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 Entropic man on August 28, 2012 at 3:30 am:
You’re kidding, right? Did you really expect to get away with that claim?
Anthony started with this graph from NSIDC, same one featured on the Sea Ice Reference page:
http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png
You’ve selected the version with the error bars added by NSIDC.
You have falsely accused Anthony Watts of removing error bars that were never there.
Surely the main point here is not the absolute quantity of ice but the change over time? As long as NSIDC uses the same method of measurement now that it used in 2007 and back to 1979 it is perfectly correct for it to say that NSIDC’s measurement of the extent is at NSIDC’s lowest level since NSIDC started its index.
In which case it really does not matter what measure you use provided it is consistently the same. The “absolute” figure is only really important when comparing methodologies (or when determining the end point when the ice has all finally disappeared). 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”.
The NSIDC error bars are only on the BaseLine, where are the error bars for the actual readings.
This might be good for the skeptic cause again as the warmists totally exaggerate and are caught out once again re: other graphs and probable increase next year ice extent NH back to normals etc. The whole discussion is actually pointless as global temperatures have NOT increased since 2002 and as you point out Antarctica has been above anomaly most of the time so no correlation whatsoever..
(Reposted from Real Science)
I’d like to know where all this extra energy is supposed to come from, if the energy comes from the sun during summer (which it does) then it would make sense to look at the data from past solar cycles. I understand it as fact that the solar cycles of the late 20th century had a higher sun spot number/activity than this solar cycle (cycle 24, although still in progress), it is blatantly obvious that successive cycles of high sun spot number, larger spots and increased CME activity have an effect on sea ice, remember we are talking about sea ice and not Ice over land which there has been little or no significant change.
Any reasonable minded person would first put the sea Ice variability down to the effects of solar activity and energy coming from the sun and interacting with the Earth and try to understand how summer arctic storms break up and disperse the sea ice, or at the very least explore and try to understand this process.
Some dishonest people are using a normal summer sea Ice melting season as a springboard to launch a campaign as if sea ice variability supports their view, when in fact it does not support a man made global warming narrative one way or the other, especially in light of the recent solar minimum between 2008 – 2011 when northern hemispheric winters got cooler, more snow cover over land and more rivers freezing up, what was the Sun doing at this time? It is interesting. If the sun has successive cycles of low activity I would expect sea Ice to increase. The cycle of arctic sea Ice variability takes many decades to increase and decrease overall. furthermore, it has only been three decades of monitoring the Sea Ice from space using satellites, I would have thought that anyone who claims to be an intelligent person studying Sea Ice would understand the significance of how insignificant three decades of satellite data of sea ice actually is compared to the much larger timescales earth cycles through and with that the cycle of sea ice variability.
According to P Gosselin
“0.006% more of the world’s ice melted this year. At this rate it’ll take 166 years to see a 1% reduction.”
“… it yields a total ice volume of: 24,808,600 cubic km stockpiled on the planet (neglecting the glaciers on mountains, which are puny in comparison).”
http://notrickszone.com/2012/08/27/oh-no-six-thousandths-of-one-percent-0-006-more-of-the-worlds-ice-melted-this-summer/
I am suffering from AOS.
Acronym Overload Syndrome
Please provide a UGOAART.
Useful Glossary Of All Acronyms Referred To.
.
I been tracking the Masie data since March when the sea ice maximum occurred (Masie only provides 30 days at a time so I started saving it).
Masie mostly tracks the NSIDC until the last 30 days when it diverges quite a bit higher – being as much as 1,000,000 km2 or 22% higher.
Here is Masie (Green) and the NSIDC (Red) charted for 2012 against all the years in the NSIDC database back to 1979. I use the same 5-day trailing average for both in the chart (moved back two days so it is at the effective right timeperiod).
http://s13.postimage.org/5f1xfu11j/NSIDC_Masie_NHSIE_Aug27_12.png
From Bill Irvine August 28, 2012 at 5:17 am:
Go to toolbar at top of any WUWT page. Go to “Resources”, click on “Glossary”.
If the acronym is not there, you can ask for it with the comment box below.
kadaka (KD Knoebel) says:
August 28, 2012 at 4:11 am
Anthony started with this graph from NSIDC, same one featured on the Sea Ice Reference page:
http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png
You’ve selected the version with the error bars added by NSIDC.
You have falsely accused Anthony Watts of removing error bars that were never there.
————————————————–
As a scientist Mr. Watts would naturally have chosen the graph with error bars.
Wearing his political lobbyist hat he has chosen the graph without error bars, preferring to avoid the possibility that his followers would consider the statistical significance of recent summer extent minima.
REPLY: It’s the same plot NSIDC presented to the public in their announcement. If it is good enough for them, good enough for me.
I’m not a political lobbyist and I don’t appreciate such an unsubstantiated label for your smearing purposes. That’s it, take a hike – bit bucket for you. – Anthony
With regard to previous sea ice around the arctic, I remember reading a book called 1421 a few years back which told of a huge Chinese fleet which explored the world at that time. Some of the claims are more believable than others but IIRC among them is that a remnant of the fleet sailed up the west and round the north coast of Greenland and managed to produce maps at the same time.
Obviously that is not possible today, but appears to have been then, perhaps more evidence of the medieval warm period and, if true, would certainly have allowed farming in southern Greenland.
If nothing else it was an interesting read, especially the discovery of America pre-Columbus.
I tried to open ‘Polar Sea Ice and Snow – Cryosphere Today’, arctic.atmos.uiuc.edu/cryosphere
to no avail!
Is this possibly a ‘Watts effect’?
@Stephen Fisher richards says, August 28, 2012 at 1:10 am
Control [in a variety of guises].
Today’s Modis satellite pictures have less cloud cover in the western Arctic than there has been for (well, 3 months really). Still cloudy but more can be seen now.
It might be a little deceiving, but there is certainly more ice in the western Arctic (although it might not reach the 15% threshold in all cases).
There is significant ice cover around Wrangel Island off the Siberian coast (and the scene of the in famous polar bear / walrus battles).
Bands 3,6,7 show ice as Red which can be useful to distinguish from the cloud (smoke will also show up in a type of Red so watch for that – it is usually banded red).
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2012241.terra.367.4km
The grey bar in the NSIDC chart is the standard deviation (x 2), NOT ‘error bars’. A standard deviation shows the spread of data around the mean. Error bars show the range of possibility for an estimate.
That NSIDC show 2 standard deviations from the mean is a testament to how much the ice coverage has receded. Right now, the NSIDC 2012 value is 7 or 8 standard deviations away from the 1979 to 2000 average. In purely statistical terms, this is a huge departure.
Paul Homewood says:
August 28, 2012 at 3:01 am This paper . . . ”
Thanks, Paul. I’m traveling today, but will read it tonight.
The post in the link you gave has the following comment:
Is this related to climate change in some way? [Beto, 3:48 pm]
I wonder what that is about?
Zen and TLM
I agree. There are two different methods of measuring arctic ice coverage. That is a good thing, just as it is good that we have both land stations and satellites to measure air temperature.
Microwave indices see more water than ice, while NIC index sees more ice than water in mixed conditions. So they will each have distinct results and trends.
My only concern is that the news only reports the microwave results, and ignores the equally valid NIC index. 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 Entropic man on August 28, 2012 at 5:51 am:
Let’s stop a moment to keep count here. So you’re admitting you have falsely accused Anthony Watts of removing error bars that were never there, right?
Whoa, what’s this?
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
It’s the IARC-JAXA Arctic Sea Ice Extent graph, and they don’t put error bars on their averages! Obviously the graph doesn’t come from scientists, but from political lobbyists!
Oh no, what’s this one?
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.arctic.png
It’s the Cryosphere Today Northern Hemisphere Sea Ice Area chart, and they don’t have error bars on the 1979-2008 mean! Dang Cryosphere Today political lobbyists don’t want viewers to consider the statistical significance of recent summer extent minimums!
*sigh* Could you get any lamer? Scientists aren’t worrying about them in their presentations, and Anthony long ago showed he’s more of a scientist than you. It’s a non-issue.
This is anecdotal, but I overflew the Arctic Ocean many times during the mid-1960s. One year, 1964, I spent about 35 days, from August into early September, flying sorties out of Eielson Air Force Base, Alaska. Back then, there was much more sea ice on the Arctic Ocean than the satellites depict for current times. Of course, back then, there were no satellites monitoring sea ice on the Arctic Ocean. On sorties we flew out toward Novo Sibersk and Severnaya Zemlaya the ocean was covered in sea ice from a few tens of miles off shore from Point Barrow. We could see leads in the pack ice, but it was pretty much solid by the time we got around 100 NM off shore. By the time we flew our last sortie, in early September, the sea ice had noticeably move in toward the shorline at Point Barrow, maybe no more than a mile or two off shore. The day in the first week of September, when we departed Eielson AFB for home, a heavy wet snow was falling.
Now, I’m citing all of this from memory, but in that period much or North America was experiencing very cold winters. I am certainly not a believer in human caused global warming, but over seven decades of casual observations, The trend has been from colder winters to, frequently, milder winters. BTW, I am old enough to remember the infamous Blizzard of ’49. It came over the area I lived in as freezing rain severe enough that it downed power lines and broke many, many trees. It was close to a week before power was restored. Back then we kept warm with coal-fired furnaces and burned candles for light. The ice was a long time melting.
Over at Sketptical Science Daniel Bailey posted a map of Arctic ice in August of 1938. It seems the sea ice extent has been dropping rapidly the last few years. From his souce of the map you can look at sea ice extents for many years and various months.
You should have highlighted that someone’s pedantry.
Here’s what one researcher found:
In other words, nobody (or hardly anyone) uses the term to mean “assuming the conclusion”. This is probably because of the terrible, awkward, and outdated translation of this meaning into English.
My advice to you is to let it go. The new meaning is well understood by everyone – even you. You only cause confusion and problems when you comment on it.
A couple of observations on the “begs the question” sub-thread going here:
1. English usage changes. “Liberal” no longer means what the Founding Fathers meant when they used the word; quite the opposite now. Similarly, logicians are in the process of losing control of “begs the question” and it now means, as well, “raises the question,” as someone has pointed out. Usage determines meaning in English, because it is an actively-used, evolving, language. Dictionaries are always getting bigger, not smaller. “Mouse,” for example, has an added meaning since I was a child, and “progressive” is in the process of undergoing the same corruption of meaning as “liberal” once did.
2. The original terminology in logic was always confusing anyway, thereby increasing the odds that it would be taken over as another usage at some point. Logicians would be well advised to relinquish “begs the question” to its new usage and devise with a more self-explanatory, self-evident, terminology. I’m no logician, by a long shot, but to me “begging the question” tends to mean “assuming the argument,” i.e., assuming a point as true, and then using that very point to argue the same point is true. Obviously, this usually takes some disguising of the point as it is being put forward as an assumption. Otherwise it becomes too obvious, e.g., “You’re stupid because you’re dumb.” But if the point is better disguised, e.g., “You’re stupid; you’re incapable of understanding my argument,” then you might just get away with it, without any need to present actual evidence to support your case, especially if you make that statement from a position of authority. Yet, in both cases, you’d have assumed as true the very argument you’re trying to make.
This begs the question, will logicians continue to fight a losing battle?
P.S. I fully expect to be called out on my interpretation of the points of logic above. As for the war over “begs the question” though, that one’s been decisively lost, and will remain lost, especially given the wholesale abandonment of a traditional “liberal” education by most of our institutions of higher learning.
Anthony, I’m afraid you failed to read the manual. “While operational analyses are usually the most accurate and timely representation of sea ice, they have errors and biases that change over time. If one is interested in long-term trends in sea ice or how it responds to changing climate forcing, generally, it is best not to use an operational product, but rather one that is consistently produced and retroactively quality controlled. The NSIDC Sea Ice Index monthly ice extent, and the satellite passive microwave data sets upon which it is based, is one example. The Sea Ice Index gives a daily image of extent as well as monthly products. However, these daily images are not meant to be used for climate studies or for inferring anything longer than seasonal trends. Satellite data are not quality controlled quickly enough; and for reasons explained in the Sea Ice Index documentation, the daily ice edge position can be off by tens of kilometers or more from the ice edge that an analyst would draw. Reasons include known errors in thin ice detection, bias in summertime concentration estimates, and the relative compactness of the marginal ice zone. See Partington et al. (2003) for an assessment of operational versus satellite-derived ice concentration.”
You are using this product in a way specifically called out by NSIDC as incorrect and fallible.
Nice to hear a different perspective on the ice melt. I would think the ice melting is a good result and should open new commercial shipping routes and allow oil, gas, and mineral extraction from the sea floor.
And I can show maps from 1600 showing open water. Doesn’t mean it’s accurate.
G.P. Hanner at 8:16 , good memory , the Columbia river froze over in the winter of 1949 . My wifes grandfather remembers it well as he was working in building construction by the river at that time and recalls it was some of the most miserable working conditions you can imagine. This occurred at Portland , Oregon .