Now we start the slow slide into the Arctic Ice Minimum, likely sometime in September.
It is important to point out that there’s a lot of ice up there, and as illustrated by the images below, the losses at ICEmax are at the periphery, not at the core.
click to enlarge
What I find curious is the fact that NSDIC’s opening statement (below) in the press release has these words: “Arctic sea ice extent” but if you look at the NSIDC provided plot above, you’ll note that they include normal lines (in orange) for areas that are outside of the Arctic circle. While perhaps a small point, it does speak to accuracy in reporting. For example, I really don’t see how sea ice off the north coast of Newfoundland can be considered “Arctic” when it doesn’t even come close to being within the Arctic Circle.
[Update: Dr. Walt Meier of NSIDC in an email agrees that the orange boundaries are “somewhat arbitrary” and has agreed to explore a “what if” question for me. I hope to have a plot from him using Arctic circle as a boundary in a couple of weeks to see if there is any significant difference – Anthony]
It’s also important to note that this NSDIC claim only represents data from a 30 year satellite record, not the all time ice record, which is spotty and incomplete. From historical anecdotes, it appears the Arctic has gone through periods of reduced ice in the past. While NSIDC claims the maximum to be a tie with the 2006-2007 period on their plot (see their press release below), I’ll point out that NANSEN’s plot, using the same SSMI sensor platform, shows it nowhere near the 2007 value at present, though there was an intersection in the month of February:
In fact, NSIDC claims the maximum was reached on March 7th, but as we see in the NANSEN plot above, the ice continues to grow as late as 3/23 when that plot was produced. This discrepancy between two organizations that use the SSMI data is curious. However, the JAXA AMSRE data does seem to support NSIDC’s claim.
More live plots are available on the WUWT Sea Ice Page
======================================================================
Here’s NSIDC’s announcement:
Annual maximum ice extent reached
Arctic sea ice extent appeared to reach its maximum extent for the year on March 7, marking the beginning of the melt season. This year’s maximum tied for the lowest in the satellite record. NSIDC will release a detailed analysis of 2010 to 2011 winter sea ice conditions during the second week of April.
Figure 1. Arctic sea ice extent on March 7 was 14.64 million square kilometers (5.65 million square miles). The orange line shows the 1979 to 2000 median extent for that day. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data.
—Credit: National Snow and Ice Data Center
Overview of conditions
On March 7, 2011, Arctic sea ice likely reached its maximum extent for the year, at 14.64 million square kilometers (5.65 million square miles). The maximum extent was 1.2 million square kilometers (471,000 square miles) below the 1979 to 2000 average of 15.86 million square kilometers (6.12 million square miles), and equal (within 0.1%) to 2006 for the lowest maximum extent in the satellite record.
Figure 2. The graph above shows daily Arctic sea ice extent as of March 22, 2011, along with daily ice extents for 2006, which had the previous lowest maximum extent, and 2007, the year with the lowest minimum extent in September. Light blue indicates 2011, green shows 2007, light green shows 2006, and dark gray shows the 1979 to 2000 average. The gray area around the average line shows the two standard deviation range of the data. Sea Ice Index data.
—Credit: National Snow and Ice Data Center
Conditions in context
As of March 22, ice extent has declined for five straight days. However there is still a chance that the ice extent could expand again. Sea ice extent in February and March tends to be quite variable, because ice near the edge is thin and often quite dispersed. The thin ice is highly sensitive to weather, moving or melting quickly in response to changing winds and temperatures, and it often oscillates near the maximum extent for several days or weeks, as it has done this year.
Since the start of the satellite record in 1979, the maximum Arctic sea ice extent has occurred as early as February 18 and as late as March 31, with an average date of March 6.
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Shouldn’t we be getting some icesat2 data?
It is a small and inflexible mind that cannot find at least two ways to look at a question. I vote with Anthony on this Arctic issue.
Next. It is possible to write “X Celsius degrees” and “X degrees Celsius” as the former is proper for a temperature change, while the latter is proper for a temperature measurement. Using kelvins may simplify the writing but not the meaning for most folks.
OT: Catlin is at it again… by -40c according to Canada’s green agitprop media peddler in chief, the Globe and Mail:
http://www.theglobeandmail.com/news/technology/science/arctic-research-hotter-than-ever/article1955915/
Is there any further information of the effect of undersea volcanoes on recent the Arctic sea ice decrease ?
http://wattsupwiththat.com/2008/06/25/surprise-explosive-volcanic-eruption-under-the-arctic-ice-found/
Oh my God!! Look at all that ice!!! Hey..wait a minute….shouldn’t the ocean levels drop when that happens?? Someone call Al Gore. When this ice melts..the ocean levels will go even higher! This will happen again next year and the year after that and so on. Somebody get us off this Escher climate disaster.
Two questions;
What might these charts look like if this work is extended to the present (ie 2011)?
Where is the ACCELERATION of ice sheet disappearance that the IPCC supporters keep telling us is occuring?
Here’s an idea: get the raw sensor data from the satellite and do our own analysis…
@Mike 6:55pm, @gaya hap 7:01pm
OK, OK. Yaawn.
I’ve heard all this before.
And lets bear in mind the fact that it has all happened before. Many times.
Remember that the net (Arctic + Antarctic) sea ice extent has not changed statistically.
Don’t forget the fact that all the supposed awful consequences are unproven at best and has otherwise been shown to be asolute piffle.
But you still expect me to jump up and down & bounce off the walls and urge the politicians to throw another trillion into “saving the planet”?
Really?
And if “Ad Hominems are a sign of weakness” perhaps you might nip over to RC or Climate Progress and wag your finger at them.
I may not “like” what R.Gates says on here. More often than not I disagree with what he says. But he doesn’t hide behind anonymity and he frequently makes thought provoking, sensible points. (OK, frequently not so much).
But I think he deserves some respect.
Anonymous trolls waving the same tired old shrouds around?
Sorry!I don’t think so.
I am bothered by the NSIDC orange line. I would suggest that a 3-sigma band be added so that I can see (understand) how far the current coverage is off. I suspect that the 3-sigma width varies a lot.
The area graph from cryosphere shows 2010/11 below 2006/7
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.area.arctic.png
so Nanson looks dubious especially with JAXA also be figured in.
In regards to Arctic sea ice, as long as they are consistent it does not really matter. Perhaps they should call it Northern Hemisphere sea ice to stop people having their own definition of what Arctic means in this case?
Andy
Some thoughts on the Celsius, Kelvin divide.
There are two units of temperature measurements in use today.
Centigrade and Fahrenheit.
There are two temperature scales that use the Centigrade units:
Kelvin and Celsius.
Kelvin starts at zero, and has no negative values.
Celsius starts at -273.15.
The “Cent” portion of the word Centigrade is in reference to the number of units between freezing and boiling water, and that is “100”.
Centigrade therefore is the proper name to use when talking about units of difference, and “C” is the letter used.
It doesn’t really matter if you use K or C as most people will understand by the context of use.
How not to use Celsius:
After the great wind storm that hit Vancouver and the Lower Mainland on December 15, 2006 an article in a local paper declared that the temperature was 68 % above normal. So instead of an average (article mistakenly used the term “normal”) temperature of 10C, it was 16.8C. (these values are approximate)
What would the % above normal be if one used the F scale using this improper method of calculation?
I get about 25 %. If you can come up with vastly different numbers to explain a phenomena just by using a different scale, then there is something wrong with your methodology.
A few weeks ago in Vancouver there was a high temperature of -3C and normal is 8. What percent hotter should it have been on that day? Lets say I warm the cold up a bit to above 0 to get rid of negative numbers. You can come up with any percent you like, 1000, 10,000 just by selecting some number close to zero.
The Kelvin scale is probably the scale to use when doing these type of calculations. Or calculating the amount of energy, in the form of heat, in Joules might be better.
I like the link Jakers supplied us with, especially the Newfoundland graph that goes clear back to 1810. 1830 must have been a balmy winter in Newfoundland, as it has one of the lowest ice extents.
http://www.socc.ca/cms/en/socc/seaIce/pastSeaIce.aspx
I also find it interesting that in most graphs 2005-2006 is one of the lowest, in terms of winter extent, but as 2006 proceded the ice didn’t melt as much as other years, so that 2006 is one of the highest, in terms of summer extent (in recent years.)
Even with the La Nina weakening, its cooling effect will “lag” through the summer, so I’m betting my nickle that the ice melt will resemble 2006.
“…the orange boundary lines on the NSIDC extent map, which look much like gerrymandered political districts. Even Walt agrees that the boundary definitions are “somewhat arbitrary””
The orange lines show the median ice extent, which is not arbitrary at all. In your eagerness to quibble over something, you seem to be confused about what exactly you are quibbling over. Is it the definition of Arctic that is bothering you, or the definition of median ice extent?
Jer0me says:
March 24, 2011 at 8:01 pm
What matters is the word “below”, which makes it a temperatur DIFFERENCE (delta-T) instead of a temperature (T). Some people use tau or t for Celsius-temperature. You are correct to say that a delta-tau of 1°C is equal to a delta-T of 1 K, but it would be wrong of course to say tau=1°C is the same as T=1K.
Arctic ice cover is in a roughly 80 year cycle. As was pointed out above, records have covered 30 years for the top of the cycle so 10 years to go to the bottom of the cycle then ice should increase. Only time will tell, not some half baked model.
sharper00 says:
March 24, 2011 at 4:09 pm
quote
“The definition is nebulous, and that’s part of the problem. “
No it isn’t, all that matters is that the area under examination is consistent. That’s it. Precisely what defines “The Arctic Ocean” is no doubt an interesting aside but ultimately it’s irrelevant just as if you were to try and bring in various border disputes with regard to regional temperature trends.
unquote
While I have a certain sympathy for this point of view, it may be that as you move further from the Pole different warming mechanisms may be involved. To treat the entire ice area as an entity will, in those circumstances, cause error.
Anyway, it’s the Kriegesmarine Effect: oil spills from the North Slope and the Okhotsk rigs smooth the water. This lowers the albedo and emissivity so the water warms quicker when the sun shines and cools more slowly at night. The edges of the ice sheet are slower to freeze in winter and quicker to melt in summer.
However*, note that a survey of the Okhotsk sea found minimal oil pollution from the rigs. No definition of ‘minimal’ was given. 5ml of light oil will smooth a hectare. It is a simple calculation to work out how much is needed to smooth the Okhotsk.
The image at:
http://www.telegraph.co.uk/earth/wildlife/4979953/Polar-bears-will-not-survive-without-urgent-action.html
shows the smoothing around melting ice. One wonders if ice entrains the pollution as it freezes, preserving it in a concentrated form to cause enhanced melting in the spring.
JF
*Thank you, Professor Feynman.
Apparently the Catlin team are having a little bother drilling throuth the 5 meter ice! They also complain about wintery conditions in late March! Perhaps the reality will soon sink in.
For the doubters regarding ice-free conditions and greatly reduced extent here is a primer.
Ice free within the last ~10,000 years
http://dx.doi.org/10.1016/j.quascirev.2010.08.016
http://adsabs.harvard.edu/abs/2007AGUFMPP11A0203F
http://geology.geoscienceworld.org/cgi/content/abstract/21/3/227
Reduced extent in more recent history.
http://docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf
http://wattsupwiththat.com/2009/06/20/historic-variation-in-arctic-ice/
http://www.john-daly.com/polar/arctic.htm
http://www.arctic-heats-up.com/chapter_1.html
Sea ice. Who needs it? A summer of unrestricted shipping thru the Arctic ocean would be a fine economic stimulus.
“R. Gates says:
March 24, 2011 at 7:16 pm
Everyone knows sea ice is my favorite topic as I feel it is the ultimate test of the validity of AGW theory.”
With the world not warming according to the model predictions, I guess those who believe in CAGW have to hang their hat on something they think will prove their theory. Unfortunately for them, Arctic ice extent isn’t going to get them there.
Historical records of past substantial low ice periods in the Arctic and the existence of early human settlements in Greenland, which wouldn’t be habitable today, all indicate that low ice extent in the Arctic is recurring and, in a historical context, not extraordinary.
A 32 year satellite record which starts at a high point and is currently at a low point, doesn’t prove CAGW regardless of whether the Arctic is ice free this year or next. The only thing that will prove CAGW theory is a constant, unprecedented rise in global temperature.
Come back when you can demonstrate that.
Mike says:
March 24, 2011 at 6:44 pm
Of course the real issue is why is the Arctic region losing ice. Is it mostly from warmer than normal ocean water that was warmed elsewhere because of AGW? Or is the water warmer because of local AGW during the summer?
++++++++++
I am interested to know Mike, what you think the mechanism is for AGW to heat the oceans. I thought they were heated almost exclusively by the sun. Perhaps you can relate the present ocean cooling (since at least 2005) to the reduction in Arctic ice cover. Well…..not really reduction… let’s say ‘approximately stable area within a narrow range’.
I ask now because it was pointed out in 2007 on this channel that much warmer water entering the Bering Strait cause some melting in the Arctic and a great deal of the loss (not melting) was ice blowing east past Greenland as was well documented in the NASA photo times series.
If the ice area is about the same as it was in 2007, is warm water still the cause? Will the continuing drop in sea temperatures around the world affect the Arctic ice extent? Will the concomittant and continuing decline in air temperatures change the picture at all?
Anthony,
Congratulations. This is the best question asked in recent years. Where?
Thanks
PS: The same question is important about the Amazon rainforest.
sharper00 says:
March 24, 2011 at 1:24 pm
EFSJunior already advocated “Northern Hemisphere Sea Ice Extent”. I assume that there is no northern hemisphere sea ice that is not in the NSIDC data (or am I missing some ice).
Perhaps we should lobby Dr. Meier to change the term to that. Given how many times AGW has been renamed, surely referring to the hemisphere instead of Arctic would be less controversial.
I grew up in northeast Ohio. While the Great Lakes are not seas, why do we measure just sea ice? Shouldn’t we be including fresh water ice too? Perhaps I should work up a theory on the Conservation of Controversies (subtitled “You Can’t Please Everyone”).
Of course, If we just look at the ice cover over the true Arctic, there should be a lot less variance in peak ice since we’ll me removing a lot of the part that brings the variance.
Since the Arctic is the “canary in the cave” of global warmers, the definition of the Arctic should be clearly defined. Further, since the effects of any warming are supposed to be seen in the Arctic first and in a more pronounced way we should expect to see these changes not at the periphery of the ice cap which is more vulnerable to local weather patterns, but in the real Arctic.
For the ice coverage in various sections of the NH check http://www.socc.ca/cms/en/socc/seaIce/pastSeaIce.aspx
“Regional Variability of Sea Ice Extent” and hover your mouse over the region of interest. The Arctic Ocean is one of the regions.
This page has the “Arctic” sea ice extent broken out into 9 separate regions for those who desire more granularity and specificity in the data.
https://sites.google.com/site/arcticseaicegraphs/
It is curious that I don’t recall Anthony complaining about the definition during last year’s late freeze even though much or the extent increase took place in the areas he is now disputing. Yes Anthony, the question is a good one it’s your timing that’s odd.
REPLY: No nefarious motives. Sometimes you don’t notice things until later. I’m genuinely curious to see what a 30 year plot of sea ice only inside the Arctic circle might show. It may show nothing new at all, but as you say, “an interesting question”. You’ll note that I previously have questioned the inclusion of the Antarctic Peninsula in the same climate zone, due to it being so far away from the mainland and affected by currents that don’t affect the main ice cap. So there’s precedence for this type of curiosity – Anthony