Guest post by Steven Goddard
The WUWT Arctic Ice Thickness Survey has been conducted from the comfort of a warm living room over the last half hour, without sponsors, excessive CO2 emissions or hypothermia. The data is collected from the US military web site http://imb.crrel.usace.army.mil. All of the active military buoys show significant thickening ice over the past six months to a year, as seen below.
Location of Catlin team relative to buoy 2008D and the North Pole
Buoy 2008B has thickened by more than half a metre since last autumn, and is more than 3 metres thick.
2008C also shows thickening by more than half a metre since last autumn, and is nearly 4 metres thick.
2008D has not been updated since early February, but showed thickening and is 3.5 metres thick. It is close to the Catlin team position.
2007J has thickened more than half a metre, and is nearly 4 metres thick.
2006C has thickened by nearly a full metre over the past year, and is more than 3 metres thick
UPDATE: The military site also has graphs which are supposed to show depth. It appears that many of these are broken, which is why I used the more reliable temperature graphs. The depth at which the ice drops below the freezing point of seawater (-2C) is of course the bottom of the ice. You can’t have water in a liquid state below it’s freezing point.
Some of the buoys have reliable depth data, and they correspond closely to the temperature data – for example 2007J which shows 400cm for both.
http://imb.crrel.usace.army.mil/buoy_plots/ice2007J.gif
http://imbcrrel.usace.army.mil/buoy_plots/2007J.gif
It stands to reason that much of what happens in the Arctic, or any other ocean, is driven by the distribution and temperature of ocean currents. It also stands to reason that changes in the behavior of those currents would lag changes in the energy inputs and other variables that drive them. So, why would one expect the apparent solar minimum that we just entered to have reached its maximal effect? I would not expect to see that happen for several more years. The effects that are entirely or mostly dependent on air temperature will probably happen faster.
By the way, since most of the Arctic is landlocked there are obvious physical limits on the extent of the ice. It could reach zero Kelvin and the extent of the ice in most areas would not increase beyond current maxima. How is this accounted for (if at all) in the analysis? I’m sure I’m not the first one to notice this problem but I have not seen any explanation of how it’s handled.
Tom, I’m a multidecadal person raised by grandparents who knew about silent movies up close and personal, and who drove through the dust bowl from Chicago to LA in a Nash. My greatgrandfather decided to homestead in Wallowa Valley because a blizzard blocked the passage through the Blue Mountains. At least in my little corner of the world, it has been a colder, warmer, dryer, and wetter April Spring than it is now at 8:25 PM in NE Oregon. I still have my studs on because snow is predicted in the pass again this weekend. Just because it is multidecadal doesn’t make it any less of a weather pattern variation tied to natural causes.
Steven, you might consider the Beaufort Gyre, the Arctic current that “slowly swirls the surface waters of the Arctic basin, turning the Polar Ice Cap along with it, making one complete rotation about every 4 years” (taken from the above link on Arctic Currents). This rotation (which can be faster or slower than 4 years, combined with strong outflow winds, can indeed make melt look like something is happening due to the PDO. But my opinion is that it is unrelated to the PDO and more likely the above rotation bringing ice flows into outgoing Atlantic currents.
Folks, for those who aren’t aware, CRREL is in Hanover, NH, a few miles from Dartmouth College (where Hansen had a little seminar the other night to grand approbium from the faculty, local Greens, CRREL staff, and World Federalist Society members). I would caution folks to get their raw data and be just as rigorous as you and CA are about anything the Hockey Team does with their data when they process it for publication.
Until Pete can come up with some detailed explanations for his criticism of Steve’s use of temperature profiles, I would suggest sticking with Steve using the temperature as a proxy for ice depth. Furthermore, while Pete may be trying to criticise Steve using temp as a proxy for depth, if you were to accept Pete’s arguments, then the ice should actually be significantly thicker than at the point where temp drops below -2C.
Should also look at how snow depth on top of ice affects ice thickness, and how snow coverage over ice changes albedo.
Anthony,
I think the temp plots show that some portion of the bouy is in the water (>-2C) and some portion is in the air (above the ice). The cold constant temp part of the plot is in the air , so only the slanted portion of each plot is ice thickness, representing the conductivity of the ice is a constant change in temp per unit length. The abrupt change in slope of the lines would at the snow to ice interface, with the snow being less conductive than ice and thus showing a larger temperature change in a short distance in the area between the ice and air.
The depths you described in the post are for the bottom of ice relative to the top of the bouy. The ice thickness is somewhat less. For example, the 2008B plot for April is 0-80 cm in the air, 80-120cm in snow (depth .4m) and 120cm-320cm in ice (depth 2m). greater than 320cm in in the water beneath the ice.
Jan, it seems most unlikely that salt is going to be “squeezed out of older ice”. Where is it going to go? Into the sea by reverse osmosis? I don’t think so.
A better theory seems to me to be that “old ice” carries a top load of ice that came from snow, not the sea. Snow ice carries no salt but its weight pushes the old ice deeper into the sea leaving the top layer reasonably salt-free and by your argument requiring a higher melt temperature.
Troppo (16:35:31) :
“. . .why doesn’t Google Earth appear to be showing any ice over
the Arctic? . . .”
Go here: http://nsidc.org/data/virtual_globes/
Take the second image: September sea ice extent, 1979-2008
Compare satellite images of September sea ice extent for the last thirty years
click on the link, then move the slider at the top
Alan Wilkinson (20:28:18) :
Jan, it seems most unlikely that salt is going to be “squeezed
out of older ice”. Where is it going to go? Into the sea by reverse
osmosis? I don’t think so.
Regarding ice, salt, water, freezing, melting
See the reference at the post above in this thread
John F. Hultquist (13:05:36) :
Pete,
2008B shows ice thickness and temperature profiles both at approximately 300cm, and nearly 50% gain in thickness since last April.
http://imb.crrel.usace.army.mil/buoy_plots/ice2008B.gif
http://imb.crrel.usace.army.mil/buoy_plots/2008B.gif
Hope this helps.
John F. Hulquist (21:44:26)
Cool….thanks
John F. Hultquist (21:59:36):
Alan Wilkinson (20:28:18):
John F. Hultquist (13:05:36):
Thanks, John, excellent link:
“Sea-ice in bulk is therefore not pure water-ice but has a salinity of as much as 15 for new ice (and less for old ice as gravity causes the brine cells to migrate downward in time.) With continued freezing, more ice freezes out within the brine cells leaving the brine more saline. Some of the salts may even crystallize out. The salinity of first-year ice is generally 4 to 10, for second year ice …. it decreases to 1-3 and for multi-year ice it may be less than 1.”
—
“Note also that less heat is needed to melt new ice (S=15) than old ice which has lower salinity.”
So indeed it seems that the salinity of frozen sea-ice is reduced over time, exactly what I was trying to suggest in my post above. Also the consequences for melting and freezing seem to hold water, as per my argument.
Phil. (14:54:41):
Tom P (13:09:03):
Thanks for responding. Yes, that quote is from my first post JAN (08:31:05), and I can confirm that the 0.7m refers to Goddard’s temperature graph of buoy 2006C in the top article. As I mentioned, this is a fairly limited study in time and coverage, so one should be careful about drawing bold conclusions based on ice thickness from one buoy over 12 months, and a few other buoys over the winter season.
I’m curious about your comment on the missing buoys though. Provided these have been pushed out of the Arctic by easterly winds and currents through the Fram strait between Greenland and Svalbard, wouldn’t it be correct to disregard them when looking at ice thickness in the Arctic? Since they are no longer in the Arctic, their measurements of zero ice is not relevant for the ice thickness of the Arctic ice, no?
I guess that thickening of ice between autumn and early spring is hardly surprising.
What is a more relevant metric is a monitoring of this thickness year on year just like area is monitored.
Any data on that?
.
>>You can’t have water in a liquid state below it’s freezing point.
Well you can, its called supercooled water. But unlikely in this context dynamic, as it requires very stable conditions to form. Any movement and it instantly freezes.
.
Please checkout the bouy description [http://imb.crrel.usace.army.mil/buoyinst.htm] and my earlier post before estimating depths at “more than 3 meters”.
“Thermistor strings were [are] PVC rod with YSI thermistors spaced every 10 cm. These rods could [can] easily be connected to assemble strings that extended from the air through the snow and ice into the upper ocean. The thermistor accuracy is better than 0.1 C.”
Found it interesting that this blob of information was theorized and datafied towards the end of the POLAR Freeze.
Might be nice DATA proof if you could provide your statements and backup data when it changes through the POLAR THAW.
How about doing this again September 15th?
GOOGLE EARTHS PHOTOS ARE ANYWHERE BETWEEN 1 and 7 YEARS OLD!
After emailing and putting in a call to GOOGLE- and their EARTH data supervisor.
I was told that the data will NOT be updated anytime soon. (2007 summer this call took place.)
I was informed that Google did not have this on their agenda.
However, we could take photos of the areas and submit them for their usage with no compensation.
Google Earth is great for a map. Microsoft is good as well.
If you want better information, use http://www.NOAA.gov
Sure, I can post these a few more times if it makes it more clear.
2008B has increased in thickness by nearly 50% since last April
http://imb.crrel.usace.army.mil/buoy_plots/ice2008B.gif
2008C has increased in thickness by nearly half a metre since last April
http://imb.crrel.usace.army.mil/buoy_plots/ice2008C.gif
2008J has increased in thickness by more than half a metre since last April
http://imb.crrel.usace.army.mil/buoy_plots/ice2007J.gif
Then there’s a headline on HuffPo “Arctic sea ice thinnest ever going into spring.”
http://www.huffingtonpost.com/2009/04/06/arctic-sea-ice-thinnest-e_n_183777.html
What you seem to have forgotten to mention is that 4 of the bouys melted out.
Paul,
That is how the Arctic works.
The ice drifts towards the warm waters of the North Atlantic and melts after a few years. Putting a buoy on the ice does not stop polar drift.
Dear anybody who may be wondering what is going on here:
The poleward shift of temperate climate zones forces sea ice to retreat.
The surface area of ocean close to the poles increases and the distance from the poles to the ocean decreases.
Increased evaporation from the newly exposed water leads to increased precipitation (in the form of snow and ice, when surface temperatures are below freezing).
The net effect is that ice caps, (or continental ice sheets down south), become thicker but lose overall surface area.
A first year meteorology student could tell you that… or even an arts student picking up a generic climate change course to fill in some subject points.
Unfortunately, a second year student (myself) has forgotten the name of this phenomena so I can’t cite properly >.< apologies to the real scientists, if you are reading this.
David,
Thank you for the freshman meteorology lecture.
Now here is your freshman quiz. Try to find the open water near the poles you were referring to which is “causing increased snowfall.”
http://nsidc.org/data/seaice_index/images/daily_images/N_daily_extent.png
One of the first rules of science is that if you make the wrong assumptions, you will come to the wrong conclusions. Maybe you will learn that in your junior year?
… I live in Australia and water manages to transport itself from the tropics to Melbourne easily enough.
Nearby is a relative term obviously, it depends what scale you’re looking at. The point is that there is more moisture in the air available for deposition at high latitudes.
Since the global temperature gradient requires air to trend poleward, and there is no circumpolar current in the north to isolate the region I see no problem with what I said.
I was unaware that all systems that could lead to precipitation over the poles were meso-scale.
If this is the case, my apologies.
oh, if you don’t know where Australia is, NT down to Melbourne is roughly 30 degrees latitude, or just over 3,000 km.
I know that we’re not a particularly well known country within America >.<