NH Jaxa 7-day Minimum Sea Ice Extent

Time to bet on the JAXA sea ice-extent minimum. We are betting on the minimum 7-day average for values posted in Version 2 here and plotted here. The current extent is 6.811403 million square kilometers.
Sea_Ice_Extent_v2_L

[sockulator(../musings/wp-content/uploads/2011/UAHBets5.php?Metric=NH SeaIce Extent Min?Units=millions of sq km?cutOffMonth=8?cutOffDay=12?cutOffYear=2014?DateMetric=2014?)sockulator]
The winner will be the person who comes closest to the minimum 7 day average based on all days reporting data.

Cutoff 8/12/2014. Tip: Values should be on the order or 0-7 million sq km, but the script is not coded to ‘fix’ insane values. If you are tempted to bet a negative value: no. That’s not going to happen. Zero is the absolute minimum value. Values less than 3 million sq km are unlikely but not physically impossible. Values higher than the current 6.81 million sq. km are highly unlikely. (Sure. Mars could attack and cause sudden freezing using their scrootch guns, but that hasn’t happened before. )

I’m going to be rather scarce for a week. But I know you want to bet. So… bet away!

21 thoughts on “NH Jaxa 7-day Minimum Sea Ice Extent”

  1. given the stadium wave, i’ll bet a little under the average. in ten years i’ll bet a bit above.

  2. Looking for the source file for the image, I found something odd. JAXA has a large version of the image here, 1440×900 pixels, file size 44,930 bytes. Their “regular size” image is here, 720×450 pixels, but its file size is 159,963 kB.

    Anyone have an idea what causes the file with one-fourth as many pixels to take up almost 4 times as much space?

  3. HaroldW,

    I think you meant 159,963 bytes or 159.963 kB.

    But the sizes of different image files has always been a mystery to me.
    I converted them to jpg and the became 373 kB for the large one and 133 kB for the small one.
    Then back to PNG and they became 165 kB and 108 kB otherwise the theoretically large one became much larger and the small one smaller!

  4. Checking the files, the “regular size” image is in 48 bit colour, which seems frankly excessive, while the “large” image is in a slightly more reasonable 24 bit colour, so that’s one factor of 2 explained. But there must be more to it than that, as there’s a factor of around 16 difference (allowing for the different number of pixels).

    Looking more carefully the “large” image is actually using a limited colour palette and appears to be the original drawing, and so will compress very easily. The “regular” image has apparently been made by down-sampling with anti-aliasing and so has far more colours and will compress far less effectively.

  5. Thanks Jonathan, good explanation. Interesting artifact of the method. Of course, JAXA probably published the “regular” size intending to provide a smaller file — funny that it wound up having an entirely opposite effect.

    And Ray — yes, good catch. I did indeed mean bytes, not kb.

  6. As everyone’s off-topic: Lucia, thanks for un-banning my ISP. I bet everyone’s missed me 😉

  7. I used an old version of Corel Photo-Paint to resample to the smaller size. Saving as a 24-bit PNG, the file size is 33,437 bytes. Given the limited colors and expanse of white space, I figured an 8-bit GIF would be smaller. So I did a ‘save as’ from MS Paint, which does a better job with GIFs than Photo-Paint. The GIF is only 22,392 bytes and indistinguishable from the PNG.

  8. Sorry for the off-topic posting, but the Mann – NR lawsuit has been a hot topic over here, so I thought Lucia and readers would be interested in NR’s brief filed yesterday:
    http://www.nationalreview.com/sites/default/files/NR_Opening-Brief.pdf

    In addition to the normal discussion about actual malice, they raise what I believe is a new argument that NR cannot be held liable for third-party statements on its website. In a far more subtle way than Steyn, they also take multiple jabs at Mann for the hypocrisy of making almost identical statement to those he is taking offense to.

  9. Re: Levi (Aug 5 08:23),

    I love those doom and gloom sites and their exponential fits. Did you notice the inset graph in the ‘Year of Projected September Sea Ice Disappearance’ graph near the bottom of the page? Obviously that hasn’t been updated recently. The actual 2013 September minimum sea ice extent was above the top of the chart rather than continuing to decline. This year should be even higher.

  10. @DeWitt
    I did notice that, it reminded me of the rash of linear and exponential fit graphs back in 2011-2012 when people were juicing up headlines with quotes about “ice free arctic by 2015-2016” and so forth. Also reminded me of the folks this year who pounced on an uptick in Nino 3.4 to immediately proclaim “catastrophic El Nino being exhaled from R’lyeh as we speak”.

    Sometimes I wish people would run their posts/articles through some sort of reading software and compare the tone with a stock article from a street preacher with a “Repent” sign to do a rational discourse check. Or, perhaps pause before posting their 5 year linear trend for sea ice (or insert short term vector of choice) to look over the last response they made to people pushing a 10 year linear trend for temperature.

  11. Right –

    ice thickness is probably more illuminating.
    And all of the 4 and 5 meter thick ice has been pushed out of the Eastern Arctic and piled into the Western Arctic ( and squeezed into the Canadian Archipelago ):

    http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim30d.gif

    Also, this year there is an arm of 3 meter thick ice north of the Bering Strait that is poking into the Eastern Hemisphere. To the extent that it survives the minimum, it would become the anchor of multi-year ice accumulation. Even if it’s not this year, my money continues to be on reversion to the mean which would be Arctic Sea Ice accumulation.

  12. Re: Climate Weenie (Aug 7 12:13),

    I’ll even go out on a limb and suggest that Antarctic Sea ice will peak and begin to decline at the same time. The reason that Arctic ice has been declining more rapidly than the models predicted is, IMO, that the models don’t include whatever causes the AMO index to oscillate with an approximately 65 year period. Generally the Antarctic does the opposite of the Arctic.

  13. Here is an analysis of this year’s betting.
    NO. OF BETS 66
    MAX 6.130
    MIN 3.840
    MEAN 4.966
    MEDIAN 5.003
    STD DEV 0.499
    MEAN PLUS 1 SD 5.465
    MEAN MINUS 1 SD 4.468
    WITHIN +/- 1 SD 44.000
    WITHIN +/- 1 SD (%) 66.667
    MEAN PLUS 2 SD 5.964
    MEAN MINUS 2 SD 3.969
    WITHIN +/- 2 SD 62
    WITHIN +/- 2 SD (%) 93.939
    ABOVE MEAN (%) 51.515
    BELOW MEAN (%) 48.485
    MEAN BETS 1-33 4.955
    MEAN BETS 34-66 4.982

    The mean is remarkably close to last years mean prediction (4.91) and last year’s actual (5.045) but I believe those were v1 figures.
    I increased my own bet at the last minute, but I regret that it may already be too high.

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