Remember the famous claims about the ‘Arctic death spiral‘? It seems their language is a bit more realistically moderated now that they’ve blown a couple of forecasts.
Seasonal Arctic summer ice extent still hard to forecast, study says
Will next year’s summer Arctic ice extent be high or low?
Can ship captains plan on navigating the famed Northwest Passage—a direct shipping route from Europe to Asia across the Arctic Ocean—to save on time and fuel?
A new study says year-to-year forecasts of the Arctic’s summer ice extent are not yet reliable.
Scientists at the National Snow and Ice Data Center (NSIDC), University College London, University of New Hampshire and University of Washington analyzed 300 summer Arctic sea ice forecasts from 2008 to 2013 and found that forecasts are quite accurate when sea ice conditions are close to the downward trend that has been observed in Arctic sea ice for the last 30 years. However, forecasts are not so accurate when sea ice conditions are unusually higher or lower compared to this trend.
“We found that in years when the sea ice extent departed strongly from the trend, such as in 2012 and 2013, predictions failed regardless of the method used to forecast the September sea ice extent,” said Julienne Stroeve, a senior scientist at NSIDC and professor at University of College London. Stroeve is lead author of the study, published recently in Geophysical Research Letters.
“That downward trend reflects Arctic climate change, but the causes of yearly variations around the trend are harder to pin down,” said Lawrence Hamilton, co-author and a researcher at the University of New Hampshire. “This collection of forecasts from many different sources highlights where they do well, and where more work is needed.”
Arctic sea ice cover grows each winter as the sun sets for several months, and shrinks each summer as the sun rises higher in the northern sky. Each year, the Arctic sea ice reaches its minimum extent in September. Scientists consider Arctic sea ice as a sensitive climate indicator and track this minimum extent every year to see if any trends emerge.
Multi-channel passive microwave satellite instruments have been tracking sea ice extent since 1979. According to the data, September sea ice extent from 1979 to 2013 has declined 13.7 percent per decade. The recent years have shown an even more dramatic reduction in Arctic ice. In September 2012, Arctic sea ice reached a record minimum: 16 percent lower than any previous September since 1979, and 45 percent lower than the average ice extent from 1981 to 2010.
Long-term predictions of summer Arctic extent made by global climate models (GCMs) suggest that the downward trend will likely lead to an ice-free Arctic summer in the middle of the century. GCMs are in overall agreement on loss of Arctic summer sea ice as a result of anticipated warming from the rise in greenhouse gases this century.
Shorter-term forecasts of summer ice extent are harder to make but are now in high demand. The shrinking ice has caught the attention of coastal communities in the Arctic and industries interested in extracting resources and in a shorter shipping route between Europe and Asia.
Many of the forecasts analyzed in the study focused on the state of the ice cover prior to the summer melt season. According to the study, including sea ice thickness and concentration could improve the seasonal forecasts.
“It may even be possible to predict sea ice cover a year in advance with high-quality observations of sea ice thickness and snow cover over the whole Arctic,” said Cecilia Bitz, co-author and professor of atmospheric sciences at the University of Washington.
“Short term predictions are achievable, but challenges remain in predicting anomalous years, and there is a need for better data for initialization of forecast models,” Stroeve said. “Of course there is always the issue that we cannot predict the weather, and summer weather patterns remain important.”
The study analyzed forecasts from the Study of Environmental Arctic Change (SEARCH) Sea Ice Outlook, a project that gathers and summarizes sea ice forecasts made by sea ice researchers and prediction centers. Contributors to the SEARCH Sea Ice Outlook project employ a variety of techniques to forecast the September sea ice extent, ranging from heuristic, to statistical, to sophisticated modeling approaches.
The National Science Foundation and the Office of Naval Research supported the study.
Information
Download a copy of the study here.
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It seems their forecasts are great looking fifty years ahead, but not so hot for next year. But isn’t fifty years from now the end point of 50 “next” years? 20 years ago the IPCC had certainty at the 95% level that it would be 0.6 degrees Celsius warmer now, but still at the 95% level are forecasting an increase of 3 degrees Celsius for this century. Certainty just ain’t what it used to be.
Basically it’s an admission that a monkey throwing darts at a prediction board has as much ice forecasting skill as the NSIDC forecast. If they get it badly wrong, as they did the last two, they just claim the “anomolous year” excuse. Stroeve’s dependence on the GCMs all pointing to ice free summers is a lot like the What We Know alarmism, its based on models that didnt predict the 17+ year pause, and refusing is accept that failure.
In cognitive dissonance theory, there are 3 resolving behaviors: acceptance, denial, and deflection. Denial is where Stroeve is best described on the model failures.
The maxima are reasonably tightly grouped because the main constraint is the available area due to the shorelines. Whereas the minima are all over the map because a small difference in wind, precip, cloud cover and air temperature prior to and during late summer can manifest as a large change in the minimum area.
The alarmists seem to think (they certain imply it) that the Arctic Ocean is somehow supposed to be remain frozen solid all-year round…..
..except that wasn’t even true during the last Ice Age :
.http://www.sciencedirect.com/science/article/pii/S0277379103003494
LOL !!! ;-D
Interestingly, the sea ice extent looks like a convolution of the temperature record with a gaussian, rather than a linear fall off. If the global climate changes that were observed, barely, are explained by energy release from the ocean to the atmosphere, and we really have a step function in the atmospheric temperature due to that, then any effect on the arctic could well be delayed by some mixing time giving that kind of shape.
Pure speculation. But I am not planning on buying real estate in Hudson’s Bay.
Arno Arrak says:
March 28, 2014 at 10:55 am
“. . . the flow pattern of North Atlantic currents that started bringing warm Gulf Stream water into the Arctic Ocean. ”
This makes me think of the phrase ‘you can’t do just one thing’.
If Gulf Stream water is newly redirected into the Arctic Ocean, what else happened? Maps show a North Atlantic Current (NAC) and a Norwegian Atlantic Current and not much else flowing into the Arctic.
Some maps show the “Gulf Stream” (GS) transitioning into the NAC. Satellite views of the North Atlantic show the warmth of the GS not much north of Boston, MA and not much east of Saint-Pierre, NL.
http://www.weatheronline.co.uk/reports/wxfacts/Gulf-Stream-image.htm
Also, items #2 and #5 here:
http://www.nasa.gov/centers/goddard/news/topstory/2004/0415gyre.html
[just using this for the graphics, not asking about their text]
It isn’t clear to me what changed, or why, and how this is reconciled with the “can’t do one thing” proposition.
Laugh all you want.
I am gonna kayak to the North Pole this year, for sure. The real North Pole. Just you watch. We’ll see who’s laughing then.
Sea ice volume is rather easier to predict though. While extent is highly variable from year to year, the long term trend is pretty clear, and ultimately that is what is most relevant.
dikranmarsupial,
Most relevant to what?
The future Arctic sea ice extent, obviously. Variation from year to year has no long term effect, a long term trend on the other hand does.
The Last Democrat:
Sure you can.
Put wheels on the kayak, spikes on the bottom of each paddle blade and off you go.
Still pretty warmist a report. The question – will the NW passage be navigable? With 5m+ thick ice barring the western end and a lot of 4m ice in the channel, it doesn’t look too promising.
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictnowcast.gif
It’ll be interesting to see what the owners of the yachts trapped last summer do this summer. Will they back out or try to push through again? Will their crews be willing to show up for another go?
Anthony, they’ve underscored their anticipation of a summer Arctic free of ice and described their problem in projecting conditions as quite good under most circumstances, the few exceptions needing additional work.
I don’t know what article you read.
The Arctic is more or less limited by land, so the maximum extend is confined to the water between the landmasses. In that way it is no big deal if it eventually more or less disappears in the summer. The Antarctic is very different in that way as it has no upper limit.
Anyway it is more about wind, current and seatemperature, and not so much about any Global Warming.
I am curious about the predictions made by WUWT and how they compare to the scientists.
Looks like WUWT got it wrong in 2012 and 2013 too, just like the scientists did. In 2013 WUWT
reported 4.8 but the real value was 5.35. In 2012, WUWT said 4.6 but the real extent was 3.61.
But WUWT also got it wrong in 2011, their guess was 5.5 but the actual value was 4.61, but now scientists did ok.
So even though the study (if I’m reading it right) says that predictions do well if the observed value is consistent with the long-term trend, WUWT predictions don’t do well no matter what the ice does.
I for one am happy no one can predict what the ice does, that would make for a boring summer of guessing the minimum each year. Any one want to make guesses for this year?
JB
If someone paid me $150,000 per year I would try harder to help the WUWT average improve beyond the WAG I usually supply (actually, I use the mean of recent years – “regression to the mean” being a reasonable assumption. My guess for the 2014 minimum will be done in the same way. And, it will be wrong again.
No mention whatsoever that the 2012 minimum was due to a storm that broke up the ice and flushed it out. And they expect to be taken seriously? Ho-hum.
“Scientists consider Arctic sea ice a sensitive indicator…”
Do they consider Antarctic sea ice a sensitive indicator? If not, why not?
How about global sea ice as a sensitive indicator? (since the topic is global, not regional climate change)
Perhaps the trends in Antarctic and global sea ice are inconvenient to the “truth” they are seeking.
Here is a criticisim of Environment Canda and their weather reporting. Can the IPCC, UN and their cronys (NGO’s) be any better than this? Well at least its laughable.
Cheers
Roger
http://www.thedemiseofchristchurch.com
Re: rogerknights says:
March 28, 2014 at 2:17 pm
Which “yachts trapped last summer” were you thinking of Roger?
Caleb.
Some melt happens from below during the bottom melt
Portion of the season. The water temp under the ice
Is sampled with bouys.
Some melt happens from above.
And some ice is exported to warmer areas.
The causes of ice melt are varied. But one thing
Is clear. When the planet warms ,as it did in the
1930s ,as it did in the holicene,it warms more in the
Arctic than it does in the rest of the world.
That increase will over time melt ice not create
Ice. Year in and year out you will see wiggles.
But as we know from the Holocene as we know from
The mwp as we know from the the 1930… a warmer planet
Means less ice in the north. Warmer planet. Less ice in the north. Its not that mysterious.
What is mysterious is the rate of loss, the role other
Factors play, and the year to year wiggles.
The other mystery is why the south pole patterns do
Not follow the north pole patterns.
So we know a warmer planet means less ice in the arctic.
Beyond that. Lots of details to argue about.
There is no evidence that a warmer planet leads to
More ice in the arctic.
They are laying in on climate change as the reason for declining sea ice but they don’t provide the air temperature data to back that up. I think sea water is the culprit and the cause is far away in the non-polar Atlantic and farther south. I also think it is a temporary thing. This all becomes obvious when you look at the maps to see where the coverage deficits are.
Some things I’ve observed: The rate of ice growth and shrinkage (the slope) each season is fairly constant over the record. What changes each year is when this happens, and that is seen as a very clear trend. If climate were to blame the seasonal rate of change would change dramatically. The problem then is not that there is too much heat in the arctic air, but that the sea currents are drawing ice out and leaving the bare spots. That implicates ice breakers, too.
Finally, there is nothing sacred about the sea ice coverage in 1979 and the years following. The record is not long enough to say that period is above or below average, and we don’t have adequate sea and air temperature records to point to climate as a cause. “Arctic Death Spiral” is a political term that is intended to affect tax revenue and to micromanage humans.
A warmer planet means less ice in the arctic ??? The UsNavy seems to agree on that