The Sea Ice Monster: it's a scaly thing

That had me going for a second. I though there was a decrease in “Arctic sea lice”!

Isn’t this a moot point, I read on here that sea ice is recovering, so all these trendlines will eventually go flat and then slope upwards, no?

JB says:
May 24, 2010 at 3:38 am
“Isn’t this a moot point, I read on here that sea ice is recovering, so all these trendlines will eventually go flat and then slope upwards, no?”
Yep, as like most things in nature, one can expect to see a sine wave eventually.

Today's State Extremes
State Highs:
Tanana	55°F
Northway	55°F
Fairbanks	54°F
Nenana	54°F
Haines	53°F
State Lows:
Tin City	24°F
Point Lay	24°F
Shishmaref	26°F
Savoonga	26°F
Noatak	26°F

Now before we get all blasé about these long, long projections of meltdown: won’t somebody think of our children’s children’s children’s children’s children’s children? Also, we must remember that if previous (alarmist) trends are anything to go by, then we can safely assume that before too long it will be considered to be “worse than we thought” and that we’ll soon have to be worrying about our children’s children’s children’s children’s children. We must act NOW! And by “we” I mean “you” and by “act” I mean “pay.”

Joe Bastardi:
“The real turn in this will come in 10-15 years when the AMO joins the PDO with cyclical cold in tandem.”
So we’ll have to put up with alarmist bleatings for another 10-15 years? Groan!

So the IPCC is correct expecting the Arctic to be Summer ice free some time after 2050.

It´s the same with global temperatures, where the Y axis is always shown in 0.1 degrees increments, being really a straight line as in the present case, where any small increase in ice extent will straighten the curve.

I think 2007 was anomalous, and that’s why we are going to get an unprecedented (in the satellite age) 3 years in a row of minimum extent growth.
I’m still sitting on 6.0-6.2M for minimum this year. The concentrations in the central core are still holding up very well compared to any previous year you look at since 1980 for this date (tho 2009 is not availabe at Cryosphere to look at because of an issue they had last spring/summer). It’s the central core that actually matters for minimum, because that’s the only place ice survives past minimum in any great quantity. There are large swaths of the core that are still north of 80% concentration that were below 80% in 2006-2008 (for instance).

Is Arctic “ice extent” a measure of the surface area covered by ice, regardless of the ice’s depth, and therefore not a measure of the total amount of ice ? If so, what the researcher from the Naval Postgraduate School said seems reasonable:
“In the end, it will just melt away quite suddenly”
I would agree, since I have observed that a thin sheet of ice covering a pond can disappear quickly while a thick sheet takes a while to disappear.
I would agree with the continued gradual melting implied in the above graphs (e.g., June will be ice free in the year 2296) if the “ice extent” measure accounts for the depth or thickness of Arctic ice. If it doesn’t, the ice could be gone much sooner than the graphs imply.
While summers might see little or no Arctic ice in the future, I would expect the ice to be back in Winter , although thinner and possibly allowing navigation by ships during more months.

Why do scientists feel like they have to give these predictions in the first place?
There is not one single person with one single active brain cell that would believe any of it.
chance of rain tomorrow – 50%
25 named hurricanes this year
human population will be X by year X…………..

My in-laws bought a vacation home on the sound in NC in the 1980’s. Their house is built next to an ancient pile of oyster shells, built up over the past thousand years by natives who would canoe over to the island and have feasts until the colonists put a stop to that in the 1600’s. Between the house and the water’s edge is about 150 feet of marsh. My engineer father-in-law placed a white pole at the waters edge in 1985.
Today the pole is off the shore’s edge and completely surrounded by water. Some family members worry that errosion is going to take the house. He and I measured the distance of the pole to the shore and estimated a monthly shoreline loss of over one eighth inch! Wow, that sounds like a lot….over one eighth inch of errosion per month! But my father-in-law laughs because at that rate it will take almost 1000 years for the shoreline to make it to the back porch (which is near the 1000 year old garbage pile of oyster shells and broken pottery). So not only is the erosion rate meaningless in our lifetime it’s probably meaningless on the timescale of at least 1000 years since for thousands of years the shoreline has not exceeded the garbage pile of oyster shells.
Do you think it’s scarier to quote the erosion as one eighth inch per month, two inches per year, one millimeter per week, or one hundred and fifty feet in one thousand years?

and everyone knows warmers can’t swim or surf, they are scared of open water but like to talk about it.
Gore can’t swim, he wears a plastic puddle duck.

With alarmists, time scales aren’t the only things that are ridiculously short.

JB
So apparently you think that the Arctic will be ice free by 2008. Nice call.

Joe Bastardi wrote, “The real turn in this will come in 10-15 years when the AMO joins the PDO with cyclical cold in tandem.”
A question: Through what mechanism would the PDO impact Arctic sea ice? The PDO does not represent SST anomalies in the North Pacific, North of 20N. It represents the leading Principal Component of monthly SST anomalies in the North Pacific Ocean,
poleward of 20N. And before you say it impacts ENSO, the PDO lags ENSO. The PDO is, in effect, an aftereffect of ENSO, but it’s also impacted by Sea Level Pressure (and possibly volcanic eruptions), which is why it appears to have longer-term variability. Refer to:
http://bobtisdale.blogspot.com/2009/04/misunderstandings-about-pdo-revised.html
And:
http://bobtisdale.blogspot.com/2009/05/revisiting-misunderstandings-about-pdo.html
And:
http://bobtisdale.blogspot.com/2010/04/is-difference-between-nino34-sst.html
Second, the AMO may have peaked around 2005, which would mean the SST anomalies of detrended North Atlantic SST anomalies are dropping. And if we look at North Atlantic SST anomalies…
http://i40.tinypic.com/11j98bl.png
…we can see that they had been dropping for a few years, contributing less to Global Surface Temperature anomalies directly, and indirectly through teleconnections.
Second question: Isn’t it the fact that the variations of the SST anomalies of the North Atlantic are greater than global SST anomalies on a multidecadal basis that causes its contribution (or lack thereof) to global temperature, and not its sign?

I respect opinion of Joe Bastardi, but present ice is in much better shape compared to 2007.
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=05&fd=23&fy=2007&sm=05&sd=23&sy=2010
The biggest melt in 2007 was from the Bering strait side, which is well bellow normal now:
http://weather.unisys.com/surface/sst_anom.html

Even if the Northwest Passage were to become ice-free, it would not be evidence of man-made global warming. It could just as easily — and more scientifically — be explained by natural warming caused by the sun and ocean oscillations.
As Joe Bastardi points out, we won’t have to worry about an ice-free arctic. We’re now in a cool PDO (and moving towards a La Nina), the sun remains quiet, and there is a very real chance of a major volcanic eruption (Katla) in Iceland. In any event, we’re not looking at warmer temperatures over the next 20 or 30 years. In my humble opinion, we’re headed for a Dalton-like minimum.
You can read my recent story (link below) describing the climate events that may lead to the “The Triple Crown of Global Cooling.” Both Joe Bastardi and Joe D’Aleo contributed to the article.
http://www.examiner.com/x-32936-Seminole-County-Environmental-News-Examiner~y2010m5d19-Triple-Crown-of-global-cooling-could-pose-serious-threat-to-humanity

One thing for sure, the current interglacial will end, and the whole mess will be covered with several km of ice(lice?). And then what will we all do?
It’s been quite cold in Florida, the water has barely warmed in our pool. By this time it would normally be mid-80 degrees.
Scales need to be uniform, not designed to give the most fright per inch.

I originally posted this at Arctic Sea Ice news #6 but it actually belongs here since it looks at the bogus use of statistics with relation to Arctic Sea Ice.
There are natural cycles of about 60 yrs (ocean) and 200 yrs (sun), but we only have data for about 30 yrs so there is no way in heck we have a good handle on the natural variability or what the “true average is”.
The graph uses data from 1979 to 2006 to compute the average. This is less than the thirty years that cover 1/2 an ocean cycle (In my numerous statistics classes I was taught to always use a minimum sample size of 30.) SO what part of the relevant ocean cycles does the average cover?
This Wiki graph – PDO (1650 – 1991) shows the PDO was mainly in a warm phase for 1979 to 2006. A more recent graph from NOAA shows there were only three years with a strongly negative PDO included in the infamous “average”.
This article shows both the arctic oscillation and the atmospheric pressure over the north pole were mainly positive.
And again the North Atlantic Oscillation was also strongly positive through the period. Wiki NAO graph
The AMO went from negative to positive during the time period. Wiki AMO graph
The sun has also been in a more active phase during that time period sunspots as proxy Here is a more complete look at the subject of the sun’s activity and TSI over time.
Not only is the “average” used for comparison a poor proxy for the “true mean” given it does not include a sampling of all the natural variability, but the gray area signifying “normal” is only one standard deviation from the average. Only 68% of data are within one standard deviation of the mean. So that is meant to cause alarm and mislead too.
The gray area should be 2.5 STD or at least 2 STD since 95% of individuals will have values within 2 standard deviations of the mean. I am sure those constructing the graph know this and that is why they chose to use only one standard deviation.
The “system” has been accumulating “heat” for thirty years. We are at the top of the sine curves starting on the downward slope. However just like you can not stop and turn an ocean liner like you can a quarter horse, you can not expect the “system” to change directions in a couple of years. I have no idea what the lag time is but given the changes we saw in the weather patterns last winter, I think the weather will be different (and become colder and colder) in the next thirty years than the last thirty. The whole darn subject and the graphs are very misleading and designed to cause alarm.
To be complete the cosmic ray count during the period. Note how 2009 has the highest cosmic ray count during the time period shown (1965 to 2009).

barry
You must have missed this post from yesterday.
http://wattsupwiththat.com/2010/05/23/wuwt-arctic-sea-ice-news-6/

Very interesting, but the assumption is the trend will be linear, rather than look something like this: (very unsophisticated graph, but gets the point across)
http://www2.norwalk-city.k12.oh.us/wordpressmu/precalc/files/2008/12/math.bmp
And taking a look at this graph, (even with the modest recovery of Sept. 2008-09 added in), we see that the trend is not linear at all:
http://newsimg.bbc.co.uk/media/images/45146000/gif/_45146192_ice_extent_466.gif
An ice free Arctic in September of 2065 would be unprecedented in human recorded history, and would have lots of other implications.
Finally, even if we all agree that the Arctic will be ice free sometime this century, two other entirely different issues are:
1)Will that be an overall good or bad thing for humans and all the other creatures that we share this planet with.
2) What the cause of the melt is? Is it AGW, or natural cycles?

Meanwhile, skeptical science tells us that the Greenland land mass is showing accelerated elevation because of the decreasing weight of overlying ice mass. I wonder if anyone has looked at their claims – it’s getting difficult to know who to believe these days.

Gail,
There are natural cycles of about 60 yrs (ocean) and 200 yrs (sun), but we only have data for about 30 yrs so there is no way in heck we have a good handle on the natural variability or what the “true average is”.
If we only have 30 years data, how can you possibly assert there are 60 or 200 year cycles?

R Gates,
Why are you posting two year old links as evidence against increase since 2007?

The following Q&A from the FAQ section of NSIDC answers my question about whether the Arctic sea ice extent measures the the thickness of the ice as well as it’s surface area. It does not.
“What is sea ice extent, and why do you monitor that particular aspect of sea ice?
Sea ice extent is a measurement of the area of ocean where there is at least some sea ice. Usually, scientists define a threshold of minimum concentration to mark where the ice ends; the most common cutoff is at 15 percent. Scientists use the 15 percent cutoff because it provides the most consistent agreement between satellite and ground observations.
Scientists tend to focus on Arctic sea ice extent more closely than other aspects of sea ice because satellites measure extent more accurately than they do other measurements, such as thickness.”
http://nsidc.org/news/press/2007_seaiceminimum/20070810_faq.html

Steven Goddard, be careful you don’t dig too deep a hole for yourself. You’re reaching levels of arrogance I only see climate scientists being accused of.
If this summer’s circumstances in cloudiness and wind etc. are anywhere near those of summer 2007 the minimum sea ice extent record will be shattered.
As you (or anybody else) cannot be certain this won’t happen, I really don’t see why you are being so incredibly cocky. You’re recklessly gambling with your and WUWT’s credibility, or what’s left of it.
REPLY: Oh Neven, puhleeze. I read what you say elsewhere about me, WUWT, and its contributors. Your “concern” is bullcaca. – Anthony

Most of the current Arctic sea ice “loss” is in the eastern Arctic. How much of that “loss” is due to the wind blowing ice out of the catchment area?

OK, so if a linear trend is not to be expected, why so much stress on it in the post?
And if it’s not going to be linear, then what will it be? Logic would seem to suggest that the loss of sea ice will accelerate, for several reasons, but particularly increased water vapor (#1 GHG) with increased open water in the Arctic (water vapor feedback), and increased absorption of shortwave radiation by that open water (albedo feedback.)

R. Gates says:
May 24, 2010 at 8:06 am
Very interesting, but the assumption is the trend will be linear, rather than look something like this: (very unsophisticated graph, but gets the point across)
http://www2.norwalk-city.k12.oh.us/wordpressmu/precalc/files/2008/12/math.bmp
————————-
I just want to comment on the above quoted first paragraph of your post, rather than your entire post.
The linked graph implies a rapid disappearance of Arctic sea ice , as measured by its extent, once it becomes thin. That makes sense because the difference between, for example, 10 and 1 is greater than the difference between 1 and 0.
Since extent measures only the ice’s surface area, what do we know about changes in its thickness or volume that might suggest when it will become thin enough to disappear for part of the year?

Steve, for you to believe the sea ice decline is going to be linear makes me wonder what else you don’t understand about how climate works. And you also seem to conflate ice free summers with ice free Arctic. No one expects the Arctic Ocean to be ice free in winters. It is the summer ice cover that is going to disappear, resulting in a sea ice climate more like Antarctica.
I would love to see you address your recovery statements you made earlier in the sea ice posts. Seems you were wrong, yet you don’t want to admit it. Sea ice is not behaving as you had hoped, making your previous posts on assumptions about this summer incorrect. Makes me wonder more and more what else you are wrong about…

jcrabb says:
May 24, 2010 at 5:12 am
So the IPCC is correct expecting the Arctic to be Summer ice free some time after 2050.
_________________________________________________________________________
NO, Climate runs in cycles. We just went through a time with all the cycles set to positive (warm). We are now due for thirty years of COLD. That means 2040’s could be like the 1970’s. It all depends on what other cycles kick in and when. If the sun continues in a funk (the source of all energy) then we could be looking at a little ice age especially if the volcanoes like Katla kick in too.
Climate science is a very new science and the subject is complicated. What we are currently seeing is the political Spinmiesters taking advantage of this to pass laws that funnel money out of your pocket and into theirs. The fact is that most funding is for papers that have the global warming catch phrase.
<i”….A 12-year low in solar “irradiance”: Careful measurements by several NASA spacecraft show that the sun’s brightness has dropped by 0.02% at visible wavelengths and 6% at extreme UV wavelengths since the solar minimum of 1996. The changes so far are not enough to reverse the course of global warming,…” NASA
“….At least 10 to 30 percent of global warming measured during the past two decades may be due to increased solar output rather than factors such as increased heat-absorbing carbon dioxide gas released by various human activities, two Duke University physicists report…. However, they emphasized that their findings do not argue against the basic theory that significant global warming is occurring because of carbon dioxide and other greenhouse gases ….” Duke Physicists Report
Here is a study where the false finding reported make me very angry.
“….Americans are likely to suffer from kidney stones in the coming years as a result of global warming, according to researchers at the University of Texas.
Kidney stones, which are formed from dissolved minerals in the urine and can be extremely painful, are often caused by caused by dehydration, either by not drinking enough liquid or losing too much due to high heat conditions.
If global warming trends continue as projected by the UN Intergovernmental Panel on Climate Change in 2007, the United States can expect as much as a 30 percent growth in kidney stone disease in some of its driest areas, said the findings published in Monday’s Proceedings of the National Academy of Sciences. …” Global warming may increase kidney stones
This is very misleading. The real cause especially in the ” “kidney stone belt” of the southeastern states of Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee. “ is ICED TEA and other caffeine laden beverages. Drinking lots of WATER, not soda and ice tea is the correct method of prevention and this minor detail is completely missing from the article. GRRRrrrrr
There are plenty of other examples. Pamela Grey mentioned at the beginning of the year how the “global warming” phrase was the necessary “get out of jail free card” needed to get her papers published and she hoped climategate would mean it would be no longer necessary.

R. Gates
Great link thanks. It shows exactly why scientists shouldn’t jump to conclusions about non-linearity based on a one-year blip. I’ll bet the authors regret having written it now.

Wren,
I didn’t realize that plotting NSIDC data was arrogant. Perhaps it would be more reasonable to forecast an ice-free Arctic by 2013?

I hereby post the predictor of predictors for any required prediction, forecast, or seer:
Multiply the average PDO year times the mean square root square of ENSO moment plus the 2nd derivative of the AMO temperature minus natural log of the distance between any two planets at midnight zulu divided by three Solar Flare units plus the standard deviation regression rate of Greenland’s Ice pack squared plus last weeks sun spot number (choose wisely) times todays solar flux minus the first deviation of Antarctica ice pack times the low cloud on a clear day times the datum curve derivative of the first integration of the specific gravity of Guinness Stout plus linear motion of the total volcanic output times the time it took to post all the above remarks.

Steve writes: A different view emerges when you take the raw data from NSIDC’s web site and plot it on graphs with a more appropriate vertical scale. Done that way, the downwards trend for April ice is 0.039 million km²/year.
———————
Can you please tell me how the trend changes when you plot the extent from 0 to 20 million sq-km? It shouldn’t so your sentence above is very misleading. And why is this a more appropriate vertical scale? If you want to highlight interannual differences, plotting it on an appropriate scale is the right thing to do.
You seem to avoid mentioning the fact that the slopes are statistically significant in all calendar months, that not much change is expected in the winter ice cover (and thus the April trend being small is what is expected), or that no one expects the trends to remain linear, and in fact the data shows the changes are not linear.

stevengoddard says:
May 24, 2010 at 9:20 am
The reason that Serreze forecast an ice free pole in 2008 was because it started out with first year ice that summer. The lesson to be learned is perhaps that even first year ice won’t disappear that far north.
—————————–
Correct. And Serreze didn’t forecast an ice free summer, but simply thought there was possibility of open water at the pole in summer of 2008 because it was covered by first-year ice. So there is a lesson to be learned there…but I would expect as temperatures in the atmosphere and ocean rise further, that even first-year ice at the pole may not survive…

wildred,
http://wattsupwiththat.com/2008/08/15/arctic-ice-extent-discrepancy-nsidc-versus-cryosphere-today/#comment-32714

Mark C. Serreze says:
August 20, 2008 at 8:14 am
Looking back at earlier posts, a few things caught my eye which I might be able to clarify:
1) The north pole issue: Back in June, there was some coverage about the possibility of the North Pole being ice free by the end of this summer. This was based on recognition that the area around the north pole was covered by firstyear ice that tends to be rather thin. Thin ice is the most vulnerable to melting our in summer. I gave it a 50/50 chance. Looks like I’ll lose my own bet and Santa Claus will be safe for another year.

http://www.dailymail.co.uk/news/article-1050990/The-North-Pole-island-time-history-ice-melts.html

2nd September 2008
The North Pole has become an island for the first time in human history. Startling satellite pictures taken three days ago show that melting ice has opened up the fabled North-West and North-East Passages – making it possible to sail around the Arctic ice cap. The opening of the passages has been eagerly awaited by shipping companies which hope they will be able to cut thousands of miles off their routes. But to climate change scientists it is yet another sign of the damage global warming is inflicting on the planet. Mark Serreze, a sea ice specialist, described the images as an ‘historic event’ – but warned they added to fears that the Arctic icecap has entered a ‘death spiral’. The pictures, produced by Nasa, mark the first time in at least 125,000 years that the two shortcuts linking the Atlantic and Pacific oceans have been ice-free at the same time.

stevengoddard says:
May 24, 2010 at 10:02 am
skye
If the April slope is statistically insignificant, why did NSIDC include it in their sea ice news?
http://nsidc.org/images/arcticseaicenews/20100504_Figure3_thumb.png
You should take that up with them – because if it weren’t for that graph, I wouldn’t have had any reason to write this article.
——————————————–
It is statistically significant. When did I say it wasn’t? Just because it’s small, doesn’t mean it’s not statistically significant. Antarctic sea ice trends are small, but have recently become statistically significant and you point to them on a regular basis as evidence for no global warming.
BTW..NSIDC shows the monthly trends for every end-of-the-month post, regardless of how large they are. If they were not statistically significant, they would have stated so.

rogerkni
May 24, 2010 at 9:10 am
If we only have 30 years data, how can you possibly assert there are 60 or 200 year cycles?
She meant to say, “satellite data” on arctic ice extent. We have other data on the PDO.
There is data on Arctic sea ice before the satellite era (as we know, the further back in time we go, the more porous the instrumental record). But if that’s what Gail meant, it applies to other data.
It’s difficult, if not impossible, to reconcile various contributions at this site. The data is deeply flawed, we are told, but then people use the data to say all sorts of things with great confidence. Solar data is good in the satellite era, but before satellites we had to use our eyes (with some telescopic assist). Yet Gail asserts with confidence that there are 200-year solar cycles – something I’ve never heard of, and assume comes from, at best, some obscure paper. The PDO is a recently discovered climate phenomenon (1997), so we rely on proxy measurements to assess it’s variability through time. How confident should we be that we have that down, let alone correlation to the instrumental temperature record?
It seems to me that people pick and choose what data supports their position. Whatever uncertainties are inherent are completely ignored when the message suits the predilection. This is so for casual conversation in blogs. In the vast majority of science papers, uncertainties feature prominently. Acknowledging uncertainties lends credence to analysis. I wish we’d see more of that in discussions of the science in the comments section. We’re too quick to judge, too slow to reflect. Not always, but too often, IMO.

barry says:
May 24, 2010 at 7:30 am
“I thought the sea ice recovered last month. Back to normal was the message from WUWT. I see that all indicators show the sea ice extent has dropped below average and is now near 2007 levels for this time of year.
Can we get an update on whether it has recovered or not?….”
______________________________________________________________________
Barry it is a complex subject with a lot of factors. Air temperature (minor) ocean temperature (major) and most of all WIND. The wind blows the ice out of the arctic circle into the warmer seas where it melts.
Juraj V. presented some very nice pictures showing the ice extent in May 2007 (the year of the greatest ice melt) and May 2010. The color on the pictures shows the percentage open water vs ice in each area. Notice that the 2010 ice is all deep purple (100% ice) while the 2007 ice had lighter purple areas throughout. This indicates 80% ice/20% open water and the fact the ice was already breaking up. This means the wind could push it out of the arctic circle more easily.
Here is Juraj V. ‘s pictures: http://weather.unisys.com/surface/sst_anom.html

barry says:
May 24, 2010 at 7:30 am
“I thought the sea ice recovered last month. Back to normal was the message from WUWT. I see that all indicators show the sea ice extent has dropped below average and is now near 2007 levels for this time of year.
____________
Barry, Arctic sea ice EXTENT almost (but not quite) returned to the 30-year normal line in April, but that gain was almost entirely driven by a persistent low pressure system over the Bering Sea that created a great deal of new and very thin ice. Almost all of that March-April “bump up” in Arctic Sea ice was from this thin ice that formed, and now is just as quickly gone, and we are back once more to the very negative anomaly situation we’ve seen in the past few years (over 1,000,000 sq. km as of today). Also, those grand statements of a “recovery” were only looking at extent, and not volume, which is far more indicative and important to the long term condition of the Arctic sea ice. Bottom line…any insinuation that the Arctic sea ice had returned to some normal conditions would be misleading at best. (with normal being based of the last 30+ plus years of reliable data, and not pictures of submarines coming up) somewhere in the Arctic in the 1950’s)

R. Gates says:
May 24, 2010 at 8:06 am
“……An ice free Arctic in September of 2065 would be unprecedented in human recorded history, and would have lots of other implications. ….”
As a disgruntled Icelander mentioned a few weeks ago. Scientist keep ignoring Icelandic history in their claims of “unprecedented warmth.” You just did it again. The Norse history is recorded in their sagas and proof that the sagas were historic has been found.
Here is the Norse history:
The Norse in the North Atlantic
online features
The Fate of Greenland’s Vikings
Here are the Greenland temperatures:
Greenland Ice Core Data
Your are twisting the facts again.

Wren,
Sorry – I was responding to Neven and accidentally put your name at the top.

barry says:
May 24, 2010 at 8:15 am
Gail,
There are natural cycles of about 60 yrs (ocean) and 200 yrs (sun), but we only have data for about 30 yrs so there is no way in heck we have a good handle on the natural variability or what the “true average is”.
If we only have 30 years data, how can you possibly assert there are 60 or 200 year cycles?
_________________________________________________________________________
Super easy. The GRAPHS are for the scientific measurement of sea Ice in the Arctic they only go back to the mid 20th century, so THAT data is only available for about 30 years. Other information from proxy, not direct measurement goes back a lot further.
If you want to pick nits (or lice) how about this graph from Greenland that shows we are in a gradual cooling phase and the last thirty years is just a minor uptick? Greenland GISP2 Ice Core – Interglacial temperature

I believe that the arctic ice extent will hold up better than people think here. the ao is still going negative at the moment as it has been doing all spring.Every year we are told that the ice extent will crash ,this year is no different then.I will wait until September and see what happens.

I see what you write elsewhere

Good, I’m glad to see you’ve noticed. There will be more, as your MO is pretty transparent as well. And while you wait to see if this year’s Arctic sea ice gamble will be as lucky as last year’s, I will wait for all of your papers that support the extraordinary conclusions that were pre-released many, many moons ago.
REPLY: Yes the paper is coming, and in the meantime, you’ve accomplished nothing. You simply hurl insults while hiding behind anonymity, which makes you and your opinion of little value. Be a man, if you believe in what you write, step up there in Passau, Neven and put your name to it like I do. – Anthony

Joe Bastardi says:
May 24, 2010 at 3:48 am
Nature abhors straight lines, and there’s no extra charge for the noise embedded on the resultant sine wave.

stevengoddard says:
May 24, 2010 at 11:08 am
Mark Serreze has apparently placed his bet for 2010
May 24, 2010 Mark Serreze of the center forecast the ice decline this year would even break 2007’s record.
Except there is no direct quote, no link – where did they source it?

Anthony, I am surprised at your downgrading comments towards Neven. Why resort to such tactics? Can’t we just discuss the observations? And what those observations imply? The reality is that Steve was wrong in his earlier posts about this “grand” recovery. The negative AO did not bring about the recovery he had hoped for. Obviously we would all hope for a recovery, but that is not the direction the Arctic sea ice has taken in recent years, nor is it true for most climate state variables in the Arctic. The continued evidence of warming in the Arctic is clear, you see it in all the major climate variables. Why not focus on what is causing this warming instead of putting each other down.
REPLY: Neven is part of a small group of people who “play nice” here, then say the most horrible things about me elsewhere. Troll doesn’t do his MO justice as a description. Like many of his ilk, he does so anonymously, spewing his poisonous opinions without fear of being held accountable. Thus, he gets the label of “coward” and I make no apologies for doing so. He libels me elsewhere, but wants respect for his opinions here. This is the distorted self important view that he carries. I refuse to give him any respect until he debates on the same plane that I operate on, with the same risk of putting your name to your words. If you’ll read my policy page, you’ll see that I describe this as “my home on the Internet”. He’s not the sort of person I would invite into my home again because he has no honor and acts boorishly. – Anthony

R. Gates says:
May 24, 2010 at 11:31 am
“Gail, I really resent being accused of “twisting facts”, but I do appreciate you providing links to fables and stories of the past. There is nothing in any of what you gave me that proves or refutes the scientific claim that an Ice Free Arctic would be a unique event in recorded human history.”
Gail is correct, you are twisting the facts by omission.
It is ridiculous to deny the evidence from many sources that the North Pole has been free of ice on occasion in the past, and to assert that only the modern satellite record has any worth. Next you’ll be claiming that the Medieval Climate Optimum and the Little Ice Age did not exist in your efforts to support your failing beliefs.
There are no linear trends regarding climate metrics which are the output of processes driven by deterministic chaos. The amount of Arctic sea ice will continue to oscillate up and down in the future as it has in the past, despite your CAGW inspired prophecies of doom.
The quasi-cyclical nature of Earth’s climate is well illustrated here:-
1410-1500 cold – Low Solar Activity(LSA?)-(Sporer minimum)
1510-1600 warm – High Solar Activity(HSA?)
1610-1700 cold – (LSA) (Maunder minimum)
1710-1800 warm – (HSA)
1810-1900 cold – (LSA) (Dalton minimum)
1910-2000 warm – (HSA)
2010-2100 (cold???) – (LSA???)

Steve, thank you so much for showing a view of this data as it actually is. Just keep putting it up in articles like this, intellegent people will draw the correct interpretation.

A good cherry pick is this one:
“It has been cooling since 2002!”
Considering that, of the last four decades, each one has been warmer than the previous.

wayne says:
May 24, 2010 at 1:28 pm
Steve, thank you so much for showing a view of this data as it actually is. Just keep putting it up in articles like this, intellegent people will draw the correct interpretation.
————————————
It’s good to show the data as it actually is, but too bad Steve drew the wrong conclusions from it. BTW Steve, there is actually less multiyear ice in the Beaufort Sea this year than in 2007…so it’s not likely that the Beaufort Sea will be seeing any recovery. Perhaps the Chukchi Sea might…but then again, having old ice that far south is probably not a good thing.

I can see some people have their “satellite era” blinders on. It is a meme that is consistent among pro-AGW posters. Focusing on a minute section of a sine wave will not help you see what the sine wave looks like.

Tenuc says:
May 24, 2010 at 1:22 pm
R. Gates says:
May 24, 2010 at 11:31 am
“Gail, I really resent being accused of “twisting facts”, but I do appreciate you providing links to fables and stories of the past. There is nothing in any of what you gave me that proves or refutes the scientific claim that an Ice Free Arctic would be a unique event in recorded human history.”
Gail is correct, you are twisting the facts by omission.
It is ridiculous to deny the evidence from many sources that the North Pole has been free of ice on occasion in the past….
_______________
First of all, nope, I’m not “twisting” anything by any errors of omission. Secondly, an ice free North Pole, is an entirely different circumstance than an ice free Arctic, and there is not one shred of scientific evidence to show that the ENTIRE ARCTIC was ice free in recorded human history, as there would be no way of knowing that until the modern satellite era.
Thirdly, I think it will be most interesting to see how the AGW skeptics spin the story if the 2010 sea ice continues on its current trajectory…and goes back down towards the low set in 2007. What will they come up with this time?

jeff brown,
You have described a chicken and egg problem, suggesting that you can’t get multi-year ice unless you already have multi-year ice.

I did a quick “google” for Beaufort Sea and Ice breakers.
Amazing how many ice breakers have been there in the past few years. Every thing from studying polar bears, to oil and gas, military, to even studying the Beaufort Gyre.
Wonder if that many ice breakers, breaking up that much ice, with the prevailing winds………
……..could have had any effect

R. Gates says:
May 24, 2010 at 11:31 am
“Gail, I really resent being accused of “twisting facts”, but I do appreciate you providing links to fables and stories of the past. There is nothing in any of what you gave me that proves or refutes the scientific claim that an Ice Free Arctic would be a unique event in recorded human history.”
___________________________________________________________________
First Norse is a written language similar to Icelandic and therefore can still be read. Second there were Catholic priests in Greenland and a church starting with Eric the Red the founder. “Erik’s farm, Brattahlid .. revealed the remains of a church…” That is why it can be stated “…24 boatloads of land-hungry settlers who set out from Iceland in the summer of 986 to colonize new territory explored several years earlier by the vagabond and outlaw, Erik the Red…” This could be stated because of the catholic calender and a WRITTEN language.
Here is the actual comment I orginally referred to.
L says:
October 26, 2009 at 12:22 pm
Back in the ’60′s when I studied Scandinavian literature, the whole first semester was spent on Icelandic sagas, not just Snorri Sturluson’s masterful “Njal’s Saga,” but on others like the sagas of “Eric the Red” and “Leif the Lucky.” It is in these that we find Vikings visiting North America proper and meeting with a hostile reception from the “Skraelings,” surely Amerinds. These are great ‘reads.’
Lest anyone think these are mere myths, recall that in the year 1000, Iceland was, by far, the most literate and democratic country in the world, hardly fertile ground for growing fairy tales. The Icelandic “Althing” (935?) is the oldest parliament on Earth.
Anyway, back then there was no question about the loss of Greenland. Very simply, climate change. As the colder climate crept southward, agriculture had to be abandoned. At the same time, increased sea ice cut off contact with Iceland and the project was finished. Whether most of the Greenlanders fled back to Iceland in time is an open question, but those who didn’t were thought to have been overwhelmed by Inuit, also fleeing the advancing cold.
Some of the Norse may have been absorbed by the incoming natives, some simply massacred. Back in the ’60′s the end was thought to have come in the late 15th Century, ironically just about the time Europeans were ‘discovering’ the Americas for what, they thought, was the first time.
What’s of value is that the entire Greenland saga illustrates the undeniable fact of natural climate change of a major amplitude well within historic times and well before CO2 had even been invented. Nothing new under the Sun.
http://wattsupwiththat.com/2009/10/26/on-the-vikings-and-greenland/#comment-212035
Don E says:
October 26, 2009 at 10:16 pm
Also in the sagas are the routes taken to North America during a 300-year period to harvest lumber. They sailed north along the coast, crossed over in calmer waters and then headed south along the coast. The longer route was safer than the direct route with loaded cargo ships. That route would be very difficult today because of the ice. They could estimate latitude fairly well. Their description of the flora and fauna does not match estimated latitude in today’s terms. It was greener farther north 1,000 years ago.
http://wattsupwiththat.com/2009/10/26/on-the-vikings-and-greenland/#comment-212368
This shows we still have copies of church entries from that area in the 1100’s
http://sacredtexts.gang.pk/neu/nda/nda09.htm
You might then like to look at the Dorset people. It is thought the remnants of the Greenland Norse fleeing the re-glaciation of Greenland crossbred with the Dorset people to produce the unique Thule people, ancestors of the modern Eskimo.
The Dorset were wiped out because of the loss of sea ice. They hunted using holes in the ice and could not adapt to the warmer climate.
http://www.absoluteastronomy.com/topics/Dorset_culture
So recorded history – CHECK
major loss of sea ice – CHECK
2010-986=1024 or
2010-1121=889 Against the year 1121 we find the entry: “Bishop Eric of Greenland went in search of Wineland
Looking at the graph we find during that time span the temperature in Greenland is a full 2C warmer than today.
You are saying we are about to have an ice free arctic summer eminently because of global warming, so how can you say a 2C warmer Greenland in 889 – 1121 did not have an ice free arctic for at least a few summers or more likely most of the time???
Therefore during recorded history, of which we have at least some remnants, the probability of at least one ice free arctic summer approaches certainty.

wildred
What are you so frantic about? September will come soon enough and everyone’s cards are on the table.

Steve Goddard: September will be ice free by the year 2065
Steve Goddard: (Note that September 2009 was right on the trend line.)
Steve Goddard: And even more interesting to me is the fact that September, 2007 was really not that interesting. It was only 1.5 standard deviations off the trend line, i.e. almost following the 30 year trend.
That is interesting. September 2009 was not interesting. Neither was September 2007. Both were within 2sd of a decreasing 30 year trend. Decreasing ice extent is the new normal
You heard it right here on WUWT.

R. Gates;
Also, your assumption that the “thick parts got thicker” has no basis to it, especially this past winter of a negative AO index when the arctic was so warm as the cold air was pushed south>>
If its cold enough to make ice, then the thick parts got thicker. I’m talking close to the edge of the ice extent. Since sea water must fall to the freezing point right to the bottom before ice can form on top (unlike fresh water) the formation of ice on the surface implies that the water beneath and the air above were both at low enough temperature to support thickening. My point however stands. Rapidly increasing ice extent implies large grow of thin ice, and so we should expect that when the melt season begins we see rapid retreat that will slow as thicker ice is encountered. That’s why the JAXA graphs all seem to converge about this time of year. The real story won’t be told until months from now when we see how the combination of AO and falling OHC affect early winter ice formation.

Ron Broberg
Yes, it is very sad that Chicago and New York are no longer buried under a mile of ice.

Gail Combs said:
“What’s of value is that the entire Greenland saga illustrates the undeniable fact of natural climate change of a major amplitude well within historic times and well before CO2 had even been invented. Nothing new under the Sun.”
________
I certainly don’t dispute the fact of natural climate change of a major amplitude within historic times…i.e. the MWP. My original comment only referred to an ice free arctic. There is no solid evidence to support the notion that the MWP got warm enough to cause the whole of the arctic to be ice free. It would take a satellite image to prove that, as even Eric the Red, or Leif Ericson, or whomever, would have no way of knowing the condition of the ice across the whole of arctic. My point- that an ice free arctic would be unique in human recorded history is valid, and would be disputed by very very few experts, “warmist” or “skeptic”.

If an Arctic free scenario depends on increased longwave re-radiation happening somewhere, then for the Arctic to melt, you have three choices, one being in situ, the other 2 being externally sourced. 1) More re-radiation sourced IN THE ARCTIC itself from greater concentrations of CO2 THERE causing increasing atmospheric temperatures in situ thus melting the ice, 2) warmer ocean currents carrying warmer waters heated up by re-radiation from OTHER locations on the globe (IE stored heat) thus melting the ice, or 3) CO2 heated air circulating into the Arctic from OTHER locations thus melting the ice.
What is the mechanism for each of these and are the mechanisms plausible under Arctic conditions?

Please discuss only the mechanisms that would be more powerful than natural variations, such as natural changes in the PDO, AMO, and AO.

Sorry about the formatting last post.

Gail Combs says:
May 24, 2010 at 12:09 pm
I am amazed! You really were not aware of the 200 year solar cycles?!? It is called the the Wolf-Gleissberg cycle.

The Wolf-Gleissberg cycle I’m familiar with is usually described as an 80 – 100 year cycle. Half the references you cited concur with that (~80 year cycle). For example:

There are evidences for the modulation of the amplitude of the 11 year solar cycle in a period of about 80 years known as Wolf-Gleissberg cycle.

http://virtualacademia.com/pdf/cli267_293.pdf (this is the full online version)
While the Nature paper you cited posits a well-known ~200-year cycle, there aren’t many references for it – but I did read up some on this (called the De Vries, or Suess cycle). Thanks for the references.
[edit while composing post]
I was a bit confused by your description of the PDO as a 60-year cycle. It’s normally described as a 30-year cycle, in line with the phase shifts.
As for the Wolf-Gleissberg cycle, the last minimum was around 1997 – in antiphase with 20 years of global warming – most of that confirmed by satellite data. It would appear to have a very weak influence on climate. I note that your references (two by the same author) posit a climatic influence at the point of phase shift. I can see no correlation to global temperatures. Wolf-Gleissberg is described as a ‘weak’ cycle. The ~11-year (or ~22-year) sun spot cycle is described as a ‘strong’ cycle.

To add to my previous point the Arctic Oscillation is negative too, isn’t it?

Ron Broberg
Yes, if the NSIDC 30 year linear trend continues, the Arctic will have brief periods free of sea ice by the end of the century.
However, I don’t that is realistic. In 2008, the North Pole started out with first year ice, and it never melted. It will be very difficult to make the ice north of 85 degrees completely melt.

#
stevengoddard says:
May 24, 2010 at 8:55 pm
Ron Broberg
Yes, if the NSIDC 30 year linear trend continues, the Arctic will have brief periods free of sea ice by the end of the century.
However, I don’t that is realistic. In 2008, the North Pole started out with first year ice, and it never melted. It will be very difficult to make the ice north of 85 degrees completely melt.
————————–
Not unless SSTs continue to warm together with air temperatures. Also remember thinner ice is more easily moved around the Arctic, so it could also be transported away from the pole by strong winds, transported to more southerly locations where it could melt out. To assume that the North Pole will never melt out, would imply that you don’t think the North Pole has ever been ice free. Is that what you believe?

nedhead
Take a look at the SST map. Temperatures on the vulnerable Pacific side of the Arctic are running well below normal. Where is the energy going to come from to melt all that ice? The 2007 melt was fed by warm water coming through the Bering Strait.
http://weather.unisys.com/surface/sst_anom.html
Not going to happen this year.

slightly OT but I was looking at cryosphere where they have sea ice extent graphed by season since 1900:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.1900-2007.jpg
I expected the major NH temperature rise from 1920 to 1950 to show up as a decline in sea ice extent. Much to my surprise, fall and winter are both flat but sea ice from spring and summer appeared to have INCREASED year over year. Now I’d be really curious to know what processes made THAT happen!

Vincent says:
May 24, 2010 at 5:00 am
…. So we’ll have to put up with alarmist bleatings for another 10-15 years? Groan!
We’ve been hearing “alarmist bleatings” since before civilization really got rolling. The “END OF THE WORLD” is a perennially popular motif in fiction and in forecasts and was since before writing was invented: Christian myth, Norse myth, Mahabharata, Mayan myth, Aztec myth, the clock of the Bulletin of the Atomic Scientists… Humanity has a naturally apocalyptic bent. Maybe it allows people to adapt to change more readily when they are imagining how much worse it will be in a little while.

latitude says:
May 24, 2010 at 3:23 pm
I did a quick “google” for Beaufort Sea and Ice breakers.
Amazing how many ice breakers have been there in the past few years. Every thing from studying polar bears, to oil and gas, military, to even studying the Beaufort Gyre.
Wonder if that many ice breakers, breaking up that much ice, with the prevailing winds………
……..could have had any effect
_______________________________________________________________________
Just what I was thinking. Sort of like the difference between crushed ice and ice cubes in a drink.
I actually did a thesis on a similar subject. The amount of surface area exposed to the water was the biggest factor according to my repeated lab experiments.
Juraj V. ‘s pictures show the ice is more intact this year than it was in 2007. It will be interesting to see if that makes any difference this year.

R. Gates says:
May 24, 2010 at 5:06 pm
“….I certainly don’t dispute the fact of natural climate change of a major amplitude within historic times…i.e. the MWP. My original comment only referred to an ice free arctic. There is no solid evidence to support the notion that the MWP got warm enough to cause the whole of the arctic to be ice free. It would take a satellite image to prove that, as even Eric the Red, or Leif Ericson, or whomever, would have no way of knowing the condition of the ice across the whole of arctic. My point- that an ice free arctic would be unique in human recorded history is valid, and would be disputed by very very few experts, “warmist” or “skeptic”.”
________________________________________________________________________
Gates, these were seafarers and they hunted on the seas, of course they were aware of the sea ice.
“…..When the Norsemen arrived in Greenland, they had the island and its waters to themselves. Now they had to contend with the Inuit, who were competing with them for animal resources. This was especially true in the Nordseta, the Greenlanders’ traditional summer hunting grounds 240 miles north of the Eastern Settlement. For years the Norsemen had been traveling to the area; they killed the walruses, narwahls, and polar bears they needed for trade with Europe and for payment of Church tithes and royal taxes. They also boiled seal blubber, filled skin bags with the oil, and gathered valuable driftwood……Upright stones divided the cow stalls; a whale shoulder blade (white partition on right) also served as a divider…” http://www.archaeology.org/online/features/greenland/
“…The settlers found that the area to the north of the Western Settlement, called the Nordseta, was good for hunting, fishing and gathering driftwood. A stone inscribed with runes has been found telling that in 1333, three Greenlanders wintered on the island of Kingigtorssuaq just below 73 degrees north. There is also evidence of voyages to the Canadian arctic. Two cairns have been discovered in Jones Sound above 76 degrees North and two more have been found on Washington Irving Island at 79 degrees north….” http://www.mnsu.edu/emuseum/prehistory/vikings/Greenland.html
For you information Washington Irving Island is at the entrance to Dobbin Bay, eastern Ellesmere Island, Nunavut, Canada See themap and notice this area is well within the arctic circle and not that far from the north pole and certainly within the Beaufort Sea Gyro.

davidmhoffer says:
May 24, 2010 at 9:56 pm
slightly OT but I was looking at cryosphere where they have sea ice extent graphed by season since 1900:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.1900-2007.jpg
I expected the major NH temperature rise from 1920 to 1950 to show up as a decline in sea ice extent. Much to my surprise, fall and winter are both flat but sea ice from spring and summer appeared to have INCREASED year over year. Now I’d be really curious to know what processes made THAT happen!
___________________________________________________________________________
That graph does looks a bit weird. You might want to look at the temperatures from this http://www.greenworldtrust.org.uk/Science/Scientific/Arctic.htm

(Although as the earth moves into a glacial period, there is more precipitation at northern latitudes and at high altitude – this is what builds the glaciers and ice sheets, I guess.)

David Gould
Glacial periods don’t have a huge impact on the surface area of the oceans. The fact that there is more water “tied up in glaciers” shouldn’t make a lot of difference to the amount of water in the atmosphere. However, lower temperatures will reduce humidity.

Ulric Lyons says:
May 25, 2010 at 5:15 am
@Gail Combs says:
May 25, 2010 at 12:51 am
“the longer solar cycles given we maybe staring down the throat of a grand minimum.”
Don`t panic! The return of a Stuiver type minimum is from around 2120AD, and a stronger cluster of LIA type minmums from around 2450AD. ….
__________________________________________________________________________
I’m not I bought insurance, a farm in the south with a good water supply. (snicker) Actually after winters in upstate NY and NH, I just got sick of shoveling snow.
This by the way is a pretty good write up on the periods of NA glaciation and the climate for laymen NORTH AMERICA DURING THE LAST 150,000
YEARS
My farm was in a mixed forest area during glaciation 28,000-25,000 years ago.
Here is a really interesting find in Mexico they found ancient pollen inside the selenite crystals. http://ngm.nationalgeographic.com/2008/11/crystal-giants/shea-text

Few have responded to my proposed questions so here is one source to talk about ideas related to in situ causes of the oft heralded death spiral. Given this information, which variable(s) in the equation provided have changed in the last 100 years? And what was the source of that change?
http://nsidc.org/arcticmet/factors/radiation.html

Pamela Gray says:
May 25, 2010 at 6:43 am
Few have responded to my proposed questions so here is one source to talk about ideas related to in situ causes of the oft heralded death spiral. Given this information, which variable(s) in the equation provided have changed in the last 100 years? And what was the source of that change?
__________________________________________________________________________
Sun=> clouds, Sun=> ocean

This is a very entertaining post as it has brought many “warmests” out to comment. Hard for this hyper denialist to see the point. It seems there is a strain of northern hemispheric bigotry in this inceeasant line of argumentation, pro or con, about arctic sea ice extent. What of the south pole? A think an ET visitor might scratch his head a bit in wondering why there is such focus on one end of the earth.
How does 30 years of data have any meaning at all…to anyone? It seems much “science” can be done without logic or context interfering.
Above all, what does this have to do with AGW? Give me 500 years worth of similar data and maybe then I’d consider such scrutiny to have merit.

Phil. says:
May 24, 2010 at 7:49 pm
Measured downwelling longwave radiation in the vicinity of the N Pole from April to September is ~300W/m^2.
Do you have a reference for that data? It sounds quite interesting.

R. Gates
The net radiation budget from the Arctic is negative. It loses more LW than it absorbs SW.
http://earthobservatory.nasa.gov/Features/EnergyBalance/images/ceres_net_radiation_200809.jpg
http://earthobservatory.nasa.gov/Features/EnergyBalance/page3.php

The differences in reflectivness (albedo) and solar illumination at different latitudes lead to net heating imbalances throughout the Earth system. At any place on Earth, the net heating is the difference between the amount of incoming sunlight and the amount heat radiated by the Earth back to space (for more on this energy exchange see Page 4). In the tropics there is a net energy surplus because the amount of sunlight absorbed is larger than the amount of heat radiated. In the polar regions, however, there is an annual energy deficit because the amount of heat radiated to space is larger than the amount of absorbed sunlight.

Ulric Lyons
The critical angle of a water/air boundary is 48 degrees. Because the surface of the ocean is not completely smooth, you still get some absorption down to lower angles. By September, there is almost no solar energy being absorbed in the Arctic ocean.

Why does IARC-JAXA show sea-ice at 11,429,375 km2 while http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png clearly shows it above 12,000,000? Is this a graphing error or what?

“”” Phil. says:
May 24, 2010 at 7:49 pm
Measured downwelling longwave radiation in the vicinity of the N Pole from April to September is ~300W/m^2. “””
Phil,
Is that a clear sky value of down IR or is that with cloud cover ?
George

Re: stevengoddard on May 25, 2010 at 12:59 pm
Steve, you’re suffering the same bit of confusion I had a short while ago until I brushed up on my optics knowledge. The critical angle applies when considering a light ray going from a medium with a higher index of refraction to one with a lower index, in this case a light ray from the water to air. At greater than about 48 degrees from the normal you would get total internal reflection, the ray couldn’t leave the water. For light going air to water it doesn’t apply.
We’re used to seeing light bounced off of water at small angles, but part of what we’re seeing is polarized light, one component tends to get reflected (strongly polarized) while the other is transmitted (weakly polarized). Here’s a relevant article on Brewster’s angle.
This in several ways is a nitpick as very little light is going to get transmitted in any case at those angles, nearly all of it gets reflected. But it’s a scientifically accurate nitpick. Of course I fully expect you to correct me if I am in error about the optics or what you were actually saying. Actually I hope you do, as I wanted to kick myself for forgetting such details even if those university optics courses were a few decades in the past. 😉

Re: kadaka (KD Knoebel) on May 25, 2010 at 2:50 pm
(currently awaiting moderation)
Ah heck, while I was writing a reply, George E. Smith wrote a rebuttal article.
Oh well, so it goes. At least mine is a faster read. 🙂

So, which one of these parameters has changed folks? And changed in a trended way? And in a way significant enough to produce the increased melt? Is there more CO2 up there? Are there more clouds up there? Less clouds? Did we get warmer ocean currents from somewhere? Is the change in the perimeter to open water changing the net imbalance? Sounds like we are still in net negative imbalance so I ask again, what has measurably and significantly changed in the equation to cause the melt trend?
If you think it is CO2 related, you have to show increased re-radiation in the air or oceans (either in situ or brought there) that increased air or ocean temps above and/or below the ice. Has that happened? As far as the Arctic data is showing, ocean temps are not outside the normal range and air temps are not outside the normal range and match well with weather pattern variations. And we are still in a negative balance up there.
What has changed folks, what has changed. Don’t tell me albedo unless you have data.

schweinsgruber
It was a lot warmer in the Triassic, so I think it is safe to say that we are on a long term cooling trend. Of course it was a lot cooler 20,000 years ago, so it is also safe to say that we are on a long term warming trend.

Pamela Gray,
I did provide data. However, if you missed it, here is a relevant quote from it:
“Arctic amplification is a clear feature of the warming over the 1989–2008 period based on the ERA-Interim reanalysis (Fig. 1). We diverge considerably from ref. 8 in finding that the maximum Arctic warming is at the surface and that warming lessens with height in all seasons except summer. This vertical structure suggests that changes at the surface, such as decreases in sea ice and snow cover, are the primary causes of recent Arctic amplification. The trends at the near-surface (herein the atmospheric levels at 950–1,000 hPa) are 1.6, 0.9, 0.5 and 1.6 °C per decade, averaged over the Arctic (herein latitudes 70–90° N) during winter, spring, summer and autumn, respectively.”
from: http://www.nature.com/nature/journal/v464/n7293/full/nature09051.html
This seems to suggest, based on the expected profile of temperature changes from various causes, that albedo changes are driving the increased warming in the Arctic, and hence the increased melt.
This is why I think that the phrase ‘death spiral’ is indeed an appropriate one: as albedo decreases, the temperature increases, decreasing albedo …
You get the picture. 🙂
However, it should be noted that other papers, such as ones referenced by the above paper, come to different conclusions.

Pamela Gray,
It is not an abstract; it is the full paper.
I have not been able to find measures of albedo changes over time. However, the paper that I have referred to you uses a proxy measure – the temperature profile – to infer that it is albedo changes and not other things, such as the ones that you mention, causing the amplification of warming in the arctic.
As to what caused the warming that is being amplified in the first place, the global temperature is increasing due to human CO2 emissions. Normal heat transportation mechanisms, both atmospheric and oceanic, have transported this increased energy proportionately to arctic regions. I understand that that is not a popular theory around here, however. 😉

So you are saying that CO2 isn’t the cause in situ. It is heated air and water from greenhouse gasses elsewhere that is heating things up here and sending warmer water and air up there. Again David, what do the SST’s show? Data? What does the air temp data show for Arctic air? Data? I found only an abstract of the paper you mentioned and could not even see the references unless I gave coinage.
There are many public sources of information on SST’s and I don’t see anything unusual going on. I tend to see SST’s as less influenced by UHI affects, disregarding of course the larger oceanic floor heat vents, while land temp sensors are all fouled up around the Arctic. If SST’s aren’t showing anything unusual, why would I expect air temps to up there?
I follow SST data fairly closely and so far, SST’s increase or decrease in concert with known changes and mechanisms related to natural oscillations in upper Pacific currents, ENSO and AMO parameters. I also follow weather pattern reports in and around the Arctic. Arctic air temperature changes are in concert with changes in weather patterns.
How can you say that AGW is causing the temps to rise when by every account, the known parameters of natural variation in ocean and weather patterns are currently explaining temps? Are the oceans hotter than what would be expected under current ENSO and AMO conditons? No. Is the air hotter than what would be expected under current weather pattern systems? No. So it appears to me that there is no room for AGW to explain any part of what we currently are seeing. Is there a switch? Can its influence be turned on and off?

Pamela Gray,
I have to say that I cannot see how the increase in temperature can be explained by anything other than increasing atmospheric CO2, so we differ. I suspect your set of ‘every accounts’ differ from mine. 😉
It is odd that you can only see an abstract while I can see the full thing. Maybe my work provides a subscription that I do not know about.
Can you provide the SST data that you refer to in your post? If you follow it fairly closely and know that it increases or decreases in concert with known mechanisms, I assume that you have a source for it. Arctic air temperatures are, according to the paper that I referenced, increasing faster than global temperatures. This is what amplification is all about.
I will look for further information on arctic temperature change over time also.

Whoops: it is actually warming three to five times more in the arctic. Sorry about the error.

@ David Gould
It would appear that something is going on in the arctic to make the temperature trends there 50 per cent more than and double of the global trends respectively.
Greater warming at the Arctic is a result of a warming planet, regardless of the cause. It’s to do with heat transport polewards, as well as a cluster of large land masses nearby (different dynamics for the Antarctic). Same thing happens when the Earth heats up out of an ice age to interglacial. The polar/Greenland ice cores show more warming than proxies from low latitudes (more than twice as much). It’s nothing (or very little to do) with local CO2 accumulation, although, the CO2 effect is more pronounced simply because it’s not very humid over the North Pole. But this is a function of the horizontal structure of the atmosphere, not a function of localised accumulation. CO2 is not perfectly evenly distributed throughout the atmosphere, but the clustering is fluid. for all intents and purposes, CO2 is ‘well-mixed’.
Here’s a video representation of concentration dynamics.