NSIDC Raises The Bar

Guest post by Steven Goddard

In past years, NSIDC has referred to “declining multi-year ice” as the problem which the Arctic faces.  Mark Serreze at NSIDC forecast a possible “Ice Free North Pole” in 2008, based on the fact that it had only first year ice.  This year, multi-year ice has increased and NSIDC is now referring to declining “2+ year old” ice as the problem.  Note the missing age group (2 year old ice) in the paragraph below from their latest press release .

First-year ice in particular is thinner and more prone to melting away than thicker, older, multi-year ice. This year, ice older than two years accounted for less than 10% of the ice cover at the end of February. From 1981 through 2000, such older ice made up an average of 30% of the total sea ice cover at this time of the year.

Due to the record minimum in 2007, it goes without saying that there isn’t a lot of three year old ice in 2009.  Maybe next year they can raise the bar to 3+ year old ice, as the multi-year ice ages one more year?

maps with sea ice age, average 1981-2000 compared to 2009 march

Multi-year ice has increased from 2008, up to nearly 25%.  Compare multi-year ice vs. last year’s map below – upper right corner. 

Two maps of sea ice age side-by-side

http://nsidc.org/arcticseaicenews/2008/040708.html

The press has picked up on the 10% figure, based on the new higher standard NSIDC has set.

Ice older than two years once accounted for some 30 to 40 percent of the Arctic’s wintertime cover and made up 25 percent as recently as 2007.

But last year it represented only 14 percent of the maximum. This year the figure fell to 10 percent.

Note too that ice extent is nearly back to normal and has not declined significantly from the winter maximum.

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143 thoughts on “NSIDC Raises The Bar

  1. I’ve seen a global ice plot (the sum of Arctic and Antarctic) from time to time on this site. I have tried to find a source for this graph but have been unsuccessful. Can anyone point me to the source of this graph? Thanks!

  2. On the Guardian’s comment section one of the most prominent defenders of alarmism said scientists know how much Arctic ice there was over the last 8000 years because of Arctic ice-core records going back that far (he means the polar cap, not Greenland or anywhere else in the Arctic circle).
    Anyone who is registered there, please give that person the biggest cyberslapdown on the history of the internet for that major blooper.

  3. voodoo (13:19:48) :
    “I’ve seen a global ice plot (the sum of Arctic and Antarctic) from time to time on this site. I have tried to find a source for this graph but have been unsuccessful. Can anyone point me to the source of this graph? Thanks!”
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg
    It’s on Cryosphere Today. Note that the global extent is slightly above the 30 year average. It should move higher over the next few months as Antarctic ice freezes faster that Arctic melts. It also speaks to how unexcited we should be about polar ice totals.

  4. I just posted this to the Catlin thread, but it’s more appropriate here
    The reports that there’s only 10% old ice in the arctic ice strikes me as very odd mathematically. Even with higher melt the last 2 seasons, ice area was around 30% of it’s peak winter area. Unless your melting “old” ice at least as fast as the new ice rate, how do you get down to 10% old ice? Theoretically, if you did, you could get to about 10%, but that would go against the AGW supposition.
    I’d be curious about the methodology of the study that defines what is new and old ice. If anyone has a link to the NASA report and/or data, I’d be interested. Comments from anyone who has looked into this would be appreciated. I’ll do some research and report if I find anything.

  5. UK Itv news ran this thin ice rubbish last night, with a comment from the Catlin Crew stating the majority of their ice drilling showed a thickness of 2 mtrs.

  6. Nothing is more imaginary than the claim that CO2 is causing global warming
    C02 Global Warming’s IPCC-created Hobglobin
    By Dr. Tim Ball Monday, April 6, 2009
    http://canadafreepress.com/index.php/article/9971
    The UN Intergovernmental Panel on Climate Change (IPCC) is responsible for providing the hobgoblin of global warming. They claim CO2 is almost the sole cause of warming while effectively ignoring the sun. Their claim that the sun is of little consequence is unbelievable and only a measure of their deception and lousy science. They only looked at one part of solar influence on weather and climate and didn’t do that accurately. Instead they used it to support their claim the temperature changes are not caused by the sun and therefore must be due to CO2. They only considered irradiance (heat and light) and concluded, incorrectly, it was of little consequence. They assume, because the variation is approximately 0.1% over approximately a 30-year period, it is of little consequence.

  7. It’s also interesting that the ice extent increased for a time in March and hasn’t declined much in April. I’m below 30 degrees latitude near Houston and I’m going to need my heat again tonight April… At least the gulf is staying cooler longer which should help during hurricane season.

  8. Voodoo:
    You’ve probably scene the “Cryosphere Today” site graphs. They have excellent graphs on 365-day data and a “Global Sea Ice Area” graph that, incidentally, is showing well above the 1979-2000 trend at the moment.
    http://arctic.atmos.uiuc.edu/cryosphere/
    Also, check out the above normal Southern Hemisphere sea ice chart…

  9. If only NSIDC would raise the bar on their science, instead of being so busy banging the alarmist drum.

  10. Interesting data, although I hardly listen to their useless predictions in any case.
    Speaking of predictions, Hathaway et al have updated their Solar prediction graph (judging from the quick look I had, not much has changed).
    Also of note, a minor cycle 23 plague appeared about 2 days ago, just below the equator but has since vanished,,, making SC 23 about 12yrs, 11 months old now.

  11. The secret to a good scare campaign is to take something that is common and to make it seem unusual.
    If there was ever permanent ice at the north pole ( that is all year, not just in winter) would not the ice get thicker and thicker? Is there any way of telling how thick the ice at the pole was say 500 years ago? If it wasn’t hundreds of metres thick we could conclude that it was frequently “ice free” in summer. Which means the fluctuations of the extent of summer ice that are happenning are not unusual.

  12. It appears the Cryosphere guys did a major change to their sea ice graphic for the Arctic, it wasn’t too long ago the graphic was showing very close to 100 percent ice from Canada to Russia and I think that was the April 3rd graphic, apparently they went back a day and ‘corrected’ the data.
    I wonder what they will do about the Antarctic ice though, its area is going up at a pretty good clip right now.
    If you’re looking at temperatures UAH shows a 2 month trend of temperatures spiking up and falling in the lowest levels, a small declining 2 month trend in the middle levels, and at 56 and 68 thousand feet a very significant 2 month warming trend, and they got rid of the near surface layer data (the lowest is now 3000 feet)

  13. I don’t know if any of you has watched CNN today.
    There was an extensive report about the collapse of the ice bridge followed by Hillary Clinton stating the effects of Global Warming in the Antarctic region were so obvious now that we had to act immediately.
    NSIDC feeding from the same trough keeps the hoax about the melting arctic alive.
    This is all part of the latest offensive to get us all in “Green Shackles”.
    Therefore, give them hell if you can.
    Who wants to be represented by a Government of liars, frauds and cheats.

  14. Well over the past ten years for the most recent 12-month period, we are now seeing a temperature trend of -7.5 degrees per century (-0.75 degrees per decade). We are now very near the “average” for the 20th Century (1901 to 2000).
    At this rate it will be snowing in Havana in another 10 years.
    REPLY: bad link there crosspatch, it is not a permalink, better to show the params or to do a screencap and post to photobucket o the like – Anthony

  15. Considering the -40C temps the arctic survey team has been experiencing it’s not surprising that there hasn’t been much of a decline from the winter maximum!

  16. I respect Dr. Meier as a Cryosphere Scientist. What I have difficulty with is his “correlation” with facts not in evidence, such as man-made global warming and the greenhouse “effect.” If such an “effect” does indeed exist, it is an atmospheric effect. The analogy is closer to the Earth being in a vacuum rather than in a greenhouse.
    The clincher is in his admitting that he cannot prove the correlative link.
    ————————————————————-
    Scientist Links Melting Polar Ice to Greenhouse Effect but His Group’s Own Research Shows Otherwise
    http://www.cnsnews.com/public/content/article.aspx?RsrcID=46203
    A scientist who tracks levels of ice and snow in the Arctic Ocean told CNSNews.com Monday that there is a “correlation” between the receding ice in the Arctic Sea and man-made global warming caused by the greenhouse effect.
    But Dr. Walter Meier, a cryosphere scientist at the National Snow and Ice Data Center (NSIDC) in Boulder, Colo., admits he can’t prove that the link is cause-and-effect.

  17. So what was causing global warming 700 years ago?

    In 2008, the NSIDC reported that summer sea ice area recovered by 9% but was still the second lowest recorded. However, based on the latest data about the much greater area of thin first-year ice and losses of multi-year ice, especially that of five years or more, they believe that in volume terms last summer was the lowest since records began in the 1930s – and probably for at least 700 years and possibly up to 8,000 years, said Walt Meier, a research scientist at the Boulder-based centre. “Our estimate is that it was probably the lowest volume on record,” Meier told the Guardian. “Certainly 2007 and 2008 [were] the two lowest [years for] volume and extent.”

    http://www.guardian.co.uk/environment/2009/apr/06/arctic-sea-ice-warning

  18. From the Catlin site:
    “In Washington, where NASA held its media briefing, scientists who track Arctic sea ice cover from space announced that this winter had the fifth-lowest maximum ice extent on record. The six lowest maximum events since satellite monitoring began in 1979 have all occurred in the past six years.”
    To my simplistic mind, if the ice melt was accelerating each year, then each new year would deliver a measurement of the “lowest maximum ice extent”. If this is the fifth lowest, and the six lowest were in the last six years, then the implication is that the ice extent is INCREASING over the last six years.

  19. Um… so, how does one define “thin” when speaking about arctice sea ice that is meters thick? What constitutes “thin”?
    I am going to take great pleasure in laughing at the NSIDC folks in May and June as the 1st year ice fails to melt at the alarming rate they are predicting. The polar area is staying colder this spring and that will greatly slow the melt rate. So far, all of the melting has been near Nova Scotia and in the sea of Okhotsk, which has nothing to do with the arctic basin…

  20. NSIDC: “How vulnerable is the ice cover as we go into the summer melt season? To answer this question, scientists also need information about ice thickness. Indications of winter ice thickness, commonly derived from ice age estimates, reveal that the ice is thinner than average”
    In short:
    Indications derived from estimates.
    Meaning:
    We have no information about the true ice thickness and no measured data.
    I start to appreciate the Catlin crew and their work. I will be keen to see their measured data. (If they can make the same trip every year, in the same position and at the same time of the year for the next 10 or so).

  21. Thanks for posting this. I had exactly the same thoughts but was busy at work and couldn’t do anything about.
    Thanks for calling out the knavery.

  22. What was that TV show where one of the hotel staff characters announced “De-ice, de-ice” every time a jet landed? Oh, never mind.

  23. I read a story today in Wall St Journal about the “decline in multi-year ice” discussed above and what jumped out at me was the blithe assurance that the satellite survey was accurately measuring not only the area of ice but its thickness, to arrive at a volume estimate. What kind of satellite instrumentation is reading the surface of the ice, and the lower border of the ice where it floats on the underlying water? What kind of roughness factor is there in that gemisch, so that a reading of “smooth” ice in one location is not over-applied to the entire surface (which I believe is both very uneven and constantly shifting to create more or at least different levels of roughness as leads open and close, and pressure ridges form and disappear)? How many measurements are in fact made by the satellites and how well do their estimates correlate with the ground truth of area, and certainly of thicknesss? From this excellent blog it’s my impression that thickness measures are few and far between; may (because roughness is so variable) not be representative of much; may (because the ice is always drifting hither and yon) ditto not be representative of much. Sorry to be so confused but I am trying to get a clear and coherent picture of this entity called “Arctic Ice” and right now it’s too variable: by time, by location, by changing and imprecise methods of measurement. Help?

  24. Thanks for this post. I read in The Times yesterday that there was great concern that Arctic sea ice was the 5th lowest on record. Since the record began in 1979, I assumed that being 5th lowest out of 30 wasn’t really worth becomming to agitated about. Surely if sea ice were decreasing year on year as they claim, it should be claiming the record every year?

  25. Did you all catch THIS at the very end of the article? :
    ” . . . This winter, some second-year ice survived the 2008 melt season only to be pushed out of the Arctic by strong winter winds. . . . since the end of September 2008, 390,000 square kilometers (150,000 square miles) of second-year ice and 190,000 square kilometers (73,000 square miles) of older (more than two years old) ice moved out of the Arctic.”
    Doesn’t this indicate that it’s a mechanical shoving rather than rising temperatures that’s caused the old ice to disappear?
    The animation at the tail-end shows it all.

  26. Steven Goddard (14:36:51)
    http://www.guardian.co.uk/environment/2009/apr/06/arctic-sea-ice-warning
    What’s interesting about this link is the video showing the loss of “old” ice. If you watch the progression, there is little disappearance of old ice within the Arctic basin and a tremendous outflow into the straight between Greenland and Iceland where it presumably melts in warmer waters. There seems to be a bigger influence of currents rather than atmospheric convection in this graphic. What would be interesting is what these currents are and has it changed in the recent past and what the future projections might be.
    If it is currents, what could mitigation strategy of lower CO2 possibly achieve to change the currents?

  27. Ron de Haan (14:28:02) :
    “Who wants to be represented by a Government of liars, frauds and cheats.”
    Maybe we always have, Ron, but in times past, the newspapers weren’t part of the government cabal. Now we have even more persuasive media formats, and a more ignorant electorate. No checks-and-balances, no pursuit of truth, and most of all, no more statesmen, just political hacks from any party.
    I miss Everett Dirksen.

  28. RE: Ron de Haan (14:28:02) :
    **I don’t know if any of you has watched CNN today.
    There was an extensive report about the collapse of the ice bridge followed by Hillary Clinton stating the effects of Global Warming in the Antarctic region were so obvious now that we had to act immediately.
    NSIDC feeding from the same trough keeps the hoax about the melting arctic alive.**
    Expect to see any ice breaking off as news if the Arctic ice continues to increase.

  29. Reality check: Isn’t this what you would expect for the end of the sun’s modern maxima? Since it ended in late 2005, the Arctic now has about 30 years to rebuild multi-year ice. I wonder when the multi year ice will cross back over the mid point. For the very first time, we have the instruments in space, and we should be able to measure that time point, I would guess probably within the next 20 years.
    Do they have any satellite data for the last 1000 years? ^_^ I would assume that it would show how the volume of multi-year ice came and went, and clarify where we are in that cycle.
    30 years seems like a real short period to try and make observation conclusions from. Note the record keeping started in 1979. And note that the media only uses the part ‘on record’. Context is everything with dealing with alarmism.

  30. I think they will strongly “resist” any new data that will show more than likely that NH ice will be on its way back to normal this or next year. Actually ALL “revisions” of BOTH NH and SH ice data have been to exagerate the melting. Fortunately, records have been kept of these changes
    http://mikelm.blogspot.com/2007/09/left-image-was-downloaded-from.html
    Anyone out there who observes this “phenomenom” is invited to post there to keep the B####ds honest as they say LOL

  31. You’re too generous. Raise the bar to 3+ year old ice? As I commented yesterday on the Mt. Redoubt post, “This AP story ( http://www.breitbart.com/article.php?id=D97D27280&show_article=1&catnum=0 ) is based on a discussion on the NSIDC website ( http://nsidc.org/arcticseaicenews/ ). It seems illustrative of confirmation bias. In the past the stories were all about first year ice and how fragile it is. Now, after a year in which it the sea ice recovered a bit, it seems we are being told that it’s even two-year-old ice that’s fragile. What’s next? Ice that’s less than 5 years old is in danger? Anything to keep on message about melting ice and the doomsday that awaits.
    The other question is about the profession of journalism — or rather, the distorted caricature that passes as journalism these days. Why wasn’t the change in message used in the NSIDC posting noticed and questioned? Even if a journalist is convinced about AGW, he should still be questioning; that’s his job, not advocacy for his personal beliefs.

  32. Arn,
    The Arctic always loses a lot of ice to wind blowing towards the North Atlantic – that is why there is never much ice more than five years old.

  33. “So what was causing global warming 700 years ago?”
    That would be the medieval warm period. Actually, it appears that climate has been in a general cooling trend with each warm period a little cooler than the preceding one. Roman warm period warmer than Medieval warm period, for example. Or put another way, it appears that for the past 2000 years we don’t quite recover as much from each cooling period.

  34. Alex (14:01:10) :
    The only change I could see is that they slid the SC-24 maximum back a month (from Jan to Feb 2013), and lowered it by two-tenths of a spot. The thing that jumps out though is a change in the 95% and 5% confidence lines, from this:
    http://i36.photobucket.com/albums/e7/niteowl496/ssn_predict_2009_03.png
    to this:
    http://i36.photobucket.com/albums/e7/niteowl496/ssn_predict_2009_03.png
    The Marshall website does say that “As the cycle progresses, the prediction process switches over to giving more weight to the fitting of the monthly values to the cycle shape function. At this phase of cycle 24 we now give little weight to the curve-fitting technique of Hathaway, Wilson, and Reichmann Solar Physics 151, 177 (1994). That technique currently gives highly uncertain (but small) values.”
    I don’t pretend to understand the details of how the “cycle shape function” differs from the “curve-fitting technique”, but they appear pretty confident that Cycle 24 is far enough along to make the change now. That is, if the minimum was indeed in 11/2008 like they’ve predicted.

  35. It’s possibly phased to the PDO. During a positive phase, one would expect ongoing decline of multiyear. Then, the the phase flips, multiyear may increase until the next flip. It will be interesting to track the above chart for a few more years, to get a feel for any potential phasing between ice characteristics and the PDO.

  36. Adam from Kansas (14:14:26) :
    Look at the maximum extent graph for the various suppliers in this post. Notice how CT “goes off the reservation” in 2006. Even though they come up with different amounts the deltas are consistent except for CT. I don’t trust their extent data anymore.

  37. OFF TOPIC
    I dunno about arctic ice, but there is fresh snow tonight on my lawn in Montreal, QC, Canada… 🙂
    The French have a saying:
    “in April, you will not uncover yourself by one thread;
    in May, do as you please;
    in June, dress with almost nothing”
    “En avril, ne te découvre pas d’un fil ; en mai, fais ce qu’il te plaît ; en juin, tu te vêtiras d’un rien”
    For the most part of my adult life, I considered this some sort silly saying, because it rhymes in the French saying. April never required too warm clothes, winter was over. But for the two last years, the saying seems to be holding again.
    I wonder when that expression was first coined.

  38. Steven Goddard (16:44:55) :
    “The Arctic always loses a lot of ice to wind blowing towards the North Atlantic – that is why there is never much ice more than five years old.”
    I agree. So that leads me to the question of what if anything has changed. AGW implies the loss of ice is higher arctic temps. What I have seen recently would say that no – it’s more wind and/or currents that are affecting ice levels. I can’t imagine that reduced CO2 wouldn’t have any affect on that. So if it is wind/currents, are there patterns or cycles that can be tied to this that might help or worsen the ice loss?

  39. Apparently ice retreat was so extensive during the MWP that it caused an entire race of highly cold-adapted people to disappear. Read up sometime on the Dorset people and their demise. These people hunted seals with spears and did not have boats or bow and arrow technology. The Inuit and Thule entered the territory as the ice retreated and the Dorset disappeared. It was probably all a result of Viking SUVs driving around Greenland.

  40. crosspatch (16:47:05) : “. . . Or put another way, it appears that for the past 2000 years we don’t quite recover as much from each cooling period.”
    Don Easterbrook claims “The climatic fluctuations over the past few hundred years suggest ~30 year climatic cycles of global warming and cooling, on a general rising trend from the Little Ice Age cool period. ”
    http://www.ac.wwu.edu/~dbunny/research/global/geoev.pdf [ p. 23 ]
    Note the “on a general rising trend”. He is working on a different time scale than your statement. Interesting!

  41. I guess all this depends on how you define ice. Ice is frozen water. Old ice takes as much energy to melt as new ice.

  42. This is perhaps a naive question, but…
    …how exactly do you determine whether ice is 1 year old or 2 years old and what is the range of measurement error on that?
    I love the psychological sleight-of-hand with the bright red and yellow colors. Its the equivalent of publishing a map of the Sahara in dark blue or purple.

  43. Jack Green (18:00:54) : new versus old ice
    The situation is more complicated than you state. Heck of a link below but I searched on “old ice” +”new ice” density melting
    and took the second link “Descriptive Physical . . . “
    http://books.google.com/books?id=94GNMv57uH8C&pg=PA229&lpg=PA229&dq=%22old+ice%22+%2B%22new+ice%22+density+melting&source=bl&ots=kWGL3Ek-wL&sig=u_E1k8oLoNqzQK3JnTvqyAjd8U8&hl=en&ei=XQbcSYe5CYnAMoOS_eIN&sa=X&oi=book_result&ct=result&resnum=2

  44. Any reversal of previous trends are what, supposed to turn around overnight? Go back to normal within the blink of an eye, a white-gloved finger lightly tapped against of Ol’ St’ Nick’s nose? A jennie’s crossed arm head nod? Samantha’s magic (and charming) facial grimace? The wave of a wand? The media is clueless. And those scientists who blab to the media prematurely in order to get the next grant are to blame. May they all lose fingers and toes to frostbite. It will be a good and proper reminder of your job and how you screwed up.

  45. I guess their rationale is these two animations:
    Covering 1981 to 2007.
    http://nsidc.org/news/press/2007_seaiceminimum/images/20070822_oldice.gif
    And then the updated one covering 2008-Feb2009.
    http://nsidc.org/images/arcticseaicenews/20090406_animation.gif
    The older sea ice keeps getting pushed out between Greenland and Iceland and then the general circulation also pushes older ice out into the western Arctic where it melts in the melt season now and, thus, there is little old ice left.
    The NSIDC just seems like a closed organization to me and will not open their data for general public review. You have to be satisified with a computer-generated graphic or you should just go away.

  46. Henry Phipps,
    “I miss Everett Dirksen.” Me too, in spades! Examples:
    “A billion trillion here, a billion trillion there, and pretty soon you’re talking about real money.”
    And: “…the basic difficulty still remains: It is the expansion of Federal power, about which I wish to express my alarm. How easily we embrace such business.”

  47. Another question.
    1 climate time-step is widely accepted to be about 30 years in length. Hence, 60 years is 2 climate time-steps, 90 years 3 climate time-steps etc. The data in this article shows changes over a ~19 yr period (less than 1 climate time-step).
    At best they are documenting the shape and characteristics of noise in the Artic ice cover over sub-climatic time scales.
    and what are we supposed to conclude?

  48. Walter Meir has his own website which posts his full 18 years fo experience, mostly as an aerospace engineer, now turned climate scientist.
    I was disturbed in AGAIN opening my daily paper and seeing another alarmist headline from Reuters: “Arctic Sea Ice continues to shrink”.
    So I wrote Walter Meir with a fairly respectful letter about how to present data as an optimist versus a pessimist as follows:
    Mr. Meir,
    I am sure you are a well meaning scientist. But just like the old saying about perception: one man will see a glass half empty, and another will see it half full.
    I am an engineer who works with data and numbers. I have done so for 33 years professionally, and 40 years if you count the fact that I have been designing since I was 14 years old. So I know how to present data and skew results to present results with optimism or pessimism with simple “steering” of my presentation during peer review.
    Last year, the NSIDC was claiming that Arctic ice was “very fragile” because of the summer of 2007 melt down and there was such a loss of “multi-year ice”. It surprised you all at the NSIDC, when in the following winter, the ice actually recovered, despite not much “multi-year” ice in many areas from the previous summer. This recent story from April 6th says the same thing, again, in sort of an alarmist fashion.
    To me, an old ice cube in my freezer, if frozen completely, is pretty much the same as a new one. And indeed, in the winter of 2007/2008, there was a surprising recovery of sorts. And this winter (2008/2009) there was even more of a recovery than last year in the Arctic. The decline was listed as -11% per decade last year, and now MAGICALLY, it is now only -2.7% per decade on your trend charts. On the other side of the Earth, the Antarctic is now trending up at +4.7% according to your monthly charts, and just a month ago it was only +2.8%.
    So what did we get from you in my newspaper today, Mr. Meir ? Headline: “Arctic Ice Continues to Shrink” (Reuters). If it were me, I would have foregone the few minutes of media attention you got and you might have said: “Trend Data Shows the Arctic is Making a Fragile Recovery the Past Couple Years”. Or perhaps “Global Ice Loss Lessens”.
    Conclusion Equation: Walter Meir = “Half Empty” = Supporter of the IPCC conclusions = Not an unbiased scientist.
    A few days ago, I used the published NSIDC data (despite some flawed and missing numbers), to calculate the GLOBAL sea ice trend. As of last week, global ice is above the 1979-2000 “average”. Global sea ice area for the past 30 years of satellite data is trending down by only -1.1% per decade based upon the NSIDC data tables. And who knows if the trend will reverse due to the low solar activity these past years as well as ocean current circulation patterns. But there are only 30 years of 350 satellite data points out of the thousands of years the past centuries of true history of the Arctic.
    We have no real long term data about ice area…and we only have sketchy records of the USS Skeet coming up in 10 places near the Arctic pole starting in the late spring in the 1950s.
    And, there is my constant gripe that you folks think 1979-2000 is some holy grail of average ice area and extent. What if “average” throughout the recent centuries is more like, um say, 1999-2009? Data is the data, but the NSIDC cherry-picked the “average” as 1979-2000, as if it was the holy grail of ice averages. If I may be so bold: that is very assumption-based science = bad reporting of data. The Arctic ROOS site does not throw away nearly 30% of the data as does the NSIDC.
    So, can Walter Meir put on some optimist glasses for a while and say, maybe, just maybe, the Arctic is slowly recovering from a normal melt cycle ?
    Mike Strong

  49. Thanks john. It would nice to know the salinity values for sea ice by year to fully understand the implications of this subject. This subject must depend on how much ice gets to lower latitudes and subject to more heat resulting in more melting.

  50. “It would nice to know the salinity values for sea ice by year to fully understand the implications of this subject. ”
    That varies with year. The amount of salt that works out of the ice is pretty much a function of the amount of sunlight it gets. If you have an unusually cloudy summer, you get less salt worked out of the ice. Now there would be a general range of what is typical, but that will change depending on where the ice was when it aged and the conditions at that location. There is no set “2 year old ice contains X% salt” chart. It will also depend on the salinity of the water when the ice formed. The salinity of the Arctic Ocean itself varies from year to year.

  51. “crosspatch (16:47:05) :
    “So what was causing global warming 700 years ago?”
    That would be the medieval warm period. Actually, it appears that climate has been in a general cooling trend with each warm period a little cooler than the preceding one. Roman warm period warmer than Medieval warm period, for example. Or put another way, it appears that for the past 2000 years we don’t quite recover as much from each cooling period.”
    I look at the history & see one thing. We have a servo moving from one position to another. It is loosely controlled & there is ringing as it reaches stabilisation in the new position. That is why optima are less intense as are pessima.
    Just an observation.
    DaveE.

  52. NBC was hyping the latest reduction in polar sea ice Monday evening. Imagine for a moment that they are miraculously right and the Arctic ocean completely cleared of ice this summer (or sometime soon).
    What do you get?
    Well, at such a small at such a sun angle (<23.5deg), there is not that much solar heating, but all that new open water (and a little solar heat) adds up to an increase in water vapor feeding into the atmosphere.
    More moisture in the atmosphere means there will be more clouds which reflect sunlight and shade the surface. If that moisture is precipitated in the cooler northern parts of the Eurasian and North American land masses, it will likely be in the form of snow, which increases surface reflectivity. In both cases, the result is a cooling.
    I think that is called a negative feedback.
    If there is a danger from an ice-free Arctic Ocean, it is that this negative feedback is a precursor to our next (overdue) Ice Age…

  53. The IPCC not functioning properly article refers to a police organization in England as far as I can tell and has nothing to do with the IPCC climate organization. I noticed this on Icecap yesterday. I assume the automatic retrieval system for that blog simply picked up the IPCC acronym.

  54. Mike Strong (18:24:21) : “. . . that you folks think 1979-2000 is some holy grail of average ice area and extent.”
    I think because of historical practices – before the computer age – climate “normals” were calculated on a 30 year data set ending in a “0” year, for example 1980, then 1990, then 2000. For your local weather normals these will be recalculated after 2010. I suspect the 1979-2000 ice data you are unhappy about because they throw away data is simply a throw-back to the pre-computer age. So I suspect eventually we will have 1981-2010, and lasting for 10 years. Then maybe 1991-2020?
    This seems unnecessary with computers – at least to me – but maybe it is a psychological thing.

  55. Well if they are going to use age as measure of anything, then I’m more worried about the age and maturity of the President of the United States of America, than the age of the sea ice 😉

  56. Mildly OT:
    A track-hoe operator in Alberta, Canada, whom I queried via e-mail told me the following things:
    1. Water mains buried to the standard minimum engineered spec of 2.6 meters had a funny habit this winter of freezing/breaking.
    2. The frost depth was unprecedented in his 35 years of work digging in the province.
    The gentleman was loathe to go on the record, as he works for the provincial government with its own strong feelings regarding dangerous manmade global warming…

  57. Mike Bryant (16:38:41) I’m not sure about the discrepancy. The DMI pic is SST, the CT is ice. The white on the DMI pic is probably water or ice at or below 0 C. The projection of the two are different. Here is a picture with the outline of the DMI picture’s white area with a constant aspect ratio, scaled as best as possible to the CT picture. It does not fit well, however, I am surprised at how well the fit is in the northern Atlantic, assuming that was your area of concern.
    On second thought, assuming these are highly accurate projections of measured areas by satellites that measure sub-millimeters, which, if either, is correct? http://i40.tinypic.com/29e4ye1.jpg

  58. Another of the typical AGW misrepresentations: any change of a climate variable (no matter how complex) is due to, and only to, increasing temperature, caused by human CO2. A NASA JPL investigation of the 2007 Arctic ice minimum found winds and currents to be responsible for pushing ice out of the Arctic, where it melted in warmer water.
    One of the things that amuses me about this subject is the claimed impact on polar bears, who hunt seals on the ice. Seals are, of course, mammals, who have to surface to breathe. To do so, they maintain breathing holes in the ice; the bears know this, and wait at the holes for a seal to surface.
    Breathing holes are possible in first year ice (if maintained), but certainly not in multiyear ice. Much too thick, much too hard. Even USN submarines have difficulty surfacing through MY ice. That’s why the SSMI algorithms attempted to differentiate FY and MY ice (actually, pretty well). SSMI was a DoD instrument.
    Bottom line, bearwise and sealwise: FY ice is good, more habitat; MY ice is bad, less habitat.

  59. O/T, but the post on watts about synchronized chaos made me think about this. Is it possible that CO2 and temps synchronized, and this turned on a natural cooling mechanism? Runaway warming suddenly halted by natural negative feedbacks?

  60. Jack Green (18:00:54) :
    I guess all this depends on how you define ice. Ice is frozen water. Old ice takes as much energy to melt as new ice.

    Not when it’s frozen saltwater.
    Mike Bryant (16:38:41) :
    At this site:
    http://ocean.dmi.dk/satellite/index.uk.php
    Choose “Arctic Ocean” on the pull down menu under “Geographical Domain”
    Then compare the Sea Ice to the picture at CT here:
    http://arctic.atmos.uiuc.edu/cryosphere/
    Now, why is there such a discrepancy?

    What discrepancy?
    http://ocean.dmi.dk/arctic/satellite/index.uk.php
    http://i302.photobucket.com/albums/nn107/Sprintstar400/arcticseaicecolor000.png
    Apart from the different projection.

  61. Tom in Texas (18:56:57) :
    In addition to “Quote of the Week”, how about “Comment of the Week”?
    I nominate Mike Strong (18:24:21) : Letter to Walter Meir

    I nominate this post as “Joke of the Week”
    Among the various howlers is the following which was already explained to him on this site!
    To me, an old ice cube in my freezer, if frozen completely, is pretty much the same as a new one. And indeed, in the winter of 2007/2008, there was a surprising recovery of sorts. And this winter (2008/2009) there was even more of a recovery than last year in the Arctic. The decline was listed as -11% per decade last year, and now MAGICALLY, it is now only -2.7% per decade on your trend charts. On the other side of the Earth, the Antarctic is now trending up at +4.7% according to your monthly charts, and just a month ago it was only +2.8%.
    The MAGICAL part of course arises because Mr Strong confused monthly trends with annual trends.

  62. If it’s still minus 40 in the Arctic how could the maximum extent of ice be Feb 28? Or is Feb 28 just an arbitrary date chosen for the end of winter ice maximum?

  63. Justin,
    Winds in the Gulf of Okhotsk have compressed the ice, causing a slight dip in extent. That is what is meant by “the start of the melt season” – while ice in the Arctic basin is of course getting thicker at -30C.

  64. Phil. (19:47:51) :
    Explain what you mean by “different projection.” I assume what Mike was referring to was the difference around Greenland and over Russia, but I don’t know much about reading these images.

  65. “Isn’t it great living in an insane asylum?”
    I wouldn’t quite call it insane. More like an “idiocracy”. We have reached a point where “the truth” is whatever validates your own opinion or the opinion of the social group you wish to identify with. Now if some of the really major music and film celebrities came out and said it was all a load of hooey, you would suddenly find the masses changing their opinions too because they want to be like the “cool kids”. Reality doesn’t matter to these people.

  66. Tim McHenry (20:25:11) :
    Phil. (19:47:51) :
    Explain what you mean by “different projection.” I assume what Mike was referring to was the difference around Greenland and over Russia, but I don’t know much about reading these images.

    As also pointed out by Steve K (below) Mike was comparing images of different quantities, I gave the corresponding image from the same source which matches extremely closely with cryosphere today image. The maps were produced with different projections (as did Steve K), meaning that a different algorithm for transforming the image of a sphere onto a flat surface.
    Steve Keohane (19:20:06) :
    Mike Bryant (16:38:41) I’m not sure about the discrepancy. The DMI pic is SST, the CT is ice. The white on the DMI pic is probably water or ice at or below 0 C. The projection of the two are different.

  67. Steven Goddard wrote:
    “The Arctic always loses a lot of ice to wind blowing towards the North Atlantic – that is why there is never much ice more than five years old.”
    Younger, thinner ice is more susceptible to being pushed around by winds than older, thicker ice.

  68. I see images of Nuclear Submarines in the 1960’s busting up through the ice in the Arctic, so looking at the graph, it’s never been that thick.
    The Caitlin Cruisers are frostbitten and exhausted, but oh that ice is so melting at -35C. The Sun is like a blowtorch up there in April, don’tch know.

  69. Arn Riewe wrote:
    “AGW implies the loss of ice is higher arctic temps. What I have seen recently would say that no – it’s more wind and/or currents that are affecting ice levels.”
    Or maybe a combination of both? First year ice is thinner and therefore more easily moved around by winds than is old ice.

  70. Bill Illis:
    “The NSIDC just seems like a closed organization to me and will not open their data for general public review.”
    Have you gone to their website and tried to download it? I just did, and it only took me a minute or 2 to find sea ice data through April 6.

  71. ” Robert Bateman (21:06:25) : ”
    My understanding is that it isn’t all that unusual for the North Pole itself to be ice-fee in the summer. It depends on which way the winds blow what remains of the sea ice. It isn’t just going to sit there at the pole, it is going to drift with the wind. I believe someone posted pictures here (or maybe it was at CA) of submarines surfacing at an ice-free pole many years ago.

  72. Multi-year ice has increased from 2008, up to nearly 25%.
    1985 was 50% ,,,, 2009 looks good for 25% ,,,,2008 looks good for 20%
    Arn Riewe (13:48:03) : where you see 30% ????
    At current recovery of 5% per year
    20% at 2007 that means in 6 years there will be 50% Multi-year old ice, 2013-2014.
    WE shall see.

  73. When we had the NSIDC sensor problem, Dr. Meier was kindly answering a few questions but stopped short of discussing the key points: 1) why does NSIDC use a 20 y average for sea ice extent? Especially now while it uses a 30 y average when it comes to ice thickness? 2) Since multiyear ice is really not that old and that back in 1980, it only comprised according to NSIDC 30% of the arctic sea ice, what happened to the 50, 100y old ice? Of course it melted which suggests that at any moment the amount of multiyear ice is never a huge proportion and thus the alarmism displayed is just the result of these scientists observing for the very first time these events with a scrutiny never achieved before. 3) The clear relation with atmospheric circulation and in particular for those who have read Marcel Leroux and his students works, the entire premise of alarmism becomes a moot point and if anything highlights a rather simplistic vision of climatic changes and/or an agenda.

  74. “Sea ice thickness has been hard to measure directly, so scientists have typically used estimates of ice age to approximate its thickness. But last year a team of researchers led by Ron Kwok of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., produced the first map of sea ice thickness over the entire Arctic basin.
    Using two years of data from NASA’s Ice, Cloud, and land Elevation Satellite (ICESat), Kwok’s team estimated thickness and volume of the Arctic Ocean ice cover for 2005 and 2006.”
    http://www.jpl.nasa.gov/news/news.cfm?release=2009-062
    So its an “estimate” of thickness a not direct measurement. wonder how accurate it is.

  75. I can hardly see how being just halfway between the average and the lowest bound (record low) is “very close to normal”.

  76. alphajuno (13:58:20) : “… At least the gulf is staying cooler longer which should help during hurricane season.
    Sorry to disappoint you, but contrary to what the alarmists say, it could be that atlantic hurricanes (the ones that hit your gulf, I believe) are more associated with global cooling than with global warming. As it seems we are now in a PDO cooling phase, you may soon experience more hurricanes not less.
    http://typhoon.atmos.colostate.edu/Forecasts/2008/aug2008/aug2008.pdf
    in the quarter-century period from 1945-1969 when the globe was undergoing a weak cooling trend, the Atlantic basin experienced 80 major (Cat 3-4-5) hurricanes and 201 major hurricane days. By contrast, in a similar 25-year period from 1970-1994 when the globe was undergoing a general warming trend, there were only 38 major hurricanes (48% as many) and 63 major hurricane days (31% as many)
    (Supported by interesting chart on page 34.)
    But – from the same team :
    http://www.breitbart.com/article.php?id=CNG.89f94643ff57e11b42acfa11b92f8e26.d41&show_article=1
    Six hurricanes are expected to churn through the Atlantic this year, a Colorado State University forecast team said Tuesday as it lowered its estimates for the upcoming storm season.
    If the predictions are accurate, 2009 would be much calmer than last year, which was one of the most active seasons on record with 16 tropical storms, including eight that became hurricanes.
    Hurricanes Bertha in July, Gustav in August, Ike in September, Omar in October and Paloma in November were all intense storms that wreaked serious damage in the United States and the Caribbean.
    Of 12 predicted tropical cyclones for 2009, six were forecast to become hurricanes, including two expected to develop into intense or major hurricanes Category Three or higher.
    Earlier predictions from the group had called for 14 tropical cyclones — or what forecasters call “named storms” — this hurricane season, lasting between June 1 and December 30.
    “We are calling for an average hurricane season this year — about as active as the average of the 1950-2000 seasons,” the team’s lead forecaster, Phil Klotzbach, said in a statement.
    The University of Colorado team based its projections on the potential for a weak El Nino maritime temperature fluctuation, along with an unusual cooling of tropical Atlantic sea surface temperatures it observed in recent months.
    Cooler water temperatures tend to make for a less active hurricane season in the region, the researchers noted.

    Confused? Looks like they are. I am.

  77. Multi-year ice has increased from 2008, up to nearly 25%.
    1985 was 50% ,,,, 2009 looks good for 25% ,,,,2008 looks good for 20%
    Arn Riewe (13:48:03) : where you see 30% ????
    At current recovery of 5% per year
    20% at 2007 that means in 6 years there will be 50% Multi-year old ice, 2013-2014.
    WE shall see.

    i am pretty shocked by this sort of calculations.
    old sea ice will NOT grow back to former percentages, while sea ice extent remains significantly below the long term average. 2009 so far was NOT a year with much ice, neither was 2008.
    it is just years with slightly more ice than 2007.
    as long as the temperatures stay above the long term average, and extent stays below it, there will NOT be a regrowth of the old sea ice. that should be obvious!

  78. There IS still a greater risk of further decline, as compared to the long-term average risk of decline. But the risk now is less than it was 2 years ago.
    I think it’s reasonable to still see things cautiously, since another perfect melting season like 2007 could do real damage.
    But a more balanced report would say: ‘The position now is more healthy than in 2007, but it will be a few years before a return to long-term norms is possible. Our long-term predictions on arctic ice will to a significant extent be impacted upon the next three annual cycles of freeze/melt. If recovery continues, we will see normal conditions returning. But a return to rapid thaw conditions may see our predictions of ice-free summer come significantly closer.’
    Now how hard was that to say?
    If an unqualified lay person can write it, either it’s nonsense or a professional could have written it too.
    Why didn’t they?

  79. Henry Phipps (15:55:21) :
    Ron de Haan (14:28:02) :
    “Who wants to be represented by a Government of liars, frauds and cheats.”
    Maybe we always have, Ron, but in times past, the newspapers weren’t part of the government cabal. Now we have even more persuasive media formats, and a more ignorant electorate. No checks-and-balances, no pursuit of truth, and most of all, no more statesmen, just political hacks from any party.
    I miss Everett Dirksen”.
    Henry,
    In regard to all the remarks you make about the state of your democracy I think the time has come to take individual action and responsibility. This always has been the basis of any democracy, one man, on vote.
    Every individual counts, every individual takes responsibility.
    As I see it you have come to the point of losing all your rights.
    Missing Everett Dirksen won’t change anything.
    A liar is a liar and any liar who holds a public office should be confronted without any exception. Especially if the subject they are lying about could result in such dire consequences like losing a countries economic future and the way of life of her inhabitants.
    It sounds to me that you can’t afford to do nothing!

  80. I notice that the nsidc have this statement in their latest analysis.
    Overall, it was a fairly warm winter in the Arctic. Air temperatures over the Arctic Ocean were an average of 1 to 2 degrees Celsius (1.8 to 3.6 degrees Fahrenheit) above normal, with notable regional variations.
    I’m not surprised, given that it has been so cold in the US and Europe this winter. The winds must have been pushing the cold air mass from the Arctic southwards, and I assume this must have been replaced by warmer air from the South. This makes me wonder how much ice we would have had in the Arctic if these weather patterns had been different. If these winds have now stopped then I guess you might expect the sudden drop in Arctic temps that we now have, and that Catlin are enjoying. If so what’s the chance that the ice will now catch up with the ‘long term’ average?

  81. I’m sorry, but I don’t get it. Do they mean to tell me that if I keep ice-cubes in my freezer for 2 or 3 years before I use them, that they will last longer in my drinks?
    Could someone please explain to me just how newer ice melts faster than older ice? I honestly don’t see where the age of the ice can make any difference at all.

  82. “what’s the chance that the ice will now catch up with the ‘long term’ average?”
    Wouldn’t that be a hoot? I doubt NSIDC will issue a press release about that if it happens. Or, if they do, it will be full of spin.
    I’ve been watching the horizontal tracing on the ice-extent chart for late March and early April; it looks as though this year’s melt-back may proceed more slowly than normal. This is what one would expect if winds are lower and if cooler water (than 2007) from the Pacific were entering the Arctic Ocean. Prof. Akasofu provided data in his paper that indicated that the latter is happening, “Two Natural Components of Recent Climate Change,” (a 50-Mb PDF), here: http://people.iarc.uaf.edu/~sakasofu/little_ice_age.php

  83. “A liar is a liar and any liar who holds a public office should be confronted without any exception. Especially if the subject they are lying about could result in such dire consequences like losing a countries economic future and the way of life of her inhabitants.
    It sounds to me that you can’t afford to do nothing!”
    When the liars have taken over Washington, when they control the arms, when they bail out the institutions that hold “their” retirement accounts with our money, when they now want to control and tax our means of livelihood and then tax even the air we breathe, what are we supposed to do?
    Maybe there should be a referendum on shutting down D. C.
    The only honest politician is Ron Paul.

  84. This is more evidence of the conspiracy at NSDIC to brainwash the public into believing there is such a thing as global warming. They are just doing it to get more funding and high salaries. I know, I’m a janitor there and have evesdropped on their conspiratorial meetings and have listened in on theor conversations when the ‘dumb’ janitor was mopping the floor and emptying the garbage.
    I can testify that these guys are cooking the data. And that they always leave the breakroom in a mess and don’t clean out the microwave. How much sense does a person have to have to know to cover they damn food in the microwave? Does that take a Phd? I mean come on people!
    Dill Weed

  85. http://www.accuweather.com/ukie/bastardi-europe-blog.asp?partner=rss
    ARCTIC SEA ICE TO MELT LESS THIS YEAR THAN LAST (HIGHER STARTING POINT NEXT YEAR).
    The development of the strong positive AO the next 3-5 weeks combined with a solar constant that refuses to come up from its sunspot minimum means the arctic sea ice will undergo a summer of less melting than last year. An interesting article showing how the cold is making a comeback can be found here: http://wattsupwiththat.com/2009/04/04/bad-news-for-catlin-expedition-satellite- data-shows-arctic-cooling-in-feb-march/
    There was an article on our global warming website declaring the melting season had begun. Part of that is because the sea ice is at more extensive levels than it has been, so it can melt quicker, but part of that is because of what you see going on now across the states. The blocking that has occurred to force this issue means it is warmer in the arctic, as the cold air is underneath. However, UNLIKE LAST YEAR, WHEN MAY TURNED VERY WARM IN THE ARCTIC, we are going the opposite direction now. In fact the UKMET April-Jun forecast still shows over 60% of the Earth is colder than normal and more significantly the Arctic. My take is the long, cold, arctic winter next year will start with more ice than it started with this past year.
    http://www.metoffice.gov.uk/weather/world/seasonal/
    The reporting on arctic sea ice is getting to be like the reporting on the ozone hole. Ever notice every now and then there are reports that the ozone is opening up? Well how does it open up if it doesn’t close? But you never hear about it closing. The AGW crowd is getting to be like an episode of the Simpsons when Homer was running around getting a law passed against anything he thought might cause a problem anywhere. So now we have a report on how scientists are worried about rapid melt of Arctic sea ice this season because 20 PERCENT OF THE ICE SHELF IS NEW ICE (AND CAN MELT FASTER). Well how the heck did it increase 20% in the first place to get there? And what if only 75% of the new ice melts this summer, doesn’t that leave you ahead to start next winter?
    So stupidly, the reporter doesn’t even ask the question, well why is so much new in the first place?
    The Arctic will be turning colder relative to normal by the end of the month, and when that happens we can get out of this pattern in the US (after the 15th) and into some relatively tranquil and much warmer weather nationwide than what we have now, and even for the next week or so. Of course as soon as it gets hot here, you will hear about it, but what they wont tell you is how cold it will be in the arctic at that time.
    In any case its interesting to look at how much cold the model is seeing. Anyone here anyone in the UKMET office talking about how cold their model looks. When it looks warm, we certainly hear about it.
    thanks for reading, ciao for now *****

  86. Jeff (21:07:54) :
    “Or maybe a combination of both? First year ice is thinner and therefore more easily moved around by winds than is old ice.”
    I don’t disagree with you logic, but the NSIDC animation seems to show no particular preference for old or new as the ice pack streams out of the Arctic between Greenland and Iceland where it then meets the Gulf Stream:
    http://nsidc.org/news/press/2007_seaiceminimum/images/20070822_oldice.gif
    To me, it become obvious this is the dominant factor in ice decline, not melting within the Arctic basin.

  87. Leave it to the Propheteers (or profiteers) of global warming to find some way to spin an increase in polar ice.
    Well since the record low in 2007 (since satellites), there has been a net seasonally adjusted increase of about 2.5 million sq km.
    To find the glass half empty instead of half full, the new criticism is that the majority of ice is only 1 or 2 years old. DUH. The polar ice has increased significantly the past 2 winters, so indeed , so they have to find some negative spin on the whole thing.

  88. Ron de Haan (01:32:45) :
    Thank you, Ron, for your thoughts and your concern. It’s comforting to find good people everywhere I venture. You’re right about the role of the citizen in a democracy. I’ve only experienced democracy twice that I can recall. Once, I saw a bar-room brawl. Truly democratic, with all the points you mentioned. The second was on DARPANET, where I first realized that one person’s thoughts counted, no matter what race, creed, color or rank. Even though my days of protest and confrontation are long past, old men like me can function to encourage others to question what they are being told. Sometimes all young people need is a nudge, like getting some kind of permission, to believe in their own ability to make judgments based on their own experiences. Our nation has little real democracy in this federal republic. A republic requires honest representatives with dedication to the will of the people. Not much of that in evidence these days. Perhaps there are no more Dirksens.
    Or perhaps they are just reading and learning, awaiting encouragement to think for themselves.
    Regards, Henry

  89. @Steven Goddard
    Thanks for the great posting. I went to sleep last night thinking about one sentence and realized that I had no clear perspective about it. “Due to the record minimum in 2007, it goes without saying that there isn’t a lot of three year old ice in 2009.” The ice extent minimum in 2007 was similar to the area of the Central and Pacific Time Zones of the continental USA added together, if my numbers aren’t wrong. Or put another way, about two-and-a-half times the size of Alaska. Granted, my math may be approximate, but that sounds like a lot of Slurpees to me. Any polar bear who can’t stand up on that is just singing Darwin’s lullaby.

  90. Lets see.
    We have NASA moving the goalposts on the solar cycle 24 forecast. Acutally, at least six times and counting.
    We have NSIDC moving the focus from baby ice to pubescent ice, and moving the focus from ice extent to ice volume.
    We have intense media focus on Arctic ice during its summer melt, and on Antarctic ice during its summer melt, but never a peep in the media about global sea ice.
    We have NASA GISS adjusting historical temperature records every month as new temperature data comes in.
    We have tropical storm naming thresholds reduced (tiny tim storms) to increase the annual storm counts.
    We have NASA GISS broadening the error bands on GCM outputs to make sure they encompass the recent temperature trends at the surface and in the mid troposphere, such that GCM error bands on forecasts are getting worse over the past twenty years. At this rate, by 2100 GCM’s will provide an infinite amount of information and contain absolutely no knowledge.
    It appears that news of Gaia’s death has been greatly exaggerated.

  91. Flanagan (23:12:56) :
    I can hardly see how being just halfway between the average and the lowest bound (record low) is “very close to normal”.

    Recovering half-way from the record low to the mean in one year is kind of significant…Particularly when the Arctic has only just recently begun to participate in the cooling trend that began between 2003 and 2005.
    From 1998 through 2007 NSIDC shows about an 8% decline in Northern Hemisphere sea ice extent (below the 1979-2000 mean) and then a recovery to about 4% below the mean in about one year…Nine years to lose 8%; one year to regain 4%…Even Hans Blix could find the significance in that recovery rate.

  92. Optimally, one would have a full 60 year (both pos and neg legs) PDO cycle worth of data to compare with as a baseline.

  93. The correlation of CO2 and Arctic ice is really quite funny. The problem with correlations (eg cross-correlation) is causality. In a closed system, this become trivial. a measure of input must measure an output.
    I do know the NSIDC is fully aware AND capable of performing statisical analysis, but it seems to vaporize once they put out a press release.
    The most interesting feature of the 30 year sea ice extent record is October of 2007. The change in sea ice extent (happened to be an increase) was the largest of the recorded period. Yet this is dismissed as due to wind changes. So wind changes can increase sea ice but only AGW can reduce sea ice? Now that is truely an amazing finding.

  94. I suspect NSIDC has been told by their superiors to become more alarmist.
    The huge 2007 arctic melt was wind driven. Even most alarmist admit that. As such common sense tells us we won’t replace all that lost ice instantaneously. Common sense tells us we would expect slow but sure increases until we get back to a temperature driven mean. If the mean temperature increases this mean will decrease slowly over time. Sure there will be lots of noise but after all is said and done there is really no logical reason for NSIDC to state anything else.
    So, why didn’t they make this obvious statement? Back to my first sentence.

  95. sod,
    There is no calculation involved. The NSIDC graph shows 25% multiyear ice.
    http://nsidc.org/arcticseaicenews/
    No need to be shocked.

    the reply i quoted used that number to calculate that we will see 100% in a few years under current conditions. we wont!
    the graph is not misleading, but pointing out an important fact: we are still losing older ice!
    your article is based on the assumption that the 2 year ice will grow older under current conditions as well. but very few of it will. temperatures are still above long time average. so is extent.
    if 2009 extent is below 2008 (looks very similar so far), then we will lose 2 years ice AND older ice again this year.
    http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Extent.png
    From 1998 through 2007 NSIDC shows about an 8% decline in Northern Hemisphere sea ice extent (below the 1979-2000 mean) and then a recovery to about 4% below the mean in about one year…Nine years to lose 8%; one year to regain 4%…Even Hans Blix could find the significance in that recovery rate.
    a comparison between a long time average and a single year doesn t make a lot of sense. why not compare with the maximum extent?
    why not compare the last few years with the long time average?

  96. Squidly (03:17:51) :
    I’m sorry, but I don’t get it. Do they mean to tell me that if I keep ice-cubes in my freezer for 2 or 3 years before I use them, that they will last longer in my drinks?
    Could someone please explain to me just how newer ice melts faster than older ice? I honestly don’t see where the age of the ice can make any difference at all.

    That’s because you don’t freeze saltwater ice in your freezer and subject it to periodic freeze/thaw cycles causing surface meltwater to percolate through taking the brine with it!

  97. Henry,
    My point about (exactly) three year old ice is that there is almost none, due to the 2007 minimum. There is however considerable ice older than three years, as you mentioned – which is the multi-year ice which survived the 2007 melt.

  98. crosspatch (18:47:26) wrote (editted):
    “It would nice to know the salinity values for sea ice by year to fully understand the implications of this subject.
    “The amount of salt that works out of the ice is pretty much a function of the amount of sunlight it gets. If you have an unusually cloudy summer, you get less salt worked out of the ice. Now there would be a general range of what is typical, but that will change depending on where the ice was when it aged and the conditions at that location…..”
    It is my understanding that sea water does not freeze and entrap salt in place. The water crystallizes as almost-pure ice and the salt is concentrated in the remaining liquid phase. (The same process of repeated melting and freezing is used to purify silicon for electronic applications.) If the freezing face remains open, the salty water will “escape” into the bulk of the sea. Only if the water is freezing around (on all sides of) a blob of sea water will any salt become entrapped within the ice. So I do not see salt “working its way” out of the ice.
    Comments invited.

  99. Ian L. McQueen (09:11:02) :
    crosspatch (18:47:26) wrote (editted):
    It is my understanding that sea water does not freeze and entrap salt in place. The water crystallizes as almost-pure ice and the salt is concentrated in the remaining liquid phase. (The same process of repeated melting and freezing is used to purify silicon for electronic applications.) If the freezing face remains open, the salty water will “escape” into the bulk of the sea. Only if the water is freezing around (on all sides of) a blob of sea water will any salt become entrapped within the ice. So I do not see salt “working its way” out of the ice.

    Your understanding is at variance with he established science on the subject:
    http://nsidc.org/seaice/characteristics/brine_salinity.html

  100. sod,
    Most of the multi-year ice was lost during the winter of 2007-2008 due to wind. Obviously there is no in-situ melting going on in the Arctic during the winter.

  101. Squidly (03:17:51) :
    I’m sorry, but I don’t get it. Do they mean to tell me that if I keep ice-cubes in my freezer for 2 or 3 years before I use them, that they will last longer in my drinks?
    Could someone please explain to me just how newer ice melts faster than older ice? I honestly don’t see where the age of the ice can make any difference at all.

    It is mostly a question of surface area to volume. A thin sheet of ice the same volume as a cube of ice has much more surface area and will melt faster when exposed to warmer air, warmer ocean currents and solar radiation.
    The Multiyear ice is thicker, so it has less exposed surface for its volume.
    This is really important when the ice gets quite thin late in the summer, but at some 3 to 3.5 meters thick I am not sure it all that significant. If we have a summer that is even slightly cooler than the recent past, or slightly cooler ocean currents all that will not matter. The other side of the coin is that thin first year ice is more prone to being pushed up into pressure ridges by the wind as it is not as strong as thicker ice. Once it gets compacted into pressure ridges that extend above and below the water surface you now have a very thick area of ice which would be very resistant to melting as its volume to surface area would be much higher than the parent thin ice sheet.
    The current ice extent plots look like the melt is progressing slower than in the past as the current ice extent plot is still converging with the 1979-2000 mean and diverging from the low extent plot. In short for this time of the year the ice is increasing compared to low ice years.
    I personally am expecting to see the ice extent plot merge with and perhaps exceed the 1979-2000 mean line in a few weeks if it maintains its current converging trend.
    Larry

  102. From 1998 through 2007 NSIDC shows about an 8% decline in Northern Hemisphere sea ice extent (below the 1979-2000 mean) and then a recovery to about 4% below the mean in about one year…Nine years to lose 8%; one year to regain 4%…Even Hans Blix could find the significance in that recovery rate.
    sod (08:37:10) :
    […]
    a comparison between a long time average and a single year doesn t make a lot of sense. why not compare with the maximum extent?
    why not compare the last few years with the long time average?

    In the case of sea ice extent records…”the long time average” is 30 years…The extent of the satellite data. That 30-year period is more or less coincident with the recent warm phase of the PDO/QDO (1978-2005). Almost all of “the long time average” falls within a 27-year warming trend.
    If the “single year” is the inflection point…It makes a lot of sense. The Northern Hemisphere sea ice extent didn’t really vary that much from 1979-1998…Basically hovering within 2% of the mean… With a slight down-trend. The down-trend steepened after 1998.
    If you download the Lower Troposphere satellite temperature data (either UAH or RSS – I prefer UAH because of the way the data are subsetted) and plot Northern Hemisphere, Southern Hemisphere, Oceans, Land, Arctic and Antarctic as separate curves…You’ll see that the Southern Hemisphere, Antarctic and Oceans warmed less and started to cool sooner than the Northern Hemisphere, Arctic and Land (probably why HadCRUT3 and GIS show more warming and less cooling than the satellite data)…The Antarctic actually shows a linear cooling trend throughout the 30-year satellite record. The peak warming in the Arctic and the cooling both occurred latest in the Arctic data set…Both of those temperature curves correlate quite well with the NSIDC Northern and Southern Hemisphere ice extent graphs.

  103. The current ice extent plots look like the melt is progressing slower than in the past as the current ice extent plot is still converging with the 1979-2000 mean and diverging from the low extent plot. In short for this time of the year the ice is increasing compared to low ice years.
    I think you’re misinterpreting the data, currently extent is below 2008 and is converging on 2007, and is 2std below the ’79-’07 average.
    I personally am expecting to see the ice extent plot merge with and perhaps exceed the 1979-2000 mean line in a few weeks if it maintains its current converging trend.
    Not very likely, at this time of year all the recent trajectories converge and by the end of the month they’re close to indistinguishable. The indications are that this season is following the same path. There’s very little relationship between what happens now and after July.

  104. Surely ice is only fresh water with the solution that it formed from becoming more salt rich?

  105. Phil. (09:42:33) :
    Thanks for the link about the formation of sea ice. I’m feeling less frazil-ed already.
    Every now and then, when I turn my head just right, a tiny amount of blood squirts through my carotid arteries, and my brain lurches into action. Today is not one of those days, however. Here is what I can remember:
    1. Three year ice is not everybody over the age of three, just three year olds.
    2. The structural part of ice is fresh water. This is the good part.
    3. All kinds of stuff can be caught in the structure of ice, including salt, Chinese black carbon, plankton, and chunks of polar bear poop. Don’t eat the ice.
    4. Young ice is thin, physically unsound, and drifts around with the breeze. It’s quite willing to melt if the conditions are right, and everybody else is doing it.
    5. Old ice is fat, lumpy, rigid, and sedentary. It is uncooperative with melting or most other forms of weight-loss. Naturally.
    6. The best way to make sure your tax-supported research says what you want it to is to change the data recording parameters. Then change the definitions. Then change the subject.
    This climate stuff is starting to look easy. I think I need a nap.

  106. Phil. (10:57:32) :

    I personally am expecting to see the ice extent plot merge with and perhaps exceed the 1979-2000 mean line in a few weeks if it maintains its current converging trend.
    Not very likely, at this time of year all the recent trajectories converge and by the end of the month they’re close to indistinguishable. The indications are that this season is following the same path. There’s very little relationship between what happens now and after July.
    It depends on which source you got to as well. As you can see in this image the current plot is parallel to the low limit plot and approaching the median plot. Although it is decreasing in absolute terms it is dropping slower than the 1979-2000 mean, which if this trend continues it will approach that mean limit over the next few weeks.
    If that persists or has any real impact on the late season melt in July is of course a different question, but given recent cold weather records, late season snow fall and attendent albedo changes, and dimming by the erruptions at Redoubt I am inclined to think the current convergence with the upper boundary (1979-200 mean) is more likely that converging with the low limit or the average of the two.
    Just seat of the pants analysis but that is all any of us really have to go on until the data is in. ; )
    http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png
    Larry

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