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    Arctic Ice August 2010 - Update #1
    By Patrick Lockerby | August 5th 2010 04:28 AM | 22 comments | Print | E-mail | Track Comments
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    Retired engineer, 60+ years young. Computer builder and programmer. Linguist specialising in language acquisition and computational linguistics....

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    Arctic Ice August 2010 - Update #1


    Most of the fires in Siberia seem to have been put out or burned out.  Meanwhile, the fires near Moscow continue to burn and there are more fires in Alaska.  I have made a mosaic composite showing the fires at the time of writing.  I have enhanced some of the red fire markers where they were faint in the MODIS originals.  Please note that the size of a red blob does not equate to the size of the fire.


    The Arctic - August 04-05 2010 - approx. 2km resolution.

    There are three red arrows pointing to the North West Passage and two sheets of shorebound ice.  In a comment to Arctic Ice August 2010, Espen asked:
    Looking through many modis 250m images, I have difficulties finding areas
    of not broken up arctic ice, do we have any figures (%) of not broken
    up ice in relation to ice extent, and how is not broken up ice defined?
    I don't think there is any sort of standard definition.  What I have done is to wade through many recent MODIS images to see if I can find any areas of continuous and consolidated ice.  One would expect to find substantial areas of continuous ice along the north coasts of the Canadian archipelago and Greenland.  Although there is dense ice in those regions, it does not appear to be consolidated.

    The only ice of substantial area which shows no signs of being merely pressed together or of showing interstitial open water lies adjacent to Flade Isblink.  Those sheets of shorebound ice are arrowed in the mosaic above.  They are not especially thick, but do contain some older ice islands and tabular bergs.

    Even more startling than the lack of sheets of ice is the roughly circular floe sitting near the middle of the North West Passage - arrowed in the above image.  It shows up nicely in the following animation - as does open water in the NWP.  The NWP looks to be about 50% ice free, which makes it just about navigable.


    North West Passage August 04 2010

    Why do I describe a single floe as 'startling'?

    As older ice disappears we are no longer seeing vast sheets of ice in summer - we are seeing loose aggregates of separate floes.  In a loose aggregate, the smaller the particle size, the greater the mobility.  The SST graphs from polar.ncep.noaa.gov seem to track ice extent nicely.  The purple areas in the animation show a mobility which we are seeing in the pack.  I am grateful to Neven for the first frames in this animation - I added the last one to show warm water penetration.  You can see how warm Pacific water is entering through the Bering Strait, left.  You can also see warmer water entering from the Atlantic.  Given enough warm air and warm water, melt proceeds rapidly even in the absence of direct sunshine.


    RTG-SST July 22 - August 04 201

    I keep reiterating the simple fact that smaller floes melt faster.  This point has been made in NSIDC's August report:
    ... smaller floes melt more easily than consolidated ice. This behavior is becoming more typical of the ice pack as the ice thins.

    http://nsidc.org/arcticseaicenews/2010/080410.html
    Old ice is vanishing.  This means that if the winter freeze produces an increase in ice extent it does so by producing new ice.  If you take the winter maximum extent and subtract the previous minimum, what you have left is the extent of first year ice.  First year ice is the fastest to disappear in summer.

    Even if this winter were to produce the greatest extent in the satellite record - which is doubtful - the new ice would likely all be gone by August 01 2011.

    This past winter's negative phase of the Arctic Oscillation transported old ice (four, five, and more years old) from an area north of the Canadian Archipelago. The ice was flushed southwards and westward into the Beaufort and Chukchi seas, as noted in our April post. Ice age data show that back in the 1970s and 1980s, old ice drifting into the Beaufort Sea would generally survive the summer melt season. However, the old, thick ice that moved into this region is now beginning to melt out, which could further deplete the Arctic’s remaining store of old, thick ice. The loss of thick ice has been implicated as a major cause of the very low September sea ice minima observed in recent years.

    http://nsidc.org/arcticseaicenews/2010/080410.html

    The NSIDC report says:
    Cool, stormy weather this July has made it less likely that the upcoming 2010 sea ice minimum will set a new record. It would take a very unusual set of conditions in August to create a new record low.
    What would constitute "unusual conditions"?  Have a look at that floe again.  It is about 200 35km. diameter.


    NWP floe - 1km resolution.

    I invite my readers to find a floe bigger than that one anywhere in the main ice pack.  From my own searches I have not found such a floe.  If the biggest individual floe in the entire Arctic is indeed only 200 35km. diameter then the ice is more mobile today than in any Arctic records.

    Does that constitute "unusual conditions"?

    Note: error '200km.' edited.  Thanks to Nick Barnes for spotting my error.
    ----------------------------------------------------------------------------
    More
    articles on the Arctic and related topics:
    The ChatterBox Arctic Index


    Recommended blog:


    Neven on Arctic Sea Ice - interesting news and data:
    http://neven1.typepad.com/blog/

    Comments

    The circular floe in Viscount Melville Sound, north of Prince of Wales Island? It came out of Austin Channel, between Byam Martin Island and Bathurst Island. It's not 200km, more like 40km.

    logicman
    Nick: many thanks for spotting my error - now corrected.  I was counting pixels at the wrong resolution.  Considering the strait is only about 100km wide just south of the floe, that shows how wide my error bars can be when I have a migraine. :-)

    I've re-measured more accurately and I now make it 35km. diameter.  Which is even more startling.

    The challenge still stands:  I can't find a bigger floe in the Arctic mosaic and wonder if I may have missed something.  There may be one hidden under a cloud, but I doubt it.

    Areas which look like continuous ice at the default scale of 4km show up as having lots of interstitial water when viewed at higher resolutions.  Even within those areas there appear to be no floes bigger than 35km across.

     
    There seems to be a lot of conflicting views. Some say the arctic icebergs are melting away causing water level to rise. Certain sources argue that icebergs are building up. Not sure which to believe. What's your view?

    logicman
    There seems to be a lot of conflicting views. Some say the arctic icebergs are melting away causing water level to rise. Certain sources argue that icebergs are building up. Not sure which to believe. What's your view?
    That's a fair question, Will.

    When ice from a glacier falls off into the sea as a berg, or is pushed into the sea as a floating tongue, then at that exact moment it displaces its own mass of water.  From then on it can add nothing to sea level.

    All glaciers which calve directly into the sea without a floating tongue add to sea level rise at the moment of calving.

    Where there is a floating tongue, the contribution of the glacier to annual sea level rise is only the amount of fresh ice pushed into the tongue annually.  If the entire tongue were to fracture and drift away, this would not - could not - raise sea levels.  Only ice moving freshly from land to sea can do that.

    Ice which has been afloat for years, decades, centuries even, has long since added its contribution to global sea levels.

    It doesn't matter if floating ice melts or not: the mass remains the same.  An iceberg displaces its own mass.  It is only fully submerged objects that displace their own volume.
    A lot of the cloud over the arctic seems to be clearing, giving us a better view of the central pack than we've had for a couple of weeks. Today's mosaic shows the same highly-fractured ice, with large leads, right over the pole. Consider this tile:
    http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r04c04.2010217...
    The pole is in the lower-left corner. A lot of that image, including areas around the pole itself, is 50%-75% concentration, kilometre-scale floes with occasional ones up to 10 or maybe 20km. But no, I can't see any floes larger than that.

    logicman
    Thanks for taking the time to check that, Nick.

    Without corroboration, it ain't science.  :-)
    Patrick,

    You may be interested to go back to before this circular floe broke free, along with several others in company. A couple of these can be made out in the pictures you've used.

    On Day 180, they can be seen clearly, still trapped in the ice in the Austin Channel, bluish in amongst more recent white/grey ice, along with about 20 or so similar if smaller floes.
    http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r04c02.2010180...
    The big one is jammed right between Byam Martin and Bathurst (as Nick mentions) filling the whole channel. I presume, since its rounded and thick that it had been drifting for a while (collisions rounding off corners) until it got stuck there and iced in. It's even clearer on the 250m resolution pic.

    By day 190 the breakup reached the southern edge. Over the next 10 days, there was a lot of breakup in these channels, stong winds/currents swinging back and forth. I can't actually see when it breaks loose, due to cloud, but by day 203, it has become free and is entering Viscount Melville Sound.
    http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r04c02.2010204...
    Day 204 is best view at that time, with about eight of these big old floes on the move either side of Byam Martin, some of which are also 100 sq kms (but not the 500+ that this one is).

    If it can squeeze between Prince of Wales and Bathurst Island (~25 August, I'd guess), and then Somerset and Cornwallis (~10 September?) then it's doomed. But I suspect it might get stuck on the small islands in those narrows and it will be hefty enough to survive until it gets frozen in again.

    There might be a bigger one, though. At at the same time as Byam Martin Channel was shaking loose, there was a lot of movement northeast of Bathurst Island as well. There was a large floe, which was actually several of these thick old chunks welded together by younger ice, drifting to the southwest of Ellef Ringnes Island at the end of July. I haven't been able to see it clearly due to cloud since Day 212 when it was about twice the size of your one. The thin matrix will be melting at shedding the thicker chunks, but its probably still larger.

    logicman
    FrankD: thanks!  I'm very grateful to you for going to all that trouble.  I am busy at the moment with focus on the new Petermann ice island  ( Chatter-box island?  Lockerby Island?).

    If you can create a series of selected images and/or an animation I'll use them with full credit.  Even better: email me an article - via my profile - and I'll post it as a guest blog.
    Patrick,

    I got home from work today planning to compile the animation of the NWP, only to find Neven the Animeister had got their first - it's only three frames, but it shows exactly what I was wittering on about.

    http://neven1.typepad.com/blog/2010/08/animation-11-canadian-archipelago...

    In the last frame, it looks like the bigger "matrix" floe has broken up against the north shore of Bathurst Island.

    logicman
    FrankD: I am about to write an article on this very aspect of science. 

    Have you noticed how ice free many of the inlets and channels are in the whole archipelago?

    You might like to compare today's ice - or lack of it - with MODIS images from August in other years:
    http://rapidfire.sci.gsfc.nasa.gov/realtime?calendar

    The MODIS images and raw data make the whole planet virtually accessible to scientists.  Especially in the case of the Arctic it is highly likely that any specially interesting area will be under observation by a number of unconnected people.  You, Neven, me, many others are linked through blogs and so can exchange new information rapidly.

    I have been glimpsing the area while waiting for just the right image of Petermann, Humboldt, Zachariae, 79N, Jakobshavn and other glaciers.  I haven't had time to even write a new Arctic ice report.  Neven the Animeister - I like that name - beat us both with this one.  He's good.  He's beaten me to the punch a few times.  Neven often beats me at this game, and I've already told him that I hate him for it. ;-)

    You may like this article by Hank Campbell:

    LiquidPublication - Publishing Without The Peer Review Hassle
    Neven
    All your animation are belong to us. ;-)
    logicman

    All your animation are belong to us. ;-)

    Hi Patrick,

    Knowing something about particles, I and I believe it is the same with ice, fragmented ice got much more surface than solid ice, therefore it evaporates (melts) quicker.
    Regards Espen

    logicman
    Correct, Espen.

    fragmented ice got much more surface than solid ice, therefore it evaporates (melts) quicker.

    In addition, every fragmentation increases the total surface area.  Since the bulk of the ice is under the water, if air and water are at the same temperature, then the water will melt more ice than does the air.  If air is too cold to melt ice but it pushes the ice into warmer waters then we can say that the wind was a contributing factor to melting.

    On the whole it is warm water that melts most ice.  Which is what is happening right now, at a time when the polar ice is the most fragmented I have ever known.
    Hi Patrick,

    Fragmentation, is the factor now, in my opinion, not ice extend and whatever, because the greater the fragmentation the quicker we will see the disappearance of the arctic sea as we know it (with ice that is), and it will be very fast at one point, so your estimate of less than 4millionkm2 this year is not unthinkable. That is the reason why I spend most of my time studying the behavior of the Arctic Sea, and especially fragmentation.
    And I will make a prediction if fragmentation develops at the same rate as now, the Arctic Sea will be free of ice more than 1 years old ice in a few years, probably within 5 years from now.
    So what is the reason for the fragmentation, that's a political question, as you probably know!

    Best regards Espen

    logicman
    Espen:  I have covered fragmentation before and will do so in my next update.  At the moment I am focused on the ice island.  I'm trying to determine how practical it is to predict how it will move and break up.  I'm also looking to see if any further calving is likely soon.  It's a bit like the mtbf and mttf predictions in engineering: either a thing will fail rapidly or it will fail eventually.  The trick - lovely word - is to use one's accumulated experience to make educated guesses about possible failure modes and translate that into most probable failure modes.

    http://en.wikipedia.org/wiki/Mean_time_between_failures

    Links to articles covering Arctic ice fragmentation and mobility:
    http://www.science20.com/search/apachesolr_search/Arctic%20fragmentation...
    Patrick,

    Following the progress of your floe; between days 211 and 221 (yesterday, depending on your time zone), it drifted 68 kms SSE. At the current rate of progress it will run aground on the north shore of Prince of Wales Island inside a week. Even if it swings more westernly, it's still 25 x 30 kms, which would seem to be too big to fit between any of the islands in Barrow Strait, so it will likely be a feature of the NWP for a while.

    Looking at this area, a thought strikes. Normal operation of the Beaufort Gyre tends to push ice against the northern shores of Ellesmere and Greenland, or out through the Nares and Fram Straits. This year, it has tended to push more westerly, against the Queen Elizabeth Islands (QEI). Since the beginning of July, the "fracture line", for want of a better word - that line south of which the ice is fractured and mobile - has been moving steadily northwards through the channels between these islands; in the month since day 190 (as I mentioned above), it has moved perhaps 500 km's north and is now nearing the interface between the QEI and the Arctic Ocean. It is probably 50 kms south of the northern end of Byam Martin Channel and Maclean Strait, and maybe 70 from the north end of Peary / Sverdlup Channel. Even Nansen Sound, between Axel Heiberg and Ellesmere is fracturing. At the current rate, all of these channels will have unconsolidated ice within perhaps 5 days. At that point I think we'll start to see ice being exported from the Arctic Basin through the NWP. I don't think thats all that unusual of itself, but I think there will be a lot more ice than usual being exported this way.

    Moving ice through the QEI is inefficient - several dead ends, changes in direction and blocking islands - but it remains that the wind and water are pushing that way, and these channels are each three of four times the width of the throat of Nares Strait.

    logicman
    FrankD:  nicely observed!

    As I mentioned in a comment over on Neven's blog,

    If those channels open more, then we shall see more ice being exported out of the Arctic ocean. In the worst case scenario, the skies clear and ice is exported by wind and currents via the Canadian archipelago, Nares Strait and Fram strait. Ice extent plummets to below 3m km2 before the freeze sets in.

    However, my forecast of 3.5 to 3.8 stands.

    http://neven1.typepad.com/blog/2010/08/animation-11-canadian-archipelago...
    Yes, You put it shorter and sweeter than I...

    I saw that after I posted my blather .

    :-)

    logicman
    Yes, You put it shorter and sweeter than I...

    But short and sweet never won a court case.  :-)
    That large floe in the NWP has changed direction - it's turned sharply to starboard, as wind and weather have pushed it to the west, and now appears to be heading down M'Clintock Channel. After stalling for a couple of days, it's now moved ~60 kms southwest in two days.

    If it doesn't get pushed against Victoria Island and run aground, it will probably get hooked up on the small islands between Victoria and Prince of Wales at the south end of the Channel, near to where Franklin's Expedition cashed its chips.

    Random - I wonder how much force it takes to change the direction of a 700 sq km chunk of ice through 90 degrees...I lost track of the zeroes...!

    logicman
    I wonder how much force it takes to change the direction of a 700 sq km chunk of ice through 90 degrees...I lost track of the zeroes...!

    You may well wonder how much more force it takes to make a glacier turn through 90 degrees.  Quite a few of them do that when they argue with each other about right of way. :-)

    Thanks for the reminder - I sort of lost track of that floe when sections of the wonderful wild web started blathering about how a giant ice island four times the size of Australia was going to endanger navigation in the Thames - or some such nonsense.  :-)

    I'll go look for it and see if it has shrunk much.  The floe - not the ... 
    Oh, you're intelligent, you figure it out!