Guest Post by Steven Goddard
The Catlin Arctic Survey has generated quite a bit of discussion, more because of the difficulties they have faced than because of the scientific merit of their expedition. Their home page is covered with testimonials about the importance of measuring “ice decline” and raising “climate change awareness.”
Normally a scientific experiment will start out with a neutral approach, where the conclusions are derived from the data, rather than arriving at conclusions prior to attempting to collect data. The appearance of presumption presented on their web site that they are measuring “ice decline,” could easily be interpreted to be putting the cart before the horse.
It is also difficult to understand how they could be measuring “ice decline” from a single set of data points taken at minus 40C, measured over an eight week period.
Are they going to come back next year and measure again? Not likely, and even if they did the ice would not be in the same place next year – as it is blown around by the wind. There is little question that the ice will continue to thicken over the next few weeks, as it normally does not start to melt near the pole until late June or early July. Fortunately we do have an objective and consistently reliable data source to work with, from that same region.
The US Army keeps a set of buoys on the ice which continuously monitor ice thickness, temperature and location year round. These buoys maintain themselves with a minimum of trauma, twittering, publicity, rescue expeditions and frostbite – and are normally able to provide more than one year of data.
The Google Earth map below shows the attempted Catlin route in green markers, and the Army buoys in yellow. The buoys are marked with approximate thickness of the ice, which I estimated based on the water depth where the temperature rapidly drops below the freezing point of seawater (minus 2C.)
As an example, I estimated the thickness at buoy 2007J as 3.5 metres, based on the graph below. Above -350 cm, the water temperature drops off quickly below -2C, which means that it is frozen.
http://imb.crrel.usace.army.mil/buoy_plots/2007J.gif
All five buoys show water temperatures indicating ice thickness in the range of 3-4 metres. Catlin is attempting to take another 10,000 or so measurements on the shifting, moving ice they are trying to travel across. While that data may be useful in understanding the local behaviour of the ice, it likely will provide little information about long-term ice trends, unless the same measurements are taken on a consistent basis over many years. You can also see in the 2007J graph above that the ice has thickened at least half a metre since March, 2008.
In most fields of science, that is considered an increase rather than a “decline.”
From the Army web site:
Data policy: We encourage the use of all data on this web site. Please reference any data use as:
Perovich, D.K., J.A. Richter-Menge, B. Elder, K. Claffey, and C. Polashenski, Observing and understanding climate change: Monitoring the mass balance, motion, and thickness of Arctic sea ice, http://www.crrel.usace.army.mil/sid/IMB/
I also agree with an earlier post about varying ice thickness from one location to the next. Looking at the underside of the ice one sees a huge variation in ice thickness – I can only liken this to small mountains, hills, peaks that all project down into the water. The only spots that are flat is the new ice that forms following a break in the ice flows – these rivers that form re-freeze within 24 hours. Any ice greater than about 2 meters in thickness typically exhibit these properties but it becomes more pronounced the closer one gets to northern Greenland.
My apologies – sonar can vary over a wide range of frequencies – but usually down in the kHz range. Same points still apply
Pragmatic (07:42:07) :
Steven Goddard (21:03:56) :
From Wikipedia –
The West Antarctic ice sheet has warmed by more than 0.1 C/decade in the last 50 years, and is strongest in winter and spring.”
This statements illustrates the value of Wikipedia. I wasn’t aware that the ice sheet could warm O.1 C/decade without melting? Someone correct that to “ambient temperature above the ice sheet has…”.
Steven Goddard (08:23:08) :
I heard that story and did a little math…assuming 110 million households (from census.gov), the per household cost of the plan is around $18,200. wow….kind of hard to fathom! of course, all of this assumes the $2 trillion price tag is even close to correct…
There are multiple techniques to infer the sea ice thickness.
Ice is transparent to radar if it has little liquid water in it so the towed radar sled used by that team should be measuring the reflection off the lower layer of the ice/water interface. Since there might be a slushy water saturated lower layer their physical measurements might help in determining a typical layer thickness for that for later use in calculations.
One is to get high precision measures of the top of the sea ice, (free board ie the amount the top surface is above the water) and compute how much it is above the open ocean level in areas of open water. Then using the ratio between how much ice sticks up above water, you can compute the average thickness of the ice below the local sea level and then the total average sea ice thickness.
http://www.isprs.org/commission3/annapolis/pdf/Forsberg.pdf
http://esamultimedia.esa.int/docs/arcgice_venice.pdf
Here are some other methods under investigation.
http://www.techbriefs.com/component/content/57?task=view
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V86-4V75YMP-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b854a267d8daeea77dd4178347f01f61
I am sure there are other ways to infer the ice thickness as well. The oldest direct measurements were based on submarine sonar measurements from under the ice pack going back to the cold war days when the subs needed to determine if the ice was thin enough they could breach it to surface, and to avoid collisions with pressure ridges which can extend well below the average bottom surface of the ice pack.
Larry
Aggie,
Thanks for doing the math. BTW – here is how cap and trade will be financed, from the President’s personal web site. Good to know that the budget will be balanced, even with many trillions in new costs.
http://www.barackobama.com/issues/fiscal/
Barack Obama and Joe Biden’s Plan
Restore Fiscal Discipline to Washington
* Reinstate PAYGO Rules: Obama and Biden believe that a critical step in restoring fiscal discipline is enforcing pay-as-you-go (PAYGO) budgeting rules which require new spending commitments or tax changes to be paid for by cuts to other programs or new revenue.
* Against Raising the Federal Debt Limit: In 2006, Obama voted against misguided Republican efforts to raise the statutory debt limit
TonyB (09:17:40) :
I can understand your empathy with people you know but unfortunately to me they give the impression of being incredible naive or their believe in global warming is verging on the religious.
hotrod (10:51:40) : …
They can measure ice burried underground on Mars from thousands of km above but can’t measure accurately floating ice here on earth??? Please explain!
Does anybody know if the U.S. navy have any published data dirived from submarine measurements of the Artic ice thickness? It would seem to me that submarine measurement would be more practical.
Bernie writes ” Are you suggesting that this was an intelligent thing to do and warrants the risks and resources?” Not at all. The answer to that question will not be obvious until we have the results of the effort. I noted at the very beginning; my expertize on this isssue is very limited. Three dedicated people, who know far more about it than I do, seem to believe that the results they will be getting, will be worth the effort and risk. There seems to be a difference opinion as to whether all these three will get are brownie points in the AGW debate, or genuine scientific results. I believe, for no particular reason, that the scientific results will be worth the effort. Whether I will turn out to be right is another question altogether.
Does Anthony know that he has “single handedly” destroyed the “Media Myth” of the last 6 months of declining ice coverage AND declining ice thickness?
I think this is wonderful.
However, I fear that Goobbles is alive and well, and the MSM (Mainstream Media) is repeating, often enough, long enough and LOUD enough…
I guess we need to take heart in the fact that by the time the Soviet Union fell less than 20% of the population believed ANYTHING their “official” media told them.
Maybe we can hope for the same here.
Artic ice extent update.
http://www.gpsl.net/climate/data/sea_ice/ijis-np-sea-ice-2009-03-19a.png
Note there was a major SSH event in the Arctic Jan/Feb 2009. That probably tripped the weather change in Europe from the very cold to normal.
Question: When the Catliners measure distance traveled is it relative to the Pole or is it their distance on ice, for example as measured by a pedometer ?
If the latter then they could publish positive headway but on a net basis it could be negative due to drifting ice.
Observation: Their website claims: The Catlin Arctic Survey is an international collaboration between polar explorers and some of the world’s foremost scientific bodies” There is no mention of these scientific bodies. If there is indeed a collaboration why is there no list? Maybe just BS?
David Porter (11:21:15) : said to me
“TonyB (09:17:40) :
I can understand your empathy with people you know but unfortunately to me they give the impression of being incredible naive or their believe in global warming is verging on the religious.”
First and foremost Pen Hadow loves the Arctic Environment and is without doubt an expert who knew what he was getting into. He will be grateful he can indulge his love of the ice without having to struggle hard to find the funding.
Secondly I am sure he believes he is doing something useful.
Thirdly he gives motivational speaking courses and this gives him a good profile and good material as he is doing something his audience will find genuinely inspirational.
The first two I think are the biggest motivations. As for the AGW religious aspect, I am sure he is concerned the environment he loves may be under threat and feels he may be able to help. I do not think he is a historian and knows the regular ice melt in 80 year cycles or so.
He is a strong minded man and if what he finds is different to what he is being told I suspect he will say so.
I hold no brief for him or what I consider an experiment of dubious value whose results will no doubt become misused, but I think his motives are honourable.
TonyB
I’m not familiar with the SPRITE ground penetrating radar system they have, but GPR is very useful for measuring ice thickness. Ice is in general invisible to radar, so the radar waves will pass through the ice with no trouble and reflect very nicely off the ice-seawater interface. Assuming they know the propagation speed in ice (close to that of air as I recall) the depth from surface to seawater should be pretty darn precise. The GPR might have trouble distinguishing the snow-ice interface though. That seems like one that would be pretty easy to verify with a slender probe though.
I, for one, find the sst anomaly in the vicinity of Tonga to be, at the very least, suggestive.
Along the same lines, I find the anomalous warmth northeast of Svalgaard to be suggestive of underwater vulcanism. While I’m at it, I find the pool of warmth (at the center of the cold horseshoe of the negative PDO), centered roughly on the Hawaiian islands, to be suggestive of vulcanism as well.
We can make calculations to our hearts’ content about whether eruptions warm the ocean. In so doing, we risk making ourselves into human GCMs, though, I fear.
We simply don’t know, and we probably won’t for a while.
Earlier today, a commenter here posted a link to my piece at CEJournal on wildly varying news coverage of the Nature paper on possible collapse of the West Antarctic Ice Sheet. Since then, I’ve updated it with additional comparisons of coverage by different news outlets. So if you’re interested in the journalism angle on these questions, have a look at http://www.cejournal.net/?p=1428
Many thanks to those of you who came over this morning and participated in the discussion!
Now the US Army buoys would show increasing ice depth wouldn’t they? After all, the US Army is a reactionary organisation devoted to President George W Bush and dedicated to oppressing freedom fighters, truthers and enviro-warriors wherever they might be found.
There’s just no way the likes of our intrepid and progressive seekers of truth could trust Climate Change denying data deviously propagated by the Buoys of the Bourgeoisie.
When are we ever going to drop this total scam visited upon us by Fat Albert Gore and his bold lies and whining voice? Will we ever be rid of this odius man?
…BERING SEA ICE OUTLOOK FOR EXTREME ICE CONDITIONS…
WEATHER MODELS ARE CONTINUING THE PATTERN OF COLD NORTHERLY WINDS
THROUGH 10 DAYS. WATER TEMPERATURES IN THE BERING SEA OVER THE BERING
SHELF ARE RUNNING -1 TO PLUS 2 DEGREES CELSIUS. THE COLD NORTHERLY
AIR WILL CAUSE WATER TEMPERATURES TO DROP AND ICE TO FORM IN THESE
AREAS. WITH THESE CONDITIONS MARINERS CAN EXPECT SEA ICE TO DEVELOP
TO THE EDGE OF THE BERING SHELF BY THE MIDDLE OF NEXT WEEK. BRISTOL
BAY WILL CLOSED OFF AT PORT MOLLER AND ICE WILL DEVELOP ALONG THE
ALASKAN PENINSULA BEYOND FALSE PASS. ICE WILL MOVE SOUTH OF SAINT
GEORGE BY MONDAY OR TUESDAY.
FORECAST THROUGH MONDAY…WEST OF 179W…VARIABLE WINDS UNDER THE
HIGH WILL TURN COLD NORTHERLY OVER THE WEEKEND. THE ICE EDGE WILL
MOVE TO THE SOUTHWEST 15 TO 25 NM WITH MOST OF THE MOVEMENT TAKING
PLACE SUNDAY AND MONDAY.
FORECAST FOR WATERS BETWEEN 179W AND 167W…COLD NORTHERLY FLOW WILL
CONTINUE THROUGH SATURDAY. SUNDAY AND MONDAY WILL SEE INCREASING
NORTHEAST WINDS WITH VERY COLD TEMPERATURES. ICE WILL DEVELOP OR MOVE
35 TO 50 NM TO THE SOUTH OR SOUTHWEST THROUGH MONDAY. SIGNIFICANT ICE
WILL SURROUND SAINT PAUL ISLAND LATE FRIDAY OR EARLY SATURDAY. SLUSH
ICE WILL DEVELOP AROUND SAINT GEORGE ISLAND FRIDAY. SIGNIFICANT ICE
WILL MOVE TO SAINT GEORGE SUNDAY. ICE WILL MOVE SOUTH OF SAINT GEORGE
MONDAY OR TUESDAY.
FORECAST FOR WATERS EAST OF 167W…INCLUDING BRISTOL BAY…STRONG AND
COLD NORTHERLY FLOW WILL CONTINUE THROUGH MONDAY. ICE WILL CLOSE
BRISTOL BAY TO PORT MOLLER BY MONDAY. ICE WILL DEVELOP ALONG THE BAYS
OF THE ALASKAN PENINSULA ON THE BERING SIDE AND PROTECTED WATERS OF
THE PACIFIC SIDE.
I seem to remember sea ice in the Bering last year as being one of the worst on record. Now we have this going on this year.
I also seem to recall back in 2007, when Antarctica was setting the maximum area on record in September, only 3 days later various teams of AGW supporters rigorously combed through the Antarctic sea ice dataset and found a processing error which led to sea ice area being slightly overestimated and not a record (at the time, because sea ice continued to increase to a record maximum extent in the satellite era later in the month). When the record was first broken and reported in various skeptic blogs (never in the MSM) is when the AGW crowd set out to disprove this record. Once the processing error was found and the record wasn’t quite broken is when the MSM picked up on the story, using cliches such as “Close but no cigar” etc. Then, as Antarctic sea ice put on a remarkable period of growth in the last couple weeks of September (a period when antarctic sea ice begins its decline normally) and finally broke the satellite era record, once again silence from the MSM (they were talking about arctic sea ice at the time). However, it took nearly 6 weeks to discover the problem in the microwave sounding unit which was causing sea ice to be underestimated this past winter. This normally wouldn’t have been an issue until the George Will article was published in the Washington Times about sea ice extent now compared to 1980 being nearly identical which drew swift criticism from the pro-AGW crowd and the statement about checking ones facts on the cryosphere today web site. There was also a blog entry here about the odd decline in sea ice to which the response was that the error ‘wasn’t newsworthy’ as I seem to recall.
Let’s see if we get any reporting from the MSM about the extreme sea ice year in the Bering in the coming days or if the only mention of the sea ice being unusually expansive from the next season of ‘Deadliest Catch’.
I hope they brought a rifle. March is really bad for polar bears. The bears can find meat from dozens of miles away and they will converge. Trappers have encountered 2-12 on their traplines.
Working from one of the “Possibly Related Posts”, I made one more link click and came up with this little jewel from CNN:
“Polar bears resort to cannibalism as Arctic ice shrinks”, Marsha Walton, CNN
http://www.cnn.com/2008/TECH/09/23/arctic.ice/index.html
…“The Arctic sea ice melt is a disaster for the polar bears,” according to Kassie Siegel, staff attorney for the Center for Biological Diversity. “They are dependent on the Arctic sea ice for all of their essential behaviors, and as the ice melts and global warming transforms the Arctic, polar bears are starving, drowning, even resorting to cannibalism because they don’t have access to their usual food sources.”…
Later… “In one documented 2004 incident in northern Alaska, a male bear broke into a female’s den and killed her.”
I can see the next headline: “Global Warming causes Domestic Violence among Polar Bears says top scientist”
Any wonder we’re skeptical of environmental journalists? Sounds like Marsha has been drinking too much Kool-Aid.
They should have used a ship. Lots warmer and has indoor plumbing. I would like to see one of the guys explain post on that website how he gets his willy out of all the layers FAR enough to write in the snow instead of dribble down his woolies. I would imagine shrinkage is a significant problem, but not for the ice.
http://people.su.se/~mjako/PDF/Darbyetal_2005EO520001.pdf
So, this team is taking radar readings of snow/ice thickness, and then they are drilling holes also to check the snow/ice thickness. Do I understand this right?
If it is so, then maybe their satelite radar callibration claim makes some sense, assuming that their on-the-ground radar would give the same reading as a satelite radar reading. The bore hole presumably would be “more correct” than a radar reading. So, the bore hole could indicate that the radar readings are systematically understated, overstated, or are dead on. Correcting for any systematic differences observed could constitute callibration.
Also, while getting to the north pole would be a plus, it probably is not absolutely necessary for the callibration data to be valuable.
Oh, another assumption: The bore hole thickness readings need to be done correctly and in an unbiased manner…. Any bias likely?
tallbloke (07:30:45) wrote :
“I wasn’t aware the satellites attempted to measure ice thickness. How would they do that?. The metrics they supply tell us about area and extent. How then will the thickness data be used to ‘calibrate satellite measurements’?
I’m all for constraining models, and alarmist handwaving though.”
Remote sensing from satellites air craft, and submarines has been used to estimate ice thickness. Here is a paper on that subject.
http://epic.awi.de/Publications/Haa2008b.pdf
Sea Ice Thickness: Hidden Key To Understanding
Arctic Change
By Christian Haas, posted on March 27th, 2008 in Articles, Climate, Earth Observation, Water
“…The lack of systematic, large-scale ice thickness information has led the European and American Space Agencies to the launch of the ICESat and CryoSat satellite missions. These satellites carry laser and radar altimeters, respectively,
with which the height of the ice surface above the water level can be retrieved. This freeboard height can then be converted into ice thickness using the same density assumptions as with upward-looking sonar profiling. However,
uncertainties due to the generally unknown snow thickness can lead to large errors of the estimated ice thickness, although the accuracy of the freeboard measurement can be as good as a few centimeters. ICESat was successfully launched in 2003.
CryoSat was first launched in 2005, but failed just minutes later. A replacement satellite is scheduled to be launched in 2009.
These novel altimetric satellite missions require careful validation of their results. An ideal technique for the validation of satellite thickness measurements is airborne electromagnetic (EM) sounding. With this classical geophysical method it is possible to determine the electrical conductivity structure of the underlying surface. In the case of sea ice, the method is sensitive to the distance to the ice underside, which is the boundary between the resistive ice and the conductive sea water. EM sounding can be performed from helicopters while flying over the ice, and thus provides
regional-scale ice thickness measurements within the range of helicopters, which can be extended by means of fuel caches on the ice. EM sounding will be extensively used for the validation of CryoSat thickness retrievals, by means of
coincident underflights of the satellite. In addition, a systematic ice mass balance monitoring program has been initiated by Canadian, American and German scientists in the region between the coasts of Canada, Alaska, and the
North Pole. This will provide accurate biannual thickness observations to better understand seasonal and interannual ice variability as a result of changes in the atmosphere-ocean system.
…
“