Earlier today in part1, I posted about the new record low claimed by NSIDC: Sea Ice News – Volume 3 Number 11, part 1 – new Arctic satellite extent record. The number given is 4.1 million square kilometers:
That of course is being trumpeted far and wide, new life has been given to Mark Serreeze’s “Arctic death spiral” in the media. But, here’s a curiosity, another NSIDC product, the new and improved “multi-sensor” MASIE product, shows no record low at ~ 4.7 million square kilometers:
Note the label at the bottom of the image in red. NSIDC doesn’t often mention this product in their press releases. They most certainly didn’t mention it today.
Another product, NOAA’s National Ice Center Interactive Multisensor Snow and Ice Mapping System (IMS) plot, also shows no reason for claiming a record at all:
Their number is (for 8/22) ~ 5.1 million square kilometers. (NOTE: NSIDC’s Dr. Walt Meir points out in comments that IMS and MASIE use the same base data, but that this one product from IMS only updates weekly, unlike all other sea ice plots which are daily. They should be in sync on the next update cycle, but right now MASIE and IMS should both be at 4.7 million sqkm. -A)
Another curiosity is here. On the NATICE interactive maps on demand page (click on Arctic Daily in the pulldown menu):
The numbers they give for 80% and marginal ice add up to an extent of 6,149, 305 square kilometers.
So who to believe? It depends on the method, and who thinks their method is most representative of reality. Measuring sea ice via satellite, especially when you use a single passive sensor system that has been show in the past to have degradation problems and outright failure (which I was told weren’t worth mentioning until they discovered I was right and pulled the plug) might be a case of putting all your eggs in one basket. I suspect that at some point, we’ll see a new basket that maybe isn’t so worn, but for now, the old basket provides a comfort for those who relish new records, even though those records may be virtual.
Note that we don’t see media pronouncements from NOAA’s NATICE center like “death spiral” and “the Arctic is screaming” like we get from its activist director, Mark Serreze. So I’d tend to take NSIDC’s number with a grain of salt, particularly since they have not actively embraced the new IMS system when it comes to reporting totals. Clearly NSDIC knows the value of the media attention when they announce new lows, and director Serreze clearly knows how to make hay from it.
But this begs the question, why not move to the new system like NOAA’s National Ice Center has done? Well, it is a lot like our July temperature records. We have a shiny new state of the art Climate Reference Network system that gives a national average that is lower for July than the old USHCN network and all of its problems, yet NCDC doesn’t tell you about the July numbers that come from it. Those tasks were left to Dr. Roy Spencer and myself.
In fairness though, I asked Dr. Walt Meier of NSIDC what he thought about MASIE, and this is what he wrote to me today:
It can provide better detail, particularly in some regions, e.g., the Northwest Passage.
However, it’s not as useful for looking at trends or year-to-year
variations because it is produced from imagery of varying quantity and quality. So the analyses done in 2007 have different imagery sources than this year. And imagery varies even day to day. If skies are clear, MODIS can be used; if it’s cloudy then MODIS is not useful. Another thing is that the imagery is then manually analyzed by ice analysts, so
there is some subjectivity in the analysis – it may depend on the amount of time an analyst has in a given day.
Our data is from passive microwave imagery. It is not affected by clouds, it obtains complete data every data (except when there may be a sensor issue), it has only consistent, automated processes. So we have much more confidence in comparing different days, years, etc. in our passive microwave data than is possible using MASIE.
Finally, MASIE’s mandate is to try to produce the best estimate they can of where there is any sea ice. So they may include even very low concentrations of ice <15%. In looking at visible imagery from MODIS, in the few cloud-free regions, there does appear to be some small concentration of ice where MASIE is mapping ice and our satellite data is not detecting ice. This is ice that is very sparse, likely quite thin. So it will probably melt out completely in the next week or two.
MASIE has tended to lag behind our data and then it catches up as the sparse ice that they map disappears. This year the difference between the two is a bit larger than we’ve seen in other years, because there is a larger area of sparse ice.
You can thank the big Arctic storm of August 4th-8th for that dispersal.
“The Great Arctic Cyclone of 2012″ effect on Arctic sea ice is seen in this before and after image:
Figure 4. These maps of sea ice concentration from the Special Sensor Microwave Imager/Sounder (SSMIS) passive microwave sensor highlight the very rapid loss of ice in the western Arctic (northwest of Alaska) during the strong Arctic storm. Magenta and purple colors indicate ice concentration near 100%; yellow, green, and pale blue indicate 60% to 20% ice concentration.
Credit: National Snow and Ice Data Center courtesy IUP Bremen
Trends -vs- records, just like July temperatures. One system might be better at trends, another might be better at absolutes used to determine records. In this case we have three other respected methods that show absolute values higher than that of NSIDC’s older method which they have a high confidence in. I suppose these systems are like children. In a competition, you always root for your children over the children of the other parents, so it is no surprise that NSIDC would root for their own well known media star “child” over that of NATICE’s IMS and NSIDC’s own lesser known child, MASIE.
Oh, and then there’s Antarctica, that other neglected ice child nobody talks about, with its above normal ice amounts right now:
No matter what though, its all just quibbling over just a little more than 30 years of satellite data, and it is important to remember that. It is also important to remember that MASIE wasn’t around during the last record low in 2007, and IMS was just barely out of beta test from 2006. As measurement systems improve, we should include them in the discussion.
UPDATE: Andrew Revkin reports on the issue in his Dot Earth article here
He’s a bit skeptical of the sound byte hype coming from NSIDC writing:
That’s one reason that, even with today’s announcement that the sea ice reached a new low extent for the satellite era, I wouldn’t bet that “the Arctic is all but certain to be virtually ice free within two decades,” as some have proposed. I’d say fifty/fifty odds, at best.
…
But is this a situation that is appropriately described as a “death spiral”? Not by my standards.
Revkin also takes Al Gore to task on Twitter:
help him out, retweet this
UPDATE2: Commenter Ron C. provides this useful information in comments that helps explain some of the differences and issues:
The main point is that NIC works with images, while the others are microwave products.
“Polar orbiting satellites are the only source of a complete look at the polar areas of the earth, since their orbits cross near the poles approximately every two hours with 12 to 13 orbits a day of useful visible data. This visible imagery can then be analyzed to detect the snow and ice fields and the difference in reflectivity of the snow and ice. By analyzing these areas each day, areas of cloud cover over a particular area of snow and ice can be kept to a minimum to allow a cloud free look at these regions. This chart can then be useful as a measure of the extent of snow and ice for any day during the year and it can also be compared to previous years for climatic studies.”
http://www.natice.noaa.gov/ims/snow_ice.html
“NIC charts are produced through the analyses of available in situ, remote sensing, and model data sources. They are generated primarily for mission planning and safety of navigation. NIC charts generally show more ice than do passive microwave derived sea ice concentrations, particularly in the summer when passive microwave algorithms tend to underestimate ice concentration. The record of sea ice concentration from the NIC series is believed to be more accurate than that from passive microwave sensors, especially from the mid-1990s on (see references at the end of this documentation), but it lacks the consistency of some passive microwave time series. ”
http://nsidc.org/data/g02172.html
Some have analyzed the underestimation by microwave products.
“We compare the ice chart data to ice concentrations from the NASA Team algorithm which, along with the Bootstrap algorithm [Comiso, 1995], has proved to be perhaps the most popular used for generating ice concentrations [Cavalieri et al.,1997]. We find a baseline difference in integrated ice concentration coverage north of 45N of 3.85% ± 0.73% during November to May (ice chart concentrations are larger). In summer, the difference between the two sources of data rises to a maximum of 23% peaking in early August, equivalent to ice coverage the size of Greenland.”
From Late twentieth century Northern Hemisphere sea-ice record from U.S. National Ice Center ice charts, Partington, Flynn, Lamb, Bertoia, and Dedrick
http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1058&context=usdeptcommercepub
The differences are even greater for Canadian regions.
“More than 1380 regional Canadian weekly sea-ice charts for four Canadian regions and 839 hemispheric U.S. weekly sea-ice charts from 1979 to 1996 are compared with passive microwave sea-ice concentration estimates using the National Aeronautics and Space Administration (NASA) Team algorithm. Compared with the Canadian regional ice charts, the NASA Team algorithm underestimates the total ice-covered area by 20.4% to 33.5% during ice melt in the summer and by 7.6% to 43.5% during ice growth in the late fall.”
From: The Use of Operational Ice Charts for Evaluating Passive Microwave Ice Concentration Data, Agnew and Howell
http://www.tandfonline.com/doi/pdf/10.3137/ao.410405
From barry on August 28, 2012 at 7:33 am:
Maybe terms got blurred over time, during the age of quick spreadsheet graphs, but the short Wikipedia Error bar entry says something somewhat different:
I’m trying to figure out exactly what they are showing. Two standard deviations is 95%, they’re working with daily measurements (smoothed with a 5-day trailing average), it looks like they’re showing the range that 95% of that day’s measurements fall in. But the reported measurements have an amount of uncertainty to them. Is that worked into those bars as well?
Rule number one: never, ever – ever admit.
I cheer for the WUWT community’s heroic effort at battling the truth.
Am looking forward to the spectacular “recovery” of 2013.
Mark Harmon
Here’s what Partington et al have to say:
“We compare the ice chart data to ice concentrations from the NASA Team algorithm which, along with the Bootstrap algorithm [Comiso, 1995], has proved to be perhaps the most popular used for generating ice concentrations [Cavalieri et al.,1997]. We find a baseline difference in integrated ice concentration coverage north of 45N of 3.85% ± 0.73% during November to May (ice chart concentrations are larger). In summer, the difference between the two sources of data rises to a maximum of 23% peaking in early August, equivalent to ice coverage the size of Greenland.”
From Late twentieth century Northern Hemisphere sea-ice record from U.S. National Ice Center ice charts, Partington, Flynn, Lamb, Bertoia, and Dedrick
http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1058&context=usdeptcommercepub
And let’s hear from Agnew and Howell (they speak of underestimation by microwave products)
“More than 1380 regional Canadian weekly sea-ice charts for four Canadian regions and 839 hemispheric U.S. weekly sea-ice charts from 1979 to 1996 are compared with passive microwave sea-ice concentration estimates using the National Aeronautics and Space Administration (NASA) Team algorithm. Compared with the Canadian regional ice charts, the NASA Team algorithm underestimates the total ice-covered area by 20.4% to 33.5% during ice melt in the summer and by 7.6% to 43.5% during ice growth in the late fall.”
From: The Use of Operational Ice Charts for Evaluating Passive Microwave Ice Concentration Data, Agnew and Howell
http://www.tandfonline.com/doi/pdf/10.3137/ao.410405
More from Partington:
“Recently released operational ice charts from the U.S. National Ice Center
provide insight into the late twentieth century behavior of Northern Hemisphere sea ice,
providing more reliable ice concentrations during summer and freeze-up than those
available from the passive microwave record.”
“Ask an Inuk”, please, or ‘one of the Inuit’ (the collective noun). You could also ask one of the Yupik or Aleuts. “Eskimo” (people who speak a different language) is considered by many to be an epithet.
“In Canada and Greenland the term Eskimo is widely held to be pejorative and has fallen out of favour, largely supplanted by the term Inuit. However, while Inuit describes all of the Eskimo peoples in Canada and Greenland, that is not true in Alaska and Siberia….Alaskans also use the term Alaska Native, which is inclusive of all Eskimo, Aleut and Indian people of Alaska…”
– http://schools-wikipedia.org/wp/e/Eskimo.htm
If it was not quite clear above, the term “Eskimo” means, “people who speak a different language”. It does not mean, “eaters of raw meat.” It also makes no sense to use it as a name for several groups of people as most people ‘speak a different language’ from our own.
Some European,
Two questions:
1. Do you understand that the Arctic regularly goes through these cycles?
2. What is the problem, exactly, with ice fluctuations?
You people run around in circles, waving your arms and shouting, “The ice is disappearing!!”
So what? Arctic sea ice cycles happen routinely. Arctic ice levels have been half what they are today during the Holocene – when CO2 was very low. You can not produce one iota of scientific evidence showing that human CO2 emissions have anything to do with Arctic ice levels. Because there is no such scientific evidence.
Without evidence, your opinions are based entirely on true belief, not science. Think about what you’re trying to sell here. There is no difference between your baseless belief that receding Arctic sea ice is bad, and a belief in the village witch doctor’s juju. Neither belief is based on science.
I have a question / contemplation about Arctic sea ice. I was wondering if the big cyclonic storm from earlier this year, is actually a mechanism in thickening the ice pack in future years? My thinking is that if the ice is pushed and piled up together, perhaps much of the volume of that ice that was covering more surface area, is now stacked up vertically, in a smaller surface area. When winter comes, this thicker body of ice will consolidate and freeze together, and some of that ice that was exposed to melting will now be protected from melting by more depth. If such storms, while they do open more water in the short run, in fact thicken a large area of ice that will survive in the long run, then this would provide another mechanism for a cyclical long term variation of ice coverage. If the whole ocean is covered, no matter how cold, the ice doesn’t thicken as much as a good storm that piles large volumes of ice into a vertical configuration. Does this sound reasonable? Are there any studies that examine this question?
So when there is a number of measurement available, the one chosen is that which gives the most alarming results, not that which is likely to be the most robust. A bit like using the latest version GISSTEMP to measure the global average temperature change.
Manic, you have it.
As of today NIC shows artic ice extent tracking slightly above 2007. The data is available here:
http://www.natice.noaa.gov/products/ice_extent_graphs/arctic_daily_ice_extent.html
Select start year 2006 and month of August.
From Mark Harmon on August 28, 2012 at 8:49 am:
Strange, some scientists don’t pay heed to NSIDC’s admonishments. For example, on PIOMAS’ home page it says:
Yet you follow that NSIDC link and it clearly says:
So PIOMAS uses data that is stated as ‘not fit for purpose’, that is incorporated into the PIOMAS model’s “sea ice volume anomaly” results, presented as a time series, with trend analysis. Yet alarmists everywhere are quite happy to report the PIOMAS figures as accurate and fully scientific.
Really, you have to figure out what NSIDC product is suitable for analyzing extent (or area) trends. NSIDC says to not use their daily Sea Ice Index numbers, use monthly. And even then, there are caveats.
http://nsidc.org/data/docs/noaa/g02135_seaice_index/
Elsewhere it is mentioned that NRTSI numbers are replaced with GSFC numbers.
So don’t try to infer much of anything from the daily Sea Ice Index numbers as there’s too much uncertainty. (Heck, you have to wait several days after they come out for them to be “set”.) Monthly is better for just about anything.
But in either case, you might have to wait until the numbers are more than 18 months old to say anything definitive, as the Goddard numbers are the final say. Maybe quite a bit longer, the NH daily GSFC-only final file (versus the NRTSI-only “provisional” file) ends on the last day of 2010, nearly 21 months ago.
But what if you needed the most accurate reliable info on the sea ice now? Like if you wanted to a quick spot check on a report of tremendously low ice? You’d use MASIE.
There´s a lot of talk right now about the warming of the Arctic. Read this article from November 1922 by George Nicolas Ifft about “The changing Arctic”. It´s happened before!
http://docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf
It’s a sad day for science when you have to use an outlier year data set to support your theory. Please note 2012 ice coverage in February and March according to the graph was in the highest range of the IMS Sea Ice 3 day mean display. So shall we talk out of both sides of our mouths and say the 2012 winter ice proves the on set of global cooling and then 6 months later claim the 2012 summer data proves AGW? I think this is demonstrates why weather is not climate.
Global Warmers need to grow up and start taking responsibility like adults IF they want to be treated as serious scientists instead of rank amateur activists peddling ignorant folk tales.
This is such an annoying debate.
A) Arctic sea ice melting tends to support the view that the Earth has warmed, but it says nothing about attribution.
B) Antarctic sea ice is trending upward, so focusing on loss of ice in the Arctic is cherry-picking, cultural bias by the NH hegemons.
C) We have only 33 years of accurate data, hardly enough to divine long term trends.
D) Anecdotal evidence suggests arctic sea ice has been lower in the past, even the fairly recent past.
Of course, the warmists claim that decreasing arctic ice and increasing antarctic ice is just what their hypotheses project, but it’s just ex-post-facto, Texas sharpshooter style spin.
All this is, is a “gotcha’ moment”, a propaganda tool to frighten lay people with a visual they can easily grasp. It means nothing at all beyond that.
From manicbeancounter on August 28, 2012 at 11:57 am:
Oh, you should love the latest NSIDC NRTSI daily numbers (year, month, day,10^6 km^2):
2012 08 20 4.33489
2012 08 21 4.33137
2012 08 22 4.29062
2012 08 23 4.19043
2012 08 24 4.08920
2012 08 25 3.97332
2012 08 26 3.94326
2012 08 27 3.85419
Wow, practically three times the loss from 8/26 to 8/27 as from 8/25 to 8/26. The loss is accelerating! How alarming!
This is pure speculation, since I have no evidence.
I am guessing that (based upon responses I have seen) that there is an ongoing tug-of-war between the Navy guys (NIC used to mean Naval Ice Center) and the NASA satellite guys with the new-fangled microwave sensors and algorithms. When you hear that “operational indices” are less good, it is a put down of the Navy guys by the the Space guys. When you hear that the algorithms underestimate the actual ice, it is the Navy guys striking back.
WUWT is one of two blogs I read to start every day here in the antipodes (sic).
From the discussion thread above and to quote “I decided to no longer use the phrase because it is so widely ‘misused’ ” sums up the issue quite neatly in terms of English usage. Unlike basic mathematical formulae languages evolve. If it didn’t then there would be a lot more f’s in the language than p’s. While there is some historical value in pointing out how a phrase may have been used, or what it meant it is currently accepted usage and meaning that defines what is says today. Asking your grandmother what “being gay” meant in her day will give a difefrent answer than asking someone a lot younger. The phrase may be ‘misused’ through a historical lens but for most the ‘new’ meaning is clear .
Respectfully,
James
Jean Meeus says:
August 27, 2012 at 11:10 pm
“Today though, looking at the NSIDC extent graph, he [Mann] seems happy, declaring it ‘official’.”
I never understand the warmists. On the one side they say they are alarmed by the “catastrophic” global warming, but at the other side they are happy that the polar ice is melting. Now, what do those guys really want: warming or cooling?
____________________________
Warming of course so they can continue to collect their nice fat checks.
Smokey says: August 28, 2012 at 11:27 am
“You can not produce one iota of scientific evidence showing that human CO2 emissions have anything to do with Arctic ice levels. Because there is no such scientific evidence.”
“Without evidence, your opinions are based entirely on true belief, not science.”
“Neither belief is based on science.”
Where is your scientific evidence that sea ice extent is natural? Show me your science please? I have asked you several times now, but why are you refusing to show it to us. Apparently we are missing something.
Why do you still keep providing the same link you also used in a previous blog that says nothing, absolutely nothing, about current sea ice conditions to be a natural phenomenon not caused by man or by the same conditions which were there 6000-7000 years ago?
Do you even know why there was less sea ice 6000-7000 years ago?
TLM says:
August 28, 2012 at 4:45 am
….. For instance it is possible for there to be a record low in extent without there being a record low in area – as that is dependent on how spread out the ice floes are.
Trawling the different measurement regimes to try and find a figure that is higher than NSIDC’s and then say “there, I told you the sea ice is not at its lowest extent” is just blatant bad science, statistics and journalism frankly.
You are comparing apples with oranges and saying “there, I told you fruit are red not orange”.
___________________________________
Actually that brings up a very interesting point.
If you look at the side by side pictorials of Arctic Sea Ice Concentration for August 4th and 9th the question becomes where did the ice go? And yes that is a valid question. Take a look at the ice pack percentage southeast of Greenland in both pictures. On the 9th the concentration of ice has INCREASED to ~ 90%
So in 4 days with near freezing air and near freezing Sea Surface Temperatures, the arctic sea ice decreased somewhere in the neighborhood of 10,000 square miles. (SWAG)
On the other hand there is very good chance all that ice is still there but is now at less than 15% concentration because the storm churned the seas like an eggbeater and flung the ice all around the “bowl” of the arctic sea. The ice is still there but spread out so it is at less than 15% concentration and therefore not counted. That means the number reported is nothing but an artifact of the counting method coupled with a nasty storm.
Notice the small island of high concentration ice near the Bering Strait has not moved so major transport of ice out that direction is unlikely. However the area through the Fram and Denmark straits are packed with ice. ( Arctic Currents )
What will be interesting is what all these far flung chunks of ice will do to the upcoming winter freeze. The Mean Temperature above 80°N has already fallen below 0°C.
Too bad the Japanese are not showing up to date images
kadaka,
For the 1979 to 2000 mean, the error bars would be the relative error of 20,000 to 30,000 sq/km.
The 2 standard deviations shown is about 2 million sq/km at September minimum.
Robbie,
It is clear that neither logic nor data will convince you of anything. But for the sake of readers who may be misled by your post, let me state once again: scientific skeptics have nothing to prove. The “carbon” conjecture is not ours, it is yours. You still believe that CO2 is the cause of runaway global warming, despite not having any supporting evidence or runaway global warming to point to [or any global warming for that matter over the past decade and a half, despite a large increase in CO2].
I have repeatedly provided solid scientific evidence showing conclusively that CO2 rises as a function of temperature. CO2 does not cause any net temperature rise. The planet is still warming from the Little Ice Age, causing CO2 to outgas from the oceans just like it outgases from a warming beer. You have cause and effect reversed. Rising CO2 is the effect, not the cause of global warming.
And my evidence that sea ice is in a natural cycle is based on the null hypothesis, which has never been falsified. Note that the null hypothesis is a corollary of the scientific method. Even Kevin Trenberth admits he does not know the causes of climate change, so go argue with him about it. Trenberth wrote in the Climategate emails: “We don’t understand cloud feedbacks.
>> We don’t understand air-sea interactions. We don’t understand
>> aerosol indirect effects. The list is long.”
But I am glad to see you admit that there was less Arctic sea ice in the past than now. That Arctic ice decline occurred when CO2 levels were much lower than currently, thus deconstructing the evidence-free belief that CO2 causes global warming.
I wish this new measurement tool was around 30 years ago, so we could compare the data now to the data then using the same tool. I wonder if it would show, using this method, that the current sea ice is the lowest recorded.
To Michael U,
You state that “At 82.3N, the northernmost reported Canadian weather station shows a daytime high of -1C today, so it looks like the melting season has ended there”. You fail to take into account that at 82N there is still significant solar insolation in the month of August. See for example http://pubs.aina.ucalgary.ca/arctic/Arctic49-2-170.pdf. Therefore, the air temperature may be below freezing, but the open water near the remaining ice fields will be heated above freezing by the absorbed solar radiation.
Let us see what the final numbers on ice extent before drawing any conclusions. I agree with one of the posters above that the appears to lack objectivity with his most recent criticisms of the sea ice extent “numbers” from the NSIDC. I note that the measurements from every source on the sea ice extent reference page are clearly equal to or below record low levels. Certainly, the storm in early August contributed to the low levels. However, this is unlikely to be the only reason in light of the accelerated melt we have seen in the past 3 weeks of August.
The marginal zone in that one depiction is huge. Frighteningly huge.