Just remember this moment, Anthony Watts! Dunning Kruger in the Arctic.

Today, finally, Anthony Watts has written about the record low Arctic ice extent that is being observed in the Arctic (and Antarctic) (archived here). He copied and pasted a press release from the National Snow and Ice Data Center (with no link to the original, as usual). What I'm writing about is the weirdly ignorant comment he added at the top. Anthony wrote:

It’s weather folks, but do remember this moment the next time we get a record high Arctic sea ice extent, the same people that are caterwauling on Twitter right now about this will tell you that it doesn’t matter. 

Yep - just remember this moment

Oh my! Anthony won't see a record high in his lifetime. It's highly likely that no-one will -  for thousands of years at least. Even just going back over the satellite record, since October 1978, there hasn't been a high record in the average annual sea ice extent since 1982. (Data is here - and the spreadsheet is here) If you analyse the monthly records, most months have the record high recorded in the first year of observations - 1978 or 1979 - almost forty years ago. The exceptions are the months of: May (1985), July (1983), August (1983), and September (1980).

In other words, the most recent record high sea ice extent in the Arctic was in May 1985, more than 30 years ago! And that's just the satellite record. If you go back to 1953, except for January when the record high was in 1979, the latest monthly record highs were in 1971 or earlier - 45 years ago.

Time to look at the Arctic sea ice 2016

There has been some unusual weather in the Arctic again and it's even captured the attention of deniers. Arctic ice watcher, Neven, has been keeping a close eye on arctic cyclones and their impact, aided by other people who have built up some knowledge in the subject. They are wondering if these sort of events will happen more often than they used to. Earlier this year, in early spring, Arctic sea ice was at record low levels for that time of the year. It's not kept this place however it is still very low, being currently the third lowest on record for the time of year, just above 2007.

Anthony Watts is a blogging climate conspiracy theorist who tries to downplay climate change. He has built up a reputation in the dim corners of the internet for promoting "climate hoax" conspiracy theories and "ice age cometh" articles. Yes, even this year, during the hottest decade on record, and what will probably be the third in a row hottest year on record, and after ten "hottest months" on record, and the hottest ever month on record. As the world heats up relentlessly, deniers are looking crazier and crazier.

Most of the Arctic sea ice is on land and other WUWT musings

Arctic sea ice from 1953

 Willis Eschenbach has been wondering about sea ice trends of the past few decades. He's written a couple of articles but seems to me to be more interested in hiding the trends than exploring them. In today's article (archived here, latest here), he has used HadISST data from the UK Met Office Hadley Centre. I don't know why he chose that over the more often cited Sea Ice Index from the National Snow and Ice Data Center.  I think he's meant his title to this latest article to be sarcastic, in the way that the Dunning-Kruger set use sarcasm: "The Awful Terrible Horrible Global Sea Ice Crisis".

Willis decided to look at the data from 1974 only because he found that for Antarctica before that time there was not good data. Then he said he removed the seasonal component, which looks like he deducted something from each month. Since Willis used HadISST data, let's look at what the authors of the authoritative text on the subject found in the 2003 paper by Rayner et al:

Despite the winter ice, Rolf E Westgard's pants catch fire at WUWT

Why can't deniers just deny science? Some of them have to go further and make up stuff.

Today there's an article by someone called Rolf E. Westgard who's a petrol head as far as I can tell.  He's been featured here before, waffling on about clouds.

This time he's decided to see how many fibs he can tell in a single "guest essay". As with all good fibs, he skirts around the facts - quite a long way around. He mostly manages to avoid bumping into them.

On Antarctic ice: The ongoing ignorance of deniers at WUWT

Some people will put down the disinformation spread by Anthony Watts to him being plain dumb and ignorant. Others will say that he's not really as dumb as he looks and sounds, he's just deceitful and has made a business out of conning the ignorant.

I don't know where on the idiot-liar scale Anthony Watts lies.

These past couple of days Anthony Watts has:

• Complained that responsible journalists don't go to flat earthers for science
• Failed ocean chemistry
• Failed surface temperatures 101

Now he's claiming (archived here) that John Cook at SkepticalScience.com said that Antarctic sea ice is the result of the Southern Ocean getting warmer. He even linked to the web page where John Cook gave the following reasons for the increase in Antarctic sea ice:

1. the drop in ozone levels over Antarctica, resulting in stronger winds, which creates polynas, which freeze up and add to sea ice.
2. a change in ocean circulation with top layer of the ocean being colder and fresher, which freezes more easily than more saline water at the same temperature. It's colder at the top because of more snow and rain as a result of warmer air temperatures.

About increasing winter Antarctic sea ice and decreasing summer Arctic sea ice

Science deniers are making a lot out of the growth in Antarctic sea ice, mostly over winter.  Strangely enough they aren't accusing scientists of fabricating the data, for a change.

Here's a chart from The Cryosphere Today (not, as Anthony's ill-informed "guest" referred to it, Today Cryosphere or maybe just Cryosphere). It's hit a record high for this time of year - ie since 1979.

Source: The Cryosphere Today

The main reasons for the increase in sea ice are described very nicely in this thread on the Arctic Sea Ice Forum (h/t Neven). As AbruptSLR points out:

...on average the Antarctic Sea Ice Area is going up by 0.2% per year, and the average thickness is going up 0.2% per year, resulting in an average sea ice volume increase of 0.4% per year.  However, these numbers are orders of magnitude lower than the corresponding changes taking place to the Arctic Sea Ice.

I did this chart last year (you can read my previous article on the subject here, with some reading material about models not projecting the observed increase in Antarctic sea ice). I combined the Arctic and Antarctic at their respective minima to illustrate the point. That means I've put the September values in the Arctic with the February values for Antarctica. It's missing the latest years. I'll update it after September if I remember to do so. Click to see it larger, as always.

Data source: NSIDC

The big impact on climate is in the summer. It's summer ice cover that affects albedo, not mid-winter ice, when the poles are in darkness. (Not that there's any sea ice at the South Pole.)

As for why the sea ice in the southern oceans is increasing, AbruptSLR has this to say (and a lot more besides):

Denialist should be aware that not only is the average water temperature in the Southern Ocean increasing with time, but also the air temperature above the Southern Ocean is increasing with time, and the following linked research makes it clear that the most significant reason why the Antarctic Sea Ice is increasing is due to the formation of the seasonal Antarctic ozone hole after the mid-1980's created by anthropologically induced chlorides in the upper atmosphere over Antarctica; which in turn caused the circumpolar Antarctic westerly wind velocity to increase (see the following abstract for the influence of this increased wind velocity on the Antarctic Sea Ice); and the linked reference indicates that the intensifying regional winds in Antarctic is one of the most significant factors accounting for the increasing maximum extent of Antarctic sea ice. 

There is a lot of useful information and references to scientific papers in that thread. I don't have time to research and write about this right now. And I doubt I could do it any better than AbruptSLR in any case, and probably a lot worse.

Again, here is a link to the discussion. It's well worth a read, especially for anyone who wants to rebut denialist nonsense on the subject.

As for what's happening in the Arctic, well somewhat surprisingly, the ice extent is dropping quite a bit. It doesn't look as if it will break the 2012 record low though. Neven's blog is the place to go to keep up with what's happening there.

Source: Arctic Sea Ice Monitor

From the WUWT comments

Anthony Watts prefers to focus his readers attention on Antarctica, rather than the Arctic and to spread his usual disinformation about. Here are some of the mindless comments he hoped for and got:

Lucius von Steinkaninchen says:

July 2, 2014 at 11:24 am
* * * It’s getting colder around Antarctica and so the ice is growing * * *
In a world of some fields of Science degenerated enough to forget Occam’s Razor, it is so refreshing to see a simple model tying up cause and effect…

Bob Diaz says:

July 2, 2014 at 11:25 am
It appears that reality does not agree with the computer models.
How could reality be so wrong??? ;-))

Ben Howison says:

July 2, 2014 at 11:27 am
Looks kinda like a hockey stick, doesn’t it? 

Shawn from High River is about the only person who says something sensible, but I doubt he realises it. He says:

July 2, 2014 at 11:29 am
When these pesky facts get in the way of the prevailing theory,they just modify the theory to suit the facts

JimS says:

July 2, 2014 at 11:41 am
It is all so logical, it is astounding that no one can catch onto a very simple principle.
At the north pole, when sea ice trends to diminish, that means it is a sign of global warming.
However, at the south pole, on the opposite side of the earth, sea ice is increasing. But since this is on the opposite end of the earth, increasing sea ice means that is a sign of global warming.
These are opposite poles you see, so the exact opposite trend means the same thing. It is all global warming! 

Sheesh! (/sarc) 

John Schwartz says:

July 2, 2014 at 11:51 am
Just doesn’t fit the narrative, does it…  

The certainty of science deniers. And what are the facts about hurricanes, tornadoes and Antarctic sea ice?

Straw men are built to be blown away.  They can be constructed from anything really.  It doesn't have to be straw.  It could be wind and rain, like tornadoes and hurricanes, or sea ice.

justthefactswuwt wrote on WUWT today (archived here):

It is amazing how easy alarmist scare forecasts/predictions can be falsified with readily available data...The data shows no increase in tornado counts or strength. Claims about increasing or more dangerous Tornadoes are unfounded.

Unfounded?  That's a strong claim! But first just what are the "claims" and who is making them?

In today's article (archived here) Justthefacts mentioned three things: tornadoes, hurricanes and Antarctic sea ice.

justthefacts is adamant that the projections of what will happen over the coming 90 years or so are completely wrong.  This complete and utter certainty is based on less than a year's data.  Not only that but justthefactswuwt appears to be very certain about what expectations are held by climate scientists.  So I thought it would be useful to see what are the forecasts/predictions for each item to see whether or not they have been falsified.

It turns out that, in contrast to the absolute certainty of justhefactswuwt, there is a lot of uncertainty and little agreement in the science itself:

• Tornadoes - might decrease relative to severe thunderstorms, although a new paper suggests an increase in frequency of severe tornadic storms over the coming century
• Hurricanes and tropical cyclones - if anything they are expected to decrease or stay the same, but with low confidence, although a new paper argues they may increase.
• Antarctic sea ice - expected to decline over the coming century, but again with low confidence.

The uncertainty and lack of strong agreement within the research is not really surprising, given the sporadic and relatively infrequent nature of tornadoes and hurricanes, and the difficulty of collecting data in the southern oceans and across the whole of the Antarctic continent.

And I must add that a single year's weather is hardly sufficient to falsify projections of climate!

Tornadoes in the USA

AR5 WG1 suggested that in the USA at least, the expectation is for more severe thunderstorms relative to tornadoes over time.  Tornadoes are expected to decrease or at least decrease relative to the number of severe storms.  It's all to do with energy vs shear.  But it won't be till towards the end of this century that trends will be able to be measured.  In any case, a single year's data isn't sufficient for "falsification" .  From AR5:

Severe thunderstorms, associated with large hail, high winds, and tornadoes, are another example of extreme weather associated with the water cycle. The large-scale environments in which they occur are characterized by large Convective Available Potential Energy (CAPE) and deep tropospheric wind shear (Brooks et al., 2003; Brooks, 2009). Del Genio et al. (2007), Trapp et al. (2007; 2009), and Van Klooster and Roebber (2009) found a general increase in the energy and decrease in the shear terms from the late 20th century to the late 21st century over the United States using a variety of regional model simulations embedded in global-model SRES scenario simulations. The relative change between these two competing factors would tend to favour more environments that would support severe thunderstorms, providing storms are initiated. Trapp et al. (2009), for example, found an increase in favourable thunderstorm conditions for all regions of the United States east of the Rocky Mountains. Large variability in both the energy and shear terms means that statistical significance is not reached until late in the 21st century under high forcing scenarios. One way of assessing the possibility of a change in frequency of future thunderstorms is to look at historical records of observed tornado, hail, and wind occurrence with respect to the environmental conditions (Brooks, 2013). This indicates that an increase in the fraction of severe thunderstorms containing non-tornadic winds would be consistent with the model projections of increased energy and decreased shear, but there has not been enough research to make a firm conclusion regarding future changes in frequency or magnitude. (Page 12-53)

I searched the AR4 and the Second Assessment report but could not find any projections for tornadoes.  I searched the third assessment report and there was this statement:

Although some evidence is available regarding increases in the intensity and frequency of some extreme weather events, it is not yet clear how tornadoes will be affected. 

By contrast, a more recent study published as open access in PNAS (Diffenbaugh et al 2013), quoted by justthefactswuwt does suggest that tornadoes, or at least severe thunderstorms, will most likely increase this century.  The paper has lots of caveats but the final paragraph in the conclusion states:

Given the substantial damage from severe thunderstorms in the current climate, uncertainty about the response of such storms to global warming has created an important barrier to climate change impacts assessment (1). Our results indicate that continued global warming might cause substantial increases in the occurrence of the atmospheric environments associated with severe thunderstorms, because the implied reduction in vertical wind shear may not be as important as previously thought. These increases include regions where severe thunderstorms currently are most common, and regions where severe thunderstorms currently are less common but where substantial assets are exposed (3, 6, 15). Although important uncertainties about storm-scale processes still exist, the fact that the projected increases in severe environments are robust across a suite of climate models, emerge in response to relatively moderate global warming, and result from robust physical changes suggests that continued increases in greenhouse forcing are likely to increase severe thunderstorm occurrence, thereby increasing the risk of thunderstorm-related damage.

Note that the above relates to "atmospheric environments associated with severe thunderstorms" and not specifically to tornadoes.  However elsewhere in the paper there is reference to tornadoes.  For example in the abstract, Diffenbaugh13 writes:

We also find that days with high convective available potential energy (CAPE) and strong low-level wind shear increase in occurrence, suggesting an increasing likelihood of atmospheric conditions that contribute to the most severe events, including tornadoes.

It is also worth pointing out that Diffenbaugh13 notes the paucity of data, writing:

First, there is no reliable, independent, long-term record of severe thunderstorms—and particularly tornadoes—with which to systematically analyze variability and trends.

The science is much less certain about tornadoes than is justthefactswuwt.

Hurricanes (and tropical cyclones and typhoons)

It doesn't look as if the projections for hurricanes have been falsified, either.  From AR5 WG1 - there has been an increase in the frequency and intensity of the strongest tropical cyclones but not overall.

In summary, this assessment does not revise the SREX conclusion of low confidence that any reported longterm (centennial) increases in tropical cyclone activity are robust, after accounting for past changes in observing capabilities. More recent assessments indicate that it is unlikely that annual numbers of tropical storms, hurricanes and major hurricanes counts have increased over the past 100 years in the North Atlantic basin. Evidence however is for a virtually certain increase in the frequency and intensity of the strongest tropical cyclones since the 1970s in that region. (Page 2-60)

And tropical cyclones are projected to stay the same or decrease, according to AR5.  But the ones that emerge will be fiercer and wetter:

There is low confidence in the projections for the tropical Atlantic, both for the mean and interannual modes, because of systematic errors in model simulations of current climate. The implications for future changes in Atlantic hurricanes, tropical South American and West African precipitation are therefore uncertain. ...

...Based on process understanding and agreement in 21st century projections, it is likely that the global frequency of occurrence of tropical cyclones will either decrease or remain essentially unchanged, concurrent with a likely increase in both global mean tropical cyclone maximum wind speed and precipitation rates. The future influence of climate change on tropical cyclones is likely to vary by region, but the specific characteristics of the changes are not yet well quantified and there is low confidence in region-specific projections of frequency and intensity.(Page 14-4)

From AR4 - tropical cyclones will become more severe and intense:

Earlier studies assessed in the TAR showed that future tropical cyclones would likely become more severe with greater wind speeds and more intense precipitation. More recent modelling experiments have addressed possible changes in tropical cyclones in a warmer climate and generally confirmed those earlier results. 

From AR4 - tropical cyclones and hurricanes will become more intense but globally, less frequent (low confidence)

Based on a range of models, it is likely that future tropical cyclones (typhoons and hurricanes) will become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical sea surface temperatures. There is less confidence in projections of a global decrease in numbers of tropical cyclones. The apparent increase in the proportion of very intense storms since 1970 in some regions is much larger than simulated by current models for that period. {9.5, 10.3, 3.8}

From the Third Assessment Report:

Climate models currently are unable to project accurately how hurricanes will change in the future. 

However not all research points to a decrease in tropical cyclones.  A recent paper by Kerry Emanuel suggests that tropical cyclones may increase, but large uncertainties remain:

An increase in global mean frequency during roughly the first three quarters of the 21st century is indicated, with a total increase in the range of 10-40%. ... most of the increase in frequency is in the North Pacific, but with substantial increases in the North Atlantic and South Indian oceans as well. The only coastal region that experiences a substantial decline in track crossings is the southeast coast of Australia....

...The differences between our results, those arrived at by applying the same technique to CMIP3 models, and the conclusions of other groups using different models and/or using different methods suggest that projections of the response of tropical cyclones to projected climate change will remain uncertain for some time to come.

All I can say once again is that justthefactswuwt is a lot more certain than the science itself.

Antarctic sea ice

On the other hand, Antarctic sea ice is expected to decrease over time - presumably over winter because there's precious little sea ice in summer.  However, but there is only low confidence in the projection.  From AR5 WG1 (page 12-5)

It is very likely that the Arctic sea ice cover will continue shrinking and thinning year-round in the course of the 21st century as global mean surface temperature rises. At the same time, in the Antarctic, a decrease in sea ice extent and volume is expected, but with low confidence....There is however low confidence in those values as projections because of the wide inter-model spread and the inability of almost all of the available models to reproduce the mean annual cycle, interannual variability and overall increase of the Antarctic sea ice areal coverage observed during the satellite era.

Again, justthefactswuwt is much more certain than the science.

From the WUWT comments

There aren't too many people jumping on justthefactswuwt bandwagon.  Maybe they've been bitten too many times in the past, jumping in too soon. Or maybe they are remembering the massive tornado that tore through Oklahoma in May this year. There are a few more Gore-bashing comments than usual, probably because justthefactswuwt let fly in the article.  (Comments archived here.)


sophocles says "it's cooling":

November 3, 2013 at 12:14 pm
The National Academy of Sciences said:
“…are forecast to see a “robust” increase across parts of the U.S. in upcoming decades because of climate change …”
===========================================================
Unfortunately, they may be correct but not for the reasons they are thinking.
If past records are any hint, the onset of cooling can bring bad storms, (from
Brian Fagan’s book “The Little Ice Age”), not warming.
The AMO and PDO have turned over, the Sun is sliding into another minimum
and cooling is already apparent (only slight, so far but…) so the next ten years
are going to be interesting …

Paul Homewood predicts the lull in tornadoes won't last and says:

November 3, 2013 at 12:17 pm
It’s extremely unextreme.
And next year, no doubt, NOAA will be bragging off about “a big jump in tornado numbers from last year”. 

Sea ice: Out of the mouths of WUWT-ers

Thought I'd post a few of the comments from WUWT.  These are from justthefactswuwt's article about global sea ice (archived here).  No, I'm not going to comment on the fact that justthefactswuwt thinks that the world has "stopped warming".  Well, maybe I'll just show one of the charts he uses as evidence, with my own notations as an animated gif. I suggest clicking on the chart for the larger version because it's very wide:

Adapted from Cryosphere Today

From the WUWT comments

Contorted thinking from Robin Hewitt who says (excerpt, my bold italics):

October 21, 2013 at 6:45 am
I rather hope the ice does not stick around. If we get a big ice anomaly year then that puts up the average ice cover that all subsequent years will have to match. The sceptics get one chance to thumb their noses at the catastrophists and then have to pay for ever more.

I think Robin is saying that even if the ice didn't melt as much one year, it's on a downward spiral in the medium term.


David in Cal has never heard of coupled ocean-atmosphere general circulation climate models.  I wonder what he'd say if he learnt about the earth system models, which include not just the ocean and the atmosphere but biogeochemical cycles like the carbon cycle, the sulphur cycle, and ozone.  David in Cal writes:

October 20, 2013 at 10:52 pm
To say that extra heat is hiding in the oceans is to admit that all the climate models are wrong. After all, no climate model specifically includes heat moving into and out of the oceans (as far as I know.)

DR thinks the greenhouse effect is old hat and says:

October 20, 2013 at 10:28 pm
Funny how the Warmastrologists want to change what was actually predicted when this all came to the forefront. When things didn’t work out as predicted, they simply make it up as they go along. The “greenhouse effect” was all the rage back then. Today they’d just wish it would go away because it just ain’t happening the way we were told it would.

MrX says "they always come back baffled" but I'm guessing it's not for the reason he thinks:

October 20, 2013 at 8:28 pm
Jimbo says: October 20, 2013 at 1:32 pm I kept trying to explain to Warmists that most sceptics are fervent proponents of climate change. The climate always changes.
——————
YES! I do the same. It’s amazing how much I get asked “What? You don’t believe in climate change?” And I always respond back, “Climate change is a skeptical position. Of course I believe in climate change. Unprecedented and catastrophic global warming is your side’s position. If it isn’t unprecedented, then it’s happened before (aka climate change) and it’s natural and not catastrophic. Nothing to worry about.”

They always come back baffled and completely confused about their own position. Sometimes they’ll throw a word in about not liking the fact that used “global warming” or some other nonsense. But they never know how to argue against the fact that it can only be climate change if it’s not unprecedented.

How's this for logic and understanding?  RACookPE1978 goes for a "cool - cool" argument:

October 20, 2013 at 9:02 pm

Chris B says: October 20, 2013 at 8:33 pm So the argument that, a decade of reductions in Arctic Sea Ice Extent indicates we are on the verge of Dangerous Warming, is unsupported then?

True. The false arguments about Arctic amplification – the fears that a continued loss of Arctic sea ice from its current extents is dangerous – ARE unsupported and ARE wrong.

The numbers show that, additional loss of arctic sea from today’s sea ice extents from mid-August through mid-April cause more loss of heat from the newly exposed ocean areas than can be absorbed from the sun. More Arctic ice loss from today’s levels means more cooling in August, September and October. More snow on the land surfaces around the Arctic as well..

On the other hand, the INCREASED Antarctic sea ice at minimum AND maximum extents all year DOES reflect more heat energy and DOES cause increased cooling of the planet.

There's a heap more convoluted thinking going on in that thread.  If you're bored you can read the archived version here.

Sea ice in the Arctic and Antarctica

Arctic sea ice watching season is here again. I was prompted to look at what is happening overall when I read a post by Perennially Puzzled Bob Tisdale. He's busy trying to prove that "all the models are wrong".  Unlike real scientists, Bob isn't about to "fix" them.  (Not sure he'd want to even if he could.)

In the case of sea ice projections, all the models are wrong, though CMIP5 is something of an improvement over the previous generation (CMIP3) models in regard to the Arctic.  In the Antarctic, more sea ice doesn't mean it's getting colder, particularly when as it warms, more ice shelves and glaciers break up and fill up the sea.

Antarctic sea ice and models

As far as Antarctica goes, researchers from the British Antarctic Survey write in the abstract of their recent paper that most models overestimate the sea ice extent at the minimum in February and some have less than two thirds of the observed ice extent at the maximum in September.  Not only that, but the models don't model the trends from 1860 to 2005 well.   The abstract concludes with this:

The negative SIE trends in most of the model runs over 1979–2005 are a continuation of an earlier decline, suggesting that the processes responsible for the observed increase over the last 30 years are not being simulated correctly.

Turner, John, Thomas J. Bracegirdle, Tony Phillips, Gareth J. Marshall, J. Scott Hosking, 2013: An Initial Assessment of Antarctic Sea Ice Extent in the CMIP5 Models. J. Climate, 26, 1473–1484. doi: http://dx.doi.org/10.1175/JCLI-D-12-00068.1

Exploring the matter further, a US team of researchers suggests that the problem may be in part due to the fact that observed internal variability in the Antarctic region is large and that the observed shifts in winds are not well simulated in the CMIP5 models.   Here is an excerpt from the abstract (my bold) and the full paper is available here:

...whether these models can be dismissed as being wrong depends on more than just the sign of change compared to observations.

We show that internal sea ice variability is large in the Antarctic region, and both the observed and modeled trends may represent natural variations along with external forcing. While several models show a negative trend, only a few of them actually show a trend that is significant compared to their internal variability on the time scales of available observational data. Furthermore, the ability of the models to simulate the mean state of sea ice is also important. The representations of Antarctic sea ice in CMIP5 models have not improved compared to CMIP3 and show an unrealistic spread in the mean state that may influence future sea ice behavior.

Finally, Antarctic climate and sea ice area will be affected not only by ocean and air temperature changes but also by changes in the winds. The majority of the CMIP5 models simulate a shift that is too weak compared to observations. Thus, this study identifies several foci for consideration in evaluating and improving the modeling of climate and climate change in the Antarctic region.

Mahlstein, I., P. R. Gent, and S. Solomon (2013), Historical Antarctic mean sea ice area, sea ice trends, and winds in CMIP5 simulations, J. Geophys. Res. Atmos., 118, doi:10.1002/jgrd.50443

Watching the sea ice disappear

To finish up here is a chart.  It shows the average extent for the minimum months in the Arctic and Antarctic. (Click the chart to enlarge it.)

Source: NSIDC

You'll see I've taken a bit of a liberty and added the areas together to give a 'total', although it's not a 'total' in any temporal sense, because the Arctic monthly average is for September whereas the Antarctic monthly average is for February.

Just the same, the minimum month at each hemisphere is when the sun shines the most on the sea. So if there is less ice then more heat is absorbed by the ocean.  In winter when there is lots of ice cover, then the sun doesn't shine anyway.  It's dark.  So the sea ice doesn't reflect sunlight back to space at that time.

WUWT poll on Arctic Sea Ice September Minima

Anthony Watts is running a poll on what readers think will be the minimum Arctic sea ice extent in September 2013.  If you vote, take note of Anthony's words of wisdom:

Of recent interest has been the recent tendency for the current data to hang between the 1990′s and the 2000 normal line.

Best observe what one of his commenters, Klench Mychiques wisely cautions:

June 6, 2013 at 2:32 am But don’t vote too low either, or it will look like WUWT is acknowledging that the climate in the Arctic is changing due to global warming. Which is nonsense, of course, and if it isn’t, it’s a natural cycle.