Thoughts on the ocean, the environment, the universe and everything from nearly a mile high.

Panorama of The Grand Tetons From the top of Table Mountain, Wyoming © Alan Holyoak, 2011

Friday, July 5, 2013

Holy cow! The 2013 Arctic sea ice melt is accelerating like crazy!

I know I just posted on the Arctic Ocean sea ice melt, but, well, that was three days ago.  And three days ago it looked like an acceleration of sea ice melt might have been on the way, but I'd say that now it's official!  Look at the difference between the 1981-2010 baseline trend and the observed sea ice melt between the latter half of June and July 4th.  Wow!

I did a little math, and here's what I came up with.

On June 21st the historical baseline (1981-2010) showed sea ice extent at about 11.4 million km2 and 10.55 million km2 on July 4th.  That's a difference of 850,000 km2 of sea ice, or a melt rate of about 65,400 km2 of sea ice per day.

By comparison, the observed time period between June 21st and July 4th 2013 showed a sea ice extent of 11.1 million km2 on June 21st and an extent of 9.6 million km2 on July 4th.  That's a difference of 1.5 million km2 over that time period for a daily sea ice melt rate of about 115,400 km2 per day.

The observed melt rate for 2013 over the past two weeks or so is therefore nearly double the baseline melt rate for the same time period.  It's doubtful that this melt rate can be maintained for long, but the next few weeks will give us a good indication about whether the 2012 sea ice minimum extent record is in jeopardy. That is, if the current sea ice melt rate will be sustained, at least over the short term.

So, it's true, things are really starting to warm up in the Arctic.

Stay's going to be an interesting summer!

Monday, July 1, 2013

Time to check in on the Arctic Ocean summer sea ice melt - 1 July 2013

It's been a while since I posted anything about what's happening in the Arctic Ocean.  In a word, the summer 2013 sea ice melt is "on".  So far this spring/summer, sea ice cover has declined from a winter maximum ice extent of just over 15 million km2 down to 10.5 million km2 as of yesterday (6-30-2013).

The maps below shows that sea ice melt is progressing much faster than the 1981-2010 average in Hudson Bay, the Barents Sea, Baffin Bay, and other areas around the Canadian Archipelago.  Sea ice melt in the Bering and Chukchi Seas are right on the historical average.

The graph below courtesy of shows the relationship between the 2013 Spring/Summer melt and that of the 1981-2010 average and the 2012 all time record low sea ice melt.  The current melt is currently about midway between the historic average melt and the record melt for this time of year.  The rate of sea ice melt has really increased (as indicated by the steep downward turn in the blue line on the graph below) over the past week or so.  The rate of sea ice melt will really have to speed up, though, if it's going to have a chance of catching last year's record pace. 

If you follow these kinds of data on a regular basis, like I do, you might be surprised to see the current rate of sea ice melt is as close as it is to the historic rate of sea ice melt.  That's because NSIDC recently updated their baseline data for comparisons from a 22-year average (1979-2000) to a 30 year average (1981-2010), since that is standard practice for baselines whenever possible.  You can read more about that change by clicking this link:  FYI, the NSIDC made this change on June 18, 2013.

So as of now, the 2013 sea ice melt is not threatening to break last year's record minimum sea ice extent.  But the only way to know what is going to happen is to be patient and keep checking back.

Have a great summer, but I hope that not too much sea ice melts!