An electromagnetic “bird” dispatched to the Arctic for the most detailed look yet at the thickness of the ice has turned up a reassuring picture.
The meltdown has not been as dire as some would suggest, said geophysicist Christian Haas of the University of Alberta. His international team flew across the top of the planet last year for the 2,412-kilometre survey.
They found large expanses of ice four to five metres thick, despite the record retreat in 2007.
“This is a nice demonstration that there is still hope for the ice,” said Haas.
The survey, which demonstrated that the “bird” probe tethered to a plane can measure ice thickness over large areas, uncovered plenty of resilient “old” ice from Norway to the North Pole to Alaska in April 2009.
There is already speculation about how the ice will fare this summer, with some scientists predicting a record melt. Haas said he doesn’t buy it.
He said the ice is in some ways in better shape going into the melt season than it has been for a couple of years. “We have more thick ice going into the summer than we did in 2009 and 2008,” he said.
Much will depend on the intensity of the winds, and how the ice fractures and is blown around, he said. “But any talk about tipping points, a sudden drop and no recovery . . . I don’t think it is going to happen.”
The more likely scenario is that the ice will continue a decline that has been underway for at least 30 years, he said. There is likely to be plenty of variability in that decline, he added, with “extreme” melts in some years, followed by “significant recoveries like we saw last year.”
Part of the problem with ice forecasting is that it based largely on data from satellites. They are good at measuring how large an area is covered by ice, but tell little about its thickness — which can measure in mere centimetres in the case of new ice, or metres in the case of ice several years old.
The thickness had “changed little since 2007, and remained within the expected range of natural variability,” the team reports in the Geophysical Research Letters.
This is great – one solid experimental measurement blows away a whole pile of spurious modeling.
A victory for deductive science over inductive. Karl Popper rest in peace! (Piomass – kiss my [snip])
Latest temp at almost the pole.
IABP PAWS Buoy latest 2010 weather data
06/16/2109Z 89.144°N 50.483°W 0.5°C 1011.9mb 12.0° 7.0m/s
phlogiston says:
June 17, 2010 at 2:22 pm
This is great – one solid experimental measurement blows away a whole pile of spurious modeling.
Unless you look at the details.
It’s probably too late to point out that this system does not actually measure ice thickness, but rather the time rate of decay of the electromagnetic field and/or the change in conductivity-thickness of the ice-water. Thickness is derived assuming things such as constant conductivity of ice (such as constant salt content – no fresh water mixing etc).
“Amino Acids in Meteorites”, channeling his inner “R. Gates”!
To correct my earlier post, thickness is derived assuming things such as constant conductivity of ice, should have read salt water, not ice.
The EM system detects the salt water. The laser altimeter measures the distance between the bird and the surface of the ice. An assumption is made that the salt water response is constant, therefore any change in amplitude is caused by a change in the distance between the bird and the salt water – the difference between the derived salt-water distance and the measured laser altimeter distance (the difference being ice thickness).
The point I wanted to make is, this is an indirect measurement of ice thickness.
A second point would be how much of the ice extent was sampled by this survey – 0.0001% or less.
I`m a big fan of geophysics, but lets not drag a great science down to the level of climate science.
Hypnos
June 17, 2010 at 8:35 am
It’s an odd math that says though it’s cold enough to have both area and concentration increase over the last three years total ice has decreased. And that ice can rot because it’s -51 degrees instead of -54.
But that’s what we’re supposed to, and some have, believed.
Hypnos
and i see the word ‘may’ used, ice ‘may’ have decreased. That’s called CYA.
Climate Models are Like Ouija Boards
if a climate model says it can happen then let’s worry!! 😉
In Academia, Climate Hysteria Rules
It’s nice to see that efforts on measuring ice go from drilling a hole, to DC3 to spaceships 🙂
Amino Acids in Meteorites, have you ever heard the expression “an empty vessel makes the most noise” ? :p
Ya Andy, you’re right. It’s so unfortunate for a guy like me that they only surveyed areas that are thicker than expected and they missed those thinner than expected areas. Because after all those unsurveyed areas ‘may’ be not just thinner than expected but ‘may’ now be much thinner than expected in order to compensate for those surveyed areas that, as it turns out, are thicker than expected. So yes Andy, the PIOMAS graph ‘may’ still be right! And the unsurveyed ice ‘may’ be even more rotted than you thought!
Attention! Attention! It’s safe for the trolls to come out from under the bridge, start using the word ‘may’, and go droning on and on about the PIOMAS graph, again!
Glory be! Shout it from the housetops, “Hallelujah! The trolls are back in business!”
Amino Acids in Meteorites says:
June 16, 2010 at 11:27 pm
P.F. says:
June 16, 2010 at 8:28 am
Wait. Just yesterday you posted that Arctic Ocean ice is retreating at 30-year record pace! I’m so confused. How can this be?
Retreat isn’t really the correct idea. That would make you think of melting. It’s not decreasing in size exclusively from melt which would make it thinner, as you are pointing out. There is a thing called shear in ice. The movement of the ice can create openings that are registered by satellite as a decrease. But it isn’t from melt.
—————————-
First create confusion over concentration and volume. Now create confusion about sea ice area. “…openings that are registered by satellite as a decrease” Sea ice area is measured as continuous if 15% or 30% is ice covered, depending on which site you look at. Hence, a few openings would be ignored as the ice extent would certainly be more than 15% or 30%. Ergo, no issue, the openings are not counted, melted or not.
Amino Acids in Meteorites says:
June 16, 2010 at 4:14 pm
June 16, 2010 at 4:15 pm
June 16, 2010 at 4:16 pm
June 16, 2010 at 4:17 pm
June 16, 2010 at 4:19 pm
June 16, 2010 at 4:19 pm
June 16, 2010 at 4:22 pm
June 16, 2010 at 4:25 pm
June 16, 2010 at 4:27 pm
June 16, 2010 at 4:33 pm
June 16, 2010 at 4:34 pm
June 16, 2010 at 4:35 pm
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Having made PIOMAS the bogey, how about PIPS 2.0
Silly me, of course, PIOMAS is wrong and PIPS 2.0 is right!
PIPS 2.0 often over-predicts
the amount of ice in the Barents Sea and therefore
often places the ice edge too far south.
Although PIPS 2.0 can predict
large-scale polynyas, it does not have the capability
to produce smaller polynyas or leads or to provide
guidance on lead orientation.
http://www.tos.org/oceanography/issues/issue_archive/issue_pdfs/15_1/15_1_preller_et_al.pdf
Amino Acids:
So a study comes out saying ice thickness has remained within natural variability since the big decline in 2007 ( which, in other words, still means it’s near the bottom of the 30 years average), while also suggesting volume could be lower.
You spin it into “Ice has recovered, it’s as thick as ever, no reason for worry” without even reading the study.
I point out that is not what the study says.
You go off on a completely unrelated tangent about the word “may” and ignore the very substantial point I made – i.e. that the study doesn’t say what you think.
I believe your accusations of trollish behavior are misdirected.
Amino Acids in Meteorites says: Stuff
Man, it seems like you still have not read the study. Or registered the dates they flew. Or looked at their tracklines and measurement locations.
This isn’t about PIOMAS, it’s that these flights were last done in April 2009, over a very, very limited area near shore.
There’s discontinuity that I don’t understand at http://ocean.dmi.dk/arctic/meant80n.uk.php For a few charts, the first value at the beginning of the year is not even close to the last value of the prior year. Am I misconstruing something? For example, the chart for year 1999 appears to end up at about 245K but year 2000 begins with a value of about 262K. Another example is between 1976 to 1977.
Mike M says:
June 18, 2010 at 11:17 am
There’s discontinuity that I don’t understand at http://ocean.dmi.dk/arctic/meant80n.uk.php
Like many (most?) here, what you are missing is that it’s output of a model – it’s not from measurements. Read the bit on the lower left under “Calculation of the Arctic Mean Temperature”
Antarctic max and min for last 30 years.
http://earthobservatory.nasa.gov/Features/SeaIce/images/antarctic_max_min_extent.gif
vs. Arctic, if interested http://chartsgraphs.files.wordpress.com/2010/01/nsidc_sie_trends.png
jakers says:
June 18, 2010 at 10:54 am
Jakers, thanks for a touch of reality. I did the following calculations. Taking the late start melt date of 31 March the ice extent for 2010 was 14.41 million KM2 and on the same date the 2009 extent was 13.97 million KM2. Hence, 2009 had a head start of 440,000 KM2.
As at 18 June the 2009 extent was 10.6 and 2010 at 9.93 KM2. Therefore, from a head start of 440,000 KM2 as of March 31, 2009 now lags 2010 by 677,500 KM2. This means that between 31 March and June 18, the 2009 melt was 3.37 million KM2 and 2010 4.48 million KM2. Hence the 2010 melt over that period exceeded the 2009 melt by 1.11 million KM2.
A projection;
Assumptions are; (1) the 2010 ice melt to end as it did in 2009 on 13 September.
(2) the 2010 melt from 18 June to 13 September will equal that of 2009.
On 18 June 2009 the extent in 2009 was 10.6 million KM2 and it dropped to 5.25 million KM2 on 13 September. Total drop over that period 5.35 million KM2. If I deduct that amount of melt from the 2010 extent of 9.93 million KM2, the projected extent for 2010 will be 4.57 million KM2, which puts it between 2007 (at 4.25) and 2008 (at 4.71) million KM2.
Prior to the record melt in 2007 the average melt (June 18 to Sept 13) 2003-2007 was 4.67 million KM2. Over 2007/8/9 the average melt was 5.73 million KM2, hence an increase of 1 million KM2. My projection for 2010 is therefore conservative and the possibility of 2009 surpassing 2007 remains.
Shouldn’t that be, “… and the possibility of
20092010’s melt-back surpassing 2007‘s remains”?Roger Knights says:
June 19, 2010 at 7:34 am
Mea Culpa, I stand corrected. A bit tired from watching World Cup soccer. Melt is notching up, last initial figure for June 19 shows a drop of 120,000 KM2 from June 18.
2009 now lags 2010 by 720,000 KM2 over period 31March to June 19. May be dragged back somewhat because between June 30 and July 5, 2009 had five 100,000 KM2 plus days. My guess is that the claw back will be marginal because there are large areas of 50% or less ice cover. When they reach critical point (less than 15%) the measured sea ice area will take a dive. Info taken from AMSR-E
http://www.iup.uni-bremen.de:8084/amsr/arctic_AMSRE_visual.png
For clarity, read “100,000 KM2 plus days” as 100,000 KM2 plus, melt days.