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.
Phil Nizialek says:
September 7, 2010 at 2:03 pm
“Mr. R Gates, I certainly never meant to question your motives in presenting your evidence, nor your credentials as a lukewarmist. The bone I have several times tried to pick with you is your reliance for your views on a 30 year trend.”
_____
It is quite true that when looking at hard satellite data on Arctic sea ice, we can go back to only about 1979, before that, there were other methods, such as aerial analysis, etc. that gives us better than anecdotal information, and seems to show that sea ice has been declining longer than just since 1979.
However, it is not just the decline in sea ice that makes me a warmist. I look at the sum total of evidence to AGW, with specific predictions made by GCM’s, to lead me to my 75% “warmist” stance. The decline in Arctic sea ice is just one piece of the evidence (though admittedly for me, a big one). The other confirmatory evidence (for me) of CO2 induced AGW are:
1.The melting of permafrost and increase methane output from peat bogs in the arctic regions (wind is not a factor here, so the “wind did it” notion from skeptics doesn’t work for permafrost)
2. The acidification of the oceans
3. The cooling of the stratosphere
4. The melting of Greenland and Antarctic ice caps
5. The rise in ocean levels
6. The general rise in Global Temps over the past century
7. The general retreat of glaciers worldwide
8. The increase in ocean heat content in the past 30 years
Now, any one of these could be explained away through some other mechanism or natural variation such as the PDO, AMO, longer-term solar variability, etc, and some may be partially influenced through some of these other natural variations, however, it is the weight of all this evidence taken as a total, with the known solid physics behind the GH properties of CO2 combined with its 40%
increase in the atmosphere in just over 200 years that makes me think it more likely than not that GCM’s in general have it right about the effect of this rapid rise in CO2 (geologically speaking) and thus about AGW in general. If only one or a few of these events were happening, I would be less inclined to believe the likelihood of AGW, but I look at the weight of the total evidence, and from my perspective, it seems convincing. Arctic sea decline ice just happens to be one of the most visible and dramatic of the predicted effects, (it’s hard for example, to get a good visual grasp of ocean acidification).
“”” Phil. says:
September 7, 2010 at 7:56 am
rbateman says:
September 7, 2010 at 5:10 am
But, 31 years ago, in 1979 (oh what a convenient starting/ending date THAT is), all the rage was the Ozone Hole in the Antarctic with UV burning all life to a cinder, and the Coming Ice Age indelible proof of cyrogenic doom in the Arctic descending upon civilization.
Really, I distinctly recall that Farman et al. discovered the Ozone Hole in 1985! “””
Are you saying Phil, that 1985 is the first formal announcement of an “Ozone Hole” ?
I would have bet any money that the discovery dated from the IGY in 1957/8; but you say it was as recent as 1985. I must be wrong on that.
Actually; Ozone holes go back even before the IGY. I have a handbook of Optics that in the chapter on Natural Light Sources; deals with the sun as the most obvious natural light source.
The handbook points out that back as far as the 1940s and 50s, it was known that the apparent color temperature of the sun varied seasonally, and also randomly from one year to another. The handbook goes on to say that the changes in color temperature of the sun are attributable to changes in the UV end of the solar spectrum.
I suspect that as long ago as that, old sol was telling us that we had holes in the ozone; but they remained unknown until somebody looked for one and found it.
We’ve always had ozone holes; now and then.
Phil. says:
September 7, 2010 at 10:09 am
I see no reason to think that Maslowski’s analysis is wrong, in fact this year’s melt supports it, so summer 2013 looks rather interesting.
Yes, I agree.
Dr. Maslowski (of the Naval Postgraduate School ) actually predicted “sometime before 2020, perhaps as early as 2013”. So if it doesn’t happen summer of 2013, that doesn’t mean “no problemo” – that means it might still happen in 2014, 2015, 2016, 2017, 2018 or 2019.
I think Dr. Maslowski has a deep insight into the Arctic melt season – before him, many researchers concentrated mainly on the air temperatures, the winds, the Arctic Oscillation, the Arctic Dipole, etc. Maslowski used a finer resolution, regional model of the Arctic and found that heat advection from the Pacific and Atlantic, and the extra solar heating of ocean top waters when the sea ice area shrinks more each summer, was leading to a thinning of the Arctic ice pack – this thinning was accelerating this decade. Even before the wakeup call of summer 2007, Dr. Maslowski was finding that his models predicted a much faster “Death Spiral” than the more conservative, low resolution models that suggested 2050 to 2100 before the Arctic summer would be ice free.
http://news.bbc.co.uk/2/hi/science/nature/7139797.stm
(keep in mind, Maslowski considers essentially “ice free” to still contain a few 100,000 sq km of thick ice directly north of Canada and Greenland for awhile – this could take another decade or two to completely disappear in the summer, but the main damage will be done before 2020)
Arctic ocean temperatures are poorly measured, because standard Argo style floats can’t operate under the ice pack, and buoy and ice station data are expensive point sources – but there are new “glider” floats that can operate autonomously under the ice for extended periods, then find open water and upload their data to the Argo network. These are starting to map the temperature data of the Arctic Ocean in more detail. I think such studies, and the soon-to-be operational Cryosat-2 ice thickness data, will show in much more detail why the warming oceans of the planet (and the summer positive feedback albedo affects of sea ice –> open water) are leading to such rapid ice mass loss in the Arctic.
The predictions for 2011 will be based on much better sea ice thickness data – and hopefully much better Arctic Ocean upper-100-meters temperatures too.
Phil
I’m interested in old maps–do you have a source for your map of the Arctic ice from 1939? I didn’t see it on the science20 site, but would be interested in the source which said this was the minimum of extent and not just general schematic. Thanks in advance.
Phil. says:
September 7, 2010 at 1:51 pm
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.
http://en.wikipedia.org/wiki/Greenhouse_gas
-Scott
At this point this may be on deaf ears, but a couple things in response to Graeme W. I’ve stated this before, but some may not have seen it before. So hopefully for a final time:
1. Regarding the submarine surfacings at the North Pole during the 1950s. Sea ice is always in motion. When it diverges, cracks open up and there is open water. This can occur anywhere in the Arctic, even in thick ice. The cracks, called “leads” expose open water. In winter, that water will quickly begin to freeze, but the ice will be thinner – in that small region. The surfacings during the 1950s were in these leads. They are not an indicator of overall thickness of the ice and are not evidence of lack of thinning. All available evidence (including from submarine sonar data from under the ice) indicates that the ice is now substantially thinner over most of the Arctic compared to the 1950s.
2. Regarding the 1953-1978 sea ice extent timeseries in conjunction with the satellite record since 1979. These data have been combined to be as consistent as possible. This cannot be done perfectly and is not as consistent as just using the satellite data. However, the errors are relatively small and while we can’t be as confident in the actual trend value, we can be very confident that recent extents have been much lower than during the 1950s.
3. Regarding another comment about Antarctic extent trends and statistical significance. It take far longer than I have now to go into statistical significance in detail. In short, the Antarctic trends are statistical significant, but at a lower confidence level, and at a lower magnitude. Monthly trends in the Arctic vary between ~-3% (winter) and ~-11% (summer) per decade; in the Antarctic, the trends are between ~+0.5% (winter) and ~+4% (summer) per decade.
walt
Catastrophe : How ?
…IF the Ice melts off Early, Sun in the Arctic is 24-hour per day.
It actually gets MORE than further South.
Ocean Currents are driven by Energy so … they Reverse.
In Winter = No Sun, it gets COLD. Without the Warm current (which will take many MONTHS to arrive at a pokey 4 knots) the temps drop so far, either the Winds take over moving that much heat – – or the Air freezes & we get the winds anyway.
300 mph is from the Oceans weighing 1900 times the atmosphere — but current paths are twisty, so we end up with 300 mph.
a reader says:
September 7, 2010 at 3:02 pm
Phil
I’m interested in old maps–do you have a source for your map of the Arctic ice from 1939? I didn’t see it on the science20 site, but would be interested in the source which said this was the minimum of extent and not just general schematic. Thanks in advance.
I’d suggest that you check with Patrick Lockerby here:
http://www.science20.com/chatter_box/arctic_ice_september_2010
Interesting NP pictures:
Check some pictures from a few days ago and compare against this one.
http://www.arctic.noaa.gov/npole/2010/images/noaa2-2010-0906-234015.jpg
Is that open water on top right of picture??
All my analogy was meant to show is that just because the concentration of a substance is small does not mean that the effects cannot be large. C02 at 280 ppm still had a large effect on the temperature of the earth – 3 to 5 degrees, depending on which sources you read. This is enough to keep us out of an ice age.
Amino Acids in Meteorites,
If the earth warms over the next 10 years and the ice continues to decline, will you cease being a sceptic regarding global warming? For myself, I laid out a while ago what it would take for me to doubt that the earth was warming: if 6 years between 2009 and 2020 inclusive were cooler than 2008 (ignoring volcanos).
On the “from 1950 ice went down” topic — I find the half-Century “trends” barely larger than a SINGLE “freak” year:
(1) Cryopsphere’s 53 year decline from 10.3 (summer) to 7.8 in 2006 just BARELY exceeds the 2007 drop to 5.5 = near half the “trend” is a single “freak” year. — and that is at the most favorable site for a constant-slope Decline. http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.1900-2007.jpg
(2) Piomas (from 1950) implies a RISE in Ice until after the 60-year Pacific Cycle reversed in 1977 ). Then, a drop. (Submarine thickness Max was 1983 — Piomas has a higher peak in the 1960s, but that is 4 Volcanos, & should be disregarded) http://psc.apl.washington.edu/IDAO/retro.html
Not only is this “trend” thus mostly the NATURAL CYCLE, not AGW …
But the other (usual) PIOMAS Chart shows the Trendline from 1979, lost 9500 km3 by 2007, but as we know from ICESAT, 2007 lost 4000 km3 from the previous year (Piomas saw less of a change, but as discussed often before, cannot “see” Melt in the Central Arctic ), again, 2007 ALONE was nearly half the size of the total “trend” http://psc.apl.washington.edu/ArcticSeaiceVolume/images/BPIOMASIceVolumeAnomalyCurrent.png — (updated to Aug 31 AS I WRITE — but little change: -9500 Anomaly = ~ 4500 km3 left, a record low ).
Again, to summarize: I see “freak years” as at least as important to Climate, as Trends – – and far more Dangerous.
Turn out the lights … the party’s over.
With the rapidly dropping temp, refreeze may start early this year.
SteveSadlov,
It does not seem to be dropping any more rapidly than any other year and, according to here: http://ocean.dmi.dk/arctic/meant80n.uk.php is still above average, above 2006, 2005 and 2009 and about equal with 2007 and 2008. Further, at this time of year it is not atmospheric temperature but water temperature and winds that are the largest determinants of when the melt season will end.
According to here: http://www7320.nrlssc.navy.mil/pips2/idis.html, movement of the ice is still quite large.
According to here: http://polar.ncep.noaa.gov/sst/ophi/color_sst_NPS_ophi0.png and http://polar.ncep.noaa.gov/sst/ophi/color_anomaly_NPS_ophi0.png we still have relatively warm areas of sea water near the ice.
We are certainly near the end. But it might not be for two weeks or so yet.
Another 59K gone, provisional JAXA extent for the 7th = 5034219.
SteveSadlov says:
September 7, 2010 at 6:38 pm
Turn out the lights … the party’s over.
With the rapidly dropping temp, refreeze may start early this year.
Open the last keg and get your bathing suit on – the party’s still on, and the water’s warm.
JAXA shows another 59,062 sq km sea ice extent loss tonight – this September is just blowing away September 2009… it’s almost like the sea ice is extra thin or something.
http://img838.imageshack.us/img838/4530/arclatestlargecircles.png
Red circles – I bet skeptics didn’t expect that.
Yellow circles – expect some more melt here in the next two weeks, till the melt season is over.
Looks like the melt season will end with 4.xx million sq km of sea ice extent.
Walt Meier says:
September 7, 2010 at 3:22 pm
At this point this may be on deaf ears, but a couple things in response to Graeme W. I’ve stated this before, but some may not have seen it before. So hopefully for a final time:
============================
Your commentary about “deaf ears” is unwarranted.
[snip] Walt Meier has made it quite clear his responses and posting on WUWT is on an individual basis and not as commentary in his official capacity. …. LK [/snip]
Let me take an interlude here and say that I think you are a marvelous technician and scientist.
Where you lose me is when you start to recite the CAGW religious creed.
What death spiral? Nice covering up for the data splices, and the 1950s thing and especially the whitewash about the South Pole.
What death spiral?
The earth is 4.6 billion years old.
I am tired of the chicken little alarms.
They do nothing to help real environmental causes. Rather, they hurt them.
Chris
Norfolk, VA, USA
Anu says:
September 7, 2010 at 9:16 pm
So how much latent heat do you estimate is being taken on board? Good picture, what is the actual source?
Upthread there were many comments espousing that there is no trend in the mid-seasons of Arctic melt/recovery. This is quite wrong. For every single month of the year, the trend in sea ice coverage has declined over the last 30 years, with the most extreme trends occurring around summer.
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/
Click on any month, then click on any ‘plot.png’, and you will get a trend to date.
e.g May and December.
The comment “deaf ears” from Walt is accurate when it comes to saying things constantly at it being ignored, the classic this year was that the NW passage was closed even after about the 50th post showing it was not and that it was very much open.
Anyhow, agree with Anu, 4.xx is very much on the cards now. I’m not convinced about that latest BREMEN ice extent picture though, I think that open water near the pole might be spurious, I will see what tonights shows though.
NSIDC have done their montly update , http://nsidc.org/arcticseaicenews/ always good reading of course.
Points of note
1. “The Northwest Passage and the Northern Sea Route are largely free of ice” ( just for people who still thought it was closed this year .. 🙂 )
2. August decline per day was slightly lower than the 1979-2000 average.
3. The dipole anomaly returned with the classic southerly winds melting and pushing the ice together, this is still ongoing I believe.
Andy
” David Gould says:
September 7, 2010 at 4:55 pm
For myself, I laid out a while ago what it would take for me to doubt that the earth was warming: if 6 years between 2009 and 2020 inclusive were cooler than 2008 (ignoring volcanos).”
This is silly. If 6 years were slightly cooler and 6 much warmer, that would not indicate an absence of warming. And you better start with 1998, since that was the warmest year lately.
The point, by the way, is not that the earth (fortunately) has been warming since the Little Ice Age. The point is that this warming was natural and not man made.
May I remind the ice aficionados that Steven Goddard seems to think that “Frasier” was better than “Cheers”, and that he is trying something similar:
http://stevengoddard.wordpress.com/
I hope it will not be another “Ropers”
AndyW says:
September 7, 2010 at 10:31 pm
The comment “deaf ears” from Walt is accurate when it comes to saying things constantly at it being ignored, the classic this year was that the NW passage was closed even after about the 50th post showing it was not and that it was very much open.
Anyhow, agree with Anu, 4.xx is very much on the cards now. I’m not convinced about that latest BREMEN ice extent picture though, I think that open water near the pole might be spurious, I will see what tonights shows though.
The open water near the pole is real, it can be seen on the MODIS images, here’s a composite image from the other day (day 250, courtesy of Neven):
http://neven1.typepad.com/.a/6a0133f03a1e37970b013487143e1f970c-pi
I agree with your response re ‘deaf ears’.
Two Sites of Interest:
1. Calculating the Open Water in the “Pole Hole”: so correct AREA numbers down ~ 87,000 km2 (0.09 million) on the 5th, 74 K now.
Gee, I guess there is Open Water (near) the Pole.
Well, 24% open.
http://neven1.typepad.com/blog/2010/09/north-hole.html#tp
2. Central Arctic Basin 1981-2009 Area:
… All years lie in a very narrow band 2500-to-2720 K km2 except: 1986 + 80 K … 2008 – 80 K … 2007 -390 K
Long term trend ~ 2650 falling to ~2600 if you.ignore 2007.
A trend of 2 / year. Then a “freak” year, below the Trend by by 490 K.
= 245 times the trend.
Source: last page of: http://www.arcus.org/files/search/sea-ice-outlook/2010/09/pdf/regional/tivyjulyoutlook.pdf
http://www.arcus.org/search/seaiceoutlook/2010/august
PS: 2010 slightly below 2500K: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.1.html
Phil, you beat me to Neven –posted while I was writing. Watts & Neven are the best.