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Arctic sea Ice Extent


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#5811
PottercountyWXobserver

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Are those records for the Laptev???? that is mega torchy to me.

#5812
The_Global_Warmer

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Are those records for the Laptev???? that is mega torchy to me.



I have no idea, but yeah it's mega torchy.


First to Jaxa. Today's prelim puts 2012 2,000km2 behind 2011. 2011 over the next 7 days only drops 200,000km2. This is when 2011 and 2007 diverged and 2011 never caught up again on Jaxa because the ice was never compacted enough for it to do so even though Sea Ice Area from Jaxa was a virtual tie and 2011 beat 2007 by roughly 110,000km2 on Cryosphere Today SIA.

July 25th: 6,977,813km2
July 26th: 6,885,781km2
July 27th: 6,723,125km2(prelim)

Given the pattern the models are showing and the state of the ice, I would expect 2012 to blow by 2011 over the next week. Below is the year to year comparison. The biggest difference is 2012 not only has far more crappy concentrated ice, we know 2012 also has thinner ice in other area's like the Laptev.


Now to the Torchy stuff. This is the Euro starting today through day 7. First we can see there will be compaction loses for the entire run. just not on as large of a scale as the models want to make it towards the end.

Posted Image



Now Days 8-10. By this point, if this actually happened. Considering how thin the ice is, it's hard to say how much and fast it would go. But it would be pretty devastating. This would guarentee a new minimum. The Robust Pacific side would be cleared out fast.

Posted Image

But this is a way's out, so stay tuned, the models can completely flip from this.

#5813
SVT450R

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Jaxa.png

#5814
frankdp23

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The revisions have been large. Sometimes almost nearly chopping the prelim in half.

#5815
TerryM

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The revisions have been large. Sometimes almost nearly chopping the prelim in half.


Yeah - the new sat has it's problems, and I hesitate to compare the results to any other years. The Japanese one should be through with calibration before too long & we'll have something a bit more reliable (I hope)

The central Arctic has taken a huge hit since the 21st, going from the middle of the pack to the bottom. The last 2 days have been particularly brutal.

ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/r11_Central_Arctic_ts.png

Every time a low comes by it leaves nothing but rubble in it's wake.

Terry

#5816
dabize

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The argument we were having a while back about the susceptibility of extent and area ice loss rates to weather conditions in 2007/11 on the one hand vs this year has been revisited by Neven at the Sea Ice Blog with an interesting new post

http://neven1.typepa...-2012.html#more

We'll found out in 2 months if your faith on a new record low extent was warranted. I do not think it is. I'm not talking ice thickness here...I'm talking record low extent which is clear in its definition.

And no, we are not "weeks ahead of 2011 and 2007"...we currently have more ice extent than 2011 and we are close to 2007, either slightly higher or slightly less depending on which source you use for extent. 2007 had a very significant decline from here on out...more than 2011 did. So you need to provide good proof that you think it will be more than 2007 from here on out. That means at a minimum we have 2011 conditions in weather patterns if you assume the ice is worse off than 2011. 2011 had a very strong high pressure anomaly parked over the central arctic ocean...which while not as favorable for ice loss as 2007, was still conductive for melting out the weaker ice pack on the Pacific side....2012 does not look to start off like that in August. Could it perhaps shift into that type of pattern? Yes it could. But right now, there isn't evidence ofthat happening yet, so there is no reason for me to believe the ice extent will decrease at the same rate.


I include the above quote because it summarizes the tone being taken by serious posters on both sides of the argument here - we were either worried (Friv, Terry, Gulley, Vergeant and me) that ice loss in 2012 would no longer be susceptible to arrest by adverse weather conditions (i.e. different from 2011/7), or we were confident that the rules of 2007/11 still prevail (ORH, Skier).

In the end, the issue seemed to be reduced to an article of faith - either one liked one side or the other, which (to me at least) wasn't terribly satisfactory for an important issue.

Hence my interest in this post at ASI, and in reawakening the dragon (you may cast anyone you want in this role, BTW!)

#5817
PhillipS

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The argument we were having a while back about the susceptibility of extent and area ice loss rates to weather conditions in 2007/11 on the one hand vs this year has been revisited by Neven at the Sea Ice Blog with an interesting new post

http://neven1.typepa...-2012.html#more



I include the above quote because it summarizes the tone being taken by serious posters on both sides of the argument here - we were either worried (Friv, Terry, Gulley, Vergeant and me) that ice loss in 2012 would no longer be susceptible to arrest by adverse weather conditions (i.e. different from 2011/7), or we were confident that the rules of 2007/11 still prevail (ORH, Skier).

In the end, the issue seemed to be reduced to an article of faith - either one liked one side or the other, which (to me at least) wasn't terribly satisfactory for an important issue.

Hence my interest in this post at ASI, and in reawakening the dragon (you may cast anyone you want in this role, BTW!)


Excellent post! Neven has a very clear style of presentation.

#5818
ORH_wxman

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Neven's post doesn't really acknowledge that his "favorable" pattern for stopping ice melt has the low pressure well too far toward Asia....it didn't replace the high pressure system in the eastern Beaufort sea, instead it still kept a fairly unfavorable PG where the highest pressures were over the North American side and lowest pressure is over the East Siberian/Laptev Seas.


Its about pressure gradients regardless of what the actual anomalies are in each spot. PG is what drives the wind, not the actual low or high pressure. So he's right that a lot of that yellow and orange in the arctic was replaced by blues and purples....but that didn't change the fact that the PG was still relatively unchanged in terms of being faovrable/unfavorable. The magnitude may have come down a tad, but overall it wasn't favorable to stop compaction. The best pattern he showed there for slowing the ice down was by far the early July 2010 pattern.

#5819
skierinvermont

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Neven's post doesn't really acknowledge that his "favorable" pattern for stopping ice melt has the low pressure well too far toward Asia....it didn't replace the high pressure system in the eastern Beaufort sea, instead it still kept a fairly unfavorable PG where the highest pressures were over the North American side and lowest pressure is over the East Siberian/Laptev Seas.


Its about pressure gradients regardless of what the actual anomalies are in each spot. PG is what drives the wind, not the actual low or high pressure. So he's right that a lot of that yellow and orange in the arctic was replaced by blues and purples....but that didn't change the fact that the PG was still relatively unchanged in terms of being faovrable/unfavorable. The magnitude may have come down a tad, but overall it wasn't favorable to stop compaction. The best pattern he showed there for slowing the ice down was by far the early July 2010 pattern.


The June 16th to June 30th period was very favorable. Probably the most favorable of the nine depicted. Only early July 2010 comes close and I would argue that the greater expansiveness of low pressures in the 2012 period at least compensates for the technically slightly more favorable location in early July 2010. The ridging in the ESB in July 2010 would have favored melt in that area, while late June 2012 had low SLP covering the entire arctic including the ESB.

2011 and 2007 clearly had much more unfavorable patterns with highly to extremely unfavorable patterns present all of June and early July. 2012 and 2010 are close each with 1 favorable, 1 unfavorable, and 1 extremely unfavorable 2 week period. I haven't yet read to see what Neven says about 2010.. I will be interested to see if he arrived at the same conclusion on the similarity of 2012 and 2010.


Also, when you include the most recent week 16th to the 27th, the pattern in 2012 has been again ice preserving, and yet we remain at record low ice area and near record low extent.

#5820
ORH_wxman

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The June 16th to June 30th period was very favorable. Probably the most favorable of the nine depicted. Only early July 2010 comes close and I would argue that the greater expansiveness of low pressures in the 2012 period at least compensates for the technically slightly more favorable location in early July 2010. The ridging in the ESB in July 2010 would have favored melt in that area, while late June 2012 had low SLP covering the entire arctic including the ESB.

2011 and 2007 clearly had much more unfavorable patterns with highly to extremely unfavorable patterns present all of June and early July. 2012 and 2010 are close each with 1 favorable, 1 unfavorable, and 1 extremely unfavorable 2 week period. I haven't yet read to see what Neven says about 2010.. I will be interested to see if he arrived at the same conclusion on the similarity of 2012 and 2010.


Also, when you include the most recent week 16th to the 27th, the pattern in 2012 has been again ice preserving, and yet we remain at record low ice area and near record low extent.



Disagree with your assessment on the late June pattern entirely...it is still a compaction pattern given the PG...even if its colder. I agree with your July 16-22 pattern that he posted...that was definitely better as the PG was more relaxed with the low being centered further toward North America.

#5821
skierinvermont

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Disagree with your assessment on the late June pattern entirely...it is still a compaction pattern given the PG...even if its colder. I agree with your July 16-22 pattern that he posted...that was definitely better as the PG was more relaxed with the low being centered further toward North America.


It is not a compaction pattern with the low centered very near to 180 longitude. That would be a neutral DA. The only area that would be compacted would be the Beaufort, which traditionally has the thickest ice of all the peripheral seas. And if you have followed the cryosphere today maps at all you will see that the ice in the Laptev ESB and Chukchi has been spreading out, not compacting.

So it is a neutral DA, with very low SLPs keeping things cooler and cloudier.

#5822
ORH_wxman

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It is not a compaction pattern with the low centered very near to 180 longitude. That would be a neutral DA. The only area that would be compacted would be he Beaufort. And if you have followed the cryosphere today maps at all you will see that the ice in the Laptev ESB and Chukchi has been spreading out, not compacting.



A low further toward the Asian side like late June and not bulging toward the CA like more recent would increase the ice extent some for the Chukchi but compact it in the ES/Laptev..esp ES as it was actually far enough north to push it toward Chukchi. The ice in the ES has been dropping pretty good since mid-June while we saw it steady out in the Chukchi for a time.

Regardless, its still not a good pattern when you see the lowest anomalies all toward the Asian side...more recently, the higher pressure anomalies were eroded on the American side with that same vortex position except slightly toward N.A. and also bulging southward toward the CA, and that is when we saw a slow down the last couple weeks.


I'm just disagreeing with Neven when he thinks that was favorable for ice retention. Its not. The low anomalies are bulged toward the Laptev in late June which is not as good as having it biased toward the C.A. like the more recent pattern he posted and the one he posted for 2010.

Since we are nitpicking between these recent years where the values aren't that far apart, then these differences will matter.

#5823
skierinvermont

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A low further toward the Asian side like late June and not bulging toward the CA like more recent would increase the ice extent some for the Chukchi but compact it in the ES/Laptev..esp ES as it was actually far enough north to push it toward Chukchi. The ice in the ES has been dropping pretty good since mid-June while we saw it steady out in the Chukchi for a time.

Regardless, its still not a good pattern when you see the lowest anomalies all toward the Asian side...more recently, the higher pressure anomalies were eroded on the American side with that same vortex position except slightly toward N.A. and also bulging southward toward the CA, and that is when we saw a slow down the last couple weeks.


I'm just disagreeing with Neven when he thinks that was favorable for ice retention. Its not. The low anomalies are bulged toward the Laptev in late June which is not as good as having it biased toward the C.A. like the more recent pattern he posted and the one he posted for 2010.

Since we are nitpicking between these recent years where the values aren't that far apart, then these differences will matter.


So you're arguing the late June pattern would have compacted the ESB? The ESB was essentially still 100% frozen at the end of June. Only the Laptev and Beaufort appear to have melted, the Laptev via in situ melt and the Beaufort as a combination of compaction and in situ melt continuing from the extremely warm early June that got the melt there going early.

#5824
skierinvermont

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A lot of the model runs lately have been showing a strong low setting up in the Kara/Laptev and driving the current heat in Asia up into the arctic. Could be a devastating pattern if it developed. In the meantime, the pattern doesn't look too bad with a brief heat shot hitting the Laptev and quickly moving east the next couple days. After that low pressure dominates although it is a little too displaced to the Asian side to be ideal. The Beaufort will continue to fair poorly, perhaps the Chukchi at times too.

#5825
The_Global_Warmer

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Pacific ice is taking a beating. A small compaction regime is underway. But this really nails the coffin in the idea that the ice on the Pacific side was stable or robust. The Beaufort has taken a torrid beating this summer and will continue too. I won't be surprised if we see reports of 3M+ ice floes melting out again this season.

The Chukchi has been hammered with ice from the Beaufort a lot this summer. Never the less it's all going to melt out.

Posted Image

#5826
ORH_wxman

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So you're arguing the late June pattern would have compacted the ESB? The ESB was essentially still 100% frozen at the end of June. Only the Laptev and Beaufort appear to have melted, the Laptev via in situ melt and the Beaufort as a combination of compaction and in situ melt continuing from the extremely warm early June that got the melt there going early.



We are arguing minor nitpicks...I already mentioned that before. ES declined sharply in late June while the Chukchi stabilized for a time. I'm not sure what you are arguing if its on a larger scale or not. But my main point was that Neven's assesrtion that just because a lot of blue appeared over the Arctic, that doesn't mean it was "good" for the ice since the greatest low anomlies were still biased toward the Asan side. The greatest low anomalies werent as biased in the recent pattern as most of the high anomalies on the N.A. evaporated compared to the June map.

If all the ice over there is mostly frozen anyway in late June, why are we having this debate at all?

The small differences matter since Neven is the one who is nitpicking between the close values at the end of June between 2007, 2011, and 2012 through right now. The debate was brought about in the first place by those who are essentiually guaranteeing a 2007 record being broken on extent. I was countering it with the current ice extent and the patterns that have happened and are forecasted.

#5827
ORH_wxman

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I think Friv's animation shows why a 2007 min is hard to achieve when you have ice that far beyond 2007 on the PAC side there...you get holes in the "in situ" melt areas but its often because of ice being blown around together...the holes appear but you can see how the northwest sde of the main ice pack got a much better concentration....so there is wasted effort getting rid of all of that before you can really eat into the main parts where 2007 succeeded in doing so while we have a ticking clock about 5 weeks long for serious losses.

#5828
skierinvermont

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We are arguing minor nitpicks...I already mentioned that before. ES declined sharply in late June while the Chukchi stabilized for a time. I'm not sure what you are arguing if its on a larger scale or not. But my main point was that Neven's assesrtion that just because a lot of blue appeared over the Arctic, that doesn't mean it was "good" for the ice since the greatest low anomlies were still biased toward the Asan side. The greatest low anomalies werent as biased in the recent pattern as most of the high anomalies on the N.A. evaporated compared to the June map.

If all the ice over there is mostly frozen anyway in late June, why are we having this debate at all?

The small differences matter since Neven is the one who is nitpicking between the close values at the end of June between 2007, 2011, and 2012 through right now. The debate was brought about in the first place by those who are essentiually guaranteeing a 2007 record being broken on extent. I was countering it with the current ice extent and the patterns that have happened and are forecasted.


I was beginning to wonder the same given everything is still mostly frozen in June anyways. I guess temperature might matter more.

And I agree that the SLP pattern in early July 2010 was the most favorable. But it's not just about the pressure gradient.. clear skies and warm temperatures are bad too. Early July 2010 did have some HP in the ESB.

Without nitpicking I think it is fair to say that June and early July 2012 are most similar to 2010 and that 2007 and 2011 were much worse. And yet we remain in a three way tie with 2007 and 2011, while 2010 was substantially better. This is despite the fact that the past 10 days have also seen a much less harsh pattern than other recent years.

This is all reasonable evidence that the ice is exceptionally thin and vulnerable.

#5829
skierinvermont

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I think Friv's animation shows why a 2007 min is hard to achieve when you have ice that far beyond 2007 on the PAC side there...you get holes in the "in situ" melt areas but its often because of ice being blown around together...the holes appear but you can see how the northwest sde of the main ice pack got a much better concentration....so there is wasted effort getting rid of all of that before you can really eat into the main parts where 2007 succeeded in doing so while we have a ticking clock about 5 weeks long for serious losses.


I'm also in agreement with this, but it will also be much easier to break the record on area than extent this year.

#5830
ORH_wxman

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I was beginning to wonder the same given everything is still mostly frozen in June anyways. I guess temperature might matter more.

And I agree that the SLP pattern in early July 2010 was the most favorable. But it's not just about the pressure gradient.. clear skies and warm temperatures are bad too. Early July 2010 did have some HP in the ESB.

Without nitpicking I think it is fair to say that June and early July 2012 are most similar to 2010 and that 2007 and 2011 were much worse. And yet we remain in a three way tie with 2007 and 2011, while 2010 was substantially better. This is despite the fact that the past 10 days have also seen a much less harsh pattern than other recent years.

This is all reasonable evidence that the ice is exceptionally thin and vulnerable.



I agree with this part....but you are also leaving out that 2010 had terrible conditions in June that caused it to drop below all years so it was climbing from a deficit...it got as low as 227,000 sq km lower than 2011 and a whopping 640,000 sq km below 2007 on 6/29.

If ice conditions are becoming progressively worse and worse recently where the patterns don't matter as much, there is no way 2010 should have been able to come back from that deficit within 18 days...and 2011 coming back from a 250,000 sq km deficit within about 10 days. (and then make it matter at the end....Vergent was claiming that these "comebacks" were false and all the ice would melt out eventually...so therefore these come backs should be fake on a seasonal level)

I guess I'm just skeptical of the talk that says that because the ice is in shambles on the periphery and that it will all melt out "in situ" that it meansthat we will pass 2007 easily without having to worry much about the weather patterns.

#5831
skierinvermont

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I agree with this part....but you are also leaving out that 2010 had terrible conditions in June that caused it to drop below all years so it was climbing from a deficit...it got as low as 227,000 sq km lower than 2011 and a whopping 640,000 sq km below 2007 on 6/29.

If ice conditions are becoming progressively worse and worse recently where the patterns don't matter as much, there is no way 2010 should have been able to come back from that deficit within 18 days...and 2011 coming back from a 250,000 sq km deficit within about 10 days. (and then make it matter at the end....Vergent was claiming that these "comebacks" were false and all the ice would melt out eventually...so therefore these come backs should be fake on a seasonal level)

I guess I'm just skeptical of the talk that says that because the ice is in shambles on the periphery and that it will all melt out "in situ" that it meansthat we will pass 2007 easily without having to worry much about the weather patterns.


Completely agree with the last statement and some people are definitely taking it too far. The weather matters. I think Neven's argument was not that the weather doesn't matter, but that similar weather to 2010 (perhaps better if you include the most recent 10 days) and significantly better weather than 2007 and 2011 is producing ice area/extent equal to 2007 and 2011 and less than 2010. A 2007 or 2011-esque pattern would have produced even lower extent/area.

#5832
ORH_wxman

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Completely agree with the last statement and some people are definitely taking it too far. The weather matters. I think Neven's argument was not that the weather doesn't matter, but that similar weather to 2010 (perhaps better if you include the most recent 10 days) and significantly better weather than 2007 and 2011 is producing ice area/extent equal to 2007 and 2011 and less than 2010. A 2007 or 2011-esque pattern would have produced even lower extent/area.



I just don't totally agree with Neven on that last part though....if you look at the maps its not obvious. The general theme has been a pretty decent PG that favors compaction and also warmer air being advected north....2009 was the closest thing to a -DA recently, but still wasnt. 2006 was the last true -DA summer.

Now that can probably be tied to the changing climate up north...i.e. the +DA is not a coincidence and even the crudest of statistical analysis says it is NOT a coincidence for anyone who knows stat101 fairly well. The reason for it though? I think that is much deeper than the AGW debate. The biggest reason I'm skeptical this change can be attributed on a massive majority by AGW is because the climate models don't predict it right...at first that sounds weak because anyone can just say "well they are underestimating the GHG forcing in the arctic"....that might be true and I would never be stupid enough to rule that out, but why is it completely underestimating it at the south pole? For it to whiff so badly on both poles in completely opposite directions tells us that there is a lot we do not know about the polar climate systems yet...and the odds of that happening on an accurate climate model even to a low confidence interval is fairly low.

We really do not have any good papers on either phenonmenon...we have papers on the arctic that say a good chunk can be explained by AGW, but then a pretty large amount cannot be and there is a lot of speculation in those papers...but for the southern polar areas, its mostly crickets except for a few theories and a couple papers that don't seem to last long...first it was aerosels, but that has been debunked by a recent paper. So we really are having a hard time getting a handle on these changes at the poles where the climate always changes the fastest anyway regardless if we are talking AGW or not.

I know that last part is bit of a side step from our current discussion, but I think its a very interesting and worthy discussion as well. Its very easy to blame the arctic on AGW and then come up with a theory to excuse the southern polar area for not cooperating. The southern polar sea is the one ocean area globally that is declining rapidly in SSTs.

#5833
skierinvermont

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I just don't totally agree with Neven on that last part though....if you look at the maps its not obvious. The general theme has been a pretty decent PG that favors compaction and also warmer air being advected north....2009 was the closest thing to a -DA recently, but still wasnt. 2006 was the last true -DA summer.

Now that can probably be tied to the changing climate up north...i.e. the +DA is not a coincidence and even the crudest of statistical analysis says it is NOT a coincidence for anyone who knows stat101 fairly well. The reason for it though? I think that is much deeper than the AGW debate. The biggest reason I'm skeptical this change can be attributed on a massive majority by AGW is because the climate models don't predict it right...at first that sounds weak because anyone can just say "well they are underestimating the GHG forcing in the arctic"....that might be true and I would never be stupid enough to rule that out, but why is it completely underestimating it at the south pole? For it to whiff so badly on both poles in completely opposite directions tells us that there is a lot we do not know about the polar climate systems yet...and the odds of that happening on an accurate climate model even to a low confidence interval is fairly low.

We really do not have any good papers on either phenonmenon...we have papers on the arctic that say a good chunk can be explained by AGW, but then a pretty large amount cannot be and there is a lot of speculation in those papers...but for the southern polar areas, its mostly crickets except for a few theories and a couple papers that don't seem to last long...first it was aerosels, but that has been debunked by a recent paper. So we really are having a hard time getting a handle on these changes at the poles where the climate always changes the fastest anyway regardless if we are talking AGW or not.

I know that last part is bit of a side step from our current discussion, but I think its a very interesting and worthy discussion as well. Its very easy to blame the arctic on AGW and then come up with a theory to excuse the southern polar area for not cooperating. The southern polar sea is the one ocean area globally that is declining rapidly in SSTs.


I think the key is the relative favorable/unfavorable conditions. You're right that no year is truly favorable except 2009 which was good but not great. So we start to focus on other things besides the DA that start to explain the differences we observe every year. Like general storminess and cool weather even in a +DA can help and the exact placement and magnitude of ridging and pressure gradients becomes important. These somewhat nitpicky differences explain 500,000 sq km swings in the anomaly mid-season. 2007 and 2011 had completely ideal melt conditions in the early season (2011 got a bit better late season). And yet we remain tied with them... the ice is clearly thinner. I don't think anybody would deny that the ice is thinner than the start of 2007.. but possibly being even thinner than 2011? That would be news. Not that Neven's analysis proves it definitively.. but it lends some evidence in favor of the continued thinning along with PIOMAS.


Also it would be news to me if the theories explaining the rising AAO (which IIRC largely concerned aerosols and/or ozone) had been discredited. Can you point me in the right direction?

#5834
ORH_wxman

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I think the key is the relative favorable/unfavorable conditions. You're right that no year is truly favorable except 2009 which was good but not great. So we start to focus on other things besides the DA that start to explain the differences we observe every year. Like general storminess and cool weather even in a +DA can help and the exact placement and magnitude of ridging and pressure gradients becomes important. These somewhat nitpicky differences explain 500,000 sq km swings in the anomaly mid-season. 2007 and 2011 had completely ideal melt conditions in the early season (2011 got a bit better late season). And yet we remain tied with them... the ice is clearly thinner. I don't think anybody would deny that the ice is thinner than the start of 2007.. but possibly being even thinner than 2011? That would be news. Not that Neven's analysis proves it definitively.. but it lends some evidence in favor of the continued thinning along with PIOMAS.



I agree this is where to look...but my biggest criticism of Neven was that once he started to nitpick the years, he decided to use generalized pattern recognition which isn't not a sufficient way to analyze the differences once you are already nitpicking small amounts in ice extent. If you are nitpicking the amounts, then you have to nitpick the pattern which he failed to do. I nitpicked the pattern...he didn't.

I also agree with you the ice is thinner than 2007...there is zero doubt about that. 2011? maybe...we had a bad winter last year that exported a lot of ice. But since this was about extent and not volume, I am not really focusing on that.

The thickness does have a level predictibility on ice extent, but its not that large on the short term....its much larger on the longer term. So a small difference in thickness between this year and last year should not produce wildly different results under the same pattern...unfortunately, we never get the same pattern from year to year...we can get similar patterns...but never the exact same.

I only bolded that one part as to give my main reason why I disagree with many that we have reached a "new threshold" where weather patterns don't matter much which I already know you agree with, but many who read and post in this thread do not agree with.

I think we have decent evidence that a "new threshold" doesn;t get reached in the arctic ice pack....but I could be wrong since the climate there is pretty wild....but the papers that support my theory try and melt all the ice out and then see what happens in the current climate and comes back quickly which means its unlikely that some mega-threshold reaches an ice free arctic all of the sudden. It seems to be a sloped process.

#5835
skierinvermont

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Also it would be news to me if the theories explaining the rising AAO (which IIRC largely concerned aerosols and/or ozone) had been discredited. Can you point me in the right direction?


bump in case you missed this edit

#5836
ORH_wxman

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bump in case you missed this edit



I'm on a crappy connection right now on an ipad...so I'll link as soon as I get back to my laptop...you should be able to find it by googling "aerosols Antarctica global warming"...the jist of the paper was that antarctica showed cooling patterns in the past without any aerosol contamination while the Arctic warmed and that the most rapid period of warming in Antarctica was during the height of aerosols basically dismissing them as the reason.

I could be wrong on the total synopsis there, but I will link the paper when I find the link. It was very recent...should be 2012. It also matches up well with the southern ocean cooling in recent years opposite of the arctic warming....which has to date been completely unexplained by any GCMs even with the input of the ozone hole over the Antarctic.

#5837
ORH_wxman

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These are the southern ocean SST anomalies...I believe they are below 60S...

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These SSTs support most of the Antarctic sea ice gain which was mostly after 2005 on the 1979-present data.

#5838
CoastalWx

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I just don't totally agree with Neven on that last part though....if you look at the maps its not obvious. The general theme has been a pretty decent PG that favors compaction and also warmer air being advected north....2009 was the closest thing to a -DA recently, but still wasnt. 2006 was the last true -DA summer.

Now that can probably be tied to the changing climate up north...i.e. the +DA is not a coincidence and even the crudest of statistical analysis says it is NOT a coincidence for anyone who knows stat101 fairly well. The reason for it though? I think that is much deeper than the AGW debate. The biggest reason I'm skeptical this change can be attributed on a massive majority by AGW is because the climate models don't predict it right...at first that sounds weak because anyone can just say "well they are underestimating the GHG forcing in the arctic"....that might be true and I would never be stupid enough to rule that out, but why is it completely underestimating it at the south pole? For it to whiff so badly on both poles in completely opposite directions tells us that there is a lot we do not know about the polar climate systems yet...and the odds of that happening on an accurate climate model even to a low confidence interval is fairly low.

We really do not have any good papers on either phenonmenon...we have papers on the arctic that say a good chunk can be explained by AGW, but then a pretty large amount cannot be and there is a lot of speculation in those papers...but for the southern polar areas, its mostly crickets except for a few theories and a couple papers that don't seem to last long...first it was aerosels, but that has been debunked by a recent paper. So we really are having a hard time getting a handle on these changes at the poles where the climate always changes the fastest anyway regardless if we are talking AGW or not.

I know that last part is bit of a side step from our current discussion, but I think its a very interesting and worthy discussion as well. Its very easy to blame the arctic on AGW and then come up with a theory to excuse the southern polar area for not cooperating. The southern polar sea is the one ocean area globally that is declining rapidly in SSTs.


That's a good post.

#5839
dabize

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Very interesting and informative exchange.

It seems to me that both of your views are much more nuanced than they seemed to be earlier when you were rebutting my concerns (and those of the other "worriers" here). It is only fair to point out that the same is true on this side of the argument (in my case at least). I am very concerned that the rules may have changed this year because of the low ice volumes and high SSTs this year and in the past few years. This is not the same as saying that the weather doesn't matter at all any more - it is saying that we can't assume that the weather is still the dominant factor driving SIE and SIA minima, which is what you appeared to be doing in earlier arguments. I am glad to see that this is not your position!

As for the Antarctic, it seems to me that there are many reasons not to expect the same changes there that have been seen in the Arctic.
It should first be pointed out that the drop in SSTs over the past few years is minimal and not remotely comparable to the magnitude of SST increases in the Arctic. Ditto for sea ice gains. That said, it is clear that there has been no warming (as seen in these parameters), and that there may have been a slight decrease. However there have been plenty of other signs of warming (e.g. ice shelf loss). Even the reports of thicker glacial/ice sheet ice could be readily attributed to the greater atmospheric heat content and greater snowfall to be expected with a warming atmosphere, especially in marginal areas.

There are obvious differences between the Arctic and Antarctic that might account for the failure to see warming in SSTs and SIA/E decreases. Two stand out in particular.

A: the presence of proportionally much more fresh water ice (i.e. glacier/ice shelf ice) than sea ice in the Antarctic than in the Arctic. There is not only more glacial and ice shelf ice total there (WAIS+EAIS>> GIS), there is also more that is being melted (the WAIS ice shelves alone must produce more than the GIS, although that might be changing as of this summer). This means that any increased heat goes disproportionately into melting land ice, which is not a factor in the SIA/E numbers. This melting DOES result in the addition of 0C fresh water to the Antarctic seawater, which tends to stay on the surface more than saltwater at the same temperature, thereby cooling SSTs (or at least restraining their rise). This also favors increased sea ice formation.

B: the obvious geographical differences - Antarctica is a continental land mass that is isolated from the rest of the world by circumpolar currents, whereas the Arctic is dominated by water, but surrounded by intruding land masses, which serve to conduct heat from the rest of the world into the area. The air temps over central Antarctica are thus the coldest on Earth and have maintained conditions (high albedo etc.) which tend to be self perpetuating and resistant to AGW. The melting in Greenland this summer is surprising and unexpected even by the "worriers" - because we all thought the GIS was ruled by the same rules as the Antarctic, but on a smaller scale. Given all this, I can't imagine what anyone would expect the same rules to apply to the Antarctic and the Arctic under current conditions.

#5840
The_Global_Warmer

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Very interesting and informative exchange.

It seems to me that both of your views are much more nuanced than they seemed to be earlier when you were rebutting my concerns (and those of the other "worriers" here). It is only fair to point out that the same is true on this side of the argument (in my case at least). I am very concerned that the rules may have changed this year because of the low ice volumes and high SSTs this year and in the past few years. This is not the same as saying that the weather doesn't matter at all any more - it is saying that we can't assume that the weather is still the dominant factor driving SIE and SIA minima, which is what you appeared to be doing in earlier arguments. I am glad to see that this is not your position!

As for the Antarctic, it seems to me that there are many reasons not to expect the same changes there that have been seen in the Arctic.
It should first be pointed out that the drop in SSTs over the past few years is minimal and not remotely comparable to the magnitude of SST increases in the Arctic. Ditto for sea ice gains. That said, it is clear that there has been no warming (as seen in these parameters), and that there may have been a slight decrease. However there have been plenty of other signs of warming (e.g. ice shelf loss). Even the reports of thicker glacial/ice sheet ice could be readily attributed to the greater atmospheric heat content and greater snowfall to be expected with a warming atmosphere, especially in marginal areas.

There are obvious differences between the Arctic and Antarctic that might account for the failure to see warming in SSTs and SIA/E decreases. Two stand out in particular.

A: the presence of proportionally much more fresh water ice (i.e. glacier/ice shelf ice) than sea ice in the Antarctic than in the Arctic. There is not only more glacial and ice shelf ice total there (WAIS+EAIS>> GIS), there is also more that is being melted (the WAIS ice shelves alone must produce more than the GIS, although that might be changing as of this summer). This means that any increased heat goes disproportionately into melting land ice, which is not a factor in the SIA/E numbers. This melting DOES result in the addition of 0C fresh water to the Antarctic seawater, which tends to stay on the surface more than saltwater at the same temperature, thereby cooling SSTs (or at least restraining their rise). This also favors increased sea ice formation.

B: the obvious geographical differences - Antarctica is a continental land mass that is isolated from the rest of the world by circumpolar currents, whereas the Arctic is dominated by water, but surrounded by intruding land masses, which serve to conduct heat from the rest of the world into the area. The air temps over central Antarctica are thus the coldest on Earth and have maintained conditions (high albedo etc.) which tend to be self perpetuating and resistant to AGW. The melting in Greenland this summer is surprising and unexpected even by the "worriers" - because we all thought the GIS was ruled by the same rules as the Antarctic, but on a smaller scale. Given all this, I can't imagine what anyone would expect the same rules to apply to the Antarctic and the Arctic under current conditions.



You are always kind and gracious. Even for a "worrier". It's amazing how quickly acceptance of reality takes place, either you accept it or you move on. I found this forum 5 years ago. Back then the notion that SSTs, solar insolation, and warm air were taking over and driving the Sea Ice into the ground was mocked, laughed at, and torn apart. 2007 was a blip and the recovery was well on it's way. No, I am not saying everyone who wasn't a "worrier" thought we would be at minimums of 6.0-7.0 mil km2 by 2012. But a continued drop in volume(which was and still is dismissed to easily), and the obvious change in SIE & SIA was not expected at all.

The arctic like every other place on this planet is non-linear. One event can lead to another that can lead to another and so on.

The Basic Players:

The Sun
The Ice
The Snow
The Water
The Wind
The Clouds
The Rain
The Land
The GHG's



I agree with you. pretty much across the board. This is a 3D non-linear system, moving on what we perceive as a linear plane. If you miss an important factor(process) in this wickedly wild system. You are going to end up to high or to low. I think Albedo was the single largest over-looked or dismissed factor. Folks either thought it to be non-important or they didn't believe Piomas. And used other sources like PIPS. Remember when the Cryosat-2 prelim graph came out. I don't know if you were around then. Besides the obvious impossible ice thickness of 2M or more over the entire covered region. What the hell you know? This was right when I took a major interest in this and started to educate myself about all things arctic. Anyways after this graph came out, I started to research albedo big time and solar insolation/ice penetration. It should have been fairly obvious to anyone who was already degreed in climotology and had any background with arctic sea ice that this was virtually impossible given the previous summer state & given the state of the ice the date this was released.


Everyone was fixated on piomas vs cryosat. What about realistic albedo? I did a google search and found papers measuring albedo and ice thickness and ice age going back a long time. An ice sheet, remember by May it would be even thicker would have a a very high albedo and in no chance end up like 2011 did. Eventually I found the info/data I was looking for and realized albedo was the blame.

Of course no two years is the same but the same overall reduction in thickness is happening all over the arctic.

It's all tied to together, what drives the pattern? How can the arctic stay cold if the ice is to thin to reflect enough sun light back for it to stay cold during the summer to keep more ice than we are seeing now? Seems like a cyclical positive feedback that was started by something out of balance that caused something else to be out of balance and so on.

With all of that said, when will the arctic go ice free? It might be longer than many think now-days, but with that said I also do not think we are going to see summer ice coverage go up passed the average of the 2007-2012 period again without outside intervention like a change in solar insolation or a counter to GHG forcing.


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#5841
bluewave

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Friv, here's a recent paper on the topic:

http://www.agu.org/p...2GL051432.shtml

There is an ongoing shift in the Arctic sea ice cover from multiyear ice to seasonal ice. Here we examine the impact of this shift on sea ice albedo. Our analysis of observations from four years of field experiments indicates that seasonal ice undergoes an albedo evolution with seven phases; cold snow, melting snow, pond formation, pond drainage, pond evolution, open water, and freezeup. Once surface ice melt begins, seasonal ice albedos are consistently less than albedos for multiyear ice resulting in more solar heat absorbed in the ice and transmitted to the ocean. The shift from a multiyear to seasonal ice cover has significant implications for the heat and mass budget of the ice and for primary productivity in the upper ocean. There will be enhanced melting of the ice cover and an increase in the amount of sunlight available in the upper ocean.

http://www.agu.org/j...8/2012GL051432/

From 1 March to 1 October, the total solar heat input to the multiyear ice was 893 MJ m−2 compared to 1235 MJ m−2 to the seasonal ice. Keeping the incident solar and the onset dates of melt and freezeup the same; the shift from multiyear to seasonal ice increased the solar heat input by 342 MJ m−2, a 38% increase and enough heat to potentially thin the ice by 1.02 m

#5842
TerryM

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Paul k's comments on Neven's post is a must read.
Paul's observations carry a huge amount of weight as anyone who followed him last year can attest.

Terry

#5843
The_Global_Warmer

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Friv, here's a recent paper on the topic:

http://www.agu.org/p...2GL051432.shtml

There is an ongoing shift in the Arctic sea ice cover from multiyear ice to seasonal ice. Here we examine the impact of this shift on sea ice albedo. Our analysis of observations from four years of field experiments indicates that seasonal ice undergoes an albedo evolution with seven phases; cold snow, melting snow, pond formation, pond drainage, pond evolution, open water, and freezeup. Once surface ice melt begins, seasonal ice albedos are consistently less than albedos for multiyear ice resulting in more solar heat absorbed in the ice and transmitted to the ocean. The shift from a multiyear to seasonal ice cover has significant implications for the heat and mass budget of the ice and for primary productivity in the upper ocean. There will be enhanced melting of the ice cover and an increase in the amount of sunlight available in the upper ocean.



I wonder if this helps enhance of even cause the dipole pattern.

Or does it help heat influx in other ways.


IIRC you have posted H5 height anomalies going back to the 1950s and it has shown a steady increase for 50-60 years in them going up.



another pattern that mimics a dipole Anomaly is this one that is showing up again. Elongated SLP over NW Canada and HP over the Canadian Archipelago with an elongated SLP over the Russian side. This not only creates a flow of compaction, obviously not as powerful as a straight up natural DPA but it does the job.

Posted Image


Posted Image

#5844
bluewave

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I wonder if this helps enhance of even cause the dipole pattern.

Or does it help heat influx in other ways.


IIRC you have posted H5 height anomalies going back to the 1950s and it has shown a steady increase for 50-60 years in them going up.



another pattern that mimics a dipole Anomaly is this one that is showing up again. Elongated SLP over NW Canada and HP over the Canadian Archipelago with an elongated SLP over the Russian side. This not only creates a flow of compaction, obviously not as powerful as a straight up natural DPA but it does the job.

Posted Image


Posted Image


Yeah, I saved the slide form Stu Ostro's presentation.



#5845
The_Global_Warmer

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Friv, here's a recent paper on the topic:

http://www.agu.org/j...8/2012GL051432/

From 1 March to 1 October, the total solar heat input to the multiyear ice was 893 MJ m−2 compared to 1235 MJ m−2 to the seasonal ice. Keeping the incident solar and the onset dates of melt and freezeup the same; the shift from multiyear to seasonal ice increased the solar heat input by 342 MJ m−2, a 38% increase and enough heat to potentially thin the ice by 1.02 m



That is amazing. Then when we take into account thickness as ice thins to .75-1.5 Meters thick pending Brine and age bottom melt starts to increase on a bell curve as the solar radiation penetrates through the ice and heats up the water below.


Most of the FYI is 2 meters thick or less.



It's July 27th and the North West Passage blew open. It was probably open for at least a couple days. But what was seemingly forever land locked ice just finally broke and disintegrated.


Back in June buoys were showing 4 CM per day ice loss on average for a couple weeks. Right before the ice melt got to bad that the buoys "fell" or "tipped" over and stopped measuring ice thickness properly we saw two days on one of the buoys in FYI North of the NWP.

http://imb.crrel.usa...y.mil/2012E.htm


it's likely most of the ice in the NWP was also 2 Meters maybe a little more or less. Melt likely started a week earlier. Temperatures were likely a bit cooler. More impressive is how cold the buoy temps are. Land temps even up there have reached 15-20C. That heat hits the ice and goes right into melt. But eventually the sunlight day after day with the HP's and warm air smoked the ice. within 40 days maybe 50. maybe less the North West Passage crumbled.

the models show the blow torch coming back big time. The remaining ice will bow out if that comes to pass, in fact I think the ice in the channels North of the NWP where those buoys are will melt out if we see a Dipole or just HP there with warm temps in August.



That is a pretty big albedo change. And we used to see Minimums in the 8-10 million square kilometer range.

It's hard to imagine actually dropping into the 2-3 mil square kilometer range at all. I think this winter is pretty crucial. A dumping of the MYI mess 2012 leaves over would leave the arctic sea ice super exposed next summer. Something has to give. Either an equilibrium of sorts will be achieved or what? Yeah, we haven't had winds to see a "blow out" But it's pretty clear the ice is in crappier shape.

So if this winter is "good" for the ice. The question is how? What is going to be so much different?



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