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Antarctic Sea Ice Claims Don’t Stand Up To Scrutiny

February 23, 2017
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By Paul Homewood

 

image

https://uk.news.yahoo.com/antarctic-ice-sheet-smallest-ever-002800989.html

 

From Yahoo:

 

A few days ago, the US National Snow and Ice Data Center announced that the Antarctic sea ice contracted to just 883,015 sq. miles, which is the smallest on record.

Experts assert that, if changes are not made to pollution and our fossil fuel industry, a number of species will be threatened as sea levels (and temperatures) continue to rise.

The Antarctic ice sheet goes through a cycle of expansion and contraction every year. Ultimately, the ice that exists around the continent melts during the southern hemisphere’s summer, which occurs towards the end of February, and expands again when autumn sets in.

However, that melting is increasing dramatically.

This week, the US National Snow and Ice Data Center (NSIDC) announced that the sea ice contracted to just 883,015 sq. miles (2.28m sq. km). The announcement came on February 13, and these numbers mean that the ice is now at the smallest extent on record, reaching just a little smaller than the previous low of 884,173 sq. miles, which was recorded February 27, 1997.

NSIDC director Mark Serreze asserts that we will need to wait for measurements in the coming days before officially confirming this new all-time low; however, he is not optimistic. “Unless something funny happens, we’re looking at a record minimum in Antarctica,” Serreze told Reuters.

https://uk.news.yahoo.com/antarctic-ice-sheet-smallest-ever-002800989.html

 

 

S_stddev_timeseries

http://nsidc.org/data/seaice_index/

 

Antarctic sea ice extent has been running below average for the last few months, and unsurprisingly the usual suspects have been jumping up and down and blaming it on global warming.

This despite the fact that Antarctic sea ice extent has been expanding in recent years, something that junk scientists, like Jim Hansen,  have been trying to blame on, yes you’ve guessed it, global warming.

 

s_plot_hires

http://nsidc.org/data/seaice_index/ 

 

NSIDC’s propagandist in chief, Mark Serreze, is quite clear:

 

Climate change skeptics have often pointed to the tendency of the Antarctic ice sheet to expand as evidence against global warming. But with world average temperatures hitting an all time high in 2016, the impact of climate change on planet Earth is getting more pronounced and harder to deny. “We’ve always thought of the Antarctic as the sleeping elephant starting to stir,” Serreze stated; “Well, maybe it’s starting to stir now.”

https://uk.news.yahoo.com/antarctic-ice-sheet-smallest-ever-002800989.html 

 

He should know, since NSIDC, the organisation he is in charge of, has already reported, the sharp drop in sea ice since September has been due to changing wind wind patterns. This is linked to the Southern Annular Mode turning negative, allowing winds to penetrate from the north, both lifting temperatures and at the same time pushing sea ice towards the coast. (See here)

This is a perfectly natural phenomenon. We also know that sea ice in the Antarctic has fluctuated wildly, both up and down during the 20thC, and there is no reason to suppose that this time is any different.

 

However, there is another side to this story. Just how accurate are the numbers we are being fed with by NSIDC?

According to them, they have been using a new satellite instrument since April 2016.

Cryosphere Today, who usually provide sea ice data as well, also report that the satellite data they have received since last April is spurious, so there is no cross check with NSIDC.

 

image

http://nsidc.org/data/docs/noaa/g02135_seaice_index/

 

NSIDC have become so politicised over the years that only a fool would trust the numbers they are putting out. And with something like sea ice , it is very easy to fudge the figures.

Which brings us onto the next point – margins of error.

As the Yahoo report points out, the extent this year is only 1158 sq miles less than recorded in 1997, just 0.1% less.

NSIDC do not publish error margins in their data archive, but even they admit that they can be huge, particularly in summer when ice concentration is low:

 

6.1 Accuracy and Precision

The accuracy of Arctic sea ice concentration at a grid cell in the source data is usually cited as within +/- 5 percent of the actual sea ice concentration in winter, and +/- 15 percent during the summer when melt ponds are present on the sea ice (GSFC Confidence Level), but some comparisons with operational charts report much larger differences (Agnew 2003, Partington et al 2003). Accuracy tends to be best within the consolidated ice pack where the sea ice is relatively thick (greater than 20 cm) and ice concentration is high. Accuracy decreases as the proportion of thin ice increases (Cavalieri 1995).

The accuracy of the median sea ice extent edge position for Sea Ice Index products has not been rigorously assessed. It would be difficult to do so, because ice edge is not a well-defined parameter. For our purposes, it is where source data grid cells transition from greater than 15 percent to less than 15 percent concentration. Operational services usually speak of a marginal ice zone of varying width over which concentration transitions from more than 90 percent to 0 percent. Spot checks of the sea ice edge position using a 15 percent concentration cutoff against NIC ice charts show that when there is a broad, diffuse ice edge, the NRTSI and GSFC products sometimes do not detect sea ice where the concentration can be as high as 60 percent (Fetterer 2003 poster). When the sea ice edge is more compact, the 15 percent concentration cutoff reflects its location fairly well (Fetterer 2002).

Defining the ice edge in SSM/I data using the 15 percent concentration contour has been common practice since the publication, in 1991, of a study that compared SSM/I ice concentration data from the NASA Team algorithm with coincident data from higher resolution airborne imagery. That study used remote sensing data acquired in March 1988 and found that aircraft-determined ice-edge positions matched the SSM/I 15 percent ice concentration contour (Cavalieri et al. 1991).

Ice concentration from low-resolution passive microwave data is not highly accurate; and for this reason, it is best not to use Sea Ice Index ice concentration images alone, out of temporal context, especially those from a single day. Ice extent images are more reliable, because the difference in emissivity between open water and sea ice, even at low concentrations, is great (Comiso and Kwok 1996). Still, the instrument’s low resolution (see Table 5) means that the ice edge, whether it is a compact or diffuse marginal ice zone, will not be represented well. For example, the daily 25 km SII extent product for 08 September 2011 is shown in Figure 21 along with the 4 km Multisensor Analyzed Sea Ice Extent (MASIE) product from the same day. MASIE resolves the ice edge with greater precision and accuracy, but it is not a long and consistently processed record. The Sea Ice Index daily product does a reasonable job, but it is evident why we place higher confidence in monthly than in daily products. Many errors due to missing data and transient weather effects are averaged out when we average daily data over a month.

http://nsidc.org/data/docs/noaa/g02135_seaice_index/#accuracy_precision

 

 

To claim a record low based on a difference of 0.1% is clearly statistically nonsense. Worse than that, it is dishonest.

No serious scientist would dream of making such a claim, but this is NSIDC we are talking about.

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17 Comments
  1. Jack Broughton permalink
    February 23, 2017 10:59 am

    I hope that Donald Trump is made aware of this; the attack of the warmists is now verging upon hysteria.

    • February 23, 2017 11:44 am

      From Forbes, February 21, 2017:

      “New Environmental Protection Agency administrator Scott Pruitt addressed EPA staff and the media Tuesday, and in a speech lasting less than 15 minutes, he spoke mostly about protecting jobs, industry and “the marketplace” and oh yeah, the environment, too.

      Pruitt comes to the Trump administration from his previous job as Oklahoma attorney general where he spent a fair amount of time suing the very federal agency that he now heads. In six years he filed more than a dozen lawsuits against the EPA over expansion of the Clean Water Act and regulations on coal-fired power plants.

      If that track record didn’t make it clear what direction Pruitt will take the EPA, reading between the words of his introduction to the career employees who have spent decades working to safeguard our natural environment solidify it in crystal.

      To start, let’s just note that the word “climate” did not pass Pruitt’s lips, so that’s clearly no longer a priority at EPA, as we suspected.”

      Donald is on the case.

  2. NeilC permalink
    February 23, 2017 11:33 am

    Serrez is obviously trying to create an inverted hockey stick! Why add oranges (from Apr2016) to the historical readings (cryosphere today) of apples? Prat.

  3. February 23, 2017 11:41 am

    Little evidence that year to year changes in monthly mean sea ice extent is a global warming phenomenon. Non-warming factors in sea ice extent are ignored to push the AGW agenda.
    https://papers.ssrn.com/sol3/papers2.cfm?abstract_id=2869646

  4. nigel permalink
    February 23, 2017 11:58 am

    To attribute everything noteable to one shadowy cause is virtually the definitition of superstition.

    I make a prediction. At present, tropical cyclone activity has almost disappeared. The old idea that global warming should reduce such storms will be RESURRECTED, and the recent assertion that global warming is increasing storminess will be conveniently forgotten. Until, of course, natural variability sends a Cat 5 hurricane America’s way.

  5. nigel permalink
    February 23, 2017 12:03 pm

    By the way. I remember from my school days that a mixture of ice and water has the same temperature regardless of whether the ice is 99% or 1%

  6. A C Osborn permalink
    February 23, 2017 12:14 pm

    Paul, I have been saying for some time that I did not believe the Values for both Arctic and Antarctic sea Ice, as they hardly ever have moved in concert, always in opposition.
    I had not realised they had changed the Satellite, which explains a lot.
    More untrustworthy than a barrel load of Monkeys.
    They have been pushing for every “Adjustment” possible in temps due to any kind of “equipment change” and yet here we have them deliberately using a change to push their agenda.

  7. MrGrimNasty permalink
    February 23, 2017 1:24 pm

    When they did the early Nimbus satellite photographic analysis, I seem to recall that within 2 years in the 1960’s, the Antarctic max. ice extent was both above, and below, previously known records. Did they look at minimum extent as well? I’m sure they’d find similar sudden NATURAL variations in that too.

  8. Athelstan permalink
    February 23, 2017 1:30 pm

    Oh God, again hocus pocus and mumbled jumblings and eh wot? da the statistics is gone funny AGAIN!?…………….dear Lord! my brain is hurting and who will rid us of these troublesome malign priests of green?

    Cometh the hour, cameth ‘The Donald’ – send in the knights please MR. President!

  9. John Ellyssen permalink
    February 23, 2017 4:19 pm

    Thank you Paul. I have been waiting for this since I received my report from the U. S. Government. I knew it had to be bogus and massaged by someone who was not a scientist because it had a paragraph warning of sea ice extent melting causing multi-feet sea level rise over the upcoming years through 2030.

  10. Tony McKenna permalink
    February 23, 2017 4:24 pm

    In para two he seems to be linking sea ice extent to sea level fears. That is desperation.

    • nigel permalink
      February 23, 2017 4:44 pm

      “…desperation…”

      Desperate stupidity, more like.

      Record this and record that…I am reminded of the line in “The Little Rascals” movie:

      “The ‘Blur’ hasn’t neen beaten since the beginning of time five years ago.”

  11. February 23, 2017 4:39 pm

    So in a nutshell Serreze, having been consistently and embarrassingly wrong about Arctic sea ice, is about to try his luck being wrong about Antarctic sea ice.

    “Send in the Clowns. Don’t bother; they’re here”!

    • nigel permalink
      February 23, 2017 5:01 pm

      Everything gets a complete “reset” twice a year near the poles. It is called. switching from relentless day to relentless night, and back again.

      How can the ocean five hundred miles out from Antarctica whirling round in the dark as the Antarctica Circumpolar Current* remember in four months’ time that “it” melted or dispersed a little more than usual along one strech of coast in the summer?

      https://nsidc.org/data/seaice_index/

      *

  12. February 23, 2017 5:06 pm

    As a skeptical skeptic I say that we should not dismiss this out of hand but add it to our library of data with which we make our decisions and form our opinions. The growing trend of Antarctic sea ice has clearly reversed; something may very well have changed. Whether this is something to be alarmed about waits to be seen.

  13. Tom Richard permalink
    February 23, 2017 7:10 pm

    Hey Paul,
    I was able to incorporate what you wrote in a new article today with attribution to you. Feel free to view it at:
    http://us.blastingnews.com/news/2017/02/debunking-claims-of-antarctica-s-record-sea-ice-loss-001497171.html

  14. February 23, 2017 10:37 pm

    We’ve just had a big El Niño which is a ‘Southern Oscillation’ (ENSO).

    Let’s see if we get a trend or if it’s a one-off dip Antarctic in sea ice this year.

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