Arctic Ice 2009

[weather eater]

The only ting that suggested a possible below 07 ice extent was that 07 and 08 were very low. However, if one looked at the global pattern and if one looked at the arctic weather and if one looked at natural cycles then there was no way in hell that 07 was going to be beaten. So thinking it will and wishing it will are the same in my book...and only pro AGW folk thought it would too.

BFTP

2007 was a blip and climate change in the Artic needs to be looked at long term. Artic summer ice retention has been poor again this year, and is looking like it might finish the third lowest. Yes its better than 2008, but if we look at 2007 as an anomaly then 2009 looks even worse. Now it might be that we are starting to see a recovery I certainly hope so, but it would be jumping the gun to presume that’s the case, the analysis over the next few years is the only way to establish that. While your confidence is admirable Fred I find it no more convincing than the alarmists doom tomorrow scenarios.

I would say that the AGW folk as you label them, feared it would be worse. Of course when you take up a position in a debate, there must be a part of you that wants to carry that debate, win it if you will, so in that regard you are no better or worse than them, you also wish to see your position vindicated.

I have to say that for the time being and most likely the next few years, short of a dramatic recovery or collapse in the Artic, the jury will remain out, maybe more so if you are right about Artic weather patterns and natural forcings, because it could be that these are just putting off the warming rather than reversing it. As of this time and despite a levelling off of global temperatures we have seen no real fall, now this may be down to the much vaunted time lag, I for one hope so.

[SteveB]

2007 was a blip and climate change in the Artic needs to be looked at long term. Artic summer ice retention has been poor again this year, and is looking like it might finish the third lowest. Yes its better than 2008, but if we look at 2007 as an anomaly then 2009 looks even worse. Now it might be that we are starting to see a recovery I certainly hope so, but it would be jumping the gun to presume that's the case, the analysis over the next few years is the only way to establish that. While your confidence is admirable Fred I find it no more convincing than the alarmists doom tomorrow scenarios.

I would say that the AGW folk as you label them, feared it would be worse. Of course when you take up a position in a debate, there must be a part of you that wants to carry that debate, win it if you will, so in that regard you are no better or worse than them, you also wish to see your position vindicated.

I have to say that for the time being and most likely the next few years, short of a dramatic recovery or collapse in the Artic, the jury will remain out, maybe more so if you are right about Artic weather patterns and natural forcings, because it could be that these are just putting off the warming rather than reversing it. As of this time and despite a levelling off of global temperatures we have seen no real fall, now this may be down to the much vaunted time lag, I for one hope so.

In your opinion, where would you have liked to see ice concentrations at this current time to be in order to feel AGW is on the wain so to speak?.

[Guest North Sea Snow Convection]

I believe it would have been unrealistic to have expected a better position than the present one following the low point of 2007. It should be remembered that we are seeing multi ice remaining intact - and that is key as a sign of a proper recovery, not a flat lining of the last stages of a total collapse. Of course it has to go further and be consolidated before too much confidence is expressed - but in terms of the best relative improvement that could have happened then lets keep some perspective and have the glass half full rather than half empty.

Weather patterns look very encouraging to kick start the seasonal upturn in ice cover with cold pooling becoming more extensive on our side of the arctic - which has suffered a lot with late starts in recent years due to warm plumes and warm anticyclones that have been hard to displace. This year, in contrast, an early developing polar vortex over the russian arctic looks like sending some early cold air into those areas which have seen the most warmth in many recent seasons.

[Stu_London]

I believe it would have been unrealistic to have expected a better position than the present one following the low point of 2007. It should be remembered that we are seeing multi ice remaining intact - and that is key as a sign of a proper recovery, not a flat lining of the last stages of a total collapse. Of course it has to go further and be consolidated before too much confidence is expressed - but in terms of the best relative improvement that could have happened then lets keep some perspective and have the glass half full rather than half empty.

A well balanced analysis in my opinion

We could of course still be in downward cycle in terms of summer ice extent and if that is the case we shouldn't necessarily expect year on year declines as there would always be outliers (such as 2007).

Then again if some sort of recovery is under way, then it does have to start somewhere and the next few years will go some way to proving or debunking that particular theory

[Thundery wintry showers]

In your opinion, where would you have liked to see ice concentrations at this current time to be in order to feel AGW is on the wain so to speak?.

Ironically, that point assumes a strong link between AGW and Arctic ice extent- the same link that most sceptics are keen to downplay!

I don't think the rate of melting and recovery says much about AGW in itself, though the melt is very likely assisted by GW. It says more about whether we're likely to enter a sustained recovery and so far the evidence for this is tentative, but it's encouraging that 2007 did not start off year on year of exceptional melt.

I believe it would have been unrealistic to have expected a better position than the present one following the low point of 2007. It should be remembered that we are seeing multi ice remaining intact - and that is key as a sign of a proper recovery, not a flat lining of the last stages of a total collapse. Of course it has to go further and be consolidated before too much confidence is expressed - but in terms of the best relative improvement that could have happened then lets keep some perspective and have the glass half full rather than half empty.

Yes I think that's about right. What is probably most encouraging about this is that we have a lot of first-year ice surviving, as it was widely hypthesised that large amounts of first-year ice would lead to exceptional melts and continued record minima being set every year.

[Anti-Mild]

As an 'ice layman' I cannot help but make a correlation between the extent of N. Hemisphere sea ice and GW, although with a slight lag. Despite the levels being quite healthy in 2009 (in comparison to the last 2 years), it is still cause for concern. However, two things to look out for that may indicate to me that we are moving in the right direction with regard to a recovery of Arctic ice: 1 - seeing an ice extent above the long term average at any stage through the coming winter, and 2 - seeing the Baltic Sea closer to it's average as I feel that the Baltic Sea more closely reflects a more local picture and in recent years has been woefully short of the mean.

http://www.fimr.fi/en/itamerinyt/en_GB/jaatilanne/

(this site hasn't been updated since May however they are still waiting for the first ice of the season and it will be updated then)

[weather eater]

I believe it would have been unrealistic to have expected a better position than the present one following the low point of 2007. It should be remembered that we are seeing multi ice remaining intact - and that is key as a sign of a proper recovery, not a flat lining of the last stages of a total collapse. Of course it has to go further and be consolidated before too much confidence is expressed - but in terms of the best relative improvement that could have happened then lets keep some perspective and have the glass half full rather than half empty.

Weather patterns look very encouraging to kick start the seasonal upturn in ice cover with cold pooling becoming more extensive on our side of the arctic - which has suffered a lot with late starts in recent years due to warm plumes and warm anticyclones that have been hard to displace. This year, in contrast, an early developing polar vortex over the russian arctic looks like sending some early cold air into those areas which have seen the most warmth in many recent seasons.

I would broadly agree with that as well, the key it seems to me, is whether we can move global temperatures from the current stable position into one of decline. I know that some members are keen on the idea of a time lag, but with temperatures having flatlined for some time now I would be expecting to see signs of a drop, however evidence for this seems to rather thin at this point of time.

In terms of the Arctic, if we look as I said at 2007 as a blip then the one year recovery from 2008 to 2009 is hardly a trend, but as others have pointed out its better than expected given the circumstances so maybe something can be drawn from that although I’m far from convinced.

Tamara I know you are keen on the phrase, glass half full, I rather look on it this way, just because a car has stopped accelerating it does not mean its about to slow down, and that really is the moot point here, I would be more than happy, as I'm sure you know, to congratulate the likes of you and Fred etc, for clear thinking in the face of adversity, but I need to see the proof, that the bulk of the scientific community that supports the idea of AGW, is wrong. At the moment it seems to me that the sceptic argument is mainly based on lack of clear evidence that the rise in global temperatures is attributable to man and not just part of natural climate cycles. That’s Ok, if you can present, clear evidence to the contrary and that’s just not happening and not likely too, given the timescales needed to prove these things hence the circular nature of the climate change threads.

As I’ve said several times, it seems inconceivable to me that most climatologist, paleoclimatologists, geologists, etc who have contributed hugely to what we know of natural cycles, have ignored what they have learned when formulating the theory behind AGW, you would have thought they would be falling over themselves in refuting AGW, but most are not, why is that.

I would agree that things look encouraging re the Russian Arctic this year but this needs to be sustained, while I forget what evidence I had for this, I seem to remember thinking the same thing last year. Whilst America had a cold winter Russia did not and has not for a good long while now, I doubt if we can get a really cold winter in the UK without a sustained cold spell in Northern Europe/Russia.

[BLAST FROM THE PAST]

I would say that the AGW folk as you label them, feared it would be worse. Of course when you take up a position in a debate, there must be a part of you that wants to carry that debate, win it if you will, so in that regard you are no better or worse than them, you also wish to see your position vindicated.

Its not about vindication, its about looking at the whole picture and not being too blinkered [everyone has a little bias]. There was no indication that the ice would be lower this year that's all I'm saying. I do think a recovery is underway but that's what I think, there is no proof yet.

TWS last paragraph is of all importance. Lots more 1st year ice, but it didn't melt like some thought.

BFTP

Edited September 10, 2009 by BLAST FROM THE PAST

[weather eater]

Its not about vindication, its about looking at the whole picture and not being too blinkered [everyone has a little bias]. There was no indication that the ice would be lower this year that's all I'm saying. I do think a recovery is underway but that's what I think, there is no proof yet.

TWS last paragraph is of all importance. Lots more 1st year ice, but it didn't melt like some thought.

BFTP

I certainly hope you're right about a recovery, but I have to say Fred I'm not sure about the whole picture I think you‘ve pretty much made your mind up and that’s fair enough.

It seems to me that their are 3 positions in the climate change threads,

1. A small group of alarmists, AGW is a real and dangerous threat to life as we know it

2. A larger group of open sceptics, by that I mean sceptical about the arguments being put forward by both camps. they feel that AGW theory has some merit, but the effects are difficult to quantify and feel that some in the AGW camp are over egging the pudding, I put myself in that group.

3. And a much larger group, sceptics, at least sceptical about AGW who have already pretty much made up their minds, its mostly if not wholly Natural cycles.

That large group is split into two groups, the first of which I would put the likes of yourself and Tamara, This group puts forward its arguments in an intelligent, reasoned and pleasant way, nothing wrong with holding a position if it can’t be proven wrong. However there is another group of sceptics, that seeks to convince by repeating themselves, dismissing anybody who fails to see their point of view as close minded, lead by the nose etc, and often uses arguments, which if they thought about it for a moment could be turned on its head to refute their own position. Some of whom when reading this will likely react with belligerence and rudeness.

I’m surprised to hear you say that there was no indication that the ice would be lower this year, you could just as easily say there was no indication that it would be higher. I think it was a fair point of view that it might have fallen lower, and had we had different weather patterns it might indeed have gone lower, it was also a fair point view to suggest that it would stay higher, its always easy with hind sight to make judgements.

[jethro]

However there is another group of sceptics, that seeks to convince by repeating themselves, dismissing anybody who fails to see their point of view as close minded, lead by the nose etc, and often uses arguments, which if they thought about it for a moment could be turned on its head to refute their own position. Some of whom when reading this will likely react with belligerence and rudeness.

I’m surprised to hear you say that there was no indication that the ice would be lower this year, you could just as easily say there was no indication that it would be higher. I think it was a fair point of view that it might have fallen lower, and had we had different weather patterns it might indeed have gone lower, it was also a fair point view to suggest that it would stay higher, its always easy with hind sight to make judgements.

To be fair weather eater, the first paragraph above applies to both sides of this debate. It says less about the position re: AGW than it does about the personality and mind set of some people. There are equally closed minded and adamant arguments from both sides, just depends which side of the fence you sit, as to which ones you notice the most.

There were/are indicators that the ice wouldn't be lower this year, as well as the prolonged Solar minimum (no one is certain about the length of lag for the effects to be felt) also, the PDO was confirmed by NASA as having entered the negative phase of cycle. The change from negative to positive phase back in 1976 was felt strongly in Alaska. This in turn has been mooted to affect the weather systems further North, although I think that's not certain.

http://www.earthandocean.robertellison.com.au/PDO%20in%20Alaska.pdf

There has been speculation that the NOA and AO were also looking likely to be largely negative, both of these have a dramatic impact upon Arctic ice.

http://uwnews.org/article.asp?articleid=3261

http://www.arctic.noaa.gov/essay_bond.html

All in all, signs were hopeful that ice loss wouldn't be so great this year.

[weather eater]

To be fair weather eater, the first paragraph above applies to both sides of this debate. It says less about the position re: AGW than it does about the personality and mind set of some people. There are equally closed minded and adamant arguments from both sides, just depends which side of the fence you sit, as to which ones you notice the most.

There were/are indicators that the ice wouldn't be lower this year, as well as the prolonged Solar minimum (no one is certain about the length of lag for the effects to be felt) also, the PDO was confirmed by NASA as having entered the negative phase of cycle. The change from negative to positive phase back in 1976 was felt strongly in Alaska. This in turn has been mooted to affect the weather systems further North, although I think that's not certain.

http://www.earthandocean.robertellison.com.au/PDO%20in%20Alaska.pdf

There has been speculation that the NOA and AO were also looking likely to be largely negative, both of these have a dramatic impact upon Arctic ice.

http://uwnews.org/article.asp?articleid=3261

http://www.arctic.noaa.gov/essay_bond.html

All in all, signs were hopeful that ice loss wouldn't be so great this year.

Two things to note, I'd say that I don’t sit on any side of the fence, to be honest I'm not too sure where the fence is to sit on it, but I do notice some pretty belligerent sceptic posts, and some from the other side but to my mind there’s more sceptics than alarmists and consequently more posts to notice.

In terms of weather patterns, indicators don’t always come off and sometimes don’t effect things in the way we think they are going to, for example, the stratospheric warming event that took place last winter. As for the solar minima lag effect, given the uncertainties of when this might kick in, it is not unreasonable to suppose it might not kick in soon, if at all, or have only a minimal effect, we just don’t know. This is what I personally find frustrating, how some people are so certain of their position and so dismissive of the opposing view, despite the fact that there is so much uncertainty on both sides of the debate.

[jethro]

Two things to note, I'd say that I don’t sit on any side of the fence, to be honest I'm not too sure where the fence is to sit on it, but I do notice some pretty belligerent sceptic posts, and some from the other side but to my mind there’s more sceptics than alarmists and consequently more posts to notice.

In terms of weather patterns, indicators don’t always come off and sometimes don’t effect things in the way we think they are going to, for example, the stratospheric warming event that took place last winter. As for the solar minima lag effect, given the uncertainties of when this might kick in, it is not unreasonable to suppose it might not kick in soon, if at all, or have only a minimal effect, we just don’t know. This is what I personally find frustrating, how some people are so certain of their position and so dismissive of the opposing view, despite the fact that there is so much uncertainty on both sides of the debate.

Glad to hear you're in no man's land, in the middle with me, and several others.

You're right, nothings definite or certain in any of this. However, the effects of a negative PDO on Alaska and negative NOA & AO on the Arctic are fairly well documented; all forecasted or confirmed as negative/looking likely to be negative, did give a fairly positive prognosis for less ice loss this year.

I think it is this which has led to predictions of a better summer for retention, same as the METO looking at the teleconnections and issuing seasonal forecasts; I think belief or otherwise in AGW had little bearing on this.

[J10]

This thread is about Arctic Ice measurements, while AGW and Climate Change may come into this, a full blown debate about AGW is better off in other more specific climate change threads.

Back on topic, the Arctic ice fell again today to only just above 2005 by a few hundred kms, the end figure for 2009 still looks around the 5.2m mark.

[stewfox]

At the moment it seems to me that the sceptic argument is mainly based on lack of clear evidence that the rise in global temperatures is attributable to man and not just part of natural climate cycles. That's Ok, if you can present, clear evidence to the contrary and that's just not happening and not likely too, given the timescales needed to prove these things hence the circular nature of the climate change threads.

All I know is, as at Sept 2009 with regard to the 'Artic ice cover', the car has stopped accelerating at present and I'll add seems to be slowing down.

[weather eater]

All I know is, as at Sept 2009 with regard to the 'Artic ice cover', the car has stopped accelerating at present and I'll add seems to be slowing down.

What evidence can you provide that the car is slowing down.

[Iceberg]

A quick assessment of the arctic ice melt from me.

I know we haven't reached the minimum quite yet, as we are still declining slightly, however using Jackones estimates which I completely agree with we can say that a figure around 5200000 is likely.

The ice extent figure for this year is now officially the third lowest on record, however it is a large improvement on 2007 and a sizable improvement on 2008.

Other important facts are that the NE passage is open, the shallow NW passage is open but the deep NW passage is not open. (See attached pictures).

My prediction was the the NW passage would open (I didn't specify deep or shallow, but I did mean deep), this means I was wrong about that. The main reason for this seems to be the deep flow of older ice still coming out of the main arctic blocking the entrance to the NW passage from the west.

June and July saw a similar melt rate to 2008 and pretty similar to 2007, however the gap from mid aug onwards really opened up, the melt slowed down and has ended up with a reasonable final figure.

Temperature conditions around the arctic were very average, slightly below in the centre, slightly above on the Russian side and slightly below on the Canadian side. The US and Canada had on average a pretty cold summer compared to recent summers.

I speculated at the start of summer how the AO effects ice melt, a negative allows more plumes and more melting a positive a stronger jet reducing the plumes. Attached is also the AO graph which strongly supports this and shows the positive AO from Mid August onwards.

Another major factor for icemelt is the amount of cloud over the arctic, I don't have figures but know from a personal perspective how frustrating this year has been looking at realtime modis images, cloud has been particularly prevalent around the Canadian side of the arctic, helping to reduce ice melt.

Another factor to consider when assessing this summers melt is the state of the ice that was left. I posted an image a few weeks ago showing the well broken ice very close to the north pole, this joins in nicely with GW's comment about the relatively spread pack, which has been broken up but not enough qualify as ice melt as it's not passed the 15% threshold.

A futher factor which we can't comment on yet is the surviving rate of the older arctic ice. 2 year old ice is more likely to survive than 1 year ice, but ice of 4 or 5 years with a decent thickness is really what's needed. The ice flow for this summer would indicate to me that the ice, apart from in a few isolated areas will be 2 years or newer this come next summer and that there has been a further decline in ice older than 2 years.

So what we really have is a mixed picture IMO. certaintly an improvment, with the ice extent this year pretty much what you would expect given the various factors, but I fully admit up on where I thought it would be. Which is good.

TBH this summers arctic melt has no bearing on AGW, as I've discussed constantly synoptics are by far the largest factor when considering ice melt, AGW will only effect the long term trends, however there is an argument to be made that it makes melt years like 2007 more likely, in the same way that it makes warm summers for the UK more likely.

Is the Arctic in terminal decline ?, impossible to judge from 1 or even 3 years, arctic ice has certainly been declining as a trend over the last 30 years and the decline has probably increased over the last 5-10 years. The arctic is still very vunerable to a synoptically similar year to 2007, which IMO would lead to an ice extent well below that of 2007, a good few years of average to below average temperatures, with cloud and few plumes are needed to take it off the in danger list.

What we are probably looking at is a new kind of arctic where the ice will rarely be more than 2 years old and will probably have half the thickness of ice 30 years years ago, this will mean that the ice melt will more than ever be linked to synoptics, some years it will be good, some years the north pole will be exposed and ice free.

What we have had IMO is a typical summer ice melt and what we should expect given the conditions. The shallow NW passage will very likely open most years so will the NE passage, the Deeper passage will IMO open much more often once the last remaining old ice disappears.

[Guest North Sea Snow Convection]

The discussion wrt AGW and METO seasonal forecasting may be largely attributed to me, but doesn't have any bearing on this discussion as far as I am aware..

Anyway, regarding the arctic ice. We know that the jet stream has taken a more northerly trajectory over recent decades and we can see that this has been one manifestation of the positive phases of various natural cycles working in tandem. The effect of this northward shift in the jet stream has been to send storm tracks further north with more frequent warm sectors into the arctic and a change in the air circulation and seasonal growth and ice break up patterns.

The main scientific focus however, rightly or wrongly, has been centred around assumed positive AGW feedbacks that have been suggested to be augmenting or enhancing the warming effects of these natural cycle phases. Much of the assumed AGW effects on the ice concern speculation about leaking gases and the effects of surplus CO2 on the polar atmosphere etc.

We know that many of the natural cycles have now turned into negative phase and so it should become possible to determine the net cooling effects of the change in feedbacks and we should be able to see any changes effected by any southward movement of the jet stream over the years ahead in accordance with these changes. It should also answer questions as to how much, if any, net effect that assumed AGW background forcings have in terms of restricting net cooling, which in turn will help determine the future direction of ice growth or otherwise.

My own view is that too many assumed AGW positive feedbacks are being reckoned to be at work, and that time will show that there are fewer of these, and in some cases that they don't actually exist at all. In tandem with the fact that effects of negative cyclical feedbacks are probably being underestimated, most especially wrt solar forcings, then a bleaker picture than reality for the future of the arctic ice may be being painted. However that is not to say that other unforseen problems might become apparent as the future prognosis starts to look different. That is why time in research has more value imo than acting on premature conclusions based on incomplete scientific hypothesis.

Changes or reversions in atmospheric patterns will imo in turn change the path of storm tracks, wind patterns, currents, frequency of warm plumes, cloud cover, air pressure patterns (as measured by the AO) and albedo effects that will all determine the ebbs and flows of arctic ice growth or decline. In the meantime, some of the assumed AGW feedbacks that are shown to be at work 'in the lab', need to show themselves as evident on the ground as well.

The coming decades will answer many of these questions and we will see what comes out 'in the wash'

Edited September 11, 2009 by North Sea Snow Convection

[stewfox]

What evidence can you provide that the car is slowing down.

At present the top speed of the car was in 2007 , we have about 1,000,000 kmsq more ice this year. That doesnt suggest acceleration or 'steady state' but a slowing down.

Of course its a weak analogy and based over 3yrs is meaningless.

I think the point i was trying to make (and not very well), skeptics dont need to 'prove' the car isnt accelerating as clearly despite all the spin it isnt at present. We have had 2 yrs of ice recovery and yes over a 30yr period it still looks poor but that still shows me the car is slowing down (still faster then 1990 of course)

Dont forget in 2007 ,run away acceleration was all the hype , and we had the perfect hype, when we were told we could have ice free summers by 2013

http://news.bbc.co.u...ech/7139797.stm

Much to play for in 2010

Edited September 11, 2009 by stewfox

[J10]

What is surprising me at the moment, is the consistent level of the falls, around the 20,000 mostly with the odd 40,000 over the past week.

On top of the 2005 figure above other figures of note are 5,312,656 (the 2003-08 average), 5,254,531 which would be 1m above 2007 and 5,207,813 which would be 500k above last year.

Given the rate of loss ranges from 95k (2004) to 363k (2007) with an average loss of 235k From 2nd Sept to minimum ice extent, then a figure of 5.15-5.20m is most likely but hopefully the ice will remain above the markers laid out.

Next update on Sunday, hopefully the first rise will happen before then. :lol:

The new ice extent is 5,254,219 so pending any late adjustments to this figure, we are below 2 of the figures above, and a final figure of around 5.15 to 5.20m is most likely.

A quick assessment of the arctic ice melt from me.

I know we haven't reached the minimum quite yet, as we are still declining slightly, however using Jackones estimates which I completely agree with we can say that a figure around 5200000 is likely.

The ice extent figure for this year is now officially the third lowest on record, however it is a large improvement on 2007 and a sizable improvement on 2008.

Other important facts are that the NE passage is open, the shallow NW passage is open but the deep NW passage is not open. (See attached pictures).

My prediction was the the NW passage would open (I didn't specify deep or shallow, but I did mean deep), this means I was wrong about that. The main reason for this seems to be the deep flow of older ice still coming out of the main arctic blocking the entrance to the NW passage from the west.

June and July saw a similar melt rate to 2008 and pretty similar to 2007, however the gap from mid aug onwards really opened up, the melt slowed down and has ended up with a reasonable final figure.

Temperature conditions around the arctic were very average, slightly below in the centre, slightly above on the Russian side and slightly below on the Canadian side. The US and Canada had on average a pretty cold summer compared to recent summers.

A futher factor which we can't comment on yet is the surviving rate of the older arctic ice. 2 year old ice is more likely to survive than 1 year ice, but ice of 4 or 5 years with a decent thickness is really what's needed. The ice flow for this summer would indicate to me that the ice, apart from in a few isolated areas will be 2 years or newer this come next summer and that there has been a further decline in ice older than 2 years.

The Central Arctic ice always looked in better shape than in the past couple of years, throughout the summer, this an be seen be looking at the Charts IJIS and Cryosphere as an example, this was masked in the early part of the summer, by the rapid loss of ice in the Siberian sectors.

IMO if we have similar weather next summer, then extent is likely to further recover, quite possibly above 2005, however if we have a 2007 type summer then a new record low is likely.

So in essence, the ice pack now is in better shape than 2008 and much better than 2007, but weaker than the years preceding that.

[J10]

The figure for Sept 11 has been increased back to 5,278,594 (but still a drop from the 10th), so we remain over 1m above 2007 and over 500k over 2008 lowpoints.

A final figure of between 5.15 to 5.20m still seems likely.

[Iceberg]

The new ice extent is 5,254,219 so pending any late adjustments to this figure, we are below 2 of the figures above, and a final figure of around 5.15 to 5.20m is most likely.

The Central Arctic ice always looked in better shape than in the past couple of years, throughout the summer, this an be seen be looking at the Charts IJIS and Cryosphere as an example, this was masked in the early part of the summer, by the rapid loss of ice in the Siberian sectors.

IMO if we have similar weather next summer, then extent is likely to further recover, quite possibly above 2005, however if we have a 2007 type summer then a new record low is likely.

So in essence, the ice pack now is in better shape than 2008 and much better than 2007, but weaker than the years preceding that.

I agree Jackone if you look purly at ice extent, but if you look at ice thickness and the age(strength of ice) 2008 was worst than 2007 and this year is likely(IMO) to be worse than 2008. We will have to wait a while though to get the data.

Looking at real time images of the arctic in 2007,2008 and 2009 (many of which have been posted up here) it's very evident that the ice pack (even at the north pole) has been more and more fractured. It all depends on whether there are the melting drivers to take advantage of this. But Ice extent, unless it's obviously showing that there is no ice left is not a very good indicator for the health of the central arctic.

[doctormog]

Have you a link to the current or indeed Arctic area ice thickness datasets? How is the ice measured andover how many locations? Presumably hundreds throughout the arctic over decades to provide a usable dataset. Or is it simply interpreted satellite data over the last few years? (i.e. slightly less accurate/useful than the ice extent and certainly the ice area both of which are significantly higher than the last couple of years).

I've yet to find this dataset for ice thickness so I can look at the numbers, (which of course is the only way to measure statistical trends etc.)

[J10]

I agree Jackone if you look purly at ice extent, but if you look at ice thickness and the age(strength of ice) 2008 was worst than 2007 and this year is likely(IMO) to be worse than 2008. We will have to wait a while though to get the data.

Looking at real time images of the arctic in 2007,2008 and 2009 (many of which have been posted up here) it's very evident that the ice pack (even at the north pole) has been more and more fractured. It all depends on whether there are the melting drivers to take advantage of this. But Ice extent, unless it's obviously showing that there is no ice left is not a very good indicator for the health of the central arctic.

I beg to differ, looking at ice strengths throughout this summer, these have held up better this year than in previous years, I am looking at thicknesses and ice percentages from sites such as IJIS and Cryosphere. As a result, it was clear from June that ice extent was likely to be up this year as the central area was holding up better, as I said so at the time.

Also of course, going into next year there will be more ice greater than one year old, as we are having more ice extent this year.

The Arctic web cam also shows the ice has held up better this year, and indeed better than recent averages. . Of course if you can show charts giving breakdowns between greater that 1 year etc, show them.

I agree that the Central Arctic is looking quite good for ice retention and better than last year, however the Russia side is looking weaker, so we may have a situation where ice retention is up this year, but with an the ice over the Arctic becoming an island.

[Iceberg]

The Arctic web cam is totally misleading though as it moves anywhere from 100 to 500 miles each summer depending on steering currents, winds etc.

Like this comment "Also of course, going into next year there will be more ice greater than one year old, as we are having more ice extent this year." Is correct but is noway the be all and end all of it. We can move ice under 2 years old but less over 2 years than the last year. This distinction is vitally important as it's the ice 2,3 or more years old(to be honest it's the ice 4 years or older which really matter) which is the balwark for the sheet ice to prevent rapid melting.

Many articles I've read have said that although 2007 was a good melt year synoptically wise, it's happened in the past, the difference in 2007 was that alot of the older ice had melted. Polyakov has a similar theory but puts it down to a build up of old ice pushed into a single area which makes the rest of the arctic ice weaker on mass.

If by June it were so clear to you then Jackone then that's fantastic, but a good many reports etc from the major ice centres (many posted on this thread), talked about the possibility of ice extents at or below 2008. The main reason that 2009 didn't meet 2008 was down to synoptics from the middle of August onward, at least IMO, but we will have to agree to disagree.

Your right Doctormog about ice thicknesses and the sparse data (the summer ice thicknesses don't tend to come out much before Oct/Nov time) I believe using the sat data etc it goes back a few years. This is still far from perfect but is the best we have until more surveys like the Catlin survey are done (shame it receieved so much critism on here). However the charts I've already posted on this thread show that ice strength was lower in 2008 than 2007, tbh I don't have the inclination to spend my sunny sunday afternoon digging them out I do alot of research and post alot of it up here, let see what 2009 brings in comparison when it comes out.

[BLAST FROM THE PAST]

Iceberg

For me now I think I will have to wait until next summer melt because you are now talking all ifs and buts.

Very important indeed is how much weaker ice has survived much better this year and with talk of record warm oceans....well an even more startling result this year?

My view, yes synoptics a big part. Jet stream moved/moving south and holding preventing warm plumes entering the arctic with any vigour.

In a way this discounts the warm currents/waters piling into the arctic...I don't think there has been any major switch in ocean currents this year? And again the warmest seas ever? Or is that NOAA fudging the figures.

BFTP