NOTE: The image below is NOT sea ice thickness, but ocean topography.
Radar data from the European satellite has been used to make a map of ocean circulation across the Arctic basin.
Cryosat’s primary mission is to measure sea-ice thickness, which has been in sharp decline in recent decades.
But its ability also to map the shape of the sea surface will tell scientists if Arctic currents are changing as a result of winds being allowed to blow more easily on ice-free waters.
“Nobody really knows how the Arctic is going to behave as the ice retreats, but we do anticipate that significant changes will occur,” said Dr Seymour Laxon, a Cryosat science team member from University College London, UK.
“This is just the first data, and it shows we now have the tool to monitor what is happening,” he told BBC News.
…
[Cryosat] carries one of the highest resolution synthetic aperture radars ever put in orbit.
The instrument sends down pulses of microwave energy which bounce off both the top of the Arctic sea-ice and the water in the cracks, or leads, which separate the floes.
By measuring the difference in height between these two surfaces, scientists will be able, using a relatively simple calculation, to work out the overall volume of the marine ice cover in the far north.
WUWT carried the story of the Cryosat launch and testing in several articles:
CryoSat-2 exceeding expectations
From the European Space Agency 070110 Participants at the Living Planet Symposium have been hearing about ESA’s most recently launched mission, CryoSat-2. In orbit for almost three months, the satellite is in excellent health with scientists very encouraged by the … Continue reading →
CryoSat passes first operational tests
From the European Space Agency, it looks like CryoSat-2 is working well. I’m sure we are all looking forward to seeing what the results are. ESA’s ice mission delivers first data 13 April 2010 ESA’s CryoSat-2 has delivered its first … Continue reading →
Successful launch for ESA’s CryoSat-2 ice satellite From the European Space Agency: 8 April 2010 ESA PR 07-2010. Europe’s first mission dedicated to studying the Earth’s ice was launched today from Kazakhstan. From its polar orbit, CryoSat-2 will send back … Continue reading →
Full story about the current data from BBC here
R. Gates
“…and so I’m sorry to be such a “downer” on your little conjecture, but the data tell the story.”
Oh, let me guess. It was CO2 what did it?
Yes, there is a decline, but could you tell me which portion is natural, and which portion is mine and your fault, please?
Sad really that as a child of the 60’s science was the spine of my upbringing.
I really should be excited about Cryosat but I’m sure it will go the same way as Satellite MSU, ARGO or indeed “simple” RSB. The data will disappear in a haze of “re-analysis products” unless it promotes the pre-determined storyline.
Sad really that having grown up with the moon landings I should, in 2010, come to see science as just very expensive PR to be auctioned off to the highest bidder. Very sad.
Ric Locke says:
December 22, 2010 at 2:30 pm
Ric, surely the line of constant acceleration will be changed by accumulation of sea water etc due to winds, tides and pressure systems and so will vary with time?
I’m nearly certain that if this data doesn’t show what the warmies want, doubt will be cast on the instruments or the assumptions behind the interpretation of the results.
But, what the heck, it’s only taxpayers money. Send more.
“Why are you wrong? Simply because the seasonal loss of sea ice in the N. Hemisphere has been greater than the seasonal gain of sea ice in the S. Hemisphere…i.e. a steeper down averaged against a less steep up equals a down…and so I’m sorry to be such a “downer” on your little conjecture, but the data tell the story.”
Not so fast R. Gates.. the little graph you linked only goes to 1979. Please post one that goes back a couple of hundred years and maybe we can see even a short term trend.
MrCannuckistan says:
December 22, 2010 at 2:35 pm
So when can we expect to see some pretty graphs using this new data? Anything similar to The Cryosphere Today page out there yet? It will be interesting to see how it compares to PIPS and PIOMAS. It may put to rest the debate over which one is more accurate when actual measurements are available for comparison.
I agree R. Gates. The fact that we will now know, as opposed to just guessing (or believing), is exciting unto itself. While it may be a time for some to gloat at the opposition, let’s hope that measurements reveal a non-issue with sea ice. Not just because I am sceptical of AGW but because then we can focus on more pressing concerns like actual pollution, poverty and corruption.
_______
You are ever the optimist, and only we could wish the world (of humans) worked in such a logical way. Regardless of where you fall on the AGW warmist/skeptic spectrum, and whether you think declining Arctic sea ice is a “problem” or not, we all know that the more we measure and study things, the more “problems” we’ll find. I’m not suggesting at all that we stop measuring and studying things, as I’m as curious as the next person, but if you give a man a hammer, suddenly the whole world becomes a nail…I’m just sayin’….
Ron says:
December 22, 2010 at 3:20 pm
“Why are you wrong? Simply because the seasonal loss of sea ice in the N. Hemisphere has been greater than the seasonal gain of sea ice in the S. Hemisphere…i.e. a steeper down averaged against a less steep up equals a down…and so I’m sorry to be such a “downer” on your little conjecture, but the data tell the story.”
Not so fast R. Gates.. the little graph you linked only goes to 1979. Please post one that goes back a couple of hundred years and maybe we can see even a short term trend.
____
Nice of you to bud…uh, I mean, join in here Ron. The specific time frame that was the topic of conversation was the “past few decades” which we clearly have data for and which clearly shows a trend– down, for global sea ice, specifically because the large decline in the Arctic is greater than the modest (very modest) gain for the Antarctic. Robert M. said:
“There has been zero trend in global sea ice extent in RECENT DECADES.” (emphasis mine) Which is flat out wrong…and I thought it proper to point that out.
But again, thanks for joining in.
“Not so fast R. Gates.. the little graph you linked only goes to 1979. Please post one that goes back a couple of hundred years and maybe we can see even a short term trend.”
This really is crucial. Studying the sea ice is interesting in itself, but as far as ANTHROPOGENIC GW goes, it can say very little. We dont have any data at all to base trends on. Anomalies since ’79 are meaningless. They could weaken or strengthen the AGW hypothesis, but only by very little. I wish the field was more open, curious and less politicized.
R.Gates. Don’t get me wrong here, this isn’t an attack. You don’t seem to be a “party line spoutin’ eco-loon”…
Does your mental model model of the Arctic include the AMO? It is just that looking at the (unadjusted) long standing weather station records available for the N. Atlantic one might believe that the AMO is what controls Arctic ice. That is to say that air temps and ice volume are the product of “warm” ocean currents rather than CO2 (hey, firm believer in atmosphere as a continuation of ocean by other means). As with the last peak in the ’40s they may well be heading the other way soon. What is your view?
(Different set-up “down south” and I fail to see a connection between the two ATM – not to say that there isn’t one)
Is the graph corrected for the inverse barometer?
Spokes around the pole look a little bit unphysical too.
Was there a strong wind blowing off the west coast of Greenland when the data was gathered, piling up the water against Baffin Island?
How does the satellite account for changes in sea level due to tide between orbits?
I think we should be told.
“”””” Ric Locke says:
December 22, 2010 at 2:30 pm
George Smith –
“Gravitational Level” is technically called “geoid”. “””””
Ric, Thanks for the explan. When you say it is the “theoretical” surface; are you talking from some model theory; or izzat an actual experimental observation; and how do they observe that; they must have some sort of absolute accelerometer; and yes I presumed that such a gizmo, if it exists would read net net net final gees, no matter the components.
And if one actually knew the exact shape of this geoid; isn’t that something one wouldn’t want some people who aren’t too friendly, to know ??
Can they measure it accurately enough say to keep up with all the ocean bottom (and land) volcanism ?
Ed Caryl says:
December 22, 2010 at 2:32 pm
Just in time to watch the ice increase again. I wonder how they will explain that?”
No problem at all. Just like Moonbat et al. are spinning the record snowstorms in the UK into the AGW narrative, they will craft increasing sea ice into that narrative as well. They will claim they’ve predicted it all along ANC that it’s due to warming elsewhere. The hotter areas of the globe cause more evaporation at the poles which removes heat and causes freezing. This creates altered wind patterns across the attic that accelerate the evaporation which causes an ice growth spiral. The hotter it gets, the more ice you get, spiraling put of control. And you can be sure it will be worse than they thought.
The following link plots arctic sea ice thickness from 1948 to 2004 using piomas type modeling.
http://psc.apl.washington.edu/zhang/IDAO/retro.html#Satellite_ice
Looking at the graph at the bottom of the page in the above link it is estimated during a twenty five year period from 1950 to 1975 sea ice volume grew by 10 x 10 <12 cu. meters during an period of negative NAO like we have started to see since last year.
http://ioc3.unesco.org/oopc/state_of_the_ocean/atm/nao.php
I suspect the cryostat 2 has already demonstrated significant thickening since last year but are waiting to decide how to spin it. I believe the short arctic summer that allowed sea ice extent almost to reach normal in March is somehow tied to the negative NAO.
I don’t know when that pic was taken, but it doesn’t bode well for ground truth observations. Warmer water expandes and colder vice versa. So could someone explain why the ocean is lower around greenland where the water is the warmest, and highest towards alaska where it’s coldest?
George: It’s a combination of measurements and theory — they measure until they can fit a relatively simple shape. Yes, there are precision gravitometers. Geologists use them all the time, but the usual tool for determining the shape of the geoid is a pendulum, which always hangs normal to the surface of the geoid. Nowadays we can measure the orbits of satellites accurately enough to determine the geoid, so field measurements are still done but are on the way out.
That being the case, it’s pointless to try to keep it any kind of secret. Countries used to have their own theoretical geoids, but once it became possible to do one for the whole world the surveyors of practically every country cooperated. Even during the height of the Cold War, US and USSR surveyors collaborated on calculating the geoid. The last major revision of the world geoid was in 1984 — if you have a GPS you may have seen “WGS-84” in the tech data; it stands for “World Geodetic System”. The heights shown by GPS (and GLONASS) are above the geoid, modified by a database of differences between terrain height and geoid.
Minor revisions and refinements continue. The world isn’t rigid on the scale we can now measure (centimeters or less — one recent modification changed the polar semidiameter of the Earth by a tenth of a millimeter). The latest work I know of is Earth Geodetic Model 2008, which differs from the WGS-84 geoid by a meter or so in some places. One reason I take things like the article cited here with a good-sized grain of salt is that they rarely or never specify what the reference surface they’re using is. EGM84? EGM96? EGM08? The differences among them are roughly the same size as the variances shown on the map, and I’ve now been out of the business long enough to have lost track of the details. Maybe the satellite is refining the geoid, which is after all “synthetic sea level”, rather than saying anything about ocean height or ice thickness!
Mike Borgelt — no, sea water isn’t massive enough, and there isn’t enough of it to affect geoid measurements at the ten-centimeter level. It might make a difference of less than a millimeter.
Regards,
Ric
Dan in California says:
December 22, 2010 at 2:01 pm
The satellite measures the thickness of ice floes by the difference in return time of radar pulses from the top of the ice and the adjacent sea surface. No problem. But how does it measure ice thickness 100s or 1000s of kilometers from any open water? I can imagine an algorithm for that, but can it *measure* ice thickness without nearby open water?
Take a look at this, bottom half, zoom in a little and you’ll see plenty of leads with open water, typical view for the summer and early fall.
http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T101972325
This is a tool to understand the Earth’s climate better. Understanding the dynamics of the climate is important. The changes in the ENSO and AMO cause significant alterations to the other weather patterns.
Knowledge is the key. This should help.
John Kehr
JEROME says
—————
several times in the last 100 years where there has been observably less ice (see pics of subs at the north pole).
————–
As far as I am aware it is common for the arctic ice to be discontinuous and so a sub surfacing at the north pole tells you only about the conditions where the sub surfaced. It tells you nothing about the conditions elsewhere. As in a few hundred feet away.
Since the sub was looking for an open spot ice free areas could be quite small.
So claims about knowledge ice conditions over hundreds of years amount to wishful thinking.
Kokomo says
————
It doesn’t seem like anything relatively simple to me. Neither the ice nor the water is flat, unlike their sweet diagram. Not every low point will be water either.
————-
Seems simple to me.
It’s the old ice berg thing. 9/10ths is under water.
So the satellite measures the height at a point on a grid. Multiply the height by 9 to get the depth. Add the height and depth to get the thickness. Multiply by the grid area to get the volume of the local cube. Add up all the cubes on the grid. You now have the total volume. Done.
LT;
Just to bring you up to speed, the relevant surface for the ice is the water. Which may or may not be visible nearby to the radar. If the grav field has raised or lowered the water but you can’t tell, which height are you going to measure by 9, exactly?
Steve Pearce:
I have actually looked at a weather map lately, although the report I referenced is from a CBC reporter in the North. See A. Watts comment a few below mine ; been there done that .
Still mild here in Nova Scotia. Raining for Christmas, 40 F 40 mph wind. It does feel cold walking the dogs, soaking wet into a North East wind but it is really warm here (mild in Ottawa too { I looked at a weather map on TV } – the world’s coldest Capital) .This is to continue for a while. Maybe another storm Monday. One would almost think that the North Atlantic is warmer than historic levels and is spinning unusually warm, windy storms at us.
Ridiculous! Noone has ever predicted unusual storm activity from global warming.
3×2 says:
December 22, 2010 at 3:49 pm
R.Gates. Don’t get me wrong here, this isn’t an attack. You don’t seem to be a “party line spoutin’ eco-loon”…
Does your mental model model of the Arctic include the AMO? It is just that looking at the (unadjusted) long standing weather station records available for the N. Atlantic one might believe that the AMO is what controls Arctic ice. That is to say that air temps and ice volume are the product of “warm” ocean currents rather than CO2 (hey, firm believer in atmosphere as a continuation of ocean by other means). As with the last peak in the ’40s they may well be heading the other way soon. What is your view?
________
Undoubtedly their are natural planetary oscillations of various periods such as the NAO, AMO, etc. that affect the arctic sea ice extent, area, and volume. Added to that are the solar oscillations, and on top of that are the astronomical oscillations such as the basic Milankovitch cycles, etc. GCM’s take all these known natural oscillations into account pretty well (with some notably exceptions, which is the source of my modest skepticsm about the the true nature the late 20th century warming). Be that as it may, GCM’s have long forecast that we’d see the first significant signs of AGW in the Arctic through seasonal sea ice decline, rapid warming, melting of permafrost, etc. and I do believe we are seeing this occur (still modulated, of course, by other natural oscillations). At the end of the day, I do happen to believe it is very likely we will see an ice free summer Arctic some time this century far earlier than the year 2100 as GCM’s were forecasting only a few years ago. Around 2030 is my current target date and the cause of this, as factored into the GCM’s is the rapid rise in CO2 over the past few centuries combined with other positive feedbacks such as the release of methane from melting permafrost, warming peat bogs, etc. While I am NOT currently a believer in C AGW, with the C being of course “Catastrophic”, I do think it more likely than not that basic physics behind, and notion that the 40% rise in CO2 since the 1700’s is affecting our climate is sound. What it will actually mean for life on earth, and specifically for humans, is not something I’ve been considering as of yet, as my basic thrust over many years was trying to get a grasp on the question of “is it happening?” before moving on to “so what are the implications?”.
Odd. You would think they would like to verify the CryoSat-2 findings, and put out extra buoys.
Only three buoys appear to be active…
http://imb.crrel.usace.army.mil/newdata.htm
2010E, 2010F, 2010H are all close to Alaska, Bering Straight.
2010C and 2010G, with no recent data, are near Canada.
I recall that in other years there were more active buoys with a better distribution. Nothing at all near the pole this year.
2009F appears to be active but not on the new data page:
http://imb.crrel.usace.army.mil/2009F.htm
The new graphs sure seem fuzzy (compare them to 2009F)
Who knew that you could adopt a buoy?
http://imb.crrel.usace.army.mil/2010E.htm (Adopted Buoy: Richmond Middle School, Hanover, NH. )
Regards,
Bob
Not sure it will turn out to be that simple. When those “flat” idealised sheets get crushed up by wind and currents they will tend to become mounds. If the dominant winds force the ice toward a shore then vast areas will mound up giving a false impression of ice depth. Conversely winds forcing the ice toward the Atlantic might look a little more as per the diagram unless they are riding large N. Atlantic waves of course. Then if the sheets are held firm in mounds there would be deposition from the atmosphere to account for. Even 30cm of snow/ice x your constant of 9 is a lot of false ice depth. Either way I don’t think it will be simple.
The BBC website today has a short page about a study of ships’ logs to get information about the extent of Arctic ice during the 18th century.
Sunderland experts study 18th Century Arctic voyages
http://www.bbc.co.uk/news/technology-12067295
The Sunderland team will be analysing log books written between 1750 and 1850.
Bob Tatz says:
December 23, 2010 at 8:27 am
2009F appears to be active but not on the new data page:
http://imb.crrel.usace.army.mil/2009F.htm
2009F was the Russian research station NP-37 which was abandoned in June, it appears to be still active because the data from the latest station (NP-38, aka 2010H) has been added to it.