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ChrisReynolds

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Re: The 2015 melting season
« Reply #2800 on: July 30, 2015, 06:17:25 PM »

What the hell is going on?

Just ignore it.

ChrisReynolds

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Re: The 2015 melting season
« Reply #2801 on: July 30, 2015, 06:21:08 PM »
I think, weatherdude, you should stop bullshitting around about things that you do not understand. Climate models (CMIP5) with updated forcings (yes, unheard of, but somehow people failed to predict volcanic eruptions...) are fully in line with the observations (and do _NOT_ overpredict temperature rise), and they do have ECS between 2.1 and 4.5K.
http://onlinelibrary.wiley.com/doi/10.1029/2012GL051607/full

Apart from that:
Combining this paper:
http://www.nature.com/ngeo/journal/v7/n9/abs/ngeo2228.html

with this one:
http://onlinelibrary.wiley.com/doi/10.1002/2015GL064888/abstract

I suppose that one can call your unfunded blunder about low climate sensitivity in the 1.5 region pretty optimistic, given that the transient response is already above 1.8K.
Maybe some divine intervention lowers the climate sensitivity below the transient response?

Seconded.

***

Right, now somewhere in this thread was an on topic and very relevant discussion of processes involved in the late summer melt, there might also be some enlightening observations about current conditions.

Puts on pith helmet and proceeds upthread pushing through the dense undergrowth.

Neven

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Re: The 2015 melting season
« Reply #2802 on: July 30, 2015, 06:27:01 PM »
Right, now somewhere in this thread was an on topic and very relevant discussion of processes involved in the late summer melt, there might also be some enlightening observations about current conditions.

Puts on pith helmet and proceeds upthread pushing through the dense undergrowth.

Exactly! There was a bloody fantastic discussion going on about the influence of clouds in the weeks to come, and now it's a mess again.

I want to urge everyone to 1) stay on-topic, and 2) when you see someone go off-topic invite him over to one of the various excellent threads on this forum.

Unless that person is me. Why? Well, to put it like Tony Montana: Who put this thing together? Me! That's who! Who do I trust? Me!  ;)

Off-topic jokes are allowed, just not the stuff that veers off many comments at a time.
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Csnavywx

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Re: The 2015 melting season
« Reply #2803 on: July 30, 2015, 06:27:50 PM »
Love the paper link. It demonstrates what happens all too often in the "skeptic"sphere -- the paper doesn't say what they think it does. This paper has literally nothing to do with radiative forcing via CO2 and everything to do with trying to improve convective parameterizations in models by using changes in model geometry and reporting the results.

BornFromTheVoid

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Re: The 2015 melting season
« Reply #2804 on: July 30, 2015, 06:28:20 PM »

The IPCC lowered the range of climate sensitivity from 2 -4.5 C down to 1.5-4.5 C in their last assessment. Over 95 percent of climate models have overestimated the warming trend since 1979. It has become increasingly clear that the climate is less sensitive then originally projected. (And in reality I predict it is much lower) The climate has always changed naturally and will continue to do so, and for you to claim warming from anthropogenic forcing are worse than predicted and to try and distinguish anthropogenic warming from warming in natural variation shows your unscientific bias. Here is a paper claiming CO2 has a radiative cooling effect. Am I claiming the earth is cooling? No Let's get back to logic and most importantly back on topic.
http://onlinelibrary.wiley.com/doi/10.1002/qj.2628/abstract

The paper you linked to isn't about the climate impacts of CO2. When the paper refers to positive or negative feedbacks at different temperatures, it's referring to feedbacks on self aggregating convection in the model they use.

It's best to think a little rather than blindly accepting what the climate denier blogs tell you.

EDIT: Sorry for going off topic, Neven. Is there a suitable thread for these comments elsewhere?
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

weatherdude88

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Re: The 2015 melting season
« Reply #2805 on: July 30, 2015, 06:47:05 PM »

The IPCC lowered the range of climate sensitivity from 2 -4.5 C down to 1.5-4.5 C in their last assessment. Over 95 percent of climate models have overestimated the warming trend since 1979. It has become increasingly clear that the climate is less sensitive then originally projected. (And in reality I predict it is much lower) The climate has always changed naturally and will continue to do so, and for you to claim warming from anthropogenic forcing are worse than predicted and to try and distinguish anthropogenic warming from warming in natural variation shows your unscientific bias. Here is a paper claiming CO2 has a radiative cooling effect. Am I claiming the earth is cooling? No Let's get back to logic and most importantly back on topic.
http://onlinelibrary.wiley.com/doi/10.1002/qj.2628/abstract

The paper you linked to isn't about the climate impacts of CO2. When the paper refers to positive or negative feedbacks at different temperatures, it's referring to feedbacks on self aggregating convection in the model they use.

It's best to think a little rather than blindly accepting what the climate denier blogs tell you.

EDIT: Sorry for going off topic, Neven. Is there a suitable thread for these comments elsewhere?

I read the paper. My point was there is no need to pick and choose articles/literature as one can find multiple to try and validate their point. There is no requirement for scientist to try and prove GHGs cannot warm the surface. It was already done. This paper uses the terminology  ‘positive feedback’ incorrectly. Solar energy cannot signify a positive feedback and green house gases can only represent one in a system. What is intriguing is a cooler atmosphere not being able to warm a surface. You cannot argue against thermodynamics. I will post all further responses in other thread.

Nick_Naylor

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Re: The 2015 melting season
« Reply #2806 on: July 30, 2015, 07:03:54 PM »
Beaufort is looking distinctly sickly the last day or two. Some significant areas may drop below 15% soon based on my uncalibrated eyeball:


ChrisReynolds

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Re: The 2015 melting season
« Reply #2807 on: July 30, 2015, 07:04:31 PM »
I don't think you can have peer-reviewed studies on something that is still unfolding, but it is common knowledge [redacted blurb - common knowledge does not meet the standards of primary peer reviewed scientific research]

The scientific literature on changes in the Arctic is replete with studies on processes that are unfolding.

ChrisReynolds

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Re: The 2015 melting season
« Reply #2808 on: July 30, 2015, 07:08:43 PM »
Love the paper link. It demonstrates what happens all too often in the "skeptic"sphere -- the paper doesn't say what they think it does. This paper has literally nothing to do with radiative forcing via CO2 and everything to do with trying to improve convective parameterizations in models by using changes in model geometry and reporting the results.

Yep, it happens so often it gets...

Boring    Boring    Boring    Boring    Boring    Boring    Boring    Boring   



Weatherdude, if you wanted to relegate your reputation to someone not worth taking seriously, way to go! You've succeeded in just a few posts.

ChrisReynolds

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Re: The 2015 melting season
« Reply #2809 on: July 30, 2015, 07:55:59 PM »
Andreas,

Thanks, so it is mixed skies, would be interesting to see the range around those averages, I'll have a look at the paper tomorrow.

Thing is, HP in the arctic doesn't necessarily give clear skies. In fact HP combined with a warm airmass is a very 'dirty' affair, and actually tends to fill the area up with fog. The LP by contrast will fill the arctic with cold snowy air which after the centre has moved on will give way to clear, fogless, cold skies. Upper troughs in the arctic seem to really cool down ridges. If we look at the area around Severnaya Zemlya which is going to be dominated by a ridge for the foreseeable future and look at the 850hpa theta E values (GFS):

31st July: 31C
4th August: 10C
5th August:20C

Before the LP we had fairly mild conditions, the LP then caused a dramatic change in the airmass reducing theta to only 10C, but crucially even after the LP moved on and the cold flow was cut off, the thetas did not rise back to their initial with the initial rapid warming slowing to a snails pace some 10C colder than original. The change in quality of the airmass will also probably clear the fog, this is far from simple.


For those that haven't heard of theta E, its full name is the equipotential temperature and it is the temperature one arrives at when condensing all the available moisture and releasing the latent heat directly into the air. Theta E not only considers, therefore, the temperature but also the humidity. Lower values represent colder, drier air which can only be a good thing.

Given all this, and the input from Chris and seaicesaloir, I'm still unsure whether this LP is friendly though I must say I am leaning in that direction. It is true that LPs tend to suck air from the lower latitudes, but this is a bigger issue when the LP came from the lower latitudes in the first place or when the LP is not centrally based. In this case (yet) neither of those criteria are satisfied so I am struggling to see any major melt coming out of this LP.

Thanks for the information.

I too am rather at a loss as to what August will bring, 2012 is probably out, 2013 and 2014 are probably out. But I wouldn't bet against 2015 getting into second place, that makes the range somewhere between second and fifth place...

Yes high pressure doesn't guarantee cloudless skies, but I have spent enough time frustrated at getting views of the ice to know that it is more likely to get good large swath views under HP.

If I am correct in my interpretation of compactness meaning that after the first week of August the emphasis shifts from radiative melt to melt from the edges of the pack (as also suggested by Blaine based on my volume rate of change / insolation graph), then the AO ensemble is looking interesting.
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index_ensm.shtml

The 11 member ensemble is grouping nicely for a shift to +ve AO, which means the collapse of the HP dominance and a shift to LP dominance. And that at about the cut off time we've been discussing, about the end of the first week of August.

The Beaufort low seems to wander about around Beaufort and into the CAA, as you say it's hard to determine what the effect will be without knowing exactly how it will be set up. Beaufort extent in winter tops out at about 0.53, it is currently 0.36, of the post 2007 years only 2013 was higher. However Beaufort area tops out around 5.1 over winter and is currently 0.14, by this time 2008 and 2012 were virtually zero. Given behaviour over the summer, I think that multi year ice is stopping the decline of Beaufort, this may continue through August. I wouldn't bet on it, but my suspicion is that Beaufort has more to lose but won't be on the low side of the post 2007 distribution and will not be ice free by mid September.


weatherdude88

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Re: The 2015 melting season
« Reply #2810 on: July 30, 2015, 08:12:15 PM »
What a difference two weeks make.


Tommy

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Re: The 2015 melting season
« Reply #2811 on: July 30, 2015, 08:49:12 PM »
<snip>

<Tommy, this is off-topic. The topic is 'The 2015 melting season'. Everything is connected in the universe. That doesn't mean we can dump everything in one single thread on a forum, especially if all the other persons want to know about what's happening NOW, and not read verbose comments about some theory. You can open a separate thread in this Arctic Sea Ice category to discuss your theory; Neven>

----

Second edit: Tommy has re-modified his comment twice, undoing my edits, and so I've decided that it's better he finds another forum to hijack. Apologies for letting this go on for as long as it did.
« Last Edit: July 30, 2015, 09:21:14 PM by Neven »

12Patrick

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Re: The 2015 melting season
« Reply #2812 on: July 30, 2015, 08:54:30 PM »
What a difference two weeks make.



Does that model project the 2nd and 3rd?

Lou

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Re: The 2015 melting season
« Reply #2813 on: July 30, 2015, 09:02:34 PM »
I've been reading this forum for some time, much more frequently lately, and this is the first time I've felt moved to say anything.

Can we please stop trying to psychoanalyze each other, read each other's minds, attribute opinions and views to each other, etc. and stick to the subject of "The 2015 Melt Season"?  That seems like a sufficiently large and important topic to keep us occupied.

The personal sniping has gotten out of hand lately, and it's significantly detracting from the value of an outstanding online resource.

Neven

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Re: The 2015 melting season
« Reply #2814 on: July 30, 2015, 09:05:50 PM »
Over at his blog RobertScribbler asked me:

Quote
As a curiosity, I was wondering if there’s any decent forecasting as to what may happen to the Atlantic side near the Kara, Laptev, and Barents? Typically, ice there has tended to be more resilient to both melt and refreeze. But we have a huge and hot pool of water developing in the Kara, a good deal of salt in the water in that region, and what appears to be some, at least moderately troubling, signs of lack of resiliency. The high is forecast to continue to be strong in that region as well. It’s not an area where we’ve traditionally seen large melts at this time of year. So the factors, to me, are somewhat of an enigma.

Thoughts?

My answer:

Quote
Well, coincidentally I had a good look at some satellite images yesterday. I’ve neglected this area a bit because I’m obsessing over the multi-year ice in the Beaufort and Chukchi Seas.

I have to say the ice east of Severnaya Zemlya looks pretty solid, though blue-grey. Which on the one hand is strange because it was supposed to be relatively thin at the start of the melting season (lots of winds blowing away from the coast during winter). In fact, I speculated that we might see open water close to the North Pole this year because of that, as it was the first time on record probably that there was first-year ice over the Pole at the end of last winter.

On the other hand most if not all of the action has been on the American-Pacific side of the Arctic, with the exception of the East Siberian Sea, where the ice is vanishing almost overnight as we speak. It hasn’t been as warm there as elsewhere and winds were relatively weak, so no big transport either.

This reverse Dipole is forecast to stay put, with that big high 1030 hPa pressure area stuck over the Kara/Laptev/CAB triangle, and so it will be interesting to see how the ice there reacts to that. Will we see massive in-situ melting starting after these couple of days, perhaps followed by a disruptive cyclone? Like you say, SSTs are ready and able to take out some ice.

Many words to hide the fact that I don’t know. :-)

Could that high-pressure area still hit the lobe of ice protruding from the CAB to Severnaya Zemlya hard? I don't know, but I hope the high-pressure area gives us glimpses the coming days.
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seaicesailor

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Re: The 2015 melting season
« Reply #2815 on: July 30, 2015, 09:17:52 PM »
[...]

The Beaufort low seems to wander about around Beaufort and into the CAA, as you say it's hard to determine what the effect will be without knowing exactly how it will be set up. Beaufort extent in winter tops out at about 0.53, it is currently 0.36, of the post 2007 years only 2013 was higher. However Beaufort area tops out around 5.1 over winter and is currently 0.14, by this time 2008 and 2012 were virtually zero. Given behaviour over the summer, I think that multi year ice is stopping the decline of Beaufort, this may continue through August. I wouldn't bet on it, but my suspicion is that Beaufort has more to lose but won't be on the low side of the post 2007 distribution and will not be ice free by mid September.

Beaufort has been and is importing a 'fresh' load of MYI, so I agree there will be ice left in September. About the MYI it was before, well, not sure. The carnage fields of the Arctic as u say.

It is interesting the combination of big scale HP and smaller scale LP has brought a bit of Gyro plus the weak divergent drift which when both  added they have caused the big "Tommy" gap and the migration of ice from the CAA

ChrisReynolds

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Re: The 2015 melting season
« Reply #2816 on: July 30, 2015, 10:16:19 PM »
Sea Ice Sailor,

Quote
About the MYI it was before, well, not sure. The carnage fields of the Arctic as u say.

I'm waiting to see PIOMAS July figures before saying anything about how much ice has been lost this year. There is reason to expect that a lot of the 2013/4 volume gain may have been lost this year, including a lot of winter's export. However the winter export this year wasn't exceptional like in 2010, so there will be some carry over. But just because MYI may be delaying the retreat to a degree, doesn't mean that MYI isn't getting severely hit. You only need over about 1/6 cover to register for extent...

OldLeatherneck

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Re: The 2015 melting season
« Reply #2817 on: July 30, 2015, 10:50:07 PM »
[...]

The Beaufort low seems to wander about around Beaufort and into the CAA, as you say it's hard to determine what the effect will be without knowing exactly how it will be set up. Beaufort extent in winter tops out at about 0.53, it is currently 0.36, of the post 2007 years only 2013 was higher. However Beaufort area tops out around 5.1 over winter and is currently 0.14, by this time 2008 and 2012 were virtually zero. Given behaviour over the summer, I think that multi year ice is stopping the decline of Beaufort, this may continue through August. I wouldn't bet on it, but my suspicion is that Beaufort has more to lose but won't be on the low side of the post 2007 distribution and will not be ice free by mid September.

Beaufort has been and is importing a 'fresh' load of MYI, so I agree there will be ice left in September. About the MYI it was before, well, not sure. The carnage fields of the Arctic as u say.

It is interesting the combination of big scale HP and smaller scale LP has brought a bit of Gyro plus the weak divergent drift which when both  added they have caused the big "Tommy" gap and the migration of ice from the CAA

I agree that a certain amount of that MYI will remain in the Beaufort co,e September, waiting to die a slow death next year or the following.  However, like Chris Reynolds has said it will be interested to see the July PIOMAS to see how much damage has been done to the volume.  As far Extent goes this year, I'm now getting concerned that we may not eclipse 2007.  Even with above average losses in August, it will take a substantial amount of additional melting in September to make a difference.  We may need a September like 2010  when the IJIS Extent dropped ~500k and didn't reach it's minimum until the 21st.

On a second note. Do we have to call the gap off of the CAA the "Tommy" Gap.  I thought it was rather presumptuous and egocentric for a "newbie" to start naming an unusual, though not unheard of, event after themselves. 
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Bob Wallace

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Re: The 2015 melting season
« Reply #2818 on: July 30, 2015, 11:27:28 PM »
Quote
Do we have to call the gap off of the CAA the "     " Gap.

How about the "He Who Shall Not Be Named" Gap?

AmbiValent

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Re: The 2015 melting season
« Reply #2819 on: July 30, 2015, 11:33:49 PM »
First we should decide whether it's important enough to need a name at all. If yes, it should be a more serious one, like "Beaufort Gyre ice gap" or something like that.
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TerryM

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Re: The 2015 melting season
« Reply #2820 on: July 30, 2015, 11:42:25 PM »
OLN
Amen.


I'd taken an interest in the gap in 2011?, wondering if the rapid expansion of the Inuit peoples towards Greenland might have been due to them following pods of whales along such a feature during the warm period that the Vikings benefited from.
Apparently the migration was very rapid & they left little evidence of their passing.


To try and claw this back closer to the topic. If the gap proves to be a feature dating back ~ 1k yrs, then it may be reasonable to assume that in warm periods, when the wind is blowing off shore, a gap will appear. With the vast fast ice shelves gone from Ellesmere & Greenland does the short term MYI now have more shore features to get tied up in, or does the gap provide a separation line allowing this ice to move more freely along the coast(s)?


Terry

jr47

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Re: The 2015 melting season
« Reply #2821 on: July 30, 2015, 11:44:35 PM »
Thank cod he's gone! i almost gave up reading the posts of real experts.

andy_t_roo

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Re: The 2015 melting season
« Reply #2822 on: July 30, 2015, 11:51:35 PM »
Yes. Extent is not worth looking at. I think the the only thing worth looking at are volume and ice thickness.
I believe, from a satellite perspective extent is the most accurately known number, as melt ponds, clouds, fog, snow cover, and a lack of resolution hinder accurate measurement of area.
Thickness is only exactly known at a few points,  so any volume measures must be a model of both area, correcting for the errors above, and thickness, estimating the thickness pattern from sparse measurements and weather patterns.

I think everyone here would agree volume is one of the most important measurements, as that is what absorbed energy directly affects, but it is also the hardest to know actually. (See discussions elsewhere on the difference between the various models)

Villabolo

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Re: The 2015 melting season
« Reply #2823 on: July 31, 2015, 12:16:14 AM »

Do we have to call the gap off of the CAA the "Tommy" Gap.  I thought it was rather presumptuous and egocentric for a "newbie" to start naming an unusual, though not unheard of, event after themselves.

I think it should be christened the "Tommy Gap" in honor of the dead.  :'(

Sorry Neven, last off topic post from me, I promise. :)

seaicesailor

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Re: The 2015 melting season
« Reply #2824 on: July 31, 2015, 12:19:14 AM »
Yes I agree, we will not forget.
Anyway I feel bad about it. I used it cause it is easy to remember now.

And what if it really becomes something?  8)

LRC1962

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Re: The 2015 melting season
« Reply #2825 on: July 31, 2015, 12:36:34 AM »
Missed a lot of fun it seems (very not).
If you follow ice Arctic history, likely do to geographical features, openings seem to always occur in the same spot almost down to the foot. The only change is when and how much.
As the melt gets worse new openings show up, but again they tend to be the same spots. Where you get a major change is when storms come in and move things around or an intense high or low comes and sits for a prolonged time. In either of those cases something different will appear because the unusual has changed the norm. Butt then again once the 'normal' weather returns you will then see the old familiar opens show up again.
What is changing now is the timing of all the openings and the size they come to. Also as the ice gets less we can start seeing new features, but again, following year after years they start being recognized as 'old familiar faces'.
Although from day to day there is always something new and it is sad to see that it is never going to return to the glory days pre 1980's, the Arctic is very predictable viewed from the broad strokes of an entire season. The bite will always show up unless there is an obvious weather pattern that stopped it. Those old leads will open up in a very predictable pattern. The new features are starting to show up year after year. The Arctic is changing but is an old friend that shows the story of its year in very familiar ways.
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Rubikscube

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Re: The 2015 melting season
« Reply #2826 on: July 31, 2015, 12:58:33 AM »
Its not just the ice north of CAA that is cracking up and leaving the shores, also some of the most resilient ice in between the islands is cracking up and exiting north. This picture is todays modis from Prince Gustav Adolf Sea (to the west) and Peary Channel, both areas which have always seen close to 100% concentration at minimum as far as satellite records go.

Lou, good post.

Michael Hauber

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Re: The 2015 melting season
« Reply #2827 on: July 31, 2015, 01:23:08 AM »
Climate models (CMIP5) with updated forcings (yes, unheard of, but somehow people failed to predict volcanic eruptions...) are fully in line with the observations (and do _NOT_ overpredict temperature rise), and they do have ECS between 2.1 and 4.5K.
http://onlinelibrary.wiley.com/doi/10.1029/2012GL051607/full



Can you see my response in the model vs observed thread
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OldLeatherneck

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Re: The 2015 melting season
« Reply #2828 on: July 31, 2015, 01:30:22 AM »
I didn't mean to start another off topic discussion regarding the name of the "Gap", however, I'm happy for the support I got in the the resulting comments and sentiments.

Glad to see the last several posts are relevant and on-topic.  Every year is a new laboratory experiment in one of the world's most remote and hostile environments.  No test plan was ever written and the only variable under human control is GHG levels and we have decided to forgo reducing that.  The remaining variables are all dependent on the laws of physics.  While we know what these laws are, we still are learning the interdependence of the many uncontrolled variables.

This is a wonderful place to discuss and learn about the many sciences as it unfolds in front of are very eyes. 

Thanks to Neven for opening such an informative learning platform.  Now back to 2015.


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Nightvid Cole

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Re: The 2015 melting season
« Reply #2829 on: July 31, 2015, 01:37:19 AM »
Its not just the ice north of CAA that is cracking up and leaving the shores, also some of the most resilient ice in between the islands is cracking up and exiting north. This picture is todays modis from Prince Gustav Adolf Sea (to the west) and Peary Channel, both areas which have always seen close to 100% concentration at minimum as far as satellite records go.

Lou, good post.

Great image. I suspected something of this sort would happen, since the amount of melt ponding in June over the CAA was just out of this world.

epiphyte

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Re: The 2015 melting season
« Reply #2830 on: July 31, 2015, 02:26:10 AM »

What the hell is going on?

Um, He stopped taking his meds?

Greenbelt

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Re: The 2015 melting season
« Reply #2831 on: July 31, 2015, 02:43:37 AM »
GFS and ECMWF now both have surface high bridging back across the pole from the Atlantic to the Pacific, with the persistent low shifting toward the Canadian Archipelago, perhaps bringing winds but finally breaking the heat wave in the Canadian islands if the low sinks far enough south.


cesium62

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Re: The 2015 melting season
« Reply #2832 on: July 31, 2015, 03:08:48 AM »
What a difference two weeks make.



The Great Compactor?

cesium62

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Re: The 2015 melting season
« Reply #2833 on: July 31, 2015, 03:13:31 AM »
Quote
Do we have to call the gap off of the CAA the "     " Gap.

How about the "He Who Shall Not Be Named" Gap?

The Voldemort Gap?

cesium62

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Re: The 2015 melting season
« Reply #2834 on: July 31, 2015, 03:17:55 AM »
Thank cod he's gone! i almost gave up reading the posts of real experts.

I was starting to miss Viddaloo...

Csnavywx

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Re: The 2015 melting season
« Reply #2835 on: July 31, 2015, 03:38:02 AM »
Quote
Do we have to call the gap off of the CAA the "     " Gap.

How about the "He Who Shall Not Be Named" Gap?

The Voldemort Gap?

Hahaha! I'm glad I wasn't the only one who thought that on first glance.

cesium62

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Re: The 2015 melting season
« Reply #2836 on: July 31, 2015, 03:43:18 AM »
Over at his blog RobertScribbler asked me:

Quote
As a curiosity, I was wondering if there’s any decent forecasting as to what may happen to the Atlantic side near the Kara, Laptev, and Barents? Typically, ice there has tended to be more resilient to both melt and refreeze. But we have a huge and hot pool of water developing in the Kara, a good deal of salt in the water in that region, and what appears to be some, at least moderately troubling, signs of lack of resiliency. The high is forecast to continue to be strong in that region as well. It’s not an area where we’ve traditionally seen large melts at this time of year. So the factors, to me, are somewhat of an enigma.

Thoughts?

My answer:

Quote
Well, coincidentally I had a good look at some satellite images yesterday. I’ve neglected this area a bit because I’m obsessing over the multi-year ice in the Beaufort and Chukchi Seas.

I have to say the ice east of Severnaya Zemlya looks pretty solid, though blue-grey. Which on the one hand is strange because it was supposed to be relatively thin at the start of the melting season (lots of winds blowing away from the coast during winter). In fact, I speculated that we might see open water close to the North Pole this year because of that, as it was the first time on record probably that there was first-year ice over the Pole at the end of last winter.

On the other hand most if not all of the action has been on the American-Pacific side of the Arctic, with the exception of the East Siberian Sea, where the ice is vanishing almost overnight as we speak. It hasn’t been as warm there as elsewhere and winds were relatively weak, so no big transport either.

This reverse Dipole is forecast to stay put, with that big high 1030 hPa pressure area stuck over the Kara/Laptev/CAB triangle, and so it will be interesting to see how the ice there reacts to that. Will we see massive in-situ melting starting after these couple of days, perhaps followed by a disruptive cyclone? Like you say, SSTs are ready and able to take out some ice.

Many words to hide the fact that I don’t know. :-)

Could that high-pressure area still hit the lobe of ice protruding from the CAB to Severnaya Zemlya hard? I don't know, but I hope the high-pressure area gives us glimpses the coming days.

I must not be understanding something here.  I'm sure one of you kind gentelmen will point out the errors of my thinking...

I thought the Kara was at the tail end of the Gulf stream and pretty much the opposite of "resilient to melt".  The Kara melted out in 1995 and ice volume losses in the Kara have been dropping because there is less ice freezing each year (on average).

The Barents is in even worse shape.

The ESS is in slightly better shape, but has been consistently melting out since 2002.

The CAA is usually resilient.  The Beaufort is resilient this year after a few bad years.  The Greenland Sea is resilient for entirely different reasons.

It seems clear to me that enough heat has moved into (or becomes available in) the Arctic to fairly consistently melt out nearly everything between 70N and 80N by mid-September.  As more heat moves in, those areas will melt out a little bit earlier in the year and the excess heat will start attacking the periphery of the CAB.

Maybe my confusion is based on me looking at these seas in mid-September and Robert is talking about what happens at the beginning of August?  But I think the above story is consistent with that.  Maximum volumes have been dropping.  Heat has been increasing.  Melt outs occur earlier.

slow wing

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Re: The 2015 melting season
« Reply #2837 on: July 31, 2015, 04:09:18 AM »
I know this has been discussed, but I forget. Surely a low pressure system will disperse rather than compact the ice, just as a high pressure system does? Surely the physics won't care about the orientation of the rotation - ACW or CW, respectively? (Naively, I would expect the ice to disperse for the same reason we fly off a merry-go-round. I may be missing some subtleties but the argument about orientation is more general and shouldn't depend on any such subtleties.)


Today's update from U. Bremen is spectacular!


Lots of action in CAA, Beaufort, Chukchi, ESS and Laptev.

Lots of CAA ice is being sucked away into the Beaufort.
Loss of concentration about where the low is parked (dispersion, I would expect), in the CAB and North of the Chukchi Sea.
The dent in the Laptev ice is making strong progress inside 80 degrees N.


Tend to agree with the view that what matters at this time of year is wind, not so much air temperature or humidity - would say the observed behaviour gives support to that view.


Click on .gif to get the progression over the past 4 days...
(Apologies if the gif animator has been messing up the colour map, which complicates viewing of the trend.)
« Last Edit: July 31, 2015, 04:23:08 AM by slow wing »

Treesong

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Re: The 2015 melting season
« Reply #2838 on: July 31, 2015, 04:46:55 AM »
Thank cod he's gone! i almost gave up reading the posts of real experts.

Amen! The Arteest who should not be named was skippable but he was riling up the sensible posters. Actually, he seemed to mix some useful stuff with the self-congratulation at first, but when he named a gap after himself I decided he was just trouble.

Shared Humanity

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Re: The 2015 melting season
« Reply #2839 on: July 31, 2015, 05:08:38 AM »
<snip>

<Tommy, this is off-topic. The topic is 'The 2015 melting season'. Everything is connected in the universe. That doesn't mean we can dump everything in one single thread on a forum, especially if all the other persons want to know about what's happening NOW, and not read verbose comments about some theory. You can open a separate thread in this Arctic Sea Ice category to discuss your theory; Neven>

----

Second edit: Tommy has re-modified his comment twice, undoing my edits, and so I've decided that it's better he finds another forum to hijack. Apologies for letting this go on for as long as it did.

Thank you.

Shared Humanity

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Re: The 2015 melting season
« Reply #2840 on: July 31, 2015, 05:10:42 AM »
Quote
Do we have to call the gap off of the CAA the "     " Gap.

How about the "He Who Shall Not Be Named" Gap?

Thank  you.

Bob Wallace

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Re: The 2015 melting season
« Reply #2841 on: July 31, 2015, 06:21:10 AM »
Quote
Do we have to call the gap off of the CAA the "     " Gap.

How about the "He Who Shall Not Be Named" Gap?

The Voldemort Gap?

Hahaha! I'm glad I wasn't the only one who thought that on first glance.

Younguns, pffff...

Rumpole of the Bailey reference. 

kingbum

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Re: The 2015 melting season
« Reply #2842 on: July 31, 2015, 06:43:35 AM »
<snip. I'm sorry, Kingbum, but this 'it's the Sun' stuff is only going to derail the discussion wrt to the 2015 melting season that is getting so interesting now. You can give it a shot in some other thread, but please remember that I'm not a fan of climate risk denial talking points; N.>

Now onto this melt season I will be interested in the new PIOMAS numbers in August just to see what kind of damage is being done. I would also like to know what are the current EUV numbers in the Arctic. If ozone is being depleted and a hole is to develop that will give an escape hatch to space for heat trying to escape the ocean and it may not transfer to the ice thus slowing melting
« Last Edit: July 31, 2015, 08:57:44 AM by Neven »

S.Pansa

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Re: The 2015 melting season
« Reply #2843 on: July 31, 2015, 07:26:11 AM »
Here is - for a while - the last update of the Topaz4 ice thickness model. I think it makes sense now to wait and see what PIOMAS has to offer. That should give us an idea if topaz4 is useful or not.
Images are for 29/07, 31/07 and the outlook for 08/08.
The output looks more realistic now on the Atlantic side and the outlook suggests continued melting and/or compaction.

seaicesailor

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Re: The 2015 melting season
« Reply #2844 on: July 31, 2015, 09:01:46 AM »

What a difference two weeks make.



The Great Compactor?

Actually it is a great disperser for the ice by virtue of Coriolis (if he put the name to the force rightfully)

Neven

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Re: The 2015 melting season
« Reply #2845 on: July 31, 2015, 09:19:34 AM »
Its not just the ice north of CAA that is cracking up and leaving the shores, also some of the most resilient ice in between the islands is cracking up and exiting north. This picture is todays modis from Prince Gustav Adolf Sea (to the west) and Peary Channel, both areas which have always seen close to 100% concentration at minimum as far as satellite records go.
I don't know about 100% concentration at minimum, RC, but things cracked up completely back in 2010 and 2011 as well (and probably 2012 too, but I can't remember), with ice moving into the CAA from the CAB. See here for an animation showing 2010:



This year might be earlier though, and it's the way around now, ie ice moving from the CAA to the CAB.
Il faut comparer, comparer, comparer, et cultiver notre jardin

seaicesailor

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Re: The 2015 melting season
« Reply #2846 on: July 31, 2015, 09:25:50 AM »

Nice post, Slow Wing! (Sorry on mobile cannot add easily quotes)
That band in Chukchi is probably cloud effect

12Patrick

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Re: The 2015 melting season
« Reply #2847 on: July 31, 2015, 09:32:20 AM »
Where is the 5 meter ice now?

6roucho

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Re: The 2015 melting season
« Reply #2848 on: July 31, 2015, 10:03:40 AM »

Actually it is a great disperser for the ice by virtue of Coriolis (if he put the name to the force rightfully)
Rightfully in the northern hemisphere. Leftfully in the south.

TerryM

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Re: The 2015 melting season
« Reply #2849 on: July 31, 2015, 10:26:26 AM »
Slow Wing


When it comes to compaction vs dispersal remember Ekman pumping. The Coriolis effect is very strong in Arctic waters turning everything toward the right.


Terry