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Kate

Excellent update, thank you Neven.
Everyone must be on the forum...If I go there time seems to fall into a black hole and no work gets done hahaha

ClimategateNL

My thoughts are with you Neven. It is so dad that you took this one dimensional natural parameter as spreadhead for your societal concerns rather then directly address human issues like stupipdity and aggression. After all these years of dedication you might as well have owned the leading anti-jihadist blog or the leading anti-consumerism blog. Now you picked the wrong indicator and you will be forces to drink the cup till the last bitter sip. You are now set up to be the documenter of the final nail in the coffin of the global warming religion!

ClimategateNL

Spearhead that was of course

Neven

Thanks for your concern, ClimategateNL, but I don't see what my dad has to do with this. ;-)

It is so dad that you took this one dimensional natural parameter as spreadhead for your societal concerns rather then directly address human issues like stupipdity and aggression.

You can mock me if you like, but I'm entirely transparent about my motives, unlike the people you probably go to for your (dis)information.

Now you picked the wrong indicator and you will be forces to drink the cup till the last bitter sip. You are now set up to be the documenter of the final nail in the coffin of the global warming religion!

Que sera, sera, and I will document things as objectively as I can. But the same thing was said in 2010, which was followed by record tying 2011 and record smashing 2012. So I wouldn't be too triumphant just yet. The Arctic isn't very cooperative that way.

As far as PR goes: this second rebound year will obviously be used to spread confusion with regards to the severity of the situation up North, where the consequences of the dramatic sea ice (and snow cover) loss are felt acutely on a regional level, through coastal erosion, melting permafrost and an increase in forest fires.

These consequences will reverberate across the Northern Hemisphere (and globe), if they don't already do. But it will probably take a while for the influence on the jet stream, carbon cycle and sea level rise to become statistically significant.

In this sense, an ice-free Arctic would be a much quicker and more difficult to deny piece of evidence that yes, human activities are changing the planet we all live on, and no, these changes will probably not have benign effects on human societies (that are already bumping into various limits to growth, like recessions, resource wars and massive public health issues).

But it's definitely better for everyone and everything if the sea ice becomes healthy again, and these rebound years are followed by harsh winters and more cold and/or windless summers, so that the sea ice becomes as thick as it was 30 years ago, and the 75% loss in sea ice volume is reversed.

So yeah, I'm all for nails in the coffin of global warming religion (and the coffin of free market fundamentalism). Even better would be if the global warming theory turned to be completely false. And for Liechtenstein to win the FIFA World Cup.

Mike H

It is possible that society is no wiser than the frog slowly boiled in a pot. The consequences of AGW are taking decades to manifest. And in Southern Ontario, the one-in-fifty cold winter followed by a very cool summer is problematic. Many people simply don't believe the planet is warming, and most of those that do have other things to worry about. A couple of tenths of a degree per decade does not alarm the average person, at least where I live.

wayne

Neven, time is better spent following the state of sea ice, which is vulnerable to dynamical meteorology at present, rather than trying to explain the Earth is not a table on four pillars. I find those johny come lately experts laughable in their interpretations of refuting the best science can offer. If one really looks at the current image of wide expanses of very loose pack ice, essentially melted well within edges next to wide open Arctic sea but with remnants in extent greater than 15% which result in a wider area and extent numbers. If one really studies, there is no reversing of science well gathered. The problem with AGW is that it is extremely slow process, well beyond the attention span of scammers.

D

I didn't participate in SEARCH because I didn't have a tested scientific way of making a prediction. Recent papers have suggested some possible ways of making a prediction a few months ahead. A fast melt pond start in May appears to correlate with a strong melt year. Obviously, weather dependent factors such as a warm sunny May will vary from year to year, causing short-term variability in the long-term trend of sea ice decline.

The point is that the troll has no scientific point at all. He's just trolling. We're here to discuss scientific data, ideas and reports, not substance free personal attacks. Neven's dad has nothing to do with this blog AFAIK.

Nevaudit

> It is possible that society is no wiser than the frog slowly boiled in a pot.

It is possible that frogs are less dumb than some ClimateBall players may presume:

http://www.snopes.com/critters/wild/frogboil.asp

Mike H

Good to know. I found the frog tale hard to believe but Al Gore said it and fooled me.

Chris Reynolds

My 2014 season review is posted:
http://dosbat.blogspot.co.uk/2014/09/2014-melt-season-review.html

TenneyNaumer

Decent sized cyclonic activity over the Chukchi:

http://weather.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg

Kate

I'm pretty sure the 'dad' was a typo for 'sad'
but anyway...

TenneyNaumer

Sad to be a denier, they seem to be full of spite, can't be pleasant for them.

Nevaudit

> Al Gore said it and fooled me.

It was a fat joke.

Here's another one:

http://imgur.com/UCDh1MM

Inspired by Dr. Roy:

http://rabett.blogspot.com/2014/08/what-part-of-hot-air-rises-do-you-not.html

D_C_S

ClimategateNL:

Note that the trend in the amount of arctic sea ice is downward. Are you predicting that this will change at some point in the near future? If so, what is the basis of your prediction? Here is a short video that explains a bit about how the trend in arctic sea ice works (and doesn't work):

https://www.youtube.com/watch?v=lH5D9P6KYfY&list=UUljE1ODdSF7LS9xx9eWq0GQ

Jim Hunt

Nev(audit) - Here's what Al Gore actually said:

http://GreatWhiteCon.info/2014/09/david-roses-apocalyptic-vision-of-al-gores-nobel-lecture/

and here's an intriguing response from the denialosphere:

https://twitter.com/jim_hunt/statuses/506713675353567232

John Christensen

Hi Chris,

Thank you for the extensive analysis/review of this years melting season.

While I am in agreement with your overall analysis and conclusion, I was wondering why you did not cover at all the NAO.

Since the NAO has been in a negative phase during summer months of 2007 - 2012, but positive or neutral in 2013 and 2014, it would seem reasonable to discuss how the change in athmospheric circulation during summer months impacted the conditions either favoring or to some degree slowing down ice melting.

TenneyNaumer

Cyclonic activity still ongoing, folks:

http://weather.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg

Chris Reynolds

John Christensen,

I didn't address it because, as you know, I am not convinced that the apparent high NAO over 2007 to 2012 is the historically typical NAO, I suspect it is a sea ice loss driven mode that is similar to the NAO/AO. You've read my droning on about this previously so I won't repeat here, but see the reference to Overland's research below.

The AO index was actually negative this summer, June July average was -0.498. AO is very similar to NAO, so on checking the NAO.
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table
The NAO for June/July was -0.395.

In terms of standard deviation (sigma), for June July for the entire series of data. 2014 June July was
AO -1.2 sigma,
NAO -0.50 sigma,
So the AO was not moderate, but was significantly negative, while the NAO was moderately negative.

Scatterplot between AO, NAO and 1 June to 30 August extent loss. (sorry I can plot tomorrow but I need a break tonight). R2 is a measure of how well the linear trend accounts for the data points (1 is an exact match, 0 is no relationship at all)

1979 to 2006 AO is 0.102, NAO is 0.016
1979 to 2013 AO is 0.200, NAO is 0.313

In both cases for the period excluding post 2007 years the R2 is lower than for the entire period 1979 to 2013 (2014 August average not yet published). This suggests that the period after 2007 strongly affects the relationship, however drawing conclusions here is risky because we cannot determine what part of summer extent loss after 2007 is due to thinner ice and increased open water formation efficiency, and what part is due to weather.

Furthermore Overland et al demonstrate that after 2007 there was an unusually strong dipole tendency, not seen in relationship to AO variations prior to 2007.
http://farm9.staticflickr.com/8170/7986372120_ba92926556_o.jpg
The presence of the Arctic Dipole is another compicating factor after 2007, suggesting the simply looking at NAO/AO after 2007 is not sound.

Therefore I am not convinced that the June/July/August NAO/AO have a strong role in summer extent losses.

Sorry.

Chris Reynolds

Damn,

I just realised that I used CT Area for the above calculations, not extent.

TenneyNaumer

http://www.nature.com/ncomms/2014/140902/ncomms5646/full/ncomms5646.html

Weakening of the stratospheric polar vortex by Arctic sea-ice loss

Successive cold winters of severely low temperatures in recent years have had critical social and economic impacts on the mid-latitude continents in the Northern Hemisphere. Although these cold winters are thought to be partly driven by dramatic losses of Arctic sea-ice, the mechanism that links sea-ice loss to cold winters remains a subject of debate. Here, by conducting observational analyses and model experiments, we show how Arctic sea-ice loss and cold winters in extra-polar regions are dynamically connected through the polar stratosphere. We find that decreased sea-ice cover during early winter months (November–December), especially over the Barents–Kara seas, enhances the upward propagation of planetary-scale waves with wavenumbers of 1 and 2, subsequently weakening the stratospheric polar vortex in mid-winter (January–February). The weakened polar vortex preferentially induces a negative phase of Arctic Oscillation at the surface, resulting in low temperatures in mid-latitudes.

jdallen_wa

TennyNaumer - Brilliant Find!

A direct tie between sea ice loss and decay of the Polar Vortex is a very significant connection!

It has profound implications for climate and civilization as a whole. I will be looking to see if other scientists start reinforcing these contributor's findings.

wayne

Tenney, "Cyclonic activity still ongoing, folks:" … And the minima is not reached, the cyclonic activity has now really spread out at the ice shores and particularly vulnerable. SST's are staggeringly high in the North Atlantic and Pacific, its cloudy and I see a delay of the minima date along with further surprises.

wayne

has spread out the ice shore pack a lot more specifically in the Russian and European quadrant….

Chris Reynolds

JDAllen,

It seems to be very similar to Petoukhov & Semenov's "A link between reduced Barents-Kara sea ice and cold winter extremes over
northern continents" Discussed by Realclimate.
http://www.realclimate.org/index.php/archives/2010/12/cold-winter-in-a-world-of-warming/

But I've not seen the actual nature paper, this is merely based on the P&S paper and the abstract of that nature paper.

Also similar to Cohen's work. It's good to see a wide variety of researchers finding similar linkages.

Tenney, thanks for posting.

Henry1

I've been skeptical that the 2007-2012 atmospheric pattern was mainly due to sea ice loss. I am of the view that it helped enhance the loss of the ice but was not caused by it. The block was centered over Greenland those summers which is typically a very warm pattern for the arctic. Subsequent seasons in 2013 and 2014 have not yielded that same pattern. 2014 had a -NAO but not like the -NAOs of 2007-2012. The main block was centered much further south.

5-6 years worth of data is pretty small to try and make an attribution.

John Christensen

Chris Reynolds,

Thank you very much for your response.

The AO and NAO are two very different indicators, since the AO has to do with highs and lows within the Arctic region, while NAO provides information about North-Atlantic atmospheric conditions.

From a relationship perspective, it seems that positive NAO during summer months allow Arctic lows to enter the Arctic region from the Kara/Laptev area, causing a higher probability of the AO turning positive (causing Arctic cyclones), as it did in 2013.
The same way, a negative NAO during summer months appear to have some correlation with AO turning negative (Arctic highs), but this is less clear.

There has been a lot of research on winter-time NAO impact on Arctic conditions, but much less on NAO during summer, so any references are anecdotal and not well documented.

I have a simple theory on NAO based on these principles:

- Negative NAO index during DJFM is good for Arctic sea ice
- For the remainder of the year, a positive NAO index is good for Arctic sea ice
- Non-decided NAO index (-0.8 - +0.8) eliminates the NAO as a factor for Arctic sea ice preservation

Why Negative NAO during DJFM is good for Arctic sea ice:
- Inflow of warmer, moist Atlantic air increases precipitation/snow cover in Arctic regions as well as Greenland
- Increase of snow cover on sea ice, delaying the onset of spring melting
- Increase of Arctic heat sink effect, lowering NH temperatures, makes use of surplus Arctic cold in deep winter where ice growth is limited

Why Positive NAO for the remainder of the year is good for Arctic sea ice:
- Heat energy from Atlantic moisture moves east across Northern Europe prior to entering the Arctic region, causing less heat to enter the Arctic

There are certainly other important factors involved, but against the records of ice extent there has been a very good correlation, although I admit I have not run the calculations. I would not use area data for summer sea ice due to the known uncertainty of this metric during summer months.

John Christensen

Regarding IJIS Sept mean extent, as I wrote on July 25:

"Based on weather in the past couple of weeks, low temps/cloud cover plus outlook for AO and NAO, I would no longer be surprised, if 2014 Sept extent and area will be in tight competition with 2013.

I find it unlikely that Sept extent should be less than 5.0M KM^2 at this point."


I will stick to that estimate, with a best estimate for Sept. mean extent to be 5.4-5.6Mkm^2.

Susan Anderson

Tenney provides more precise information on the point I was going to mention (thanks).

The problem is that these cold patches are conveying the wrong impression to low-information populations, who are easily misled by the ever-active propaganda machine. A meteorologist friend mentions that he thinks it not unlikely that we will have more winters like the one just past. It was devastating with huge ice storms and very low temperatures that did enormous damage to every kind of plant, including many trees down, in southern New Jersey, and even worse further south.

If this pattern continues, even intermittently, until the Arctic is largely melted out, there will be hellsapoppin' trouble.

Kevin McKinney

Yeah, I posted the "Weakening of the stratospheric polar vortex by Arctic sea-ice loss" link to RC the other day. I'd really like to see the full paper, though.

Chris Reynolds

John Christensen,

Using extent data. R2's as in my earlier (long) post.

1979 to 2006 AO is 0.0907, NAO is 0.0135
1979 to 2014 AO is 0.1768, NAO is 0.2852

So even with extent data the relationship between AO and NAO, and the 1 June to 30 Aug extent loss behaves the same as area.

There is little relationship between summer AO/NAO and sea ice loss during the period 1979 to 2006, it is only by including post 2007 data with the full period 1979 to 2014 that the relationship strengthens. In the above post I said I used 1979 to 2013, that was wrong, when I came to paste in the etent data it was 1979 to 2014.

Using extent as opposed to area still suggests that the period after 2007 strongly affects the relationship, however once again drawing conclusions here is risky because we cannot determine what part of summer extent loss after 2007 is due to thinner ice and increased open water formation efficiency, and what part is due to weather.

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