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
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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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It’s also important to note that this NSDIC claim only represents data from a 30 year satellite record,
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Start your record keeping at a time when predictions were that we were going into another ice age and glaciers would soon cover us all….
……because there was too much ice
and you would hope that ice extent would go down………
….Winter max and summer min are always weather
May and Dec it all comes back together
[snip – rant]
Maybe NSDIC is a little too fast out of the gate. Winds are different from last year, so is the temperature record, so is the AO etc. Looking at the temperature trends I suspect that ice extent may continue for a day or another week.
I see no mention of multi year ice or ice thickness which was deemed to be so important previously when the ice extent wasn’t following the script. From the 2007 v 2011 images that our host has shown above, the ice this year looks pretty solid.
In fact, if the Catlin expedition is going to be repeated again this year then I think they might have a straight run to the pole like BBCs Top Gear team had when they drove. The only thing likely to slow them down is the time it is going to take to drill through all that ice.
Thanks for bringing this up, Anthony, I’ve also wondered about that. Hudson’s Bay fits into the same category.
I think we’ve built up some nice multi-year ice in the Arctic, so it will be interesting to watch this in coming months.
“[snip – rant]”
The “rant” was a link to the to the wikipedia entry which defines the Arctic Ocean which is of course what the NSIDC tracks, not the Arctic Circle.
REPLY: Well then you are welcome to submit that again, minus the ranting that surrounded it, but I must point out that this map included in that article:
http://en.wikipedia.org/wiki/File:Arctic_Ocean_-_en.png
Does not show the coast of Newfoundland down to St. Johns as being part of it. That’s my point. And clearly, the Sea of Okhotsk is not part of the Arctic Ocean, yet NSIDC tracks “Arctic sea ice” there. Take these non-Arctic areas out, and let’s see how the true Arctic has fared over the last 30 years. – Anthony
– Anthony
In the charts displayed above, NSIDC presents a reference curve of an average of 1979-2000, and NANSEN uses an average of 1979-2006. In the anomaly charts on the reference page, anomalies are computed relative to a 30-year baseline 1979-2008; the period of 30 years has an unusually privileged place among baselines. I’m curious why neither institution has changed its graph to use a 30-year-long average. Has the question been asked?
“Start your record keeping at a time when predictions were that we were going into another ice age and glaciers would soon cover us all….
……because there was too much ice”
Hm, never heard that one before, that there was “too much ice” in 1979!
This looks back to 1950, and for NS, to 1810.
http://www.socc.ca/cms/en/socc/seaIce/pastSeaIce.aspx
Well, the temperature in the Arctic is about 21 K below freezing. Not a lot of thawing within the Circle.
and so it begins….
“Does not show the coast of Newfoundland down to St. Johns as being part of it. That’s my point. “
http://en.wikipedia.org/wiki/Arctic_Ocean#Extent is the full link I posted the first time.
Now that you’ve actually looked at the link you’ll have noted the definition is not the same as the Arctic Circle, the actual definition of what comprises the Arctic Ocean depends on what you’re talking about with different organisations using different definitions.
The NSIDC provides the answer to your question
http://nsidc.org/arcticmet/basics/arctic_definition.html
“Arctic researchers also define the Arctic region as:
The area north of the treeline (the northern limit of upright tree growth)
Locations in high latitudes where the average daily summer temperature does not rise above 10 degrees Celsius”
There is nothing incorrect or “inaccurate” as noted above.
REPLY:The definition is nebulous, and that’s part of the problem. You say nothing incorrect or “inaccurate”….except that treelines are not relevant to sea ice and the Sea of Okhotsk is not the Arctic Ocean. Rationalization won’t make it so. – Anthony
Peter Plail says:
March 24, 2011 at 1:20 pm
***In fact, if the Catlin expedition is going to be repeated again this year then I think they might have a straight run to the pole like BBCs Top Gear team had when they drove. ***
Top Gear did not go to the geographic North Pole – They went to the magnetic pole.
jakers says:
March 24, 2011 at 1:40 pm
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jakers, can you not look at the chart you posted and see that the 70’s and 1980 were the highest sea ice in the Arctic?
..and that 2000 has a lot more ice than 1950?
Look at the chart you posted and figure out what happens when you start at 1980 and consider 1980 “normal”
http://www.socc.ca/cms/en/socc/seaIce/pastSeaIce.aspx
Hm..I are we sure that maximum has been reached yet. 2010 peaked at the very end of March/early April, and Norsex seems to be ticking up.
Gerald Machnee says:
March 24, 2011 at 2:33 pm
From there, there will pretty much always be ice all the way to the actual pole, so they could just as easily have reached that. The point was made that there is, in fact, plenty of ice. So much ice that you can drive all the way to the pole (either one). And it was made very, very, well!
It is still something I love to pint out to those who yell shrilly about the Arctic being ice free in [take your pick, Big Al says 3 more?] years.
‘Ice-a, ice-a, baby…’
Sorry, folks – just having a senior moment…..!
@ur momisugly Peter Plail asked about ice thinkness. Here is volume info:
http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/
See I no longer have to go to Stonehenge to find out if it is Spring; izzat the First Point of Aries or some such Salem Witch monicker. I just have to come to WUWT to see if the great ice vanish has started. Here we all go again Anthony; must be a year since we last did this !
Just looking at the AMSRE (IJIS) graphic, the extent is apparently > 2005 and 2007 while above the extent for 2006.
http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Extent_L.png
@ur momisugly Tim Clark says: March 24, 2011 at 1:45 pm “Well, the temperature in the Arctic is about 21 K below freezing. Not a lot of thawing within the Circle.”
I am not sure, but I think some of the melting is from warmer ocean water below.
“”””” Tim Clark says:
March 24, 2011 at 1:45 pm
Well, the temperature in the Arctic is about 21 K below freezing. Not a lot of thawing within the Circle. “””””
Well how in the hell did the Arctic get to 21 K; and you are correct; that certainly is below freezing.
Are you sure you don’t mean -21 deg C ??
“”””” CRS, Dr.P.H. says:
March 24, 2011 at 1:23 pm
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.
Thanks for bringing this up, Anthony, I’ve also wondered about that. Hudson’s Bay fits into the same category. “””””
Well I may be an old fuddy duddy; but “The Arctic” and the “Arctic Circle” are not one an the same; synonyms for each other.
When I went to shool, , “The Arctic” was anything North of +60 deg Latitude. The “Arctic circle” is a menagery lion that runs around the earth right where the sun never rises (gometrically) in winter, and it wanders around in Latitude as the earth’s polar axis shifts. The “Arctic” however always stays put at +60 deg Latitude.
If you would like to dispute that, then stop calling the “Antarctic Peninsula” the “Antarctic”.
Here is my forecast
2011 Minimum Extent:
September 17th 2011.
6.23 M km^2 (JAXA’s AMSR-E 15%)
Anthony writes,
“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. ”
I’m surprised that you find this curious. I don’t know of any Arctic ice researchers who define “Arctic” as “north of Arctic Circle.” Do you? Perhaps WUWT could lead the way by creating the first dataset of sea ice extent exclusively within the Arctic Circle, and see what that tells us.
“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.”
(Nansen was a man, not an acronym.) I tend to view NSIDC data as most definitive, and credit their “claim” of a May 7 max. That roughly agrees with the peaks not only for IJIS but also Uni Bremen and Cryosphere Today. But each research group uses different algorithms, so there are bound to be some differences in the results. Do you have a reason for preferring Arctic ROOS when they disagree? Will that preference be followed through the rest of the season?
REPLY: Walt Meier from NSIDC has agreed to provide a plot, let’s see what it says, isn’t that what science is all about, exploring new ideas? As for your objection to my use of NANSEN, I made no claims of it being an acronym, I only capitalized it to make sure readers knew clearly what it was. I’m well aware of the history of his travels.
You also seemed to have conveniently missed the sentence I made about JAXA AMSRE (which IS an acronym). But, since your purpose here is (and always has been) to denigrate from the comfort of anonymity, you go “Gneiss”.
– Anthony
Luther Wu writes,
“Just looking at the AMSRE (IJIS) graphic, the extent is apparently > 2005 and 2007 while above the extent for 2006.”
That is correct, if you mean that IJIS max this year is *below* 2005 and 2007, while still above 2006.