Sea Ice, North and South

Arctic sea ice has been in decline so long, and so far, that deniers have had to make up some truly ludicrous stories about it. They embarass themselves on the topic.

But for some time, they crowed about the actual increase of Antarctic sea ice. They rarely mentioned that its increase wasn’t as great as the Arctic decrease (or they outright lied and said it was). They also tended to add the Arctic and Antarctic extents together to form a global figure, because the Antarctic increase partly cancelled out the Arctic decrease, making it seem not so bad.

For now at least, they won’t be crowing.

Arctic sea ice is at an all-time low for this day of the year (2016 in red):


Antarctic sea ice is also at an all-time low for this day of the year (2016 in red):


That means, of course, that global sea ice extent is at an all-time low for this day of the year. What’s surprising is just how low it is:


The planet is changing, a lot faster than we want it to.

This blog is made possible by readers like you; join others by donating at Peaseblossom’s Closet.

28 responses to “Sea Ice, North and South

  1. How are they going to cherry-pick their way out of this graph? It’s kinda fun to try and guess. Personally, I like accurate representations of reality.

  2. David B. Benson

    The title of the second graph is in need of repair.

  3. Let’s not forget that Antarctic sea ice extent is expected in the short-term under physical models as a consequence of the South Pole being straddled by a thumping great continental land mass, contrasted with the North Pole which is simply ice over a similarly large ocean of water. The presence of land completely changes the dynamics of sea ice production, so any expectation of similar ice trends at each of the poles is simply the product of an ignorance of physics, whether deliberate or involuntary.

  4. Just this week, I saw someone wondering how much of the Arctic melt should be ascribed to Russian nuclear submarines.

  5. The F-17 satellite sensor failure back in April means the Cryosphere Today daily Sea Ice Area data has been absent for the last few months. Given the drama being played out down in the Antarctic, I decided to fix this by splicing a re-based JAXA daily Sea Ice Extent onto my plot of the ‘timebased’ SIA anomaly record. This gives a different perspective to the ‘year-on-year’ plots of the OP which shows a time-of-year comparison but at the expense of the chronology. See here (usually 2 clicks to ‘download your attachment’) (In updating this graph just now, I see JAXA’s splendid new VISHOP page is now providing data back to 1978 so a JAXA SIE graph of the whole period is now possible.)
    The graph has just been updated to include 16/11/16 data and captures an ‘almost’ moment. The re-based JAXA data is ‘almost’ on the zero-anomaly axis (2,000 sq km short) ending its 5-year upward adventure and the daily anomaly is ‘almost’ dropped below the lowest on the Cryosphere Today record set back in 1980 (28,000 sq km short). (I note with the JAXA data now available back to 1978, the second ‘almost’ is actually come & gone. The 16/11/16 anomaly (1990-2015 base) is 102k sq km lower than the JAXA record set on 10/6/86).

  6. The global sea ice extent, how far is it below the 1981-2010 average, for this day of the year?
    Is it 4, 5, 6, or even more standard deviations?

    [Response: About 6.9 standard deviations below the 1981-2010 mean.]

  7. That global sea ice trend is about as dramatic as one could imagine, and it should be quite alarming to anyone with any sense!!

    • The ice data is so dramatic that if it was just ice data showing it you would question if the satellite sensors were on the blink (again). But the drama is being played out in other data. Andrew Slater of NSIDC has a graph of reanalysis data plotting North Pole temperatures (like the DMI graphs but with statistical intervals shown) which show how crazy the temperatures are up there at the moment. And the RSS TLT satellite measurements (data tables here) show that as of October both polar regions are far warmer than measured before. The Arctic has had some warm months since the start of the year (although the summer months saw cooler anomalies) with January giving a record anomaly on the full record. It appears likely that November will snach that record from January. (The UAH TLTv5.6 (data tables) splits the latitudes into ocean & land and shows a record-breaking Arctic Ocean anomaly for October. So what November is going to look like – hold onto your hats!!) Down in the Antarctic the TLT warmth appeared just this October which posted a record high anomaly, not by a great deal on the full record (+0.09ºC above the previous) but quite a leap in the record for the time of year October, by +0.8ºC.

  8. I agree with @Al Rodger. Multiple sensors showing same thing.
    Based on this post and what I have been seeing in the Southern Hemisphere this spring I wrote a blog post with a couple of movies on.
    The absence of ice in the Kara Sea at the moment is striking.

  9. If I tell people that sea ice is 6.9 standard deviations below the mean, their eyes will glaze over. What is the probability that this amount of ice is attributable to random fluctuation? I am , sadly, too math ignorant to know how to compute that number.

    [Response: Well, if it followed the normal distribution it would be less than one chance out of 100 billion. But it doesn’t follow the normal distribution. Still, the probability it’s just random is in that neighborhood. Feel free to say “1 out of a billion.”]

  10. > I saw someone wondering how much of the Arctic melt
    > should be ascribed to Russian nuclear submarines.

    I sure hope that was me. The timing is about right.

    I was trying to make a joke about how far they’d reach for spurious explanations. I hope you’re remembering what I wrote, not someone making my prediction come true so soon. Alas.

    Ray Bradbury said he didn’t write to predict the future, but to prevent it.

  11. I think it is time to ease up a little on this stuff. Since Obama is now destined to obscurity and Trump is going to solve the AGW problem with a stroke of a pen, we have nothing to worry about.

    • I imagine that this is meant as sarcasm, but it can be hard to tell, sometimes–especially lately. The Onion has looked more and more like straight news.

  12. Just looked at NSIDC’s arctic page: The chart there shows an actual downturn of the sum of 15% coverage regions. And that is mid-November, which is often the month with a higher rate of increase than other months. That begs a moment of thought.

    • Nov 20 Arctic sea ice extent is the lowest in the record for that day of the year by more than 1 million sq kms (NSIDC data). Record calendar year lows have been broken every day since October 16.

      1982 and 2001 saw ‘pauses’ in the November regrowth of ice similar to recent. 2001 had a very slow November.