we have shown that this warming was associated with and presumably initiated by a major increase in the westerly to southwesterly wind north of Norway leading to enhanced atmospheric and ocean heat transport from the comparatively warm North Atlantic Current through the passage between northern Norway and Spitsbergen into the Barents Sea."
But I am still none the wiser to why sea ice extent near Svalbard rapidly declined after 1917 ? Was it due to a sudden change in the AMOC ? Anthropogenic CO
2 changes were quite small back then.
It is very interesting to note the low extent circa late 16th and early 17th centuries. Evidently the ice edge at this part of the world is subject to large and quite rapid changes.
