Antarctic Sea Ice Complete Video
by Jeff Id , reposted here by invitation. The video animation Jeff put together is well worth watching, see it below the “read more” line. – Anthony
Antarctic temperatures and sea ice are becoming quite a hobby. It should make for some interesting discussion around the campfire this summer – not really. It takes my computer about 15 hours to calculate this movie and it took all day to figure out how to make the movie work. Actually it takes a minute then wait, then a minute and wait again. I finally got a reasonable quality video at 15 frames per second, one frame per day from 1978 – 2009. Before you watch the video Figure 1 is a map of the Wilkins ice shelf which apparently is about to melt every hot January summer at the south pole.
The melting of the Wilkins ice shelf has happened over and over prompting numerous articles like the following.
Wilkins Ice Shelf About to Break Off and Alter the Map of Antarctica
Vast Antarctic Ice Shelf on Verge of Collapse
The headlines are truly endless and will continue this year as well.
Here is a video which is particularly pertinent in it’s discussion and the fact that it ends with a discussion of climate science by Hillary Clinton. I recommend it to everyone before watching the video below.
Wilkins Ice Shelf Collapse Video
Below is a plot of the sea ice area anomaly in the antarctic calculated from the NSIDC NasaTeam algorithm data. It shows an upward trend in sea ice extent over the last 30 years.
Figure 2I’ve pointed out here many times that the trends do in fact exist if the even if the statistical certainty created by typical high frequency climate activity can create a trend of the same magnitude. This is an important differentiation which certain ‘over the top’ scientists in AGW crowd tend to blur. Statistical certainty of a trend does not always mean the trend does or does not exist, a trend is a trend to the certainty of the measurement error (different than certainty created from other noise). Some global warming bloggers like to blur that distinction.
The interpretation of a trend’s meaning does change with the statistical certainty of the trend. In the case of Antarctic sea ice growth I have seen one example demonstrating the trend is statistically significant despite climate noise. However the point of ice shrinking or growing is to interpret the consequences of a trend with regards to global warming. When interpreting the consequences of ice growth or shrinkage in my opinion the arbitrary significance threshold and linear trend has little meaning.
The annual variance of the sea ice is shown in Figure 3.
Figure 3
The huge annual variation dwarfs any apparent trend with the signal dropping to near zero every year. The thermal inertia of the ice creates a smooth cyclical process allows us to make pretty anomaly plots like Figure 2 but trend wise there isn’t much to say. So I guess I’m fired from my budding climatology career again. The reason they have little meaning becomes apparent in the wildly dynamic sea ice video presented below.
Below is a link to a video file of the Antarctic sea ice trends for 30 years.
Figure 4 – Antarctic Sea Ice Video – Click to play
Now consider that each pixel of the Antarctic ice data is 25 km and in the video of the Wilkins ice shelf, the crack is 40miles long – that is about 2.6 pixels in the Figure 4 video.
What’s really interesting about the video is the clockwise rotation of the ice which becomes especially visible during maximum extent. Another interesting point is the peninsula acts as a shelter to the ice on its leeward side. The Wilkins shelf get’s blasted by air and water currents every year from the south in this image, once we understand that combined with in the CNN video (link above) the reason the ice bridge exists is obviously due to protection from ocean and air currents by a small island (look at the angle of the ice bridge in the CNN video compared to current flow). The Island has protected this very small piece of ice from cracking for some time probably because the amazing circularity of the Antarctic continent doesn’t experience very large current changes.
I’ve watched the above video a dozen or so times (wouldn’t you after a day’s work) I noticed that there does appear to be a change in weather patterns in more recent years as the upward flow below the peninsula cuts away at the maximum ice extent on the West side of the image. The same is true for the East side of the image.
I had the advantage of doing a trend by pixel plot previously which led me to look for the effect. The plot done by myself in a previous post using a slightly older version of the same data is shown in Figure 5. The loss of ice on the West and East sides of the Antarctic is visible as blue pixels at the extreme edges of the range.
Figrure 5 – Antarctic sea ice trend by pixelIts difficult to imagine after watching this video that this ice shelf hasn’t collapsed (or whatever it’s called) and re-formed in the last several hundred years, more than once. Remember the ice from the shelf forms on land and flows out to sea. Either way, considering the natural variation of Antarctic sea ice, can we really say the current Antarctic ice trend or the change of an ice shelf in such a tiny area has a powerful meaning for the future of Earth?
If you missed the Arctic version of the video the link is here: Arctic Ice Video
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Folks,
Everyone needs to understand the difference between sea ice and ice shelves. Though the intro makes it sound like the post is relevant to the Wilkins ice shelf, the only thing discussed in the rest of the post and in the animations (nice work Jeff) is sea ice. There is a fundamental distinction between sea ice and ice shelves.
Antarctic sea ice = 1-2 meters thick, survives 2-3 years, strong seasonal growth/melt cycle, moves up to several kilometers per day with winds and ocean currents
Ice shelves = over 100 meters thick, have been in place for thousands of years, move slowly (a few kilometers per year at most) due to flow from upstream glaciers
Normal ice shelf cycle = occasionally calving of icebergs, some of which can be quite large (e.g,, the size of Rhode Island), due to normal flow from the glaciers upstream. Has routinely occurred for as long as anyone has observed Antarctica.
Wilkins ice shelf collapse = sudden “shattering” of a large area into small shards of ice due to a combination of long-term climate changes (warming temperatures) and triggering mechanisms (surface melt, ocean heat, ocean waves). This type of break-up had never been seen before the mid-1990s.
Walt Meier
National Snow and Ice Data Center
Graeme Rodaughan (19:44:11) :
Evil Humanity were busily using FREON, and hurling CFCs into the Atmosphere… These caused a Gaping Hole in the OZONE Layer over Antartica.
And where is that “gaping hole” you say? There are not “gaping holes” over Antarctica. It’s another case of environmentalist abuse of language.
Great video !! Really appreciate the time spent on this. Reinforces the acronym WWNV=Well Within Natural Variation. Wonder what Stieg et al would say about this? Would they even watch it? If Gavin is worried about making a living, might I suggest he quite his job, change sides and write a “tell all” book about how his bosses made him lie under threat of dismissal. Hey, it could happen, …….. :^])
Nasif Nahle (21:47:23) :
Graeme Rodaughan (19:44:11) :
Evil Humanity were busily using FREON, and hurling CFCs into the Atmosphere… These caused a Gaping Hole in the OZONE Layer over Antartica.
And where is that “gaping hole” you say? There are not “gaping holes” over Antarctica. It’s another case of environmentalist abuse of language.
Hmmm – it was parody.
“I’m sure there were larger burgs … in the last 100 years.”
Perhaps when BurgerKing offered an all-you-can-eat special in Texas.
Graeme Rodaughan (22:25:18) :
Nasif Nahle (21:47:23) :
And where is that “gaping hole” you say? There are not “gaping holes” over Antarctica. It’s another case of environmentalist abuse of language.
Hmmm – it was parody.
Heh! Sorry… 🙂
Wilkins ice shelf collapse = sudden “shattering” of a large area into small shards of ice due to a combination of long-term climate changes (warming temperatures) and triggering mechanisms (surface melt, ocean heat, ocean waves). This type of break-up had never been seen before the mid-1990s.
Walt Meier
National Snow and Ice Data Center
So your theory is that a 3C rise in temps, in a place where the median temp is somewhere between -20C and -30C or worse and the max temp never actually gets to 0C or even really that close, is responsible for 100 meter thick shelves of ice shattering into “small shards”. I’m a little slow, so maybe you could explain to me exactly how that works.
Walt Meier (21:16:41) :
“This type of break-up had never been seen before the mid-1990s. ”
Walt, you might want to look at “Implications of the break-up of Wordie Ice Shelf, Antarctica for sea level” by DAVID G. VAUGHAN, Antarctic Science 5 (4): 403-408 (1993)
The paper describes the breakup as follows:
“In the last few decades Wordie Ice Shelf has rapidly disintegrated to its current state; little more than a few disconnected and retreating glacier
tongues (Doake & Vaughan 1991)
Using the position of the ice front in 1966 mapped from aerial photography, they estimated that the ice shelf area decreased from about 2000 km2 in 1966 to about 700 kin2 in 1989. My analysis of more recent ERS-1 synthetic aperture radar images showing only sections of the ice shelf, indicates that the break-up is continuing at a similar pace.”
Apparently breakups of this category have been seen before the mid-1990s.
Nasif Nahle (22:59:46) :
Graeme Rodaughan (22:25:18) :
Nasif Nahle (21:47:23) :
And where is that “gaping hole” you say? There are not “gaping holes” over Antarctica. It’s another case of environmentalist abuse of language.
Hmmm – it was parody.
Heh! Sorry… 🙂
No Drama – all good. G
Walt Meier said ..”This type of break-up had never been seen before the mid-1990s.”
Is that restricted to observations from satellites? Or does it include all observations?
Apparently…..
“The largest Antarctic iceberg was spotted in 1956 – it was about as big as Belgium! Now that’s a serious ice cube.”
http://www.montshire.org/minute/mm980810.html
In February 1963 I drove my Mini Cooper S down the River Thames from Old Windsor the Magna Carta Island, Runnymeade and back and later held an ice party for 450 opposite the Bells of Ouzeley pub. All the scientific journals were commenting on an approaching Ice Age around that time.
Interesting video. The first thing that struck me when I started watching it was the clockwise rotation you refer to which is presumably down to wind and/or ocean currents. After watching it a couple of times it appeared to me that the rotation of the eighties had moderated somewhat by the nineties – although this was purely down to eyeballing the film. Nevertheless, it appeared to be a sufficient change for even a scientific lamebrain like me to notice. I don’t know if that slowdown in rotation is significant or even relevant, but it does suggest to me that there is always more going on at the poles than just warming and cooling.
To get some perspective on the current “collapse” of Antarctic Ice Shelves:
“The Larsen Ice Shelf extends along most of the east coast of Graham Land, and at its northern extremity nearly 1000 km2 has broken away in recent years (Koerner, 1964, p. 39). Ice shelves are confined to the southern part of the warmer west coast, and in King George VI Sound the ice front retreated about 45 km during the 1940s at both the northern and southwestern ends (Fuchs, 1951, fig. 2, 4). In East Antarctica Buinitskii (1964/1960, p. 217) notes that many of the ice shelves are becoming smaller. In the late 1950s Mellor and McKinnon (1960, p. 32) noted that the Amery Ice Shelf, which is close to the 0°C isotherm for January, was subject to greater melting than
were most other ice shelves: melt pools lay in hollows between pressure ridges, and the banding of icebergs indicated summer melt layers. This indicates that the ice shelf was subpolar in its northern parts, and thus vulnerable to climatic warming. In 1963, 11,000 km2 of the ice shelf broke away, the largest breakout ever recorded from any ice shelf (Swithinbank, 1966, p. 467).”
Mercer, J. A. 1966. “Antarctic ice and Sangamon Sea-Level”. International Association of Scientific Hydrology (IASH) General Assembly of Bern 25 Sept. – 7 Oct. 1967, Commission of Snow and Ice, Rreports and Discussions, pp. 217-225.
Note that we have practically no continuous data about Antarctica before the IGY 1957, so we can’t really expect to ever know what happened before then.
So, you’re now suggesting that Antarctica goes thro’ about of Global Warming followed by a bout of Global Cooling, each year, & expect us to believe it? Utter tosh!
Seriously tho’ a great video clip & prepared with great patience! Was I really detecting a slight rotational movement clockwise during ics expansion which was presumably due to ocean current circulation, or was it more imagined than seen? More impotantly, I didn’t really see a lot of difference of the 30 year timeframe between either maxima or minima.
Sorry chaps that should have read “a bout” not “about”! Sticky fingers due to all this heat I expect.
AtB
If we take the Svensmark hypothesis that as the planet warms, Antarctica cools AND VICE VERSA, then there would seem to be strong likelihood that Antarctica would have cast off a lot of its ice calves in the 1940-1975 patch. If consistent measurements of great ice calving only started after that, no doubt it would take time before calving started again. And don’t forget, not just local volcanoes – the recently warmed oceans also stream down south off the South American tip to warm up the nearby Antarctic Peninsula.
Meier says these sheets are 100m thick and thousands of years old. Yet they are said to move “only” a few kilometers each year. This suggests they are simply the continental ice sheet spreading out to the sea via glaciers (etc?) as the ice sheet pressure builds up. It doesn’t make sense otherwise, to me, to see a huge difference between massively thick ice sheets and very much thinner annual sea ice.
Jeff, hats off! Great stuff! I shall put it on my website as prominently as I can.
Now I’d like to add my own little animation, which took hold of Smokey’s yesterday’s blink comparator of sea level rise graphs and tidied it up so that the suspiciously strange difference is immediately, undeniably apparent. WUWT, for goodness sake, WUWT??
Reply: You new blink comparator is deceptive as the label doesn’t change between inverse barometer applied and not applied, which is the difference between the two graphs. (I’m not calling the use of inverse barometer adjustment correct or incorrect, just pointing out what the graphs mean.) ~ charles the moderator
Thanks Charles, you’re right. I’m taking it down again.
I’m actually already on the case, just downloaded all four graphs from Colorado University, finally found them. This ref doesn’t seem to be in the WUWT resources list, but I’ll check the replies and add it if not. I wanted to get to the bottom of this. Shame they don’t actually label each graph clearly. But I shall do so.
Should have said, silly me, leaping to premature conclusions…
Everyone knows that polar bears & penguins are mortal enemies. The penguins killed off the polar bears in the Antarctic & the polar bears won out in the Arctic!
Great video…will you create one for the Arctic?
Thank you for providing this video. It should silence the Al Gore worshippers once and for all in regarding ice situations in Antarctica. Meanwhile we see data from the North Pole that shows ice thickness actually getting thicker not less. The Church of Global Warming insists we not look at the mini ice age of the medieval period when grapes were grown in England and farming was done in Greenland. What will it take before the media starts reporting the truth about the myth of global warming?
Dave Wendt (20:41:48) :
My desktop thermometer says its 25 degrees – how does that sound as an average for the 1st of July?
I challenge any AGW’er to say their cherrypicked figure is more valid than mine!
Can I pick a charity, can I!
Excellent piece of work Jeff, effort appreciated
Walt Meier (21:16:41) :
Thanks for the comments.
Wilkins ice shelf collapse = sudden “shattering” of a large area into small shards of ice due to a combination of long-term climate changes (warming temperatures) and triggering mechanisms (surface melt, ocean heat, ocean waves). This type of break-up had never been seen before the mid-1990s.
I don’t see the evidence that long term warming has broken this ice shelf and am a natural skeptic of big claims. I have claimed no expertise in this area which is something most of the readers here are fully aware of. Anthony, generously let’s some of my work show here for the interest of his audience.
My point above is that the ice is globally tiny, the environment is incredibly dynamic and we don’t ‘really’ know how often this actually happens – there is still discussion of this in published work. As an Engineer when I think of it from an energy input perspective, the Wilkins shelf would be more influenced by a small change in current than 0.8C of warming. Even equal temp water at a very slightly increased flow rate would carry heat in at dramatically different levels. It would also have the side affect of peninsula warming BTW.
As a non-expert like most here, I appreciate the scientists like yourself stopping by to discuss these issues and am uninterested in disagreement in favor of improved understanding. Your comment leaves me some questions that you may be able to clear up.
If the ice shelf is replaced at a couple of kilometers a year, how fast would you say a wiped out shelf would rebuild in a zero anomaly environment?
After it slides back in place at some increased rate due to reduction of back pressure on the glacier, how do we know how long the shelf was there previously as the ice would appear to be very old?
“This type of break-up had never been seen before the mid-1990s.”
Walt Meier
National Snow and Ice Data Center
You are right Walt. It’s never been seen before the mid 1990’s. Why? Hmm, maybe because Man didn’t have satellites to see it in 1187 or 1345 or 1821. Yikes, it’s amazing how some ‘smart’ people think this little time THEY have been alive is pertinent to anything.
Hottest day on record “aka since 1880 when we started measuring”
Good thing the dust bowl happened in the 1930’s and not the 1550’s because the ‘European man’ would not believe those Native Americans and their ‘stories’ of great dust storms. ‘European man’ has never seen it happen so there for it never happened.
Does ice make a sound when it snaps if ‘European man’ is not there to hear it?
Stan (01:43:21) :
You saw what I also noticed. I think it’s a change in currents.
Look at the last figure in the post above which shows the pixel by pixel linear trend. You can see that the sides (in the image) of the sea ice have contracted while the top and bottom have expanded. This plot gives a clue of where to look for changes over the length of the video.
Just finished reading the same post over at The Air Vent . Might I suggest that Pragmatic and tty post their comments over there . The links provided to Angelika Humbert ‘ s interview were very interesting and go a long way toward explaining the collapse . Thanks , Jeff .