In the latest ARCUS Sea Ice Outlook, WUWT, Stroeve (NSIDC), and Meier (NSIDC) agree at 4.5 million square km. Whether those values turn out to be high due to the recent ice loss as a result of a strong Arctic storm which broke up a lot of sea ice remains to be seen. Here is the storm report from NASA:
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Image mosaic of Arctic storm. (Credit: NASA/Goddard/MODIS Rapid Response Team)
› Related image and story from NASA’s Earth Observatory
An unusually strong storm formed off the coast of Alaska on August 5 and tracked into the center of the Arctic Ocean, where it slowly dissipated over the next several days.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color mosaic image on Aug. 6, 2012. The center of the storm at that date was located in the middle of the Arctic Ocean.
The storm had an unusually low central pressure area. Paul A. Newman, chief scientist for Atmospheric Sciences at NASA’s Goddard Space Flight Center in Greenbelt, Md., estimates that there have only been about eight storms of similar strength during the month of August in the last 34 years of satellite records. “It’s an uncommon event, especially because it’s occurring in the summer. Polar lows are more usual in the winter,” Newman said.
Arctic storms such as this one can have a large impact on the sea ice, causing it to melt rapidly through many mechanisms, such as tearing off large swaths of ice and pushing them to warmer sites, churning the ice and making it slushier, or lifting warmer waters from the depths of the Arctic Ocean.
“It seems that this storm has detached a large chunk of ice from the main sea ice pack. This could lead to a more serious decay of the summertime ice cover than would have been the case otherwise, even perhaps leading to a new Arctic sea ice minimum,” said Claire Parkinson, a climate scientist with NASA Goddard. “Decades ago, a storm of the same magnitude would have been less likely to have as large an impact on the sea ice, because at that time the ice cover was thicker and more expansive.”
Aqua passes over the poles many times a day, and the MODIS Rapid Response System stitches together images from throughout each day to generate a daily mosaic view of the Arctic. This technique creates the diagonal lines that give the image its “pie slice” appearance.
In the image, the bright white ice sheet of Greenland is seen in the lower left.
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My best guess is that because of this storm breaking up ice packs, the September minimum will be lower than 4.5 million sqkm. The median of August ARCUS outlooks is 4.3, but the possibility exists that it will come in lower than that.
The value for the JAXA plot is similar:
And the most recent JAXA value for 8/13/2012 is 5,152,969 sqkm (data source here). More maps and graphs exist on the WUWT Sea Ice Reference Page.
Here’s the August ARCUS report compiled by Helen Wiggins:
With 23 (thank you!) responses for the Pan-Arctic Outlook (plus 5 regional Outlook contributions), the August Sea Ice Outlook projects a September 2012 arctic sea extent median value of 4.3 million square kilometers, with a range of 3.9–4.9 (Figure 1). The quartiles for August are 4.1 and 4.6 million square kilometers, a narrow range given that the uncertainty of individual estimates is on the order of 0.5 million square kilometers. The consensus is for continued low values of September 2012 sea ice extent. The August Outlook median is lower by 0.3 million square kilometers than the July estimate, consistent with low summer 2012 observed values. According to the National Snow and Ice Data Center (NSIDC), the arctic sea ice extent for July 2012 was the second lowest in the satellite record behind 2011; the ice extent recorded for August 1st of 6.5 million square kilometers is the lowest in the satellite record. Twelve of the contributions give a value equal to or lower than the 2007 record minimum (monthly average) extent of 4.3 million square kilometers.
Individual responses are based on a range of methods: statistical, numerical models, comparison with previous rates of sea ice loss, composites of several approaches, estimates based on various non-sea ice datasets and trends, and subjective information.
Again, we are comparing these Outlook values to the September average sea ice extent as provided by NSIDC. NSIDC is not the only data source for ice extent; their estimate is based on a long-term time series and we use their value as an operational definition.
Download High Resolution Version of Figure 1.
DEVELOPMENT OF SUMMER 2012 SEA ICE CONDITIONS AND RECENT WEATHER
The NSIDC time history for 2012 compared with previous years is shown in Figure 2. As noted in previous Sea Ice Outlook reports this year, sea ice extent in May started higher than several previous years and there were indications of increased thickness on the North American side. But late May and the first half of June had the Arctic Dipole (AD) Pressure pattern that is favorable for ice loss, resulting in a record trend in sea ice loss. At the end of June the AD was replaced by low sea level pressure. At this point, the sea ice loss showed more of a historical loss trend, but because of the low June value it has remained below the previous lowest value from 2007. The sea level pressure field for the second half of July and early August (Figure 3) shows that the low pressure centered along the dateline has persisted for most of the summer. This a a fairly typical historical summer pattern, if perhaps a bit stronger.
The pattern in Figure 3 is favorable for sea ice loss near the Canadian side of the North Pole and in the Kara Sea, but not in the Pacific Arctic as in previous summers. The recent NSIDC sea ice chart from 9 August (Figure 4) shows major open water areas in the eastern Beaufort Sea, East Siberian Sea, and Kara Sea, and a strip of sea ice continuing in the Chukchi Sea. These areas opened up quickly in the last few weeks. Also note the open areas within the ice pack.
Except for early June, the weather was not particularly favorable for sea ice loss in summer 2012 as it was in 2007 and some other recent years. Given the lack of meteorological support and several indications that the sea ice was rather thin, we note that thermodynamic melting of thin, mobile sea ice is now a dominant process, justifying the low sea ice predictions in the Sea Ice Outlook.
KEY STATEMENTS FROM INDIVIDUAL OUTLOOKS
Wang et al, 3.9 +/-0.3, Model
The outlook is based on a CFSv2 ensemble of 40 members initialized from Jul 27-Aug 5, 2012. The model’s systematic bias, forecast RMS errors, and anomaly correlation skill are estimated based on its historical forecasts for 1982-2011. The CFSv2 has shown long-term decrease of sea ice extent during the past 3 decades, as in the observation. The CFSv2 was also found to have some skill in predicting year to year variability at seasonal time scales.
Arbetter, 4.0, n/a, Statistical (updated 13 August)
Using conditions from week 30 of 2012 (ie August 1, 2012), a revised minimum Arctic sea ice extent of 4.03 million km2 is projected for the week of September 7, 2012. This is substantially lower than the earlier estimates, reflecting both lower than average sea ice extent used as initial conditions this summer and a persistent downward trend in sea ice extent over the past decade (and longer). The output continues to suggest 2012 will be at or below the previous record minimum September ice extent, recorded in 2007 and repeated in 2011.
Klazes, 4.0 +/- 0.7, Statistical
Extent is predicted by first estimating minimum ice volume for September. Using a linear minimum ice volume-extent model the extent is calculated. Only data up to 2011 is used. The method is statistical, based on mean September ice extent and minimum September ice volume (PIOMAS, Zhang and Rothrock, 2003).
Hamilton, 4.0 +/- 0.3, Statistical
A simple regression model for NSIDC mean September extent as a function of mean daily sea ice area from August 1 to 5, 2012 (and a quadratic function of time) predicts a mean September 2012 extent of 4.02 million km2, with a confidence interval of plus or minus .32. This supersedes an earlier year-in-advance prediction based on a Gompertz (asymmetrical S curve) model that used data only through September 2011.
Beitsch et al, 4.1 +/- 0.1, Statistical
The KlimaCampus’s outlook is based on statistical analysis of satellite derived sea ice area.
We introduced the following method: use of near-real-time (SSMI/S) sea ice concentration data combined with long data sets (SSM/I: 1992{2011), a time-domain _lter that reduces observational noise, and a space-domain selection that neglects the outer seasonal ice zones. The daily estimate of the September extent, the anomaly of the current day and a time series of daily estimates since May 2012 can be found on our ftp-server: ftp://ftp-projects.zmaw.de/seaice/prediction/2012/
Folkerts, 4.1 ± 0.2, Statistical
A variety of publicly available monthly data from 1978 forward (including area, extent, volume, regional extent, NCEP Reanalysis Data, and various climate indices) was collected. For each year, monthly data up to 24 months before the September minimum extent was organized and correlated with the minimum extent. Multiple regression analysis was also performed on a variety of combinations of these explanatory variables, seeking sets of data that correlate well with September extent, while trying to avoid overfitting. In addiction, analysis was also performed using the annual change in extent as the dependent variable (which, together with the extent the previous September, also allows predictions of the upcoming minimum).
Andersen, 4.1, n/a, Statistical
Same as last month.
Morison, 4.2, n/a, Heuristic
Same as last month.
Randles, 4.2, ± 0.7, Statistical
I use an average of two methods. One is as used in my previous submissions this year of a linear regression to predict the expected residual from a gompertz fit of September Extent using the residual from a gompertz fit of Cryosphere Today area. The other method is to calculate a weighted average of Cryosphere Today area and NSIDC Extent giving 1.5 weight to area. The difference between this and the NSIDC September average extent is calculated and estimated with a linear trend.
Naval Research Laboratory, 4.3 +/- 0.6, Model
The Arctic Cap Nowcast Forecast System (ACNFS) was run in forward model mode, without assimilation, initialized with a July 1, 2012 analysis, for nine simulations using archived Navy atmospheric forcing fields from 2003-2011. The mean ice extent in September, averaged across all ensemble members, is our projected ice extent. The standard deviation across the ensemble mean ice extents is an estimate of the uncertainty of our projection given we do not know the atmospheric conditions that will occur this summer. Please note, this is a developmental model that has not been fully validated in non-assimilative mode, but the assimilative system has been validated to provide an accurate ice forecast [Posey et al. 2010].
Netweather.tv, 4.3, n/a, Heuristic
The prediction method was based on a poll of Netweather.tv forum members. The question was “What do you think the MEAN September sea ice extent will be?” The mean (4,338,095km2) of the…votes was rounded to the closest 100,000 and used to form the prediction.
Lukovich et al, 4.3, n/a, Heuristic
It is hypothesized that the 2012 fall sea ice extent will attain values comparable to those of 2011 based on a heuristic assessment of sea ice and surface atmospheric dynamics, with regional losses governed by local wind and ice conditions.
Zhang and Lindsay, 4.4, +/- 0.4, Model
These results are obtained from a numerical ensemble seasonal forecasting system. The forecasting system is based on a synthesis of a model, the NCEP/NCAR reanalysis data, and satellite observations of ice concentration and sea surface temperature. The model is the Pan-Arctic Ice-Ocean Modeling and Assimilation System (PIOMAS, Zhang and Rothrock, 2003). The ensemble consists of seven members each of which uses a unique set of NCEP/NCAR atmospheric forcing fields from recent years, representing recent climate, such that ensemble member 1 uses 2005 NCEP/NCAR forcing, member 2 uses 2006 forcing …, and member 7 uses 2011 forcing…In addition, the recently available IceBridge and helicopter-based electromagnetic (HEM) ice thickness quicklook data are assimilated into the initial 12-category sea ice thickness distribution fields in order to improve the initial conditions for the predictions.
Keen et al (Met Office), 4.4, +/-0.9, Model
Same as last month.
Kauker et al, 4.5, +/- 0.4, Model
Sea ice-ocean model ensemble run – For a more detailed description we refer to our July report. The ensemble model experiments for the August outlook all start from the same initial conditions on July 30th 2012. The simulated daily ice extent for all 20 realizations of the ensemble is shown in Figure 1 from the initialization until end of September. Note that August and September atmospheric conditions similar to 2007 would result in a September minimum of 3.6 million km2 (thick black line in Figure 1). Atmospheric forcing similar to the years 2008 and 2010 would give a September mean of about 4.0 million km2 .The mean September value of the ensemble mean is 4.46 million kmÇ (bias corrected). The standard deviation of the ensemble is 0.38 million km2 which we provide as uncertainty estimate of the prediction.
Meier et al, 4.5, +/-0.3, Statistical
This statistical method uses previous years’ daily extent change rates from August 1 through September 30 to calculate projected daily extents starting from July 31. The September daily extents are averaged to calculate the monthly extent. Rates from recent years are more likely to occur because of the change in ice cover. Thus, the official projection is based on the rates for 2002-2011, yielding a September 2012 average of 4.47 million square kilometers; the range however is still quite large with a standard deviation of 335,000 square kilometers. Using all years (1979-2011) yields a slightly higher estimate of 4.66 million square kilometers, but a similar range of 337,000 square kilometers. Five out of the 33 scenarios (using rates from 1979, 1999, 2004, 2007 and 2008) would yield a new record minimum September extent. This suggests the chance for a record low this year is ~15%, though this probably underestimates the probability because recent years have tended to follow faster decline rates.
WattsUpWithThat.com, 4.5, n/a, Heuristic
Reader poll.
Stroeve et al, 4.6, range 4.1-5.2, Statistical
Same as last month.
Tivy, 4.7, +/-0.5, Statistical
A persistence forecast based on anomalies in July extent where the mean period is defined as the average of the previous five years. Persistence is a benchmark for more sophisticated techniques.
Kay et al, 4.7, range 4.0-5.7, Heuristic
An informal pool of 23 climate scientists on June 1, 2012 estimates that the September 2012 Arctic sea ice extent will be 4.68 million sq. km. (stdev. 0.32, min. 4.00, max. 5.70). In 2008, 2009, and 2011, our informal pool estimates of the mean September ice extent were within 0.10 million sq. km. of the corresponding observed value, making our informal method competitive with more sophisticated prediction efforts.
Canadian Ice Service, 4.7, n/a, Multiple Methods
As with CIS contributions in June 2009, 2010 and 2011, the 2012 forecast was derived using a combination of three methods: 1) a qualitative heuristic method based on observed end-of-winter Arctic ice thicknesses and extents, as well as an examination of Surface Air Temperature (SAT), Sea Level Pressure (SLP) and vector wind anomaly patterns and trends; 2) an experimental Optimal Filtering Based (OFB) Model which uses an optimal linear data filter to extrapolate NSIDC’s September Arctic Ice Extent time series into the future; and 3) an experimental Multiple Linear Regression (MLR) prediction system that tests ocean, atmosphere and sea ice predictors.
Wu et al, 4.7, +/-0.3, Model
Same as last month.
Blanchard-Wrigglesworth et al, 4.9, +/-0.6, Model
Same as last month.
Welcome back to the 1800’s:)
Oh ye with little faith :p
Fresh water freeze has begun and salt water will start by Friday. This summer year has been cool 80+ deg north. Nail-biting indeed.
Which only goes to show how utterly worthless such so called predictions are.
You would do as well, if not better, with a dartboard or a set of tarot cards.
As for meaning there isn’t any: the ice will do what the ice will do and there’s no doing anything about it.
As i have said before on this blog please wake me up when something exciting happens in the Arctic.
Such as somebody discovering the pot of gold at the end of the rainbow at the North pole. Or possibly Mr. Claus’s workshop. Or such like.
Whatever.
Kindest Regards
Very comprehensive post. I’m kinda worried about all the extra autumn heat loss from the open Arctic water, as that has led to brutal winters in UK recently.
“There have only been about eight storms of similar strength during the month of August in the last 34 years of satellite records. “It’s an uncommon event, especially because it’s occurring in the summer. Polar lows are more usual in the winter.” ”
8 in 34 years doesn’t seem uncommon to me – it seems more like a frquent event. 1 in 4.25, or a 23.5% probability of occurence in any August.
I expect the minimum will occur at a record early date because there’s no southern Atlantic-side ice left to melt in late August. The ice ridge from Alaska to Siberia looks robust, and once the temperature drops below freezing it will engender record gains in ice early in September — as long as that ice ridge does not melt out.
I am going to echo NZ willy’s comment and Intrepid wonders…the melt that is left is mostly due to weather conditions since in a week its too cold for farther melt to occur over most of the ice pack.
We will see more loss over the next couple of weeks obviously, but like last year this year appears to be similar in weather meaning that the minimum is a couple weeks away if not coming up. Sure, it could be close to a record, but time is running out as they say.
I thought all the ice was melted….? It’s 2012 isn’t it?. Yeah well. All the ice is melted. I don’t know why you people insist on saying that it is still there.
What we all need to do now, is to work out ways of saving the polar bears…… I was thinkin’ that towing up icebergs from the Antarctic would do it… Yes, yes, I know. But I’m too humble to allow you to fall at my feet in awe… Anyway about three million tug boats and a really big esky should do it… 🙂
This deserves emphasis:
Except for early June, the weather was not particularly favorable for sea ice loss in summer 2012 as it was in 2007 and some other recent years.
Not as favorable weather, but still 2012 is lower than all previous record years on all extent and area graphs.
I’ll bet on another year of record Arctic sea ice formation over the winter.
Although we aren’t supposed to talk about that.
Whatever it is, it will be unprecedented, dangerous and result in the watermelons grand plan accelerating.
Important statement: “Decades ago, a storm of the same magnitude would have been less likely to have as large an impact on the sea ice, because at that time the ice cover was thicker and more expansive.” This observation seems to portend more frequent occurrence of record breaking low summertime minimums in the coming years. And not too many years at that if this trend continues. I have to agree with those responses that question the viability of any model, physical or statistical, to accurately predict the ongoing transformation of the annual Arctic ice cycle. Does anyone really understand the detailed mechanisms causing this downward trend? Other than unsupported WA guesses?
As predicted by Piers Corbyn
http://twitpic.com/ahwlgh/full
and http://www.weatheraction.com/displayarticle.asp?a=481&c=5
[ http://youtu.be/7ei9xRJfIrg ]
http://twitpic.com/afchcl/full
looking forward to Willis scientific study of Piers solar-lunar technique
The early melting of ice that has occurred this summer within the Arctic has exposed more ocean surface to solar warming during the 24/7 arctic ‘day’. That thermal energy will have to be lost for winter freezing to occur, warming the air within the polar vortex.
This reduces the temperature differential between the Arctic and the temperate latitudes which in turn affects the position and stability of the jet-streams.
Weakening and movement of the jet-streams has significant effects on the subsequent weather at lower latitudes as the last couple of years have indicated. Extreme weather has not been the direct effect of warming, but of the weakening of the polar vortex and the meridinal temperature differential. What happens in the Arctic has strong effects on weather of the N American continent and N europe.
That is going to continue to disrupt grain and corn production raising food prices.
None of this was predicted by computer models, all of which grossly underestimated the speed and severity of the ice loss. It is clear that most of us will live to see an effectively ice free summer Arctic ocean.
Is anybody else a bit nervous about how far 2012 is below the +- 2 Standard Deviation lines in Figure 2, Historical arctic sea ice extents from NSIDC? When are we going to get back up to that region?
Is anyone else worried about how far we are below the +- 2 Standard Deviation area in Figure 2, Historical arctic sea ice extents from NSIDC?
8 in 34 years is much the same as once in every 4yrs. So hardly an uncommon event
Looking ar the sea ice reference page and the ocean reference page a few things stick out.
Arctic sea ice is below normal. Arctic air temperatures above 80 North have been slightly lower than normal this summer. Global ocean temperatures are mainly normal or below normal except those in high Northern lattitudes which are above nornal. Antarctic sea ice extent is above normal.
Once those Northern Oceans lose their excess of heat the amount of ice in the Arctic and thus total global sea ice which even now is only half below the mean than it was in 2007 could rise very quicly indeed.
“The Day After Tomorrow” – redux.
Where’s Roland Emmerich when you need him…?
Can someone please distinguish the loss of arctic icecover by melt from the loss of arctic icecover by shattering the icesheet through strong winds below the 15-percent-threshold for me?
Because from the data given, I can’t! IMHO, we are comparing apples and oranges here.
“I’ll bet on another year of record Arctic sea ice formation over the winter.
Although we aren’t supposed to talk about that.”
Try thinking about it first.
Winter sea ice cover has declined, but not as much as summer time sea ice loss (over the satellite record). If this pattern continues – summer time decline greater than wintertime – then the area of sea ice formation will continue to get larger, inevitably breaking records. This is what is expected to happen under the scenario predicted by the mainstream observers, where the Arctic pack becomes thinner over time. With a modicum of thought, it makes complete sense.
By all means, talk about it.
If the reported temperatures keep falling,
http://psc.apl.washington.edu/northpole/
Then it should make the coming re-freeze even more interesting than last year. Note, all of the melt re-freezes, the worry would be if it didn’t.
But, shhhhh, don’t mention that pesky place down South, the alarmists love to pretend doesn’t exist…
“or lifting warmer waters from the depths of the Arctic Ocean.”
Non comprende. What kind of physics is that?
Sure, I’ll talk about it: Ice remains at the North Pole area not because of the enthalpic inertia of melting it, but because it’s too cold to melt up there. If you magically removed all the Arctic ice in August, the Arctic Ocean north of 82 deg would re-freeze — yes, in August. To achieve an ice-free Arctic, the Earth must heat up even more than now. Alarmists say it will, skeptics say the Earth will cool because of the Sun’s quieting down. I’m with the skeptics, and expect the ice trend to increase after this year.
I’ll also repeat an earlier point about the importance of calibration of satellite data — the operators can get a wide range of results. Me-too-ism is playing a big role in where these curves are going. The DMI graph recently made a bee-line for a record low ice cover, but the operators pulled it smartly back before it got there — now it’s hovering at near-low levels and looks a right mess. Expect a clean-up soon, as DMI does. As the Arctic ice anomaly plunges, the Antarctic ice rises — the operators are hedging. Anthropogenic warming, indeed.
J Hansford – what a waste of diesel, those Antarctic icebergs will melt when they get warm (and anyway they’re an invasive species). I vote for giant inflatable white plastic bubbles to re-create the albedo effect and provide a safe haven for poolar bears. Might even make ’em full of holes like swiss cheese for the damn seals to come up and get whacked.