This week was a true roller coaster ride with Arctic Sea Ice. It is best summed up by looking at the JAXA graph for extent, shown below:
Below, see the area of interest magnified.
I’ve added the 5 million square kilometer line for reference.
The roller coaster ride actually looked for a day like it might cross the 2009 line, but soon turned down again, ending this week at 5,142,813. Here’s the recent JAXA data
08,28,2010,5342656 08,29,2010,5352500 08,30,2010,5348281 08,31,2010,5329375 09,01,2010,5332344 09,02,2010,5304219 09,03,2010,5245625 09,04,2010,5192188 09,05,2010,5142813
Source: http://www.ijis.iarc.uaf.edu/seaice/extent/plot.csv
JAXA sea ice area has dropped to 2008 levels:
JAXA AMSR-E Sea Ice Area – click to enlarge
Sea ice concentration from JAXA:
While JAXA shows extent now lower than 2009, DMI and NANSEN plots show it to be about even. The differences in observing sensor/platform AMSRE -vs-SSMI and methodologies at agencies are in play.
Above: Danish Meteorological Institute Arctic Sea Ice Extent – 30% or greater. Note that while this graph shows 30% concentration at the cutoff point, it is valuable to compare.
Above: NANSEN Artic ROOS- Sea ice extent 15% or greater – click for larger image
The differences appear to be in the low end of concentration, the 15% to 30% range. It suggests that the brief gains we saw may be wind related, blowing floating ice around, compacting it when winds are strong versus allowing expansion when winds are weak.
Temperature, after holding near freezing, now appears headed sharply downward.
Above: Danish Meteorological Institute – Mean Temperature above 80°N
Some light refreezing may take place before the end of September, which could minimize the ability of wind to sharply change extent like we saw recently.
With all these variables in play, choosing a winner will be as much a game of luck as of skill. Based on what we’ve seen, it seems probable that it will come from the middle of the pack between 2008 and 2009.
From SEARCH:
The estimates from the scientific community range from 4.0 to 5.6 million square kilometers, with 8 of the contributors suggesting a September minimum below 5.0 million square kilometers, 3 contributors suggesting a minimum of 5.0 million square kilometers, and 5 contributors suggesting a September minimum above 5.0 million square kilometers. Two contributors forecast a September minimum below that of 2007 at 4.0 million square kilometers and 3 contributors suggest a return to the long term downward linear trend for September sea ice loss (5.5 to 5.6 million square kilometers). None of the contributors indicate a return to the climatological sea ice extent of 6.7 million square kilometers.
Including all 18 contributions gives a September ice extent minimum of 4.8 +/- 0.77 million square kilometers, with a range of 2.5 to 5.6 million square kilometers.
Individual responses were based on a range of methods: statistical, numerical models, comparison with previous observations and rates of ice loss, or composites of several approaches.
AJB says:
September 7, 2010 at 9:59 pm
So how much latent heat do you estimate is being taken on board? Good picture, what is the actual source?
A cubic meter of pure water is 1000 kg, sea ice will be slightly less depending on salinity, temperature. About 17 thousand of cubic kilometers of sea ice have melted from April to now, and the latent heat of water is 334 kiloJoules per kilogram. You could work out a fairly good estimate, but suffice it to say “lots of heat”.
University of Hamburg, Germany serves those images twice a day:
ftp://ftp-projects.zmaw.de/seaice/NEAR_REAL_TIME/Arc_latest_large.png
I just grabbed the most recent one and circled areas of interest.
savethesharks says:
September 7, 2010 at 9:35 pm
Your commentary about “deaf ears” is unwarranted.
He doesn’t actually think you’re deaf – he just thinks you won’t “get” what he’s saying. I know, those idioms are oblique.
Where you lose me is when you start to recite the CAGW religious creed.
Did people “lose you” when they said the Arctic sea ice would not recover this summer, and would be less than in 2009 ? Continuing the accelerating decline of Arctic sea ice summer after summer ?
http://tamino.files.wordpress.com/2010/07/pred2010.jpg
If you grasped that, just try it for another 6 or 8 summers.
Step by step.
You’ll get it.
http://soa.arcus.org/sites/soa.arcus.org/files/sessions/1-1-advances-understanding-arctic-system-components/pdf/1-1-7-maslowski-wieslaw.pdf
What death spiral?
That’s the spirit – keep asking questions. What jet stream movements ? What precipitation patterns ? What ocean heat content ?
I am tired of the chicken little alarms.
The actual data will be even more exhausting. Maybe you’re too close to all the bad news – plenty of people just ignore the whole depressing topic.
They do nothing to help real environmental causes. Rather, they hurt them.
Yes, I suppose enthusiasm for cleaning up the local beach for your kids might wane a bit in the face of a looming, possible global agriculture crash in a few decades, throwing all of Civilization into chaos.
Don’t worry, I’m sure people will wake up after the Arctic Death Spiral.
The Arctic Death Spiral just took another hit. The planet once again disagrees with the climate alarmists.
I also wrote a text answering Graeme W’s submarine meme, but it never showed up. Maybe it got stuck in the spam filter? OTOH, it was preceded by a slightly snarky comment, so maybe both were snipped.
Thank you, Walt Meier, for dropping in.
Anu says:
September 8, 2010 at 7:44 am
Did people “lose you” when they said the Arctic sea ice would not recover this summer, and would be less than in 2009 ? Continuing the accelerating decline of Arctic sea ice summer after summer ?
Interesting logic here – two years of extent recovery in 2008 and 2009 are just statistical fluctuation non affecting a downward trend, while a 2010 minimum that may (or may not) go below 2008 is trousered as “continuing the accelerating decline”.
This is “bobbing and weaving” regarding statistics and reference points. And not entirely honest.
OK it is still true that in the last 30 years, our favorite frame of reference, that Arctic ice decline is significant. Even he whose name shall not be mentioned (Steven Goddard) emphasised that even if the 2010 extent minimum was the highest of the decade, the downward trend would still be intact. This is trivial and is not the point. Non-CAGW climate scientists – i.e. those who heretically believe that factors other than CO2 might affect climate – and who (equally heretically) recognise cycles in climate, have an a priory reason to expect a climate and Arctic turn-around somewhere around 2004-2008. PDO cycles, phase relation shifts between PDO/AMO etc (e.g. Tsonis et al), solar system barycentric oscillation inflection in 2007, solar cycle length rate of change (Paul Vaughan), solar activity, just plain looking at the undulating climate temperature record, etc. etc.
In this context, signs of flattening / reversal of the Arctic “death spiral” since 2007 are important and significant – although another few years will be needed for any statistical significance. To argue “decline is still significant” relies on time period cherry-picking and misses the point. In the last 6 million years, starting from before the current glacial period, the Arctic trend is strongly upward. Equally irrelevant.
Climate scientists sometimes like to detrend data. One way to detrend or normalise Arctic ice curves would be to correct somehow for weather patterns – compare years with similar Arctic weather, to focus on the status of the ice itself. The Arctic dipole and sustained warm pole-ward winds have compacted the ice and increased melt this year. The same happened in 2007. 2007 was – like this year – at the start of a La Nina rebounding from el Nino type conditions (stronger this time than in 2007). With gyres of el Nino warmed water scuttling clockwise round the Pacific rim and eventually warming the Arctic (dumping their heat to space at the Arctic). So it may be arguable that the most relevant comparison with the 2010 extent curve is that of 2007. And I dont see many predictions of 2010 going below 2007.
At least we’re agreed on the agriculture crash, just differ on whether heat / cold will cause it. If cooling climate causes it, the warmistas will have no trouble bobbing and weaving to that it is what they were predicting all along (“when did I say anything about warming?”)
If you grasped that, just try it for another 6 or 8 summers.
Step by step.
You’ll get it.
Anu says:
September 8, 2010 at 7:44 am
“[…]Yes, I suppose enthusiasm for cleaning up the local beach for your kids might wane a bit in the face of a looming, possible global agriculture crash in a few decades, throwing all of Civilization into chaos.”
Need a bridge?
Scott says:
September 7, 2010 at 3:15 pm
Phil. says:
September 7, 2010 at 1:51 pm
“In that context N2 & Ar are zero contributors, O2 a trace gas, O3 a major component and CO2 the major component and water a major but variable contributor (remember we’re considering the whole atmosphere).”
I would agree with that except for water should be listed as the major component with CO2 in 2nd place as major contributor, rather than the other way around. Water’s variability (absolute humidity) makes calculations on this not so trivial.
Not for the whole atmosphere.
I think the melt minimum will occur this weekend. For example, the forecast for Resolute, Nunavut, Canada: http://www.weatheroffice.gc.ca/city/pages/nu-27_metric_e.html
Early next week mean temps will be below average. The freeze up will commence.
Updating the ensemble Arctic sea ice extent slopes (km^2/Day) of Bremen (8/26-9/8), JAXA (8/25-9/7), and NSIDC (8/25-9/7), the ensemble (combining the data from all three indicies) slope is -35K/Day (R^2 = 0.91).
Bremen, JAXA, and NSIDC all use the same 15% concentration cutoff definition, so combining all three should increase the confidence of the resultng ensemble slope (at least in the very short term of a few days).
For each individual dataset;
Bremen slope is -26K/Day (R^2 = 0.91)
JAXA slope is -32K/Day (R^2 = 0.93)
NSIDC slope is -46K/Day (R^2 = 0.99)
NOTE: Fitting a quadratic to either the ensamble or any of the individual datasets results in concave down trend lines at this time. The whole purpose of the ensemble was to try to detect a concave up composite trend line (in other words, another method of determining the magnitude and timing of the 2010 minimum).
The following sequence of hypothetical daily losses for the JAXA dataset is of very low probability (~ 2.3% at this time) but is consistent with the current ensemble slope;
-30,595 (9/8)
-30,154
-29,126
-27,922
-26,988
-26,367
-25,971
-25,238
-23,609
-20,946
-18,161
-14,972
-10,993
-6,415
-1,921 (9/22)
Final hypothetical extent = 4,707,812 km^2 (beating the 2008 JAXA minimum by one km^2)
YFNWG says:
September 8, 2010 at 9:31 am
I think the melt minimum will occur this weekend. For example, the forecast for Resolute, Nunavut, Canada: http://www.weatheroffice.gc.ca/city/pages/nu-27_metric_e.html
Early next week mean temps will be below average. The freeze up will commence.
More importantly, Barrow and Svalbard are both going to remain warm. Also, SSTs in the waters near the edge of the ice are warm yet – http://polar.ncep.noaa.gov/sst/ophi/color_anomaly_NPS_ophi0.png
Smokey says:
September 8, 2010 at 8:36 am
The Arctic Death Spiral just took another hit. The planet once again disagrees with the climate alarmists.
But perhaps the planet does not disagree with climate scientists… since those earlier ice loss estimates were much higher than the IPCC report numbers.
phlogiston says:
September 8, 2010 at 8:50 am
the last 30 years, our favorite frame of reference…
If your talking cycles (that they are somewhat longer than 30 years), how about ice extent since 1953-
http://nsidc.org/sotc/images/mean_anomaly_1953-2009.png
How about extent since 1900, 107 years?
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.1900-2007.jpg
jakers says:
“Boy, Gates, Anu, Neil, etc. sure seemed to have raised the ire of the regular readership, who apparently want an echo chamber site.”
That is nonsense. If this site was an echo chamber, contrary opinion would be censored out – just like it is on most CAGW blogs like realclimate, climate progress, etc.
If the ‘regular readership’ wanted an echo chamber, they would not have boosted the WUWT traffic count from zero to over 50 million hits in only three years, leaving those alarmist blogs in the dust. If this site was an echo chamber, it would never allow articles to be posted from folks like Dr Meier and other purveyors of the belief-based CO2=CAGW conjecture.
People very much want to hear all sides of the story — and they don’t get that from the media or from warmist blogs. Sorry jakers can’t understand the difference.
The ice is starting to look like a Canadian Maple leaf up there
http://www.iup.uni-bremen.de:8084/amsr/arctic_AMSRE_visual.png
I don’t really know how there can be such a large spike towards the East Siberian sea and yetbe melted to left and right, but it has. Looking at the Bremen ice loss movie it always seems to have a spike there, to greater or lesser extent, apart from 2007 when it got wiped out. Why does that segment of the Arctic basin nearly always have less ice loss? Very strange
Looking at the Bremen maps tonight Phil and Charles were right, it is surprisingly Swiss cheese like around the pole and also to towards Svalbaard. This backs up Walt’s claim about thin ice nowadays compared to the 1950’s. Sub’s wouldn’t have to look for leads it seems at the moment.
There seems to have been quite a lot of melt on the Atlantic side this year also.
Andy
No interesting logic needed, just maths. 2008 was below the trend line, and so was 2009, but only just. Take a look.
http://nsidc.org/images/arcticseaicenews/20091005_Figure3.png
2008 and 2009 values steepened the declining trend, despite being greater than 2007.
If the 2010 September average extent is under 5.25 million square km, then this year will also be under the trend line, and thus steepened. But the last few years are mainly about weather variations, and not much can be read into them for long-term trends. 2007 may have been a tipping point, step-change, or just an anomaly. Time will tell. If not this year, then one soon, the September minimum will fall above the trend line, but until we get a succession of years reversing the trend significantly, a few fluctuations are only going to amount to weather variation around an obviously declining trend.
My apologies for making you state something that you’ve stated before. I wasn’t aware of all of these details. I did see the comment on the website about how there appeared to be a good correlation between the two datasets, but I’ll admit that I found it suspicious that there seemed to be a change in trend around the same time as the change in dataset.
And your comments were definitely not falling on deaf ears here. When I ask questions, most of the time it’s because I realise there are things I don’t know. The major trick is dredging through the responses looking for the correct answers!
Data must be examined in context, and when data is taken out of context that it leads to confusion. You’ve provided the context for the submarine surfacing data, so thank you!
Confirmed JAXA 15% extent for Sept 6th: 5027188. Updated charts (late, busy day)…
15-day: http://img442.imageshack.us/img442/5673/15day20100907.png
7-day: http://img188.imageshack.us/img188/6019/7day20100907.png
The 15-day critical point has arrived and there’s not much doubt about where we’re headed now. Temps still appear to be on the high side. I suspect a major cycle regime shift is underway which may yet surprise even the warmists here, both this autumn and beyond. A while ago I posted this:
http://wattsupwiththat.com/2010/08/22/sea-ice-news-19/#comment-469245
Some more food for thought:
http://img828.imageshack.us/img828/515/thinkingoutloud.png
I don’t put much stock in chocolate tea-pots like R squared when derived from stochastic datasets, especially when hysteresis is present. They are what they are and should never be taken at face value. EFS_Junior correctly observes:
While I like this approach, it is likely to underestimate the eventual melt for a while yet IMHO but will gradually zero in. I look forward to daily updates with interest. Anu, many thanks for the useful link.
Alexej Buergin,
Picking 2008 as the year of interest is the key to this. If there is warming, we would expect 2008 not to be a minimum, given that it was a la nina year in the middle of a deep solar low. If 6 of the those years are lower than it, it would be a pretty clear indication to me that the world was not warming as predicted.
As for the argument being about whether the warming is human caused or not, that may be the case with some people. However, the person whom I was taking to, Amino Acids in Meteorites, says that the world is cooling. So, the first step in convincing them of the danger is to convince them that the earth is indeed warming.
Smokey says:
September 8, 2010 at 8:36 am
The Arctic Death Spiral just took another hit. The planet once again disagrees with the climate alarmists.
Do you even know what “Arctic Death Spiral” means ?
http://news.nationalgeographic.com/news/2008/09/080917-sea-ice.html
Oops: I meant ‘to be a minimum’.
barry says:
September 8, 2010 at 3:44 pm
.
.
.
If the 2010 September average extent is under 5.25 million square km, then this year will also be under the trend line, and thus steepened.
_____________________________________________________________
Actually, if we’re both using the same monthly NSIDC data set (http://nsidc.org/data/g02135.html), a value of 5.37E6 km^2 would maintain the current 1979-2009 September trend line slope.
It now appears (using seven days of NSIDC data and seven days of JAXA data and comparing to the 30 day JAXA September monthly averages) that the NSIDC 2010 monthly average will be ~4.9E6 km^2 (+/- 0.69E6 km^2 95% confidence), and will most likely be the 3rd lowest monthly average in the 1979-2010 NSIDC dataset.
Three out of four lowest years (2007, 2008, 2010) or four out of the four lowest years (2007, 2008, 2010, 2009) for the 1979-2010 time span is highly suggestive of something (e. g. very low sea ice volumes over the past four Arctic seasons).
phlogiston says:
September 8, 2010 at 8:50 am
Interesting logic here – two years of extent recovery in 2008 and 2009 are just statistical fluctuation non affecting a downward trend, while a 2010 minimum that may (or may not) go below 2008 is trousered as “continuing the accelerating decline”.
“Non affecting a downward trend” ? They are part of that downward trend.
See for yourself:
http://img204.imageshack.us/img204/3219/septemberminimums.jpg
2008, 2009 and expected 2010 data point are circled in purple – these are all just datapoints on the accelerating decline curve. Calling 2008 and 2009 “extent recovery” doesn’t affect the trend at all. Try calling them “icy yearnings for normalcy” – maybe that will slow down the Arctic Death Spiral.
“This is “bobbing and weaving” regarding statistics and reference points. And not entirely honest.”
Yes, sorry to confuse you with a simple graph.
OK it is still true that in the last 30 years, our favorite frame of reference, that Arctic ice decline is significant.
Or 32 years – our favorite unbroken series of satellite data.
Or 39 years – if you throw in the 1972 to 1978 satellite data (which had a gap, so is often not used – but University of Bremen still uses the early data in calculating its average):
http://iup.physik.uni-bremen.de:8084/amsr/ice_ext_n.png
Non-CAGW climate scientists – i.e. those who heretically believe that factors other than CO2 might affect climate – and who (equally heretically) recognise cycles in climate…
I don’t think you realize what climatology is. Both things are in basic climatology textbooks.
In this context, signs of flattening / reversal of the Arctic “death spiral” since 2007 are important and significant – although another few years will be needed for any statistical significance.
Maybe that explains the poll I mentioned above, where almost all “skeptics” at WUWT predicted 2010 minimum sea ice extent would be above the 2009 value – the prediction value given by Watts and Goddard was “another 500,000 km2 of Arctic sea ice recovery in 2010”.
As of right now, that bit of WishfulThinking was 772,500 sq km too high. More than 3/4 of a million sq km.
Think about that.
And the summer is not over yet.
Compare this to the trendline prediction – almost an exact fit.
One way to detrend or normalise Arctic ice curves would be to correct somehow for weather patterns – compare years with similar Arctic weather, to focus on the status of the ice itself.
Every summer has Arctic weather that is hard to predict – yet the sea ice extent keeps trending down. (Did I mention the trend is accelerating ?) There is a physical reason for this:
http://soa.arcus.org/sites/soa.arcus.org/files/sessions/1-1-advances-understanding-arctic-system-components/pdf/1-1-7-maslowski-wieslaw.pdf
Keep watching the Arctic this decade. Eventually you’ll have your “aha” moment.
IJIS extent has just gone below 5 million km2 and currently stands at 4,977,344 km2. I wonder when extent will stop dropping like a rock. Should be any day now.
Phil Nizialek,
“Sorry to offend, Mr. Djon, but I think you missed my point. I’ve read a bit here and there about what Mr Gore, Mr. Hansen and others propose to do about AGW. I guess I could be a bit lazy, not having read it all, and maybe I needed to be more clear that I find most such ‘solutions” to be, at least to me, far worse and unpredictable than the perceived problem. My hope was to generate a conversation on possible solutions, since many here seem to think any further discussion of the nature of the problem is futile.”
It wasn’t particularly offensive, just…. I’ll stick with lazy, even though I wouldn’t expect anyone to have read anywhere near all that has been written on the topic. After all, how are we supposed to get your point when you didn’t bother to express it but instead stated, inaccurately, that you didn’t know what solutions people are advocating be implemented? Even with your last post, you haven’t specified what proposed solutions you are aware of nor which you think are problematic and which, not included in “most” you presumably think aren’t problematic, nor what your objections are to the ones you think would be worse than the possible consequences of future AGW.
Phil. says: September 8, 2010 at 5:19 am
Not for the whole atmosphere.
Please elaborate.