Figure 1
The post a few days ago on the Talkshop Could Instrumentation Drift Account for Arctic Sea Ice Decline? has led to a little discussion but also pushed me to take a brief look at sea ice, a subject where I spent some time, although before I started posting here. My loss of interest, was partly having found out as much as I was likely to and partly the parlous state of the data providers, a mess which continues. On top of that there aren’t many people interesting in the information side, is mostly armchair politics.
What I am now showing is all based on dataset d02135, monthly.
Extent and area follow each other quite closely, extent is used.
First for fun here is a plot as loved by NSIDC etc., one point per year by month, except I have put it all in one.
Figure 2
Figure 3
Nothing surprising. Might be useful for someone.
Now we come to the fun
Figure 4
I’d like to swear, resisted, what is going on? I know what is coming next. Waiting to see how things pan out there has been some kind of modal switch to much larger swings.
Opinion: In other work not shown here the drop in northern ice seems to fit with a rise is solar UV starting about start of solar cycle 23 but this is highly contentious. Let’s carry on with the next exhibit.
Figure 5
This was a shock, unexpected: to a large degree Arctic and Antartic sea ice extent have a complementary increase in excursions post 2007. What on earth is going on? This suggests a global effect.
It then occured to me to do something unusual. Repeat figure 1.
Figure 1
This suggests a step change in variation, confirming eyeball MK1.
I don’t know why. An observation based on work not shown, is it possible polar ice varies much more during low solar activity? This is not entirely off-the-wall because of the solar magnetic linkage into polar regions and of UV into the outer atmosphere.
Post by Tim Channon, co-moderator
Data appendix
Data ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/ which is used by NSIDC and my trust is low.
This is about as awkward is possible, including a cantakerous FTP server.
Data is in subdirectories by named month Jan etc., time series as month values in two files in each of the 12 directories, eg. N_01_area.txt and S_01_area.txt for Jan which contains both area and extent. Format is a bit strange. Note there are missing months with data omitted, not marked and compensation has to be applied to some early data, details in the file header text.
Alternatively trust me (I don’t). I have code which computes a conventional time series and also deannualised versions. Looking at the code I think it is using whole dataset mean.
As usual for WordPress the only practical data format is XLS, spreadsheet is here (1M) with all additional results.
Tallbloke's Talkshop 
On your comment:
“This was a shock, unexpected: to a large degree Arctic and Antartic sea ice extent have a complementary increase in excursions post 2007. What on earth is going on? This suggests a global effect.”
I have wondered about that for ages. It seems to me that if the NH is shrinking and the SH is growing, then it can’t be global temperature change driven by either the sun or CO2 (which presumably would effect both equally) but is something else.
For my puny brain it begs the question of whether the NH is getting slightly more solar radiation and the SH slightly less because the tilt has wobbled every so slightly. Obviously someone would know if that is the case or not .. but I don’t and I wouldn’t know where to start.
As you can gather this is a comment by a total ignoramous!!!! I still though would be interested to know the answer.
If I knew I wouldn’t be an ignoramus. 8)
The cancelling of the general ice extent north/south is long noticed, seasons mirror but the cancelling of the larger recent swings was new to me.
There is a north/south tilt in the air temperature data, both ground and satellite sensed. I think this is long term cyclic but that is a different subject.
Must be a shift in the Earth’s axis hmmm? 🙂
http://www.divulgence.net/solar_angle_variables.htm
Actually I apologise for that one, it’s a really bad one. I’m sure many of you have seen the increasing prevalence of commentary on the Interwebs about a shift in the earth’s axis, I thought this one was a fair representation of the breed. But maybe not. Anyways, it was for amusement value only…
What we are looking at in the Arctic at least is an abrupt change in seasonal ice extent beginning in 2007, with slightly more winter ice than before and a lot less summer ice.
I’ll be back if I can think of a reason why this should have happened 🙂
This dumb bunny layman asks: the land area of the planet is some 30% of the global surface. Most of that land is in the northern hemisphere. UV has more effect on water than land. Therefore any change in UV would reflect in a north/south effect?
Thanks, Tim, for a nice clear post of how Earth’s extremities are doing.
This shows that the Arctic is having an ozone crisis…
Unprecedented Arctic ozone loss in 2011
http://www.nature.com/nature/journal/v478/n7370/full/nature10556.html
Interesting that Arctic sea ice extend is doing rather well compared to recent years…
Despite temperatures oscillating well above the average…
http://ocean.dmi.dk/arctic/meant80n.uk.php
Not sure how good any of the above data is, but seems to show that the Arctic sea ice ‘death spiral’ is yet another CAGW myth.
The reasons for ice loss/gain in Arctic Ocean and around Antarctica are completely different.
The Arctic ice tends to be melted primarily by warmer water ingress to the Arctic Ocean under the ice past Spitzbergen which in turn is a delayed consequence of El Nino conditions in the Pacific as the warmer currents complete their journey from equator to pole.
Antarctic sea ice amounts depend on the air circulation around the Antarctic continent. There is a constant variation in the balance between winds whizzing around the Antarctic zonally or in and out of Antarctica meridionally.
The amount of sea ice around Antarctica depends on that balance.
Since the West Antarctic peninsula projects northward a zonal flow around Antarctica affects it more than the rest of Antarctica so even whilst the peninsula is losing ice then ice is being gained elsewhere due to less ingress of warm air which is what happened during the late 20th century warming spell with its more zonal winds.
Generally warmer oceans and stronger El Ninos are accompanied by more zonal winds so during warming spells the Arctic ice will reduce as a result of warmer water beneath it whilst Antarctic ice increases because the growth elsewhere is more than the loss in the West Antarctic peninsula.
Cooler oceans and weaker El Ninos give a reduced flow of warm water under the Arctic ice which then recovers but the more meridional winds over Antarctica causes losses around the entire continent to exceed gains on the West Antarctic peninsula.
I think the West Antarctic peninsula is a favoured exit route for cold air flowing out of Antarctica during periods of increased meridionality. The reason being the shape of the Antarctic land mass and the proximity of South America combining to configure the rotational wind flow to favour that exit route. Hence the semi permanent nature of the West Antarctic peninsula always projecting more to the north than the rest of the continent.
I should add that the level of solar activity seems to affect zonality/meridionality of the air circulation by exerting a top down influence on the polar vortices.
That in turn affects global cloudiness and albedo as I have mentioned elsewhere and so skews the balance between El Nino and La Nina.
So in light of the above findings I’m pretty sure that in due course we will have enough modern data to link it all together. Hopefully in accordance with my general proposals.
Looking at Fig 4 I would suggest the following:
i) A warming spell results in Antarctic ice increasing whilst Arctic ice decreases and the opposite for a cooling spell.
ii) The degree of meridionality / zonality is revealed by the size of the swings in both Arctic and Antarctic from year to year.
Is the data available to extend fig 4 back to say 1900 ?
I assume not if the data is satellite derived.
For the LIA I would expect to see large annual swings and Arctic sea ice proportionately higher than Antarctic sea ice.
For the MWP and Current Warm Period I think we would see smaller annual swings and Arctic sea ice proportionately less than Antarctic sea ice.
The switch between the modes being effected by changes in solar activity levels via ozone quantity variations at different levels in the vertical column of the atmosphere induced by UV variations and/or other chemical or physical interactions between the upper atmosphere and the mix of particles and wavelengths from the sun.
The intensity of the polar vortices and the extent of the surface spread of the polar air masses appears to be closely linked to some aspect of solar variability other than raw TSI.
We are currently in a transition period and all will depend on how long it lasts.
SW,
“Is the data available to extend fig 4 back to say 1900 ?
I assume not if the data is satellite derived.”
No, see Jonathan Drake’s post linked at the start. I am using exactly the same satellite originated data as NSIDC/NOAA which is normally used to scare the chickens. I don’t like the zig-zag plots, pretty pointless, about emotion, extremes. Sea ice is very regular, there is little abnormal variation.
A year ago I put a post up on my own neglected blog about annual the ice variation
which explains this is a combination of orbital movement and axis tilt, is very simple.
A plot from there
Strictly speaking the extent shown with the year variation removed is inaccurate on proportion, reckoned clarity beats pedantic. How exactly would this is be shown?
Thanks Tim.
You said this over on your site:
“(the solar magnetics tell a different story and why there is an underlying slower magnetic cycle)”
I wonder whether it is that underlying slower magnetic cycle that I describe and which amplifies or suppresses the machanisms that you describe ?
Fascinating, Tim.
Question. Do you ever see similar patterns in, say temperature data sets. I occasionally see data on blogs [just “looking at it” as William M. Briggs recommends :)], and say to myself “are those swings getting greater in amplitude and/or frequency, irrespective of the so-called trend?”.
I’ve never seen it commented on directly and I’m not familiar enough with all of it to make any comments.
http://www.earthweek.com/2011/ew110311/ew110311h.html
Is there any connection between the postion/drift of the North Magnetic Pole and northern polar ice?
Just a thought
@tchannon
Putting it all together, orbital parameters are affecting ocean currents.
Been a couple of emails flying with Roger Andrews who does more than a watching interest, so I expect he will comment shortly.
The reply to what he is about to say (see, we are ever so clever at the Talkshop, clairvoyant) the answer is yes there is an abrupt change in climatology (the annual cycle). I’d not looked, want other people thinking. As it happens I am exceptionally well placed to work on very short data, have developed the software, so I can work out what is different.
The major question is why the change?
pochas,
Yes ocean currents have been mentioned yet other things are haywire too.
Tim:
I’m just going to post the two graphs I sent you earlier
Interested parties can look at them and make up their own minds whether the sea ice extent records show an abrupt change in climatology in 2007.
@Roger / Tim…
Big change in Arctic 2007, not so clear that anything special happening then in Antarctic.
Perhaps the answer lies in ozone levels, or something(s) for which ozone level acts as a proxy, is/are the reason for the step change. Solar UV could be at least part of the answer. Difficult to know when dealing with non-linear systems, where trends can be interesting, but have no real meaning.
This is the difference in Arctic annual cycle.
Roger A: What do the scales on the Y axes of your graphs represent?
Tim: Old and new?
Tenuc: Looking at Bob Tisdale’s latitude graph at the top of the energy crossing the equator post, I’d say atmospheric changes are bigger than sea water chages under the polar cap. But we don’t really know what is going on under there, the data is extrapolated guesswork. Roy Spencer’s AQUA borne MSU readings for SST are untrending from 2004, though the quasi biennial changes are bigger swings, just as Tim’s standard dev plot shows. Maybe the big swings are indicative of a change in the climatology. Time will tell.
tchannon says: April 19, 2012 at 6:42 pm
It looks more like GISS data…
Drop some stations/pixels here…
Pickup some stations/pixels there…
Pick-up some late freezing “water” here…
Oops picked-up some late thawing “water” too…
But hey – it gives you a better plunge…
Altogether now: Wheeeeeeeeeeeeeeee
Tenuc:
No shortage of explanations for the Arctic ice retreat in 2007 (wind shifts, ocean current changes, the AO, the NAO, the AMO, ENSO events, a step increase in Arctic air temperatures in 2005, a decrease in Arctic cloud cover, or all, some, or maybe none of the above – some claim it was all caused by CO2). Haven’t found anything about ozone though.
TB:
Good question. KNMI don’t say what the units are. But comparing the graphs with Tim’s graphs shows that 0.1 equals about 1.5 sq km.
Whoops. Try 1.5 million sq km 🙂
Is there any chance that there are thermal vents to the West of Svalbard that effect the amount of melt in conjunction with the currents there? Just a thought from an ignoramous.
“Old and new”
1978..2007 and 2007 .. 2012
This is mainly an increase in annual amplitude and is huge for a parameter like this
12%
That said ~10% on data tends to go unnoticed and is small enough to be difficult for source location.
Not actually checked IJIS/JAXA which covers the change at daily, no doubt the answer will be the same. It is also from a different sensor, implying the change is real.
It was preceded by an unusual general ice lost, appearing at the start of recovery.
An amplitude change does not sound like a general melt, not a lot going on from that point of view.
We know that wind blew ice out of the Arctic near the start of this. Also warm currents have been mentioned.
Another possibility is that this is an effect of less old ice.
The south pole would cool quicker than the north pole for the simple reason that the northern hemisphere has the majority of exposed land mass, the north pole is an ocean and the south pole is a huge isolated continent, the highest of energy input from the sun would not be enough to melt the south pole, but as that energy input fell off, it would gradually accumulate more ice.
Roger Andrews says:
April 19, 2012 at 8:24 pm
“Tenuc: No shortage of explanations for the Arctic ice retreat in 2007 (wind shifts, ocean current changes, the AO, the NAO, the AMO, ENSO events, a step increase in Arctic air temperatures in 2005, a decrease in Arctic cloud cover, or all, some, or maybe none of the above – some claim it was all caused by CO2). Haven’t found anything about ozone though…
Press Release – Increasing Antarctic sea ice extent linked to the ozone hole
“Increased growth in Antarctic sea ice during the past 30 years is a result of changing weather patterns caused by the ozone hole according to new research published this week (Thurs 23 April 2009).”
http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=838
Unprecedented Arctic ozone loss in 2011
http://www.nature.com/nature/journal/v478/n7370/full/nature10556.html
Interesting that Arctic sea ice extend is doing rather well compared to recent years…
Arctic sea ice extent now running above 1979 – 2006 monthly average.
Gave up looking at sea ice long ago. The whole thing is clearly hysteretic over multiple years and subject to huge amounts of noise from wind, currents, etc. You’ll go blind looking at that stuff! Mind you, the north/south thing is an interesting conundrum. I guess you’d probably need a couple of centuries worth of data of far better quality than anything we have now to make any sense of it though.
Tenuc
Good spot on the ozone papers. I was particularly struck by the following comment from the BAS:
“While there is increasing evidence that the loss of sea ice in the Arctic has occurred due to human activity, in the Antarctic human influence through the ozone hole has had the reverse effect and resulted in more ice.”
So no we know the answer. More ice is caused by less ozone and less CO2 and less ice is caused by more ozone and more CO2. And ozone and CO2 levels are both controlled by human activities, so the solution is in our hands.
But what solution do we adopt? Do we continue with business as usual and watch the ice go away, or do we repeal the Montreal Protocol, emit more CFCs, save the ice, but get fried by UV radiation?
Can’t win for losing in this game. 😉
Quite so, an occasional look.
Something useful has come out of this but at the moment is very unclear. There might be a novel development, I’m up to something.
Roger Andrews says:
April 20, 2012 at 3:43 pm
Tenuc: …So no we know the answer. More ice is caused by less ozone and less CO2 and less ice is caused by more ozone and more CO2. And ozone and CO2 levels are both controlled by human activities, so the solution is in our hands…
If only it were that simple Roger… 🙂
Unfortunately there is little real evidence that CFC have much impact on ozone levels, and it is more likely that solar UV is the dominant driver of change. I think, as far as Arctic sea ice levels go ozone is not the cause, rather a proxy for UV or other solar energy driver.
Not sure how CO2 fits into the equation, unless you are using it as a (rather poor) proxy for polar atmospheric temperature? Here I suspect sea temperature is more relevant to the amount of ice, although level of snow and wind strength/direction are also important.
The Arctic ocean is a CO2 sponge with part of the mechanism the variation in gas solubility, then the biggie which is the start of the great ocean conveyor, the subduction zone drawing down whatever is in the cold water. One of the other ends is the middle north Pacific where the water surfaces and will bring gas with it. This is the chosen site of the single CO2 measurement station.
wikipedia
Expect more on this (a minor side point) in connection with a future article.
Tenuc:
I wasn’t serious. 🙂
“Unfortunately there is little real evidence that CFCs have much impact on ozone levels”. Not much doubt about that.
25 years ago in 1987 the Montreal Protocol banned CFCs because they were supposedly destroying the ozone in the stratosphere and generating the Antarctic Ozone Hole. But the Antarctic Ozone Hole still shows no signs of going away, and now it seems we have an ozone hole in the Arctic too.
But not to worry, say the scientists. Computer models show that ozone will have recovered by – well, the last time I checked it was by the middle of this century, but according to the BAS it’s now been put back to the end of the century.
And the Montreal Protocol is regarded as a success. A lesson there somewhere, I think.
Tim:
“This is the chosen site of the single CO2 measurement station.”
CO2 measurements aren’t taken just at Mauna Loa. They’re also taken at Christmas and Kermadec Islands in the Pacific, at La Jolla, California, at Barrow, Alaska, at Baring Head, New Zealand, at Alert, Northwest Territories and at the South Pole. All these stations record comparable CO2 concentrations.
Roger A: CFC’s… Read this:
http://cfc.geologist-1011.net/
Here’s a paper on an ozone depletion link to GCR’s. in Physics Reports 487, 141-167(2010)], Qing-Bin Lu has shown that there exists not only a clear correlation between cosmic ray intensity and total ozone in the polar hole, but also a nice correlation between cosmic ray intensity and stratospheric cooling induced by polar ozone loss.
Cosmic-ray-driven electron-induced reactions of halogenated molecules adsorbed on ice surfaces: Implications for atmospheric ozone depletion and global climate change.
“The cosmic-ray-driven electron-induced reaction of halogenated molecules adsorbed on ice surfaces has been proposed as a new mechanism for the formation of the polar ozone hole. Here, experimental findings of dissociative electron transfer reactions of halogenated molecules on ice surfaces in electron stimulated desorption, electron trapping and femtosecond time-resolved laser spectroscopic measurements are reviewed.
This is followed by a review of the evidence from recent satellite observations of this new mechanism for the Antarctic ozone hole, and all other possible physical mechanisms are discussed. Moreover, new observations of the 11-year cyclic variations of both polar ozone loss and stratospheric cooling and the seasonal variations of CFCs and CH4 in the polar stratosphere are presented, and quantitative predictions of the Antarctic ozone hole in the future are given.
Finally, a new observation of the effects of CFCs and cosmic-ray-driven ozone depletion on global climate change is also presented and discussed.”
http://www.sciencedirect.com/science/journal/03701573/487/5
(Full paper pay-walled)… 😦
RA,
Poorly worded, s/single/primary/
anon2nz says:
April 19, 2012 at 2:36 am
I have wondered about that for ages. It seems to me that if the NH is shrinking and the SH is growing, then it can’t be global temperature change driven by either the sun or CO2 (which presumably would effect both equally) but is something else.
As I recall Vuk has put forward an interesting series of plots that tends to show a correlation between polar ice change and the change in the earth’s magnetic field.
A huge amount of energy/particles reaches the polar regions depending on both the earth’s and the sun’s magnetic fields, which is largely ignored by climate science in their CO2 navel gazing.
Increased growth in Antarctic sea ice during the past 30 years is a result of changing weather patterns caused by the ozone hole according to new research published this week
The paper puts forward the theory that the ozone hole is caused by CFC’s and increases winds in the antarctic, while ignoring the evidence that CFC’s have no effect on the ozone hole. Rather the hole is a result of descending winds sweeping ozone out of the polar atmosphere, and thus an increase in winds increases the size of the hole.
“Rather the hole is a result of descending winds sweeping ozone out of the polar atmosphere, and thus an increase in winds increases the size of the hole.”
Exactly as per my proposition that solar variability affects the intensity and shape of the polar vortices.
Wunderful!
I’ve been code bashing, long story but I’ve just got a result. This was on the to-do list but put back as far too hard to do. (complex C program)
Here is first art, incomplete, lots of things not quite right, worked first time on the data.
This is the amplitude of the 1 year. Analyser software is doing what a filter can’t.
04:30, I am shattered.
I have a question, I seem to remember some where that during an ice age the arctic is reasonably ice free. The ice seems to move down to Europe and North America. Paleoclimate and archaeology seems to be in agreement. Must be a reason? I for one do not want the ice to go away it does not portend warming.
WJ, I don’t recall that one but a bald pate might make sense if precipitation varies, little at the pole.
On the other hand I have seen a pre-paper which implies temperatures were not lower, was uneven ice and more to do with dryness, perhaps messing up a proxy assumed to relate isotope ratio to temperature but also related to precipitation.
Evidence is eye opening. (wouldn’t be ethical to say what other than physical, what was and wasn’t but I have not had a chance to look at the data)
I’m not sure which thread to post this to so this will be a copy from the original thread.
Using the calculated trend from DMSP satellites relative to AQUA to correct the Arctic sea ice extent gives the following result:
http://www.globalwarmingskeptics.info/attachment.php?aid=472
Spent the day sorting the software, it works, much as shown above except the time axis is fixed. Too early to say whether it does useful things.
This confirms the original running std dev, caused as others pointed out by an increase in the amplitude of the annual ice cycle.
Jonathan has now shown (immediate above comment) a drift correction.
To me this raises more questions than provides answers.
Drift of what exactly? Why was this not noticed?
[…] Al riguardo c’è una interessante serie di immagini su Tallbloke. […]
Reason I am posting is a curious discovery. As part of a huge post which will appear soon I was comparing various datasets. On compare of sunshine hours against air temperature something unexpected turned up.
Compare with mean temperatures, zero match.
Compare with maximum temperatures and there is a noticeable positive correlation, makes sense, sunny, tends to be warm.
Compare with minimum temperatures and there is a less noticeable negative correlation. On immediate sight this is nuts but on thought it makes sense, if it is sunny it also might be cold clear weather including particularly cold at night. Not been confirmed.
Yet mean shows neither.
This will be very dependent on the exact data, in this case monthly, annual removed but otherwise as-is.
[…] Cullen: The Mystery of the…Joe Lalonde on Tim Cullen: The Mystery of the…tchannon on Strange things in the polar…adolfogiurfa on Tim Cullen: The Mystery of the…Michele Casati on Tim Cullen: The Mystery of […]
Sorry, posted this to the original thread but I guess this is more active now.
Partington et al 2003: http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1058&context=usdeptcommercepub
“Both chart data and passive microwave data show a negative trend in integrated arctic-wide concentration over the period 1979-1994. The difference between the passive microwave and chart trends is statistically significant only in the summer, where it is about 2 percent per decade steeper in passive microwave data.”
“Differences between the NIC ice chart sea ice record and the passive microwave sea ice record are highly significant despite the fact that the NIC charts are semi-dependent on the passive microwave data, and it is worth noting these differences.”
AQUA platform with AMSR-E was launched 2002 so that was not available to Partington et al.