I thought it was time to look at the sea ice data as the summer Arctic melt proceeds.
The image below shows the mean sea ice extent 1989-93 on 22 July, the sea ice extent 22 July 2017, and the difference between the two data sets. Reds imply less sea ice than the mean 1989-93, and blues an increased sea ice extent.
As we would expect, compared with the 1989-93 data the sea ice edge is consistently further north. Things that stand out for me are the virtually open water in the Barents and Kara Seas. This region was very slow to freeze over in the autumn and winter of 2016, so I would have expected the sea ice there to be relatively thin at the end of the Arctic winter.
Overall the area of the Arctic Ocean covered with sea ice is low. Some will note it is currently above the record low in 2012, but it's only 90,000 km2 above that. To me that is not that significant.
What is significant is the sea ice 22 July 2017 is ~1.7 million km2 below the median extent from 1981-2010.
I looked a couple of days ago at the sea ice in the North West Passage (19 July 2017), and it is starting to open up.
The yellow line traces out possible ship routes through the North West Passage and whilst there is still ~1200 km of sea ice on that route, when you compare the region to the longer term data you can see how low this is compared the historical record.
It may be this year that the passage may not open at all, but taken together the two plots are a a good example of how we can expect the north west passage to become consistently open as the Arctic continues to warm.
Approaching the middle of May and well into the Arctic sea ice retreat we can see that the sea ice extent (area of ocean with at least 15% sea ice) is still well below the mean over the satellite record.
I like a geographic perspective, so this is the mean sea ice extent 1989-93 on 13 May, the sea ice extent 13 May 2017, and the difference between the two data sets. Reds imply less sea ice than the mean 1989-93, and blues an increased sea ice extent.
There appears to be a general trend of the Arctic sea ice edge retreating between the two data sets, but I think this is in places meteorological - that is the winds are compressing the sea ice. I think this because there is a lot of blue (i.e. more sea ice than the 89-93 mean) just north of the sea ice edge.
The Bering Sea appears relatively sea ice free at this time.