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Arctic sea ice watch

Filed under: — group @ 10 August 2007

A few people have already remarked on some pretty surprising numbers in Arctic sea ice extent this year (the New York Times has also noticed). The minimum extent is usually in early to mid September, but this year, conditions by Aug 9 had already beaten all previous record minima. Given that there is at least a few more weeks of melting to go, it looks like the record set in 2005 will be unequivocally surpassed. It could be interesting to follow especially in light of model predictions discussed previously.

There are a number of places to go to get Arctic sea ice information. Cryosphere Today has good anomaly plots. The Naval Sea ice center has a few different algorithms (different ways of processing the data) that give some sense of the observational uncertainty, and the National Snow and Ice Data Center give monthly updates. All of them show pretty much the same thing.

Just to give a sense of how dramatic the changes have been over the last 28 years, the figures below show the minimum ice extent in September 1979, and the situation today (Aug 9, 2007).

Sep 05 1979Aug 09 2007

The reduction is around 1.2 million square km of ice, a little bit larger than the size of California and Texas combined.

Update: As noted by Andy Revkin below, some of the discussion is about ice extent and some is about ice area. The Cryosphere Today numbers are for area. The difference is whether you count ‘leads’ (the small amounts of water between ice floes) as being ice or water – for the area calculation they are not included with the ice, for the extent calculation they are.

Update: From the comments: NSIDC will now be tracking this on a weekly basis.

504 Responses to “Arctic sea ice watch”

  1. 501
    SteveSadlov says:

    I hereby apologise for referring to the Vertical Circumnavigation’s sailor as “Wrong Way Flanagan.” Sadly, I was roped in by some very inaccurate news reporting. In fact, this project is highly competent, and Flanagan is doing it the way I would do it:

    By the way, this has been a very good experience in terms of learning and advancement of the sailing arts. I believe that Vertical Circumnavigation will in fact succeed someday, no matter what the sea ice trend is. Timing is the key. And luck.

  2. 502
    SteveSadlov says:

    RE: #495 – There is good reason to believe that the existence of large fetches of open water in the Arctic during the Fall, can indeed lead to increased storminess. Also, not to engage in hype or doom and gloom myself, but, although Whitley Strieber and Art Bell’s book “Global Superstorm” is rife with non physical / scientifically impossible aspects, at the 50K foot level, it is not unthinkable that low sea ice extent, noise / excursions in the THC and other factors could in fact induce the end of the current interglacial. Earth history is on the side of being conservative and keeping the possibility of relatively rapid (e.g. millenneal scale) major climate change on the table as a possibility. “Day After Tomorrow” is hype, but, a hundreds of years long version of such events is possible.

  3. 503
    Parm Gander says:


    I am a Research and Development technician, but study climate change as a side interest. I have a BAD feeling when it comes to societal viability over the next 30 years or so. It’s just my opinion…and I am not a climatologist, but I think we’re screwed (my best scientific description). It’s not that we meant to end most of the mammalian life on the planet…we just didn’t know the extent we were damaging the earth (debatable I know). I believe that there has been an absolutely CRITICAL balance of CO2, Oxygen, Nitrogen, Nitrous Oxide, Methane, etc, present on the earth for Eons. We have disrupted that balance. It’s not biblical…nor magical, just simply physics that we failed to understand in time (not that we really understand it now..but we’re beginning to). It’s my opinion that this critical gas balance has been and is the earths perfect thermostat. We have turned up that thermostat…but unfortunately AFTER we build our society, cities, and established our way of life. The melting of glaciers, ice-sheets, etc is ONLY THE BEGINNING. And I do mean the beginning. It is going to get FAR worse. WE have seen NOTHING yet. Wait 30 years…we will see in our lifetimes…situations we thought we impossible…weather that will SCARE you. It is going to be an interesting future. The worst part about this…is that I think the government knows…and I don’t just mean they know about global warming…that is real..I mean they KNOW how bad it really is…and how bad it is going to get. Which is why there is so much disinformation about global warming out there…so many deniers…$10,000 payoffs to scientists willing to trash global warming science. I am not the smartest man on the planet…but am I the only one who feels that this is the case????? Get back to me!!


  4. 504
    Stuart Jensen says:

    Ryan @ 494,

    This, also, is my first post here, and I can’t claim any credentials beyond a few stray neurons sporadically firing after decades of abuse.

    Your first complaint is burial by “the media”, and an attempt to mislead by reporting old information.

    The US Congress is holding hearings that have been hyped for many months on an issue that is preeminent to consumers of “media” output. That is major noise.

    Selling both Chevy Suburbans and solar panel kits is easier with Polar Bears than IR satellite output. There is a legal issue driving the research underling the CNN story in your first link — a petition to up-list Polar Bears under the Endangered Species Act is pending. CNN and its ilk are responding to the conclusions published by
    Overland and Wang in Geophysical Research Letters. The authors publish when they publish, and they use the data they have.

    The second link seems to refute your point. Four days later the extent of this year’s ice is the subject.

    Your second ‘plaint, that Serreze “pulled the rug out from under our feet” is based on what? That he failed to support your prediction – apparently made elsewhere, if made a month ago and this is your first contribution – of the outside date for the Arctic Ocean being seasonally ice free is 2015?

    I’m probably every bit as alarmed as you. I’m just cautioning you to remember and respect the “real” part of this forum’s title, and not amplify the noise at the expense of the signal.