OPEN WATER SEAS
A Blue Ocean Event is when the Arctic Seas (even for one day) become an open water sea. We all look at the ice , when perhaps we should be looking at the change to Open Water Seas with a maritime climate as opposed to ice-covered deserts. This is what this series of posts is all about.
The graphs look at open water (i.e. free of ice) as a percentage of the area of each sea. The sea ice measure used is NSIDC ice area
The Arctic Seas are in very different environments. I have invented some rough groupings. This fourth grouping I have named the Central Arctic Basin Protected Seas
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Group 4 :- the protected seas of the Central Arctic Basin – being the Beaufort, Eastern Siberia and Central Arctic Seas
In winter, these seas are bounded by frozen land and/or frozen water, and are the last to be exposed to open water. It is often assumed that they will be the last to lose their ice.
The Beaufort Sea, bounded by Alaska and Canada to the South, the Chukchi to the West, and the Central Arctic to the North and East.
Yearly average open water has increased from around 15% to 30%.
In March (maximum sea ice) open water has decreased from around 5% almost zero.
In contrast, in the 3 months of August to October (minimum ice) open water has increased more than doubled, from around 35% to 75%.
It is therefore entirely a story about summer melting. It is still very much an “ice desert” sea.
The Eastern Siberian Sea (ESS) has the Central Arctic Sea to the North, the Chukchi to the East, the Laptev to the West, and Central- Eastern Siberia to the South. It is, on occasion, vulnerable to Atlantic winds and currents when the Laptev has melted out.
Yearly average open water has increased from just under 10% just under 30% from 1980 to date.
In the 3 months of August to October (minimum ice) open water more than doubled from around 30% open water to 75%. In these months volatility from year to year is also very high.
March open water (the month of maximum ice is zero as near as makes no difference.
It is therefore entirely a story about summer melting. It is still very much an “ice desert” sea.
The Central Arctic Sea is the largest sea by far, at 3.2 million km2 and over 20% of the total area of the Arctic Seas. Centred on the North Pole, t is bounded by the CAA, Beaufort, Chukchi, ESS, Latev, Kara, Barents, and Greenland Seas plus North Greenland and Canadian Islands.
Yearly average open water has increased from around 5% to around 10% from 1980 to date. Most of this increase happened abruptly, at around 2006.
In the 3 months of August to October (minimum ice) open water has increased from around 15% to 30% Again, most of this increase happened abruptly, at around 2006. At that time annual volatility also increased markedly.
March open water (maximum ice) has increased from nearly zero to approaching 5% since 2012.
At an average open water percentage during the year of 10%, it is still very much an “ice desert” sea. This sea is never ice free, and at current rates of decline, it will be many years before it is ice free even in the month of minimum ice area.
The graph makes it clear how much of that sea is permanently ice covered