Tag Archives: Chukchi Sea

2 Comments

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.

The mean Arctic sea ice for the years 1989-93 on 22 July, the sea ice concentration on 22 July 2017 and the difference between the two data sets. Blue shades imply more sea ice and reds imply decreased sea ice compared with the mean. The original data come from the DMSP SMMI data set at the NSIDC.
The mean Arctic sea ice for the years 1989-93 on 22 July, the sea ice concentration on 22 July 2017 and the difference between the two data sets. Blue shades imply more sea ice and reds imply decreased sea ice compared with the mean. The original data come from the DMSP SMMI data set at the NSIDC.

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.

Also the Chukchi Sea is opening.

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 kmabove that. To me that is not that significant.

Arctic sea ice extent to 22 July 2017 from NSIDC.
Arctic sea ice extent to 22 July 2017 from NSIDC.

What is significant is the sea ice 22 July 2017 is ~1.7 million kmbelow 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 North West Passage. Image 22 July 2017 from the Suomi National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite.
The North West Passage. Image 19 July 2017 from the Suomi National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite.

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.

The difference in the sea ice in the NW Passage on 22 July 2017 compared with the mean for the years 1989-93 on 22 July. Blue shades imply more sea ice and reds imply decreased sea ice compared with the mean. The original data come from the DMSP SMMI data set at the NSIDC.
The difference in the sea ice in the NW Passage on 22 July 2017 compared with the mean for the years 1989-93 on 22 July. Blue shades imply more sea ice and reds imply decreased sea ice compared with the mean. The original data come from the DMSP SMMI data set at the NSIDC.

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.

 

4 Comments

The summer of 2016 saw the joint second lowest Arctic sea ice extent. But in the middle of October unusual Arctic weather has led to it becoming the lowest extent. At the same time, Antarctic sea ice extent has also reached record lows. Tamino has a simple and clear post about what a surprising thing this is.

The Northern Hemisphere Sea Ice extent from Tamino's blog
The Northern Hemisphere Sea Ice extent from Tamino's blog "Open Mind". The current year 2016 is in Red

 

Why is it so low?

The plot below shows the mean November Arctic sea ice extent, the sea ice extent on 16 November 2016, and the difference between the extents from 1993 to 2016. Regions shaded at the top end of the scale (the red colours) mean there is less ice now compared with in 1993.

The mean Arctic sea ice extent in November 1993, the daily sea ice extent on 16 November 2016, and the difference between them
The mean Arctic sea ice extent in November 1993, the daily sea ice extent on 16 November 2016, and the difference between them.

The stand out region (to me!) is North Russia where the Kara Sea is almost entirely clear, followed by Hudson Bay, Baffin Bay, East Greenland and the edge of the Chukchi Sea. I was interested in what was going on in the Kara Sea so I made a movie of the sea ice extent from 1 November 2016 to 16 November 2016.

Arctic sea ice 1 to 16 November 2016.
Arctic sea ice 1 to 16 November 2016.

The striking thing in the clip for November 2016 is that the sea ice extent has actually reduced in the Kara Sea!

The sea ice extent in Chukchi Sea is increasing, but very slowly - and you can see from my previous image that it is very low compared with 1993.

Clearly the Arctic is experiencing strange conditions at the moment. On the climatereanalyzer.org website you can see the 5-day forecast from 17 November 2016 (tomorrow).

The temperature departure from average is off the scale over the Arctic Ocean. It's much colder over Russia.

The 5 day forecast from 17 November 2016 from Climate Reanalyzer.org.
The 5 day forecast from 17 November 2016 from ClimateReanalyzer.org.

These are astonishing observations. When the winds change and the cold air currently over Russia ends up over the ocean I would expect it to freeze up rapidly (once the surface layers have cooled). But starting so late in the year the sea ice could end up thin enough for something impressive in the near future.

I made a gif of the full current Arctic growing season up to 16 November 2016.

I have already written a little about the this years Antarctic sea ice extent in the Antarctic Peninsula sea ice late winter 2016, in The Western Weddell Sea ice factory, in The development of the Amundsen Sea Polynya, in Dotson Getz Polynya ice growth, and in The Prince Gustav Channel is opening.

For interest, I chose November 1993 for comparison for two reasons, first it’s just before the big Arctic sea decline, and secondly I was in the Arctic for 4 months that year doing my PhD research.

Tamino is noting that the global sea ice is "About 6.9 standard deviations below the 1981-2010 mean." . Amazing times.