Cryosat produces its first Arctic ice thickness map

Arctic sea-ice thickness 2011

CLICK TO ENLARGE IMAGE - CryoSat’s exceptionally detailed data have been used to generate this map of sea-ice thickness in the Arctic. Data from January and February this year have been used to show the thickness of the ice as it approaches its annual maximum. Thanks to CryoSat’s orbit, ice thickness close to the North Pole can be seen for the first time. Credits: CPOM/UCL/ESA

From the European Space Agency (ESA):

New ice thickness map of the Arctic unveiled


The first map of sea-ice thickness from ESA’s CryoSat mission was revealed today at the Paris Air and Space Show. This new information is set to change our understanding of the complex relationship between ice and climate.

From an altitude of just over 700 km and reaching unprecedented latitudes of 88º, CryoSat has spent the last seven months delivering precise measurements to study changes in the thickness of Earth’s ice.

Satellites have already shown that the extent of sea ice in the Arctic is diminishing. In fact, spring 2011 is the third lowest extent recorded by satellite.

However, to understand fully how climate change is affecting the fragile polar regions, there is a need to determine exactly how the thickness of the ice is changing.
To answer this question, a group of scientists together with Prof. Duncan Wingham from University College London proposed the CryoSat mission to ESA in 1998. The loss of the original CryoSat satellite in 2005 as a result of a launch failure has unfortunately made this a longer than normal wait.

ESA's ice mission

ESA's ice mission

Nevertheless, the launch of the replacement satellite in April 2010 has resulted in these first maps of ice thickness. They clearly demonstrate that CryoSat is a mission of excellence and will greatly advance polar science.

CryoSat at Paris Air and Space Show

CryoSat at Paris Air and Space Show

The results were presented at the Le Bourget air and space show by Volker Liebig, ESA’s Director of Earth Observation Programmes, Duncan Wingham and René Forsberg from the National Space Institute at the Technical University of Denmark.
Prof. Wingham said, “A new mission is always risky. There’s quite a long wait and then everyone gets to see if it really can deliver.

“What’s really nice about these results is that they show not only that the hardware is really excellent – which we already knew – but that it can deliver the geophysical information we need too.

“It’s a credit to the teams at ESA and UCL who have worked really hard and I’m very happy with these new results.”

CryoSat measures the height of the sea ice above the water line, known as the freeboard, to calculate the thickness. The measurements used to generate this first map of the Arctic were from January and February 2011, as the ice approaches its annual maximum.

Antarctic ice sheet

Antarctic ice sheet - For the first time, data from ESA’s CryoSat mission have been used to map the height of the ice sheet that blankets Antarctica. The preliminary data used here are from February and March 2011. More data still need to be collected to study the ice sheet in detail. Nevertheless, CryoSat's ability to map the edges of the ice sheet is demonstrated by the detail that can be seen of the flow from east Antarctica onto the Ronne-Filchner ice shelf in the west. Orbiting closer to the poles than other Earth observation missions, CryoSat offers additional coverage. The outer white circle represents the limits of earlier missions and the inner circle shows that CryoSat is collecting data up 88° latitude. Credits: CPOM/UCL/ESA/Planetary Visions

Download: HI-RES JPEG (Size: 498 kb)

The data are exceptionally detailed and considerably better than the mission’s specification. They even show lineations in the central Arctic that reflect the ice’s response to wind stress.

Prof. Liebig said, “This major result comes just one year after launch. It is another important step towards achieving one of the primary objectives of the mission; namely, to determine how much the sea ice in the Arctic is thinning in response to a changing climate.”

A new map of Antarctica has also been created showing the height of the ice sheet. This is more preliminary because more data are needed here to see what CryoSat can do.

Even so, the extra coverage CryoSat offers near the poles can be demonstrated: parts of Antarctica can now be seen for the first time from space.

CryoSat's orbit reaches latitudes of 88°

Download: HI-RES MP4 (Size: 5 779 kb)

In addition, detail of edges of the ice sheet where it meets the ocean can now closely monitored thanks to CryoSat’s sophisticated radar techniques. This is important because this is where changes are occuring.

“It is very satisfying to see these exciting results,” said ESA’s Richard Francis, who was the CryoSat-2 Project Manager during its development.

“It has taken about ten years to convert the initial proposal into a flying mission: ten years of hard work and dedication from a core team of less than a hundred people, ably assisted with crucial expertise from a few hundred more.”

ESA’s CryoSat Mission Manager, Tommaso Parrinello, added, “These first results are very exciting as we begin to see the mission’s potential realised.

“The coming months will be dedicated to completing the picture to gain better insight into how polar ice is changing.”

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Steve Goddard points out that there is good agreement with the Navy PIPS map:

For the past two years I have been getting constant flak from alarmists for using Navy PIPS2 maps. Turns out PIPS2 is very accurate. However, they seem to have been taken offline as of May 23.

NSIDC’s Dr. Walt Meier wrote about PIPS in a guest post last year on WUWT

PIPS vs. PIOMAS revisited

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54 Responses to Cryosat produces its first Arctic ice thickness map

  1. TerryS says:

    However, to understand fully how climate change is affecting the fragile polar regions,

    Oddly enough, I’ve heard many places in the world, even some local to me, described as fragile and yet I can’t recall anybody describing one as robust. Curious that isn’t it.

    I often wonder how life ever survived on this planet in all these fragile environments.

  2. Steeptown says:

    Oh no, no more ice treks to keep us in stitches!

  3. matthu says:

    Slightly odd that thick ice shows up as red, thin ice as dark blue…

  4. James H says:

    Individual species or creatures may be “fragile” to some degree, but life is very robust. If certain species aren’t able to adapt, other species take their place.

  5. woodNfish says:

    TerryS says: June 21, 2011 at 8:58 am “I often wonder how life ever survived on this planet in all these fragile environments.”

    It has always been a battle of words, Terry. Much of the alarmist’s propaganda is based on simple techniques to brainwash children and ignorant adults. And it works.

  6. moptop says:

    We will have reached a certain level of saneness when the phrase “climate change” is replaced by “climate variability” except where the first actually makes sense. Not holding my breath.

  7. Wil says:

    Arctic ice? It grows and diminishes? Surprise! Exactly as it has since man first ventured into the Arctic region. Maybe these headlines can help.

    1881: “This past Winter, both inside and outside the Arctic circle, appears to have been unusually mild. The ice is very light and rapidly melting …”

    • 1932: “NEXT GREAT DELUGE FORECAST BY SCIENCE; Melting Polar Ice Caps to Raise the Level of Seas and Flood the Continents”

    • 1934: “New Evidence Supports Geology’s View That the Arctic Is Growing Warmer”

    • 1937: “Continued warm weather at the Pole, melting snow and ice.”

    How about: The calendar says summer starts tomorrow in the Northern Hemisphere. The snow falling in the mountains of Colorado tells a different story.

    A storm that has prompted a tornado watch across Nebraska and Kansas today also left 2 to 4 inches of snow in the Rocky Mountains, said Joe Ramey, a weather service meteorologist in Grand Junction, Colorado.

    And here in Norther Alberta I’m experience overnight frost for the first time in my 35 years – Five night in a row – never experienced that until this year.

  8. Alicia FRost says:

    Unfortunately we cannot really believe any of this (ice caps melting), they have been saying for years that the poles are melting. I ain’t seen anything yet has anyone here?
    http://ocean.dmi.dk/arctic/icecover.uk.php
    Each year since 2007 has been above. Antarctica has been mostly above anomaly for past 6 years so? Please explain nonsense

  9. Wil says:

    Sorry. Each of those headlines were supposed to have a URl from the NYT but none of them showed up for some reason.

  10. gator69 says:

    Hey Terry! I was watching an adventure show on PBS following two men crossing a section of Denali National Park in Alaska. The narrator kept referring to the ‘delicate’ and ‘fragile’ ecosystem while dodging grizzly bears. I never knew the great grizz’s to be dainty.

  11. Douglas DC says:

    What remains is when refreeze starts, we are at summer, now but it is a short oh 11 weeks or so until freeze
    up begins anew. Also what the article says it that this is the:”Third lowest extent since Satellite measurment
    began.” Thirty years ago-hmmm…
    Not enough time to get a solid trend and, the fact that now that measurements are better, you get more
    ”unprecedented ” , ”worse than we thought” results…

  12. Colin in Mission BC says:

    Prof. Liebig said, “This major result comes just one year after launch. It is another important step towards achieving one of the primary objectives of the mission; namely, to determine how much the sea ice in the Arctic is thinning in response to a changing climate.”

    There’s nothing quite like a scientist approaching a topic with a pre-determined conclusion. What, I wonder, will he think if arctic ice is not thinning? Likely come up with some half-assed excuse as to how thickening ice “is consistent” with CAWG theory hypothesis conjecture.

  13. Tom Davidson says:

    I believe I see a ‘ridge’ in the first image, extending from the NE corner of Greenland towards the Laptev Sea that coincides almost *perfectly* with the Gakkel Ridge.

  14. Doug says:

    “Cryosat produces its first Arctic ice thickness map”

    And it’s the thinnest it’s ever recorded…

  15. Dave Wendt says:

    The fact that the large tongue of sea ice along the east coast of Greenland is composed almost entirely of the thickest and oldest ice tends to support the notion put forward in Rigor and Wallace 2004 that the prime driver of the Arctic sea ice decline was a paradigm shift in the surface circulation patterns of the Arctic

    http://iabp.apl.washington.edu/research_seaiceageextent.html

    “This animation of the age of sea ice shows:
    1.) A large Beaufort Gyre which covers most of the Arctic Ocean during the 1980s, and a transpolar drift stream shifted towards the Eurasian Arctic. Older, thicker sea ice (white ice) covers about 80% of the Arctic Ocean up to 1988. The date is shown in the upper left corner.
    2.) With the step to high-AO conditions in 1989, the Beaufort Gyre shrinks and is confined to the corner between Alaska and Canada. The Transpolar Drift Stream now sweeps across most of the Arctic Ocean, carrying most of the older, thicker sea ice out of the Arctic Ocean through Fram Strait (lower right). By 1990, only about 30% of the Arctic Ocean is covered by older thicker sea ice.
    3.) During the high-AO years that follow (1991 and on), this younger thinner sea ice is shown to recirculated back to the Alaskan coast where extensive open water has been observed during summer.
    The age of sea ice drifting towards the coast explains over 50% of the variance in summer sea ice extent (compared to less than 15% of the variance explained by the seasonal redistribution of sea ice, and advection of heat by summer winds).”

    Here is an updated animation that Rigor made about a year and a half ago. The inclusion of the buoy drift tracks makes it fairly easy to see the dramatic change in the BG and the TPD in the late 80s. I have seen no reasonable argument that these circulation pattern changes are in any way related to anthropogenic CO2 emissions.

  16. As the climate grew colder, the northern(‘western’) colony became less viable, and at the same time the Black Death hit Iceland, freeing up homesteads that Greenlendings had legal claim to, so many moved back to Iceland at that time. Fishermen out of Bristol England, when they didn’t get a good catch on the Grand Banks, would then sail to the “East” Colony to take slaves. The Greenlendings told them that the West colony reverted to paganism (there is no evidence of this) so the fishermen/slavers were sent up there, where no one lived anymore. The last Greenland Norse appear to have passed away around 1453, not that long before Columbus.
    The 1362 expedition was in response to the rumor that the West Colony had reverted to paganism, but of course they weren’t there anymore. It appears that they then sailed into Hudson’s Bay (consider a magnetic compass and and translators with the Algonquian speaking of large bodies of water to the south and a great river) seeking a way home, avoiding the ice.
    It is curious that the Norse who converted many Dorset and intermarried with them, did not adopt any of their cultural artifacts for dealing with the ice. Norse trade goods are found in the remains of Dorest camps throughout Baffin Island and other eastern parts of northern Canada. However, the lure of better farmland in Iceland, and the blood-thirstiness of the newly arriving Inuit may have simply made returning to Iceland a much more attractive prospect. You mustn’t think of the Norse in the fourteenth and fifteenth centuries as Vikings. They were very much medieval Europeans at this point in time.
    The Kensington Runestone has been shown to be written in the Bohuslansk dialect of the period, and the weathering of the inscription is not remotely consistant with a nineteenth century forgery. The forgery theory is old and has been disproven, however the idea of Europeans in America that far back is not PC.
    It -is- impossible to separate religion from culture. Privilaging materialistic ontology and epistemology to those not limited by naturalism is simply the logical fallacy of special pleading.

  17. Chaveratti says:

    NASA: Arctic Ocean Could be Mostly Ice Free in 2013

  18. John Silver says:

    Excellent!
    Now all we have to do, is wait 30 years for the first climate data point. And 60 years for the next. Then we can make an alarming extrapolation.

  19. Ric Werme says:

    Wil says:
    June 21, 2011 at 9:26 am

    > Sorry. Each of those headlines were supposed to have a URl from the NYT but none of them showed up for some reason.

    Just put in the URL without any HTML decoration. or angle brackets.

    Or just send them to http://www.mrc.org/bmi/uploads/pdf/FireandIce.pdf

  20. SteveSadlov says:

    As I’ve suggested for several years, quite the pile up against the Canadian Shield craton. Winds and currents result in immense lateral stress, which translates into both strain and outright stacking of individual pieces of ice. I wonder what THIS does to “the models?”

  21. geo says:

    Now, give us as many per year of these as they can manage. It’s not clear from the above whether it takes a full two months to do one, but that seems to be the outside limit (January & February it said, but that would also be true if the did it on Jan 31 and Feb 1!).

    How does it look vs PIOMAS?

  22. Bob Kutz says:

    Help me out here; is that thickness map indicating the Canadian Archipelago is ice free? Is the Northwest passage really open already in June?

    (Before setting sail, I recommend you check another source, because it just isn’t so.)

    I guess I’m curious why the cryosat can’t or doesn’t measure ice thickness in that particular area. In fact, it seems to have trouble measuring ice thickness anywhere the sea is adjacent to land, except in the eastern hemisphere. Doesn’t seem to be as much of a problem along the Siberian coast.

  23. Bill Illis says:

    This is great because we now appear to have reliable ice thickness data (and they say they will be able to continually update the map from now on).

    It certainly shows there is much thicker sea ice in the Arctic than other estimates showed and the PIOMAS model, for example, had (and I note they just brought in a new version that increased the volume – the older and newer versions are both off by a significant amount, however, because the math just does not work).

  24. George Turner says:

    TerryS, the only ecosystem that are robust are the kudzu that covers the South and the roaches in New York City, but any story that mentioned them would just say “climate scientists predict that only cockroaches and kudzu will survive the coming climate apocalypse.”

  25. glen martin says:

    What’s the over under for when they declare it worse than we thought?

  26. Wil says:

    Ric Werme
    Thanks for the info. Here’s the URLs

    • 1881: http://query.nytimes.com/mem/archive-free/pdf?res=9B02E6DC133EE433A25752C2A9619C94609FD7CF “This past Winter, both inside and outside the Arctic circle, appears to have been unusually mild. The ice is very light and rapidly melting …”

    • 1932: http://select.nytimes.com/gst/abstract.html?res=F30710F73E5A13738DDDAC0994DD405B828FF1D3&scp=314&sq=arctic%20melting&st=cse “NEXT GREAT DELUGE FORECAST BY SCIENCE; Melting Polar Ice Caps to Raise the Level of Seas and Flood the Continents”

    • 1934: http://select.nytimes.com/gst/abstract.html?res=F00815F6395A107A93CAAB178AD85F408385F9&scp=308&sq=arctic%20melting&st=cse “New Evidence Supports Geology’s View That the Arctic Is Growing Warmer”

    • 1937: http://query.nytimes.com/search/sitesearch?query=arctic+melting&more=date_all&n=10&prev=166&frow=176&page=18 “Continued warm weather at the Pole, melting snow and ice.”

  27. higley7 says:

    Third lowest ice extent recorded “by satellite.” Ice extent margins vary with the weather of each year. Looking at the ice volume in the multiyear ice gives a much better idea of how much “persistent ice” there is and a better idea of how much excess there is. Simple 2-D thinking in terms of area is fraught with dangers as high and low pressure systems in Spring or Fall can change the sea ice extent quite drastically.

    Few know that the Summer 2007 low ice extent was mainly due to the sea ice being blown to warmer latitudes—it did not melt in the Arctic—and a large bolus of warm water that was pumped into the Arctic basin by the NAO—those who admit to knowing basic science know that warm water not only melts ice faster than warm air (which really was not all that warm), but warm water also is less dense and would stay at the surface of the water column against the bottom of the ice. Summer 2007 was a perfect storm of melting, even ignoring the warm water produced by some sea floor hot vents and volcanic activity that summer.

  28. Dave Wendt says:

    Bob Kutz says:
    June 21, 2011 at 10:55 am

    “I guess I’m curious why the cryosat can’t or doesn’t measure ice thickness in that particular area. In fact, it seems to have trouble measuring ice thickness anywhere the sea is adjacent to land, except in the eastern hemisphere. Doesn’t seem to be as much of a problem along the Siberian coast.”

    None of the satellites do an adequate job of capturing sea ice data in coastal areas. Data uncertainty is greatly increased in coastal areas. If you look at the video animation that I linked in my comment above you will note that in the 80s the residual sea ice at summer minimum was largely in the area of open ocean between the Pole and the Bering Strait, where coastal interference was not significant. After the current circulations changes that occurred in 1989 the residual ice was increasingly confined to the area along the Canadian archipelago where coastal interference is basically ubiquitous. At the IJIS sea ice graph site this note is included.

    “In principle, SIC data could have errors of 10% at most, particularly for the area of thin sea ice seen around the edge of sea-ice cover and melted sea ice seen in summer. Also, SIC along coastal lines could also have errors due to sub-pixel contamination of land cover in an instantaneous field of view of AMSR-E data.”

    SIC= Sea Ice Cover

    Theoretically those preparing the data make allowance for the greatly increased data uncertainty that results from the much higher ratio of coastal concentrations of sea ice, but I’ve not found any positive declarations that that is actually the case.

  29. Seems to me that another un-investigated issue with sea ice thickness is that the majority of the thin ice just happens to correspond with areas where active efforts are made to keep shipping lanes open with ice breakers as late as possible during the freezing cycle and then break the ice up as early as possible when the thaw starts.

    You don’t suppose that a significant fraction of that thinning is due to the man made mechanical breaking of the ice and opening pathways for warmer water to be exposed both to the sun and to warm the air near the ice surface, rather than general warming due to CO2 or any other cause?

    Larry

  30. Berényi Péter says:

    Something does not add up here.

    PIOMAS shows average Arctic ice volume for Jan/Feb 2011 as 17,341km³. On the other hand ice thicker than 2 m in the Cryosat image above covers about 9 million km² and at least half of it is thicker than 3 m. That is, ice volume is more than 23,500 km³. It’s a huge relative error, some 35%! And that is for a lower bound.

  31. Graeme says:

    Poor Peh Hugh – obsolete at such a young age.

  32. HR says:

    There is a video of the Paris Airshow press conference. Enjoy!.

    http://multimedia.esa.int/Videos/2011/06/CryoSat-Arctic-ice-map-unveiled

  33. Gerald Machnee says:

    **Even so, the extra coverage CryoSat offers near the poles can be demonstrated: parts of Antarctica can now be seen for the first time from space.**
    Really? They have “never” seen it?

  34. Jim G says:

    All that melting ice from the arctic has ended up right here in the Big Horn Mountains which at last report have 500% of “normal” snow cover, whatever normal is. Folks who have lived here all their lives have never seen this much snow on the mountains. Have any of these “scientists” ever heard of local events? We have not had much if any glaciers in the Big Horns for many years but will have by this Fall. Since normal has been no snow cover by August, for many years now, I guess we will have infinite, or more precisely, undefined percent of snow by then as we are dividing by a 0 normal at that time of the year.

  35. SteveSadlov says:

    One other thought. Once you get up to 4 – 5 meters of thickness, the question really needs to be asked regarding the true origins of icebergs. Granted, larger bergs are due to calving off of continental glaciers. But the smaller ones? Are they all from calving? Or are some actually from very thick areas of sea ice? Consider currents in the Canadian Archipelago and through the Davis Strait.

  36. richcar1225 says:

    Arctic ocean heat content appears to be a good proxy for arctic sea ice volume. From Bob Tisdale:
    http://i53.tinypic.com/214s085.jpg
    Note that the OHC reached a low in 1980 when sattelite monitoring sea ice extent began. Note the decline since 2008. The Piomasss model evidentlly uses positive NAO to model the sea ice volume. The NAO is now negative, OHC is declining and sea ice volume is building. I cant wait for next years cryosat data so we can claim the world will soon be covered in ice.

  37. jones says:

    Doug says:
    June 21, 2011 at 9:54 am

    “Cryosat produces its first Arctic ice thickness map”

    And it’s the thinnest it’s ever recorded…

    HAHAHAHAHAHHAHAHAHAHAHA………………..top one!

  38. Konrad says:

    It is good to see some results from Cryosat. While the spatial resolution appears good, there maybe two further data sets required to make a judgement as to the actual quality of the data. The first would be a high resolution map of the rills or open water used to measure freeboard (likely patchy to non existent toward the centre of the ice sheet much of the year). The second would be a barometric pressure map for 10km grid squares (empirical measurement only).

  39. R.S.Brown says:

    Has that Norwegian White Rat taken the weekend off on this topic ?

  40. peterhodges says:

    Jim G says:
    June 21, 2011 at 1:29 pm

    Same thing down here in the Sierra Nevada Jim. Snowpack is ‘undefined’ percent of normal. Still 15-20ft in the high country.

    I was watching a guy ice fishing today…on the summer solstice. They have brought the horses and mules to the local pack stations but the uncleared snow is still higher than the fences of the pens…no one is going packing for awhile!

    Ski lifts however are running…and not just on a few strips of snow, the entire mountain is still white.

  41. Jack Simmons says:

    I thought the Catlin survey determined the thickness of all that ice up there?

    Why was all the money wasted on this satellite?

  42. jason says:

    Considering the hulabaloo last year on here I am surprised at the lack of comments and debate, and follow up info. Is the initial data showing ice thickness as we thought?

  43. “fragile polar regions”!
    Of course, they are made of ice!
    ESA should have enough money to have them built of iron!

  44. Mark says:

    Andres Valencia says:

    “fragile polar regions”!
    Of course, they are made of ice!
    ESA should have enough money to have them built of iron!

    The RMS Titanic sinking nearly a century ago would tend to imply the opposite.

  45. Tom P says:

    Berényi Péter:

    “Something doesn’t add up here.”

    On the contrary, Cryosat gives results which look to be consistent with PIOMAS. PIOMAS only calculates volumes for the central portion of the Arctic Ocean: see for example fig. 6 at http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/pubs/IceVolume-2011-06-02-accepted-with-figures.pdf.

    This amounts to a sea area of 6 million square kilometres, so the corresponding 17,000 cubic kilometres for PIOMAS would imply an average thickness of around 3 m. That looks a reasonable value from the Cryosat map.

    PIOMAS values for the ice-volume minimum, when nearly all of the ice is within the area of its calculation, were also in reasonable agreement with the recently terminated PIPS 2.0 model results: http://img808.imageshack.us/img808/6980/pipsvspiomasvsicesat.png

    This first Cryosat result seems to indicate that the models, both current PIOMAS and past PIPS 2.0, might have both been doing a reasonable job of estimating the ice volumes.

  46. FergalR says:

    Tom P,

    Figure 6 in that doesn’t show what you think it shows. The “P” in PIOMAS stand for “Pan-Arctic”.

    PIPS 2 and PIOMAS are nowhere near in “reasonable agreement” with each other despite your unreferenced graph. How you think they could both be in reasonable agreement with something else is beyond me.

  47. Tom P says:

    FergalR,

    From the PIOMAS website itself:
    “Comparison of winter total volumes with other volume estimates need to account for the fact that the PIOMAS domain currently does not extend southward far enough to cover all areas that can have winter time ice cover.”

    I calculated the plot showing reasonable agreement between PIPS 2.0 and PIOMAS trends for the minimum volume extents: the code was posted on WUWT last year as to how to calculate ice volumes from PIOMAS. If you have some alternative analysis that demonstrates disagreement, why don’t you present it?

  48. FergalR says:

    Tom P,
    You can see exactly how far south PIOMAS extends on their website:
    http://psc.apl.washington.edu/zhang/IDAO/seasonal_outlook.html

    Seems like they miss out on the Baltic and Eastern China.

    You’re welcome to extract stills from their animations and compare them for the same date according to PIPS. They bear only passing resemblance to each other.

    Google has found where you posted your plot last year. There’s no sign of your elusive “code”.

  49. Tom P says:

    FergalR,

    Here’s a quick comparison of my PIPS-derived values to the recently released continuous PIOMAS dataset: http://imageshack.us/photo/my-images/29/pipsvspiomascont.png/

    PIOMAS in black, PIPS in red. It shows quite clearly reasonable agreement between the trends for the minimum volume, and a clear discrepancy for the maxima. That’s just as expected given the more limited extent of PIOMAS, with a comparison only possible in the summer.

    Here’s my MATLAB code for PIPS:
    % Calculation of arctic volumes, thicknesses and extents from the PIPS2.0 data
    % Change startdate and stopdate to define period
    % TomP 20100601
    format long g;
    startdate=’20101101′;
    stopdate=’20101130′;
    calcdate=startdate;
    calcdate=datestr(addtodate(datenum(calcdate,’yyyymmdd’),-1,’day’),’yyyymmdd’);
    IceDate=zeros(0,4);
    IceTime=zeros(0,4);
    newplot
    while strcmp(calcdate,stopdate)==0
    DateValue=datenum(calcdate,’yyyymmdd’);
    calcdate=datestr(addtodate(DateValue,1,’day’),’yyyymmdd’)
    calcyear=datestr(datenum(calcdate,’yyyymmdd’),’yyyy’);
    ThickURL=['http://www7320.nrlssc.navy.mil/pips2/archive/pips2_thick/' calcyear '/pips2_thick.' calcdate '00.gif'];
    AreaURL=['http://www7320.nrlssc.navy.mil/pips2/archive/pips2_area/' calcyear '/pips2_area.' calcdate '00.gif'];
    try
    [ThickInd,ThickMap]=imread(ThickURL,’GIF’);
    catch end;
    try
    [AreaInd,AreaMap]=imread(AreaURL,’GIF’);
    catch end;
    ThickRGB=ind2rgb(ThickInd,ThickMap);
    image(ThickRGB)
    drawnow
    AreaRGB=ind2rgb(AreaInd,AreaMap);
    ThickHSV=rgb2hsv(ThickRGB);
    AreaHSV=rgb2hsv(AreaRGB);
    ThickH=ThickHSV(:,:,1);%Extracts height array
    ThickS=ThickHSV(:,:,2);%Makes mask for ice area
    AreaH=AreaHSV(:,:,1);%Extracts concentration array
    Thick=(ThickH*255)*(-.02)+4.86;%Fit to PIPS2.0 thickness colour scale
    Conc=(AreaH*255)*(-0.353)+97.4;%Fit to PIPS2.0 concentration colour scale
    VolValue=sum(sum(Thick.*Conc.*ThickS))*(31.2^2/(10^8));%in km^3. Each PIPS2.0 pixel is 0.28 degrees square
    AreaValue=sum(sum(ThickS))*(31.2^2/(10^6));%in km^2.
    HeightValue=sum(sum(Thick.*ThickS.*Conc))/sum(sum(ThickS.*Conc));%in m
    IceDate=[DateValue,AreaValue,VolValue,HeightValue]
    IceTime=[IceTime; IceDate];
    image(ThickRGB)
    end
    IceTime
    mean(IceTime)

  50. FergalR says:

    Tom P,

    Thank you.

    Why do you choose to use the forecast concentration instead of the SSMI observations? The satellite sees mostly 100% concentration even at the height of the melt season in areas PIPS imagines 60%.

    http://www7320.nrlssc.navy.mil/pips2/archive/retrievepic.html?filetype=Concentration&year=2007&month=9&day=15

  51. Tom P says:

    FergalR,

    If you look at text on your link, you’ll find your question answered:

    “SSM/I plots are mainly used to check the validity of the ice edge of the PIPS 2.0 forecasts. Thus, the central polar regions on the SSM/I plots generally have significant variations from actual conditions.”

  52. FergalR says:

    Tom P,

    There is ~100% ice in those areas according to JAXA and the U of Bremen.

    Presumably, 1m ice at 60% on PIPS means that the other 40% is somewhat less than 1m – since it certainly isn’t open sea.

  53. FergalR says:

    . . . outside of the blind spot at the pole, that is.

    http://www.ijis.iarc.uaf.edu/seaice/data/200709/P1AME20070915IC0.png

  54. Rob says:

    After 53 responses, it may be too late to reduce excitement about ‘consistency’ between Cryophere’s first map and PIPS or consistentcy between both these reports and the real world.

    To spoil the fun : It seems that both are heavily biased towards excessive ice volume.

    For one, the Cryosphere map has been validated with only two measurements, both in multi-year ice, and they seemed to have interpreted snow cover as solid ice.

    And PIPS was taken offline for a reason :
    http://www7320.nrlssc.navy.mil/pips2/

    Since late April/early May 2011, PIPS 2.0 has developed an unrealistic opening in the North Pole region. On 22 May 2011, PIPS 2.0 stopped running because of a numerical instability. Since that time, we have been carefully trying to diagnose this problem (checking for anomalous atmospheric forcing, initial fields, boundary conditions, assimilated satellite ice fields, etc). During this process, the system’s ocean model time step was reduced and the system is currently running again. The unobserved opening near the North Pole is still present and can be seen in the ice concentration and ice thickness fields. PLEASE USE THESE FIELDS WITH CAUTION! We have subsequently filled in the period from October 2010 to present with the hindcast using the reduced ocean model time step. Because PIPS 2.0 is a legacy system and will soon be replaced with a new ice nowcast/forecast system (see below), little additional effort will be expended to keep it running.

    In short, PIPS will be replaced with a much more updated system. Most of us ice watchers are looking forward to the new system, which you can observe in action (with animations and all) here :
    http://www7320.nrlssc.navy.mil/hycomARC/arctic.html

    I hope that this new system (the Arctic Cap Nowcast/Forecast System (ACNFS)) will be more accurate than PIPS 2.0, considering that on multiple occasions it reported 4 meter ice where open ocean was clearly visible from MODIS pictures, and in general (despite it’s popularity here on WUWT) seemed to be out of touch with reality. For confirmation of this observation, consider that currently sea ice extent (both in the Actic as well as globally) is breaking all time record lows, and shows no slowdown in breaking the minimium extent record (of 2007).

    If you want to see a picture of what really goes on in the Arctic right now, then check this out (latest picture taken at the North Pole) :
    http://www.arctic.noaa.gov/latest/noaa2.jpg

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