An update on Jeff Id's excellent sea ice video

Arctic Sea Ice Video Update

by Jeff Id

As we approach the Arctic Sea Ice minimum, a lot of eyes are looking and projecting what the minimum will be. In a previous post I calculated the centroid of the sea ice as a method for determining how the weather patterns were affecting the data. About a month ago, it seemed that the weather pattern was going to support a leveling off of the sea ice shrink rate so that’s what I predicted and that’s what happened. The curve cut across the 2008 line and reached over until it touched the 2005 line.

AMSRE_Sea_Ice_Extent[1]

Unfortunately, from this centroid video, it looks like the winds from the Southeast in the image which created the huge reduction in Sea Ice in 2007 appears the have restarted this year. It’s already starting to accelerate the melting which caused this year’s red line to dip below the 2005 green line.

The shift in weather pattern is most visible in the shadows on the ice which are actually clouds blowing through. The shadows indicate the 29GhZ microwave data is sensitive to clouds which is part of the noise in the long term signal.

Below is an updated 2007 – present video.

Click to play

If you missed the original video which is full record length and shows the unusualness of the current weather patterns in the last 30 years, it’s linked at this post below.

Arctic Ice Weather Patterns

That post explains the arrow vector and the source of the data.

I’m going to update my prediction from this shift in weather. Now I think the ice level will dip quickly downward in relation to 2005 but will still sit above the 2008 minimums. It looks like the ice has been thinned by the recent blasts of weather from the southeast and if this pattern maintains itself the dip will be fairly strong.  Of course I’m an engineer and not a meteorologist so we’ll see.


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87 thoughts on “An update on Jeff Id's excellent sea ice video

  1. The wind vector makes the video perfect.
    It must have been a lot of work.
    Thanks for posting it.

  2. Thanks, Jeff — for both the original and this update.
    I’m still not sure what the significance would be if this Ocean becomes ice-free, or nearly so, for a few weeks even as I doubt that will happen. Will not the energy of the water move to the atmosphere faster with no ice cover? When southern currents bring warm water that undercuts the ice layer is that not also increasing the loss of energy from ocean to atmosphere to space? And the DMI Polar Temp is below freezing so the solar heating has faded. Seems to me this part of Earth is like a freezer with an open door pulling energy from the Earth system and dumping it out. Is a cold NH winter on the way?

  3. Cool,
    Unfortunately few people are going to accept this as anything other then evidence that the arctic sea ice is going the way of the Dodo. It will always be global warming that is the cause not a shift in weather patterns.

  4. There’s got to be a better way of referencing vectors than the usual N, E, S and W at the poles!

  5. I like it that time lapses slowly in the video.
    The prediction of an ice free North Pole in 5 years looks to be wrong.

  6. Jeff: I’m always in awe of your mapping capabilites when I view these.
    Don’t we have less baby ice this year (more of it in the terrible twos and threes)than we did in 2007?
    Regardless of whether the ice area is greater or less than 2005’s, the AGW crowd will continue to harp on the fact that it’s below the 1979-2000 average, no matter how many ways we try to show that elevated SST anomalies and TLT anomalies of the mid-to-high latitudes of the Northern Hemisphere are the results step changes caused by ENSO events.
    Hmmm, thinking of your graphics capabilities… Do you know how to create Hovmoller plots?

  7. Britannic no-see-um (15:32:04) : “There’s got to be a better way of referencing vectors than the usual N, E, S and W at the poles!”
    Well, North and South still work, but East & West are iffy. Perhaps this-a-way (sinister) and that-a-way (dexter)? Or maybe deosil and widdershins? The latter sounds unscientific enough to fit right into the post-modernist bent of latter-day science.

  8. John F. Hultquist (14:51:33) : “…I’m still not sure what the significance would be if this Ocean becomes ice-free, or nearly so, for a few weeks even as I doubt that will happen. Will not the energy of the water move to the atmosphere faster with no ice cover?”
    Yes, given that (1) the emissivity of open water is about 0.993, much higher than ice, and (2) ice is an insulator, and (3) the nights will be getting longer in just another month, (autumnal equinox = Sept 22, 2009; 5:18 P.M. EDT), there would be very high energy loss. Add to this a hypothetical decrease in nighttime sky black body temperature during a solar minimum, and the result would be rapid rebound of Arctic Ice in October, perhaps at record rates.

  9. Creating catastrophe
    by Ian Plimer
    August 22, 2009
    Destroying the factory, building the bureaucracy
    The government’s Carbon Pollution Reduction Scheme has the potential to ruin Australia’s productive economies and to build an even greater bureaucracy. Even the name of this bill should ring warning bells as carbon is the foundation of life and is not a pollutant.
    It is claimed that there is a scientific consensus about human-induced climate change. Consensus is a process of politics not science. There is certainly no scientific consensus about human-induced climate change and the loudest voice does not win scientific discussions. Science is married to evidence, no matter how uncomfortable.

  10. [b]jorgekafkazar (16:10:41) : [/b]
    [i]Britannic no-see-um (15:32:04) : “There’s got to be a better way of referencing vectors than the usual N, E, S and W at the poles!”
    Well, North and South still work, but East & West are iffy. Perhaps this-a-way (sinister) and that-a-way (dexter)? Or maybe deosil and widdershins? The latter sounds unscientific enough to fit right into the post-modernist bent of latter-day science.[/i]
    I believe that it would be North and South that become unuseable as when you are at the North pole, all directions are south and vice versa. The only references that work are those towards eastern and western ehmispheres.

  11. Seems like the accelerated melt so far is not quite accelerating, actually the melt rate has been the same for a few days now.
    However Intellicast’s forecast maps show near to below freezing temperatures in parts of northern Canada and some areas in Siberia near the Arctic Ocean, if those areas continue to slowly cool off then it could possible just slow any ice melt from temps. in those areas.
    Also we have also heard of SST’s in parts of the Arctic more than 10 degrees above average, assuming they use centigrade I look at Unisys SST anomalies and it’s not showing that, 2-3 degrees maybe but not 10.

  12. jorgekafkazar (16:25:33) :
    Pretty much the way I see it.
    The Ice albedo thing is a strawman, the big thing is the additional heat loss because of the presence of open ocean. I hypothesise that this is a cycle.
    1) the Earth warms, creating weather conditions suitable for ice melt.
    2) The ice melts, allowing the Earth to cool & the ice to re-grow.
    3) This inability to lose heat may even be one of the causes of the ends of ice ages.
    DaveE.

  13. bryan (16:30:19) :
    Actually, at the poles ONLY North or South work, (Depending on the pole you are at.)
    DaveE.

  14. Nogw (16:58:51) :
    bryan (16:30:19) : for your html code to work you must use, instead: ()
    What Nogw meant was enclose the HTML in left & right caret, ie [shift], & [shift].
    All the best.
    DaveE.
    [On this site you must use <, > for your HTML, rather than brackets: [, ]. ~dbstealey, mod.]

  15. Where is the wind direction/strength data coming from, i.e., is there a source data file? Or is the vector (the length/direction of the red arrow), merely calculated from the centroid variation data?
    Compare the difference between these two plots:
    http://www.arctic.noaa.gov/images/weatherdata/2004/wx_2004.gif
    http://www.arctic.noaa.gov/images/weatherdata/2009/wx_2009.gif
    then look at all the available weather data plots from 2002-present here:
    http://www.arctic.noaa.gov/gallery_np.html
    I would draw attention to the wind speed scales against the wind plots – recent years have seen almost no stormy weather.
    The Arctic drifting buoys that are set up in the spring near the pole seem to tell a different story. Over the last few years – apart from the recent instability of the ice making longer-term measurements impossible for unmanned buoy deployments, compared to previous year’s deployments, which recorded more-or-less the whole year’s weather – the last few years show much less windy weather since 2004-5.
    The recent years of calm Arctic weather (more southerly Jet etc.) have not led to pack-ice formation, – the surface sea ice topology has remained relatively flat, and has not contributed to either atmospheric/ice surface turbulence or at the interface between sea and floating ice – mechanically it has all been able to move more smoothly. Winds and ocean currents have been able to work together, with the net effect that ice has been able to flow away, or build up thicker single year layers, without piling up sheets of ice, and forming tall and deep ice structures during storm impaction events.

  16. OT – slightly
    you are now getting sunrise/sets in the high arctic islands (Grise Fjord started earlier this week and Eureka 80N should start theirs in the next day or so), so the sun angle is getting down lower. Around Oct 26(when I was there), was the last sun rise until the following Feb. Temps should be tailing off now too, however, they still get the odd blast of warmer weather before winter digs in.

  17. Anthony: “I’m going to update my prediction from this shift in weather. Now I think the ice level will dip quickly downward in relation to 2005 but will still sit above the 2008 minimums. It looks like the ice has been thinned by the recent blasts of weather from the southeast and if this pattern maintains itself the dip will be fairly strong. Of course I’m an engineer and not a meteorologist so we’ll see.”
    Hi Anthony, I am a great believer in the power if intelligent use of generalist knowledge. By applying some general physical principles you are putting an ‘outer envelope’ on the prediction. More detailed knowledge could maybe improve it, or even lead one astray if one gets bogged down in intricate details and overlooks something. It’s harder to find mistakes in complicated reasoning. If the wind stokes up, I think you will be proved right. Of course the decrease will still be put down to CO2 in certain circles. Completely predictable!
    REPLY: that’s from Jeff Id, not me, see the title of the post. – A

  18. If you watch this map for a while (in conjunction with how the sea ice extent tracks) it’s pretty obvious that the melt over the week will be more than in 2005 but less than in 2008. (Click the image to enlarge and count the darkest individual pixels. The watch them disappear day by day.)
    http://nsidc.org/data/seaice_index/images/daily_images/N_daily_concentration_hires.png
    This year’s ice will soon be WAY ahead of 2008’s and the main channel of the northwest passage will NOT open this year. Some boats will get though the southern route (with help from ice-beakers) but the big opening of the last two years ain’t happening this year.

  19. Here is a demonstration of the constancy of the sea ice cycle year after year.
    Explaining very simply, the data from 2002.5 through to 2006.5 is least square best fit with the sum of 4 sine wave generators, the dark blue graph line. These are constant in frequency, phase and amplitude for the whole graph.
    Yellow is the data seen for lsqr match. (data is truncated and the right hand side of the graph is a projection forward in time)
    For clarity It also shows the separate sine waves.
    Finally it shows the actual ice data from 2002 through to 2009.5
    THE LSQR MATCH HAS NEVER SEEN THE ACTUAL DATA AFTER 2006
    http://www.gpsl.net/climate/data/sea_ice/demo-ice-regular-func.png

  20. There is only 21 more days of melt left on average. The average minimum is on September 12th (2007 went a few days over this but not by much).
    The average melt per day fluctuates quite a bit right now but it declines steadily from about 45,000 km^2 per day right now down to 5,000 km^2 on the 12th.
    So take 20,000 times 21 days equals just 420,000 km^2 below todays number from Jaxa and on Sept 12th, the minimum is 5.4M which will be above 2007, 2008, 2002 and 1999.

  21. Hi,
    If you take the years listed you will see that it may start to dive in the very short term but historically it will level to that of 2005. Even 2007 at this time or year could not go down that fast. So I will bet it will be 2005.

  22. The AMSR-E update is out (normally around 11pm eastern time) and the Arctic Sea Ice Extent took a big hit.
    http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
    Note:
    1) The download data button gets you a CSV file, which is useful.
    2) The 5,737,344 number for August 23rd will be revised sometime in the next 12 hours or so. It’s usually upwards, especially after a big drop, but that’s not a guarantee. (August 22 was 5,823,281.)
    3) The plots has some misleading features. The days are plotted 1-365 with the months just marked off as 1/12 of a year each — so the date can get off a bit. Also, since they don’t compensate in a leap year, they’re showing August 22, 2008 at the same horizontal position as August 23 in non-leap years.

  23. Isn’t it a whole lot easier to just say, “Great!” when the AGW’ers talk about less summer ice in the Arctic? Shouldn’t we make them explain what they are so afraid of? All we have to do is say, “Not as much ice as recent years eh?, Well – what’s the harm in that??”

  24. So to achieve a record “melt” this year we need some fierce winds to blow the ice away!
    The ice melts elsewhere. That implies a cooling process. Current exposed polar sea will be radiating out to sunless space. Looks to be a cold winter up in the Arctic this year. 🙂

  25. Yes, Frederick, the Arctic lost 85937 km2 yesterday, which is very much for this time of the year. We’ll see…

  26. I will never forget the Independent headlines in June 2008 (and have saved a copy for future reference):
    “Exclusive: Scientists warn that there may be no ice at North Pole this summer”
    And first sentence:
    “It seems unthinkable, but for the first time in human history, ice is on course to disappear entirely from the North Pole this year.”
    By ‘Science’ Editor, Steve Connor
    http://www.independent.co.uk/environment/climate-change/exclusive-scientists-warn-that-there-may-be-no-ice-at-north-pole-this-summer-855406.html
    Steve Connor later sheelpishly aknowledged the inaccuracy (but stood by it) in:
    “Steve Connor: Best still on for ice-free North Pole” (though now not a headlines, just ‘Science notebook’.
    He says “How could we have got it so wrong? First, I’d like to make it clear that we of course stand by our story.” Going on to conclude:
    “It is surely only a matter of time before we will see an ice-free North Pole, and indeed a totally ice-free Arctic Ocean,during summer. My own bet is that we will see the former within the next decade.”
    ‘Within the next decade’ still seems a bold prediction.
    http://www.independent.co.uk/opinion/commentators/steve-connor-bets-still-on-for-icefree-north-pole-949661.html

  27. Bill Illis (19:55:47) :
    Have to disagree with you Bill. We have had two consecutive days of around 80,000 in decrease and that is highly unusual this time of year. If it should average 40,000 per day rather than 20,000 (not saying it will), look at where that would put the minimum. I still think we will end up slightly higher than 2008 but the race with 2005 appears to be over. As in all things though, Mother Nature will decide where it ends up definitively, not us humans.

  28. Michael Jennings (4:25:05)
    Yes, a couple of days of 158,000 km^2 in melt total kind of throw my calculations out the window (although there is is still 20 days left of declining melt – each day compared to the average will determine the final number).

  29. Greenpeace give up…
    “09:16 am CDT Aug 20, 2009
    (ThePoles.com/TheOceans.net) Eric Phillips who is on a Greenpeace vessel at the coast of Greenland sent an update about their recent activities. …
    Here goes Eric’s report:
    Peterman glacier
    “After 5 weeks in the Petermann and Humboldt glaciers region of Northwest Greenland, we have had to steam south in order to meet our arrival date at Sermilik Fiord on the east coast.”
    “The Petermann was expected to break up this season but the freeze has begun and may just hold it in place until next summer. Petermann is the longest floating glacier in the northern hemisphere and an area over 100 sq/km is expected to break away, if not this year, then next.””
    http://www.theoceans.net/news.php?id=18605
    I add, and probably breaks off regularly. A fed glacier must do this.

  30. Adam from Kan.
    Go to:
    http://ocean.dmi.dk/arctic/meant80n.uk.php
    for Arctic temp information. It would be fun to see if the temp presented at the web site is a leading indicator of future ice area/extent.
    Flanagan – While ice area/extent numbers have all those digits, not all are significant. There is about a 10% error area/extent estimation numbers, especially in the summer.

  31. Bill Illis (05:58:25) :
    NSIDC’s Arctic sea ice concentration map shows few pixels ready to drop below 15%, so expect things to level off in a week or so. Also, 2005’s mysterious drop in late Sept. means that 2009’s minimum could still be above 2005’s.
    We’re getting some negative numbers here.
    http://www.athropolis.com/map2.htm

  32. I’m famous again, thanks Anthony.
    Let’s see,
    Bob Tisdale.
    I’m sure it’s possible to do Hovmoller plots, is there something you would like to see in particular on each axis?
    The ice did appear to be thicker multi-year ice this season (less gray) until the last few frames where I noticed some thinning at the windward edge.
    —–
    —–
    Some notes for everyone:
    My prediction of ice shrinkage should be taken with a grain of salt because it’s really based on very little information. The clouds just started racing upward from the Bering Strait and the centroid vector really shifted and elongated. There are only 4 (I believe) years in the 30 year record which have shown that sort of off kilter centroid. Two of those years were 07 and 08 which had high melt once the pattern started. We are of course near the end of the melt season. The full 30 year record is at the link to the other air vent post.
    DeWitt Payne pointed out on tAV thread that extent has gone down but Area has increased over the last 3 days. This probably indicates a compaction of the ice against the Greenland continent.

  33. Once again, I don’t think the ice is melting, I think it is thickening. IE, ice edges are being pushed together and piled up into psuedo-multiyear ice packs. See the following for great info on current wind patterns. These strong winds say to me that ice is piling up at the center and any “ice extent” or “ice area” data will be an artifact of this process, not melting.
    http://squall.sfsu.edu/gif/jetstream_norhem_00.gif

  34. That’s very nice Jeff. I like the slow rate of the video; there are so many nooks and crannies to look at that I need time to see it all. I liked watching Hudson’s Bay fill up; and I agree the wind vector is a useful addition.
    If you ever want to add some knobs to the video; a Pause and Resume would be nice so we could compare the picture with the clock to get familiar with what it looks like at any calendar date.
    Data is no good in itself, if there isn’t a way to present that data in an infromative way. Your video is an example of efficient data presentation.
    Thanks for the effort; it truly is helpful.
    George

  35. On that Ian Pilmer link, I sometimes wonder if he knows what he’s talking about. In one paragraph he writes that in the past, carbon dioxide levels were 1,000 times higher than the present.
    Utter nonsense!

  36. Thought: Maybe a return to normal extent, area, and thickness of ice is two fold:
    Lower Summer melt due to colder temperatures in the air and ocean.
    Lower Summer melt due to wind compaction instead of transportation.

  37. Maybe I’m wrong, but it appears that the focus of the NSIDC’s semi-monthly Arctic sea ice report at http://nsidc.org/arcticseaicenews/ has recently changed. Until recently, it seemed that most reports contained an alarmist reference to “global warming.” The current report (dated August 18) does not mention that term at all. Instead, recent changes in Arctic sea ice melt patterns are explained by a very good analysis of how atmospheric circulation patterns push ice around. The following passage is particularly relevant to recent comments in this thread:
    Recent research by Stephen Howell at the University of Waterloo in Canada shows that whether the Northwest Passage clears depends less on how much melt occurs, and more on whether multi-year sea ice is pushed into the channels. Counterintuitively, as the ice cover thins, ice may flow more easily into the channels, preventing the Northwest Passage from regularly opening in coming decades.

  38. Frank Lansner (04:11:28) :
    “One picture says more than 1000 words:”
    http://www.klimadebat.dk/forum/vedhaeftninger/seaice4years.gif
    Reply: Thanks for the picture, shows exactly what’s going on up there.
    Pamela Gray (10:24:30) :
    Lower Summer melt due to colder temperatures in the air and ocean.
    Lower Summer melt due to wind compaction instead of transportation.
    Reply: I’ll go with that hypothesis – perhaps 2009 will still turn out to be close to the 2005 ice volume. Arctic temp still below freezing and with less of the more penetrating short wavelength UV around the ice should survive better.

  39. “Counterintuitively, as the ice cover thins, ice may flow more easily into the channels, preventing the Northwest Passage from regularly opening in coming decades.”
    So, if the Northwest Passage opens, it’s due to increased “melting” caused by global warming. If the Northwest Passage doesn’t open, it’s due to more easily flow of ice into the channels, caused by global warming.
    Yep, that sounds like classic “Climate Science” alright.

  40. According to the NORSEX chart it does look like the ice is compacting more because the rate of loss for area has that tiny uptick and and extent is still going down.
    Whatever this means, it means the ice is getting better prepared for future melt seasons and thus prove Al Gore wrong.

  41. “Vincent (09:45:02) :
    On that Ian Pilmer link, I sometimes wonder if he knows what he’s talking about. In one paragraph he writes that in the past, carbon dioxide levels were 1,000 times higher than the present.
    Utter nonsense!”
    Assuming he means precambrian.
    Careful. So far as I know that is a matter of great dispute, with 30% by no means the upper guess, some think CO2 was the principle gas. A lot papers mention this, mostly geological and that is Plimer’s disipline.
    I’ll leave it for you to dig out any papers you wish.

  42. OT, but Pielke Snr is really laying the boot into the (Un)RealClimate lot!
    “My current weblog is an invitation to them to comment on the above paragraph (either as guest weblogs or on their sites). If they ignore this request, it would further demonstrate that they are commenting outside of their expertise on the subject of our papers, and that their real goal is simply to malign papers they disagree with.”
    http://pielkeclimatesci.wordpress.com/

  43. Tenuc at 12:00:11 today.
    -regarding photos from link you posted at- klimadebat.dk/forum/vedhaeftninger/seaice4years.gif
    Great photos, could you please post the original source for these, it would be interesting for future comparisons.

  44. Concerning the sea-ice-extent trend, have you considered plotting a 365-day moving average? That would remove the seasonal variation. Trends would be more apparent. Thanks.

  45. Bryan (14:22:16) : Well of course it is the wind that is melting the ice and blowing it out of the arctic polar area. It certainly can’t be the fact that the pole is still at 41dF or 5dC that is melting the ice
    http://www.arctic.noaa.gov/npole/2009/images/noaa1-2009-0823-055938.jpg

    Bryan no it cant be because it is not a “fact”. That picture you sent is about the netcam not a recording of the temp.
    Weather Bouy readings:
    08/24/1311Z 84.185°N 2.028°W -0.5°C
    08/24/1600Z 84.182°N 1.847°W 0.2°C
    08/24/1600Z 89.114°N 74.322°E 0.2°C
    08/24/1304Z 85.870°N 53.835°W -3.3°C

  46. Pamela Gray (10:24:30) : said
    “Once again, I don’t think the ice is melting, I think it is thickening. IE, ice edges are being pushed together and piled up into psuedo-multiyear ice packs. See the following for great info on current wind patterns. These strong winds say to me that ice is piling up at the center and any “ice extent” or “ice area” data will be an artifact of this process, not melting.”
    If that was the case then the extent should be lower this year, however it is likely to be higher. One of the reasons ice extent in 2008 was higher than 2007 was because a different wind pattern spread the ice out more leading to greater extent.
    Regards
    Andy

  47. Ah, sorry Andy but from the JAXA data the difference is now only 170,000! 2009 had a series of large sea ice losses.

  48. According to Nansen, who use more than one satellite, the ice area is (at the moment) about 700 000 km^2 greater than in 2008 and about 1.1 million km^2 greater than 2007. (Ice “area” is just that, ice “extend” includes the water between. So if the wind pushes the ice together, extend will shrink, but area might not)

  49. astonishing! on 1st of june at least 3 of the curves show a very dramtic daily peak that cannot be seen anywhere else in the diagram.
    either someone is firing 100k rockets into sky making much dust (isnt the US celebrating on 4th of july?) or there is some really bad bug in the computation pipeline that produced those track.

  50. logisch (03:32:00) : astonishing! on 1st of june at least 3 of the curves show a very dramtic daily peak that cannot be seen anywhere else in the diagram.
    On the 1st and 2nd of june they obviously make some “adjustment” every year. For example on the 1st and 2nd June this year the ice went up by 43906 and 77031 sq kms if it is to be believed. Obviously not true. I commented on this earlier. The year where they made the least adjustment was in 2007.
    Adjustments are being made quite often on a weekly and even daily basis.

  51. Read it and weep:
    According to a study done using NASA ICEsat satellite data, ice volume shrank dramatically 2004 to 2008:
    http://www.nasa.gov/images/content/365869main_earth2-20090707-full.jpg

    NASA Satellite Reveals Dramatic Arctic Ice Thinning
    07.07.09
    PASADENA, Calif. – Arctic sea ice thinned dramatically between the winters of 2004 and 2008, with thin seasonal ice replacing thick older ice as the dominant type for the first time on record. The new results, based on data from a NASA Earth-orbiting spacecraft, provide further evidence for the rapid, ongoing transformation of the Arctic’s ice cover.
    Scientists from NASA and the University of Washington in Seattle conducted the most comprehensive survey to date using observations from NASA’s Ice, Cloud and land Elevation Satellite, known as ICESat, to make the first basin-wide estimate of the thickness and volume of the Arctic Ocean’s ice cover. Ron Kwok of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., led the research team, which published its findings July 7 in the Journal of Geophysical Research-Oceans.
    The Arctic ice cap grows each winter as the sun sets for several months and intense cold ensues. In the summer, wind and ocean currents cause some of the ice naturally to flow out of the Arctic, while much of it melts in place. But not all of the Arctic ice melts each summer; the thicker, older ice is more likely to survive. Seasonal sea ice usually reaches about 2 meters (6 feet) in thickness, while multi-year ice averages 3 meters (9 feet).
    Using ICESat measurements, scientists found that overall Arctic sea ice thinned about 0.17 meters (7 inches) a year, for a total of 0.68 meters (2.2 feet) over four winters. The total area covered by the thicker, older “multi-year” ice that has survived one or more summers shrank by 42 percent.
    Previously, scientists relied only on measurements of area to determine how much of the Arctic Ocean is covered in ice, but ICESat makes it possible to monitor ice thickness and volume changes over the entire Arctic Ocean for the first time. The results give scientists a better understanding of the regional distribution of ice and provide better insight into what is happening in the Arctic.
    “Ice volume allows us to calculate annual ice production and gives us an inventory of the freshwater and total ice mass stored in Arctic sea ice,” said Kwok. “Even in years when the overall extent of sea ice remains stable or grows slightly, the thickness and volume of the ice cover is continuing to decline, making the ice more vulnerable to continued shrinkage. Our data will help scientists better understand how fast the volume of Arctic ice is decreasing and how soon we might see a nearly ice-free Arctic in the summer.”
    In recent years, the amount of ice replaced in the winter has not been sufficient to offset summer ice losses. The result is more open water in summer, which then absorbs more heat, warming the ocean and further melting the ice. Between 2004 and 2008, multi-year ice cover shrank 1.54 million square kilometers (595,000 square miles) — nearly the size of Alaska’s land area.
    During the study period, the relative contributions of the two ice types to the total volume of the Arctic’s ice cover were reversed. In 2003, 62 percent of the Arctic’s total ice volume was stored in multi-year ice, with 38 percent stored in first-year seasonal ice. By 2008, 68 percent of the total ice volume was first-year ice, with 32 percent multi-year ice.
    “One of the main things that has been missing from information about what is happening with sea ice is comprehensive data about ice thickness,” said Jay Zwally, study co-author and ICESat project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md. “U.S. Navy submarines provide a long-term, high-resolution record of ice thickness over only parts of the Arctic. The submarine data agree with the ICESat measurements, giving us great confidence in satellites as a way of monitoring thickness across the whole Arctic Basin.”
    The research team attributes the changes in the overall thickness and volume of Arctic Ocean sea ice to the recent warming and anomalies in patterns of sea ice circulation.
    “The near-zero replenishment of the multi-year ice cover, combined with unusual exports of ice out of the Arctic after the summers of 2005 and 2007, have both played significant roles in the loss of Arctic sea ice volume over the ICESat record,” said Kwok.

  52. ” Leland Palmer (22:15:33) :
    Read it and weep:
    According to a study done using NASA ICEsat satellite data, ice volume shrank dramatically 2004 to 2008:”
    What is more exact: Measuring per satellite from 1000 km up, or by plane from low down?
    When Polar 5-data is finally published, this stuff will be obsolete.

  53. Hi Alexej-

    What is more exact: Measuring per satellite from 1000 km up, or by plane from low down?
    When Polar 5-data is finally published, this stuff will be obsolete.

    http://www.nasa.gov/topics/earth/features/icesat-20090707r.html
    Above is a link to the NASA ICESat website, which gives the text of the original news release.
    The satellite measurements could very well be much more accurate than aircraft data. The satellite was designed to measure ice volume, using a laser altimeter, and has a unique vantage point, able to see the whole area. It was also subject to a whole program of validation before data from it was used. The orbit is 600 km above the surface of the earth. Laser altimeters are capable of extreme accuracy:
    http://en.wikipedia.org/wiki/LIDAR
    Here’s a link to the validation plan, from NASA, and here are the cryosphere (ice measurement) specs:
    http://www.csr.utexas.edu/glas/pdf/plan/validation_plan_v1_oct2001.pdf

    Cryosphere: the measurements should support determination of elevation change to an accuracy of 1.5 cm/yr in a 100 km x 100 km region where surface slopes are < 0.6° (1:100), which is typical for more than 80% of the polar ice-sheet surface; however, on the East Antarctic plains where surface slopes are < 0.2°, the accuracy requirement is 0.5 cm/yr in a 200,000 km2.

    This is hard scientific data, showing a massive change in ice volume compared to any reasonable experimental error. It comes from a satellite in space, far from most reasonable sources of accidental human interference.
    It’s apparently working the way it was designed to work, but is telling the readers of WUWT something they don’t want to hear.
    Will they listen?

  54. Re: Leland Palmer (07:10:32)
    Listen to what? That we can sail around more up there now? That’s good! That some areas in Northern Canada may be able to support a settlement of people soon? That’s good! Just exactly what are people afraid of?
    I’ll say it for the “umpteenth” time: warmth is good!!

  55. Leland Palmer said ” According to a study done using NASA ICEsat satellite data, ice volume shrank dramatically 2004 to 2008″.
    So that is nice to know Leland but what did the ice volume do in 1933-37? How about 1868-73? What about 1704-09? Then there is always 1445-1449 etc.. Do you have those answers for me?

  56. “”” jorgekafkazar (16:25:33) :
    John F. Hultquist (14:51:33) : “…I’m still not sure what the significance would be if this Ocean becomes ice-free, or nearly so, for a few weeks even as I doubt that will happen. Will not the energy of the water move to the atmosphere faster with no ice cover?”
    Yes, given that (1) the emissivity of open water is about 0.993, much higher than ice, “””
    jorje, I’m interested in your source for the emissivity of open water; also over what spectral range is that.
    It’s not that I am doubting you; I would just like to know the reference source of that figure.
    For solar spectrum wavelengths, I would expect a number more like 0.97, given that the normal incidence reflection coefficient is about 2%, and about 3% for diffuse reflectance. But I can appreciate that since water is almost totally absorbing in the 10-100 micron range, that the IR emissivity would be high.
    Is that a measured or a calculated value ? By the way; what IS the corresponding figure for ice ?
    George

  57. Evidently, Leland thinks that the record of arctic ice since polar orbit satellites first started looking at it in 1979 is somehow remarkable. When we dig further we find that “ice cover”: means less than 85% of open water; hardly my idea of ice coverage.
    And let me guess, they read the altitude of the ice surface (above sea level), and use the differential to infer an ice thickness, then allowing for the underwater volume they compute the total ice volume, or something like that.
    So what is the resolution of their camera in terms of how small a piece of ice can it see, and is their spatial sampling sufficient to correctly determine the ice area; or is it like most sampling studies, severely compromised by aliassing noise, of even the average.
    Based on the inputs from that silly stuck in the ice yacht, the spatial frequency of the ice areas is quite high; so I would have to be convinced there isn’t a Nyquist violation in the data; but then nobody else worries about that so why should I.

  58. Answer-
    Apparently not. sad to say.
    Hi George E. Smith-
    Here’s their methodology:
    http://www.nasa.gov/topics/earth/features/icesat-20090707.html

    Figure 1: ICESat measures the distances to the top of the snow cover and to the sea surface. The difference between the two quantities gives the total “freeboard” measurement; that is, the amount of ice above the water line relative to the local sea level. Credit: Courtesy of Norbert Untersteiner, University of Washington
    > Larger image
    This schematic shows the geometric relationship between the amount of ice above the water line, snow depth, and ice thickness. Figure 2: This schematic shows the geometric relationship between freeboard (the amount of ice above the water line), snow depth, and ice thickness. Buoyancy causes a fraction (about 10 percent) of sea ice to stick out above the sea surface. By knowing the density of the ice and applying “Archimedes’ Principle” — an object immersed in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the object — the total thickness of the ice can be calculated. Credit: Ron Kwok, NASA/JPL
    > Larger image
    ICESat measurements of the distribution of winter sea ice thickness over the Arctic Ocean between 2004 and 2008 Figure 3: ICESat measurements of the distribution of winter sea ice thickness over the Arctic Ocean between 2004 and 2008, along with the corresponding trends in overall, multi-year and first-year winter ice thickness. Credit: Ron Kwok, NASA/JPL

    Nice video, showing delcine in ice volume, year by year.
    http://www.nasa.gov/mov/326195main_winter_seaicethickness30fps.mov

  59. “Leland Palmer (22:34:04) :
    Answer-
    Apparently not. sad to say.
    Hi George E. Smith-
    Here’s their methodology: etc etc”
    So George was right. I still believe it is møch måre æccurate if you are møch nearer. But we have to wait whåt the Eisdeckendickemessinstrument said.

  60. Leland Palmer (22:15:33) : Read it and weep: According to a study done using NASA ICEsat satellite data, ice volume shrank dramatically 2004 to 2008:…
    Leland Palmer what is the gloom and doom all about? Why dont you go away and weep by yourself at your imaginary perils. Maybe they seem real to you, but you seem impervious to logic, so I really dont know how you can be helped.
    Have a look at the temperature records of the GIPS2 ice core data. During much of the Medieval warm period the temperature in Green land was 1 to 1.5 C warmer than today. There was nothing catastrophic about this period, quite the contrary. The catastrophe happened when the world cooled after this period into the little ice age and didnt recover till we warmed up again.
    During the last century and a half when we have warmed slightly we have addded billions to our population and yet managed to feed ourselves.
    Just think about all this and then come back and tell me if this makes any sense to you.

  61. Hi all-
    The ice thickness declined by 2.2 feet over only four years, according to NASA. This is good, hard scientific data, gathered from an extremely good, well calibrated source. The measured decline is far above any reasonable experimental error.
    [snip – waaaayyyyy off topic. When we have a thread on methane you can post this. Right now the discussion is sea ice, and I won’t have you hijack this thread to satisfy that whim. – Anthony]

  62. Hi Anthony-
    Since I’m not allowed to respond to questions about what the significance of a 2.2 ft decline in ice thickness in only four years is, beyond the narrowly defined limits of this thread, let’s talk about the ice/albedo feedback:
    http://en.wikipedia.org/wiki/User:Atmoz/Climate_change_feedbacks

    Sea ice feedbacks
    Aerial photograph showing a section of sea ice. The lighter blue areas are melt ponds and the darkest areas are open water, both have a lower albedo than the white sea ice. The melting ice contributes to the ice-albedo feedback.
    At high latitudes, temperatures get low enough that sea water freezes into ice. Sea ice strongly impacts the climate through two different positive feedbacks. First is the sea ice-albedo feedback (or ice-albedo feedback). As temperatures increase, the sea ice melts, resulting in a lower surface albedo, and increasing the amount of solar radiation absorbed, which reinforces the initial warming.[27] Reviews of various models show that the magnitude of this feedback is uncertain due to differences in ice dynamics, and in their treatment of clouds.[28] The albedo has been shown to change in two ways: changes in the areal extent of the ice, and changes in the multi-year ice such as ice thickness, and melt pond characteristics. Sea ice models that incorporate the multi-year ice feedback are more sensitive to initial changes in temperature.[27]
    Sea ice also acts as an insulator between the ocean and the atmosphere. As the ice melts, it allows more liquid water to evaporate into the air. This latent heat flux from the ocean to the atmosphere results in additional warming of the boundary layer. Melting of sea ice also results in an increase in the poleward moisture flux from the tropical oceans.[29]

    For readers who are interested, beyond the narrowly defined limits of this thread, in the significance of these findings from NASA, the Wikipedia article lists several other positive feedback effects that are very worrisome, IMO.

  63. Hi all-
    What the NASA satellite ICESat is telling us is that there was a massive change in ice volume, that coincided in time with the 2007 ice extent minimum.
    So, apparently, ice volume does correlate with ice extent. The wind does not significantly decouple this correlation, apparently.
    The bottom line from this NASA data is that the Arctic is melting. These are huge changes, occurring far ahead of schedule.
    Some expect the effects of Arctic melting to be good, or at least economically good.
    Others, expect the effects of polar icecap melting to be very bad, and expect that those effects will extend far beyond the narrowly defined limits of this thread.
    The climate is indeed all connected, fortunately or unfortunately.

  64. Leland Palmer (07:13:41) : You seem to keep repeating like a parrot that the ice is thinning. This might be expected if the Earth has warmed and is in a warm phase. Why should you be surprised. You sound like a broken record stuck in a groove.
    If this is happening now then, probably more than this happened during the several centuries in human historical memory (the Medieval warm period) when it was warmer than now.
    Do you have anything to say about that?

  65. Hi Richard-
    We don’t know about Arctic ice extent in the Medieval warm period, or at least I don’t.
    What I do know is that an extremely dramatic melting of the polar icecap has occurred in the last few years, at the same time as thousands of other well established scientific indicators of global warming are telling us that dramatic warming is occurring.
    The data from the polar icecap melting (decrease in ice volume) is dramatic, and scientifically established to be far beyond any reasonable experimental error.
    Ice volume decreased from 2003 to 2008, a fact that has been disputed on this blog.
    Posters on this board who thought that the wind just happened to be piling the Arctic sea ice up were apparently wrong.
    The original article, that says the the changes in ice extent in 2007 were due to the wind is wrong.
    The changes in ice area that occurred in 2007 were correlated with measured changes in ice volume in 2007.
    That ice area and volume are correlated is of course obvious, and should have been seen as the simplest assumption on this blog all along.
    When taken in context with thousands of other indicators of global warming, including land and sea temperature records, this is another indicator of probable catastrophe. Certainly, such huge declines are totally unsustainable, if they continue. These changes in ice volume and extent are real, the ICESat data tells us, and appear to be orders of magnitude larger than in the reasonably undisturbed baseline period from the 1970’s through 2000.

  66. Leland Palmer (13:42:11) : We don’t know about Arctic ice extent in the Medieval warm period, or at least I don’t…
    Thats where your trouble lies.
    Please educate yourself on this. If your realise that the Earth has been in warmer periods during many periods during our current Holocene interglacial, including during the Medievalk Warm Period, then you will understand that whatever is happeneing now has happened before in our recent past and thus there is no reason to fear any catastrophe.
    Here is a good place to start: http://www.co2science.org/data/mwp/mwpp.php
    Now that I have brought you glad tidings of great joy, please treat yourself to a coffee. Relax and enjoy life.

  67. Hi Richard-

    Now that I have brought you glad tidings of great joy, please treat yourself to a coffee. Relax and enjoy life.

    Thanks, I think.
    But, if runaway climate change accelerates, humanity won’t be doing much relaxing and enjoying of life, IMO. And if they do, fiddle while Rome burns, so to speak, should they?
    Huge decreases in ice volume in only a few years are fully consistent with a runaway climate change scenario, unfortunately.

  68. Leland Palmer (06:08:17) : … if runaway climate change accelerates, humanity won’t be doing much relaxing and enjoying of life, IMO.
    IF… you seem to be stuck in a groove, caught in a closed loop of just one irrational thought. Please try and think beyond the square, or loop if you prefer.
    Temperatures go up and temperatures go down. I told you that the Earth has been in warmer periods many times during our current Holocene interglacial, there is no reason to fear any catastrophe.
    Did you have a look at the evidence of Medieval Warm Period? If you realise the above fact then all your subsequent arguments for a doomsday scenario become superfluous.
    And if they do, fiddle while Rome burns, so to speak, should they?
    Undoubtedly. Better than living in misery under the weight of carbon taxes to support the perpetrators of this scam in a life of luxury, which will accomplish nothing even according to the faulty science espoused by the doomsayers.

  69. The southern route of the northwest passage is now showing an increase in sea ice. The northern, direct, route didn’t open.
    That’s not good news for lots of folks. A reliably open northwest passage would be a shippers dream.

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