According to data just now available, the total surface area of the summertime Arctic Sea that is covered in ice has reached the lowest point ever recorded.

Every (northern) summer the sea ice in the Arctic melts to some degree, reaching a minimum around the middle of September. Over the last several years, the amount of ice at this minimal point has been lower than previously recorded. Accurate records go back only a few decades, so this shift in ice cover reflects only the most recent period of Anthropogenic Global Warming (AGW).

Today, I got an email from my colleague John Abraham (the John Abraham from this podcast) noting that this morning’s data indicated that the ice had reached this minimum extent, as shown in this graph from the Arctic Sea Ice Monitor:


From the Arctic Sea Ice Monitor. "The latest value : 4,189,375 km2 (August 24, 2012)"

It is now August 24th, so there are about three weeks, more or less, of melting still to come. Therefore, we can say with some confidence that we will in the end have the smallest extent of ice so far in this data set.

With so much of the sea exposed, the water itself will warm from sunlight which would otherwise be reflected away by the shinier ice and snow … the albedo of the arctic is at a long-tem low because of this melting. Some people feel, and it is just a guess at this point, that the date of minimum ice extent might be getting later, moving towards late September from mid September. Statistically, this can not be said to be true at this point, but it does make sense that with less ice, there can be a warmer sea, and thus a slower re-start to the Arctic Ocean icing over again. Over the next few years we may well see the average date of sea ice minimum, which is a number with a lot of variation so this will be hard to detect, move later.

I’ve recently discussed the overall pattern of melting in the Arctic, and just yesterday I posted a piece on global warming and sea level rise in the Daily Kos Blogathon, and of course, melting ice (but mainly continental glacial ice) is key to that. Also, I hear last night that Al Gore and some of his colleagues will be posting at that Blogathon this morning, so go check that out.

Comments

  1. #1 Physicalist
    August 24, 2012

    total surface area of the Arctic Sea that is not covered in ice has reached the lowest point ever recorded

    Typo. The area *not* covered (or better, outside the ice, since we’re talking about extent), is at a maximum. It’s the area covered with ice (or inside the ice perimeter) that’s the lowest recorded.

  2. #2 Johnny Vector
    United States
    August 24, 2012

    W00T! Now we can look forward to 5 or 6 years of “Arctic ice has been recovering since 2012!!ZOMG!!!” Not even hitting them over the head repeatedly with a lead PIOMAS will help.

  3. #3 Rick
    August 24, 2012

    Is there any simple explanation to why the variation in the sea ice minimum appears to be so much more pronounced that of the sea ice maximum?

  4. #4 Greg Laden
    August 24, 2012

    Rick: Yes. My climate scientist friends tell me that it is because the freezing happens to a maximum (at present) and that is always the same (obviously) while at present the minimum is not the minimum possible, so it is a simple geometric relationship. Also, Grant Foster suggested this for you:

    http://tamino.wordpress.com/2010/08/22/on-ice-with-a-twist/

    Good question.

  5. #5 Kenya Davis
    Miami,FL
    August 24, 2012

    I am unable to support you financially… I do want to thank each and everyone who has taken this battle in their hands and done what you have. #1 sharing the knowledge in doing so reaching “minority” like myself. I struggle financially, am a single parent… please tell me of ways I can help. Sincerely and huge thanks, Ms.Davis

  6. #6 median
    August 24, 2012

    Worrisome and troubling; add the methane spouts in and the historic droughts and forest fires of 2012 in and things are looking critical. Oh yeah, and the fish and ocean life state … looks like an extinction event unfolding before our eyes in slow motion to me.

  7. #7 Pierce R. Butler
    August 24, 2012

    [Ahem!]

    AGW = Anthropogenic Global Warming.

  8. #8 MadScientist
    August 24, 2012

    Channeling Lomborg in 3 .. 2 .. 1 ..

    This is an excellent result; the Northern Passages will now be open longer and ships with greater draughts will be able to pass through safely. This will lower shipping costs and end the current global recession. The concomitant sea level rise and accelerated melting of ice will also contribute to more navigable channels for global shipping – everyone wins! Environmentally conscious operators may even offer free cruises to polar bears, which is proof that libertarianism works.

  9. #9 Kelly Manning
    Victoria, British Columbia
    August 25, 2012

    Rick asked why the decline in Maximum Sea Ice Extent is less than the decline in Minimum.

    Open Arctic Ice will freeze about 1.3 meters thick over winter, so it ends up being part of the maximum extent again, thawing during the next melt season and adding to the feedback loop.

    In the past those areas contained ice projecting 2 or 3 meters above sea level, and held up by 10s of meters of ice below seal level. That thick multi-year ice remained over the summer, keeping the minimum annual extent high.

    That old ice is mostly gone, so the summer minimum declines.

    In 1968 and 1969 the “Ice Ramming” MV Manhattan kept getting stuck in 20 meter ice ridges trying to bust its way through the McClure Parry International, Deep Water NW Passage at ice minimum. Since 2007 Manhattan would have had no trouble with McClure Parry.

    The Manhattan had to be rescued repeatedly by uninvited and unwelcome CCG Ice Breaker escort, John A MacDonald, after the USCG Staten Island developed engine trouble and was unable to free itself.

    Both times the Manhattan gave up and changed course to more dangerous, narrow, shallow water, passages farther south, entirely within Internationally recognized Canadian Territorial waters. Manhattan limped into port with holes in the outer hull big enough to drive freight trucks through.

    Oil companies sent the non ice-strengthened oil barges Learmonth and Norburg into the same area earlier, in a reckless attempt to supply arctic drilling platforms by sea.

    Those were single hulled barges used on the Great Lakes. The only provision for ice conditions was that Learmonth had been fitted with an “Alexbow”, which had some success with ice 1.5 meters thick on the Great lakes. That Axelbow was of no use against 20 meter, or more, ice ridges common in the arctic at that time. Learmonth was punctured and sank. Norborg proved impossible for the escorting tug to maneuver, being abandoned after 6 of it’s 8 oil tanks were punctured and ice wedged in one of the puncture holes.

    images.maritimehistoryofthegreatlakes.ca/63114/page/54

    As US(A) Navy Chief Navigator and Oceanographer Admiral Titley points out, the McClure Parry Passage and the passage along Russia will be side shows when the arctic is ice free at the pole for 3 months a year.

    You can follow the US(A) Navy Task Force Climate Change on Facebook.-)

    http://www.facebook.com/NavyTFCC

    Or down load the US(A) Navy Climate Change Roadmap from the web.

    http://www.navy.mil/submit/display.asp?story_id=53562

  10. #10 David Spratt
    Melbourne Australia
    August 25, 2012

    What is stunning are the JAXA sea-ice daily extent loss figures of around 120,000 square kilometres per day for the last three days, when compared to daily rate of sea-ice extent loss for 1-24 August in previous years:
    * 2007 62,976 square kilometres per day
    * 2008 72,785 square kilometres per day
    * 2009 53,859 square kilometres per day
    * 2010 55,109 square kilometres per day
    * 2011 63,342 square kilometres per day
    The melt is accelerating very late in the melt season in a pattern that has never before been observed. It looks like 2012 may in retrospect be seen as the year when a new melt regime took hold.
    http://www.climatecodered.org/2012/08/arctic-sea-ice-melt-record-more-than.html
    David Spratt

  11. [...] Breaking: Arctic Sea Ice Reaches Historic Minimum [Greg Laden's Blog] (scienceblogs.com) [...]

  12. #12 Frank
    August 28, 2012

    @Rick, maximum sea ice has a simple limit: the size of the Arctic Ocean. Sea ice stops at the shore, by definition. The variability is how far it pushes into the Bering, around Greenland, etc.

  13. #13 SplatterPatterns
    August 28, 2012

    David Sprat,

    89,650 km^2 daily average loss through the 27th of August. 55,750 km^2 daily average loss over the 2003-2011 period through August 28th. I find that anything less than weekly rates really don’t have much value. IARC/JAXA uses a three day moving average, IIR.

    Agree almost everyone seems to missing the huge increase in the rate of decline over August. Everyone should click on the graphic and really look at the August trend. Things are getting very screwy.

  14. #14 Kelly Manning
    Victoria, BC
    August 30, 2012

    Seasonal Ice has all but disappeared from the Gulf of St. Lawrence and from the waters around Newfoundland.

    An ironic consequence is that the controversy about the annual seal pup fishery / cull has be come a non-issue.

    Seal pups need 60% ice cover 30 to 60 cm thick to survive.

    With no place for pregnant seals to haul out on to give birth the pups are born in the water and drown, some washing up on shore.

    Canadian Fisheries experts estimate 75% pup mortality in 2007, rising to 100% in 2010.

    Unprotected shore line is not safe for adult seals or pups, which are welcome food for wolves and other predators.

    Mother seals have tried raising pups on the shores of a few island wildlife refuges, but a bit of protected shoreline can’t make up for the disappearance of vast areas of sea ice in recent decades.