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greatdying2

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Re: The 2015 melting season
« Reply #2400 on: July 22, 2015, 05:49:01 PM »
Yes, it looks like the Pacific Blob has been seeping into the Arctic, the warm water staying on the surface, melting a much bigger area than equivalent date in 2012, and snaking around the edges melting those places.
No, you've got the direction of the currents backwards. Between Severnaya Zemlya and the mainland, the flow is West to East (i.e. Atlantic to Pacific).

http://polardiscovery.whoi.edu/arctic/circulation.html


http://psc.apl.washington.edu/HLD/Chukchi/Chukchi.html
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

ChrisReynolds

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Re: The 2015 melting season
« Reply #2401 on: July 22, 2015, 06:20:52 PM »
Rotten Ice...
What Andreas and Jim said...

Barber 2009 doesn't really address what I said. They were concerned with MYI not actually being as MYI and being largely FYI, this is a problem I have previously pointed out with the method behind the Drift Age Model.

But if anyone wants to pursue this I think a new thread would be in order, or we may have on old rotten ice thread. I'll be blogging on the issue I raised later this year.

epiphyte

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Re: The 2015 melting season
« Reply #2402 on: July 22, 2015, 06:26:34 PM »
... a several week's journey at n million pounds per day in order to find out why a gif on a website is slightly the wrong colour according to the numbers produced by that same website?

How much does a satellite cost? We all know that models have their limitations and spending that amount of money even for a month should be worth it in order to give direct and useful information. In any case I'm having problems giving HYCOM much credibility.
Start at 1 billion $US and go up from there.

Just to put things in perspective, local news is reporting here that the new Minnesota Vikings stadium cost more than the New Horizons trip to Pluto

Peter Ellis

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Re: The 2015 melting season
« Reply #2403 on: July 22, 2015, 06:26:49 PM »
Nightvid Cole

Ok, I see. Thanks.
Does that mean that when the last ice-bridge to Russia melts, cooler water will flow in from the Atlantic, dive under the warm surface water coming from the Pacific Blob, ultimately pushing that water back towards the Pacific?

Sea ice isn't thick enough to have appreciable effects on ocean currents in the way you suggest.  It can't act as a dam to block water flow.

Bruce Steele

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Re: The 2015 melting season
« Reply #2404 on: July 22, 2015, 06:37:22 PM »
Re. The Blob and Arctic ocean heating. From earlier posting

24
Arctic sea ice / Re: The 2015 melting season
« on: June 27, 2015, 05:14:14 PM »
Tzupancic, Pacific water flows through narrow passes in the Aleutian Islands and north along the Alaskan coast. " Moreover, the movement of Pacific Water from the Aleutian Passes to the Bering Sea takes more than one year, with the exception of the small portion that enters the shelf through
Zemchug Canyon, which takes 8 months. Hence, most of the water of Pacific origin entering Bering
Strait has gone through a seasonal cycle on the journey and thus cooled to near freezing
(-1.8 C )"

http://www.sciencedirect.com/science/article/pii/S0079661115001020

I have seen several claims of late that somehow " the blob " is transporting Pacific heat into the Arctic but the evidence of a decade of buoy data collected in the Bering Strait 2001-2010 and published by Woodgate 2005, 2006, and 2010 shows bottom water moving north through the Strait is -1.8 C for the first three months of the year and only begins to heat after the surface ice has melted. About April - May each year.
I realize it has been a few years since the end of that data-set and I do not know of any current buoy arrays that are giving current readings but without evidence that something has changed I think claims of Pacific heat or " the Blob " moving heat into the Chukchi or Beaufort is speculation and
probably in error.
 
 So Pacific( the blob ) water takes a year to reach the Chukchi and is cooled to -1.8 C in the winter months of that journey .
 
 The direction of the current flow ( red arrows ) by Tommy were correct except that portion along the Siberian coast where flow is usually west to east. Sometimes that current, the Siberian Coastal Current , fails to form as was documented in 1995. So sometimes the red arrows that Tommy drew were correct. He was completely correct in the Pacific to Atlantic direction of that flow . The heat carried however is from surface heating in the open waters of the Bering and Chukchi and not heat transport from the Pacific. That may change in the future but until ice fails to form in the Bering Sea during winter , heat is supplied by local surface heating and not transport from " the blob. " 

Tor Bejnar

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Re: The 2015 melting season
« Reply #2405 on: July 22, 2015, 07:05:13 PM »
From Neven's 2012 Ocean heat flux blog post:

Quote
... But in summer Pacific waters carry significant amounts of heat into the Arctic, and although highly variable from year to year, the heat flux (relative to the freezing temperature of seawater) is enough to melt 1–2 million km2 of 1 m thick ice (Woodgate et al., 2010). One of the reasons that made 2007 such a spectacular melt year was the fact that the Bering Strait oceanic heat flux was over twice that in 2001.
If what Neven reported is true, lots of North Pacific heat may have entered the Arctic already, causing the thinning of 1M km2 of sea ice by 1 meter.
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Bruce Steele

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Re: The 2015 melting season
« Reply #2406 on: July 22, 2015, 07:33:27 PM »
Tor Bejnar, I don't often disagree with Neven but on this one I do. Robert Scribbler also said Pacific water and the "blob" are moving heat via the Bering Sea into the Arctic so I am swimming upstream but I will include a quote from the paper linked above , also from a prior posting.


33
Arctic sea ice / Re: Relative height of North Pacific and Atlantic
« on: June 05, 2015, 12:56:57 AM »
Plinius, Maybe it's bad form but I am going to copy a post I made on another page.

I have been wondering about the transfer of warm water from the Pacific through the Aleutians  and via the Alaskan Coastal current into the Beaufort and Chukchi Seas. Wood et 2015

http://www.sciencedirect.com/science/article/pii/S0079661115001020

From the article



"Steele et al 2010 showed that 80% of the ocean heating in the Pacific Arctic north of Alaska is from ocean heat flux, and only 20% due to ocean lateral heat flux( e.g. Bering Sea inflow), which mostly occurs within a few hundred kilometers from the coast. Moreover, the movement of Pacific Water from the Aleutian Passes to BeringStrait takes more than one year, with the exception of the small
portion that enters the shelf through the Zemchug Canyon, which takes 8 months.
Hence , most of the water of Pacific origin entering the Bering Strait has gone through a seasonal cycle on the journey and thus cooled to near freezing ( -1.8 *C )
( Stabeno et al, in press ) as reflected in the low temperatures recorded at the mooring array in the Strait."
" This would imply that most of the warm water advected into into the Bering Strait ( and available to melt sea ice ) must be heated in transit from the atmosphere ( insolation and downward long wave radiation ) in the Northern Bering  Sea ( Woodward et al 2010 ) "

   It seems to me there will be much more advection of Pacific heat via the Alaskan Coastal Current when the Bering Sea warms to the point that Bristol Bay and Norton Sound stay mostly ice free year round. Then summer insolation and long wave radiation will work on coastal waters for longer periods and that heat can then move into the Beaufort and Chukchi earlier.  I am not going to speculate on when this may happen but when the ACC starts with water above -1.8 C  each spring the extra heat moved North will add substantially to current heat transfer from the Pacific.
 Neven speculated on the effects of the Pacific warm water "blob" over on the Sea Ice Blog last post before vacation .   
 


The part in quotes is directly quoted from the paper linked. Paywalled but worth the $.
'A decade of environmental change in the Pacific Arctic region'  Kevin R Wood, Nicholas A Bond, Seth L Danielson, James E Overland, Sigrid A Salo. Phylis Stabeno, Jonathon Whitefield

Tor Bejnar

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Re: The 2015 melting season
« Reply #2407 on: July 22, 2015, 08:21:31 PM »
I almost wrote the "If" in my previous message "If (big if)".  I, of course, am no expert in this matter.
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JimD

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Re: The 2015 melting season
« Reply #2408 on: July 22, 2015, 08:53:23 PM »
... a several week's journey at n million pounds per day in order to find out why a gif on a website is slightly the wrong colour according to the numbers produced by that same website?

Sounds better than invading a country looking for WMDs!  ;D

Yeah, but the thing that got me was the idea that Hansen has some sort of high standing with the President.  I am sure they had a few drinks if not a party the day he retired and was no longer an "official" thorn in their side and could now be completely ignored.
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cesium62

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Re: The 2015 melting season
« Reply #2409 on: July 22, 2015, 09:33:38 PM »
Yes, it looks like the Pacific Blob has been seeping into the Arctic, the warm water staying on the surface, melting a much bigger area than equivalent date in 2012, and snaking around the edges melting those places.

It looked to me like the MacKenzie river had produced the melted area north of western Canada.  This opened up in April or May as the MacKenzie river flow started gushing and we were getting warm southerlies at the time.

Similarily, the melted area in the Laptev corresponds to the Lena river.

Google search finds me this map of the watersheds involved.

« Last Edit: July 22, 2015, 09:57:28 PM by cesium62 »

ChrisReynolds

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Re: The 2015 melting season
« Reply #2410 on: July 22, 2015, 10:21:57 PM »
Chukchi compactness has just passed the 0.4 level and remains one of the lowest, but on 21 July, 1993 has the lowest compactness! Chukchi extent keeps dropping at above  average levels, if the average loss for the last ten days continues Chukchi should be ice free by 4 August, make that the first week of August rather than haggling over exact dates. Because the ice edge can keep retreating beyone Chukchi the date of zero is not necessarily preceded by a slowing of loss rate. Should the weather hold up and Chukchi go ice free in the first week of August it will be one of the earliest on record, it could still be the earliest.

Beaufort extent has cut across the other post 2007 extent tracks, going from the earliest start and lowest extent in early May to the highest post 2007 extent. Despite what looks like a crash of area in the Bremen plots Beaufort area loss is around average for 1981 to 2010 since late May. However compactness might be taking a rather indirect downward slope right now (winds?). MYI must be resisting melt in Beaufort, to what degree this can hold up through August I don't know.

If we don't see solid above average drops in compactness and extent by the end of this month Beaufort probably won't melt out this year.

Central Arctic: This has now reached the time when extent starts to drop, it remains level. However compactness is dropping, and is amongst the lowest on record. For the last seven days of data, 15 July to 21 July here are the lowest compactnesses for the Central Arctic (7 day average).

2012   0.753
2015   0.776
2007   0.789
2001   0.789
2010   0.799
2013   0.800
2008   0.800
1998   0.811
2009   0.812
1983   0.814

Compactness bottoms out late August.

Sorry for no graphs, been working on a mid summer blog post which I will post over the next few days.
« Last Edit: July 22, 2015, 10:42:40 PM by ChrisReynolds »

Neven

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Re: The 2015 melting season
« Reply #2411 on: July 22, 2015, 11:06:36 PM »
ECMWF now forecasts a faster shift of high pressure to Siberia. 3 more days of this and then the change starts. 7-10 days forecast has high pressure leaving the Arctic entirely.

Will we see a stall, or will the decrease continue steadily, well below 2013 and 2014?
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ChrisReynolds

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Re: The 2015 melting season
« Reply #2412 on: July 22, 2015, 11:12:12 PM »
One last thing, the ESS is well ahead of schedule, if current rates of loss continue ESS should ice free a little after 10 August.

ChrisReynolds

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Re: The 2015 melting season
« Reply #2413 on: July 22, 2015, 11:22:27 PM »
ECMWF now forecasts a faster shift of high pressure to Siberia. 3 more days of this and then the change starts. 7-10 days forecast has high pressure leaving the Arctic entirely.

Will we see a stall, or will the decrease continue steadily, well below 2013 and 2014?

GFS shows high continuing with moderately tight isobar gradient over the Siberian coast by 30 July. AO ensemble shows moderate negative AO through to early June. But the AD is associated with low pressure dominance over the UK (-ve AO) and Western Europe according to one study. BBC News long term forecast shows two more lows coming into the UK, but the assertion of a blocking high was mentioned for early August as a distinct possibility

One can only guess for the rest of the season, based on the past behaviour I suspect the AD will return. I don't think we will see a stall through the whole of August.

ChrisReynolds

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Re: The 2015 melting season
« Reply #2414 on: July 22, 2015, 11:24:36 PM »
OK, know...

I've doomed the Arctic Ocean to shivering cold and snowfall through the whole of August.  :(
« Last Edit: July 23, 2015, 07:57:29 AM by ChrisReynolds »

Bob Wallace

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Re: The 2015 melting season
« Reply #2415 on: July 22, 2015, 11:32:08 PM »
... a several week's journey at n million pounds per day in order to find out why a gif on a website is slightly the wrong colour according to the numbers produced by that same website?

Sounds better than invading a country looking for WMDs!  ;D

Yeah, but the thing that got me was the idea that Hansen has some sort of high standing with the President.  I am sure they had a few drinks if not a party the day he retired and was no longer an "official" thorn in their side and could now be completely ignored.

Bush and Cheney left office long before Hansen retired.

Neven

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Re: The 2015 melting season
« Reply #2416 on: July 22, 2015, 11:33:30 PM »
GFS shows high continuing with moderately tight isobar gradient over the Siberian coast by 30 July. AO ensemble shows moderate negative AO through to early June. But the AD is associated with low pressure dominance over the UK (-ve AO) and Western Europe according to one study. BBC News long term forecast shows two more lows coming into the UK, but the assertion of a blocking high was mentioned for early August as a distinct possibility

One can only guess for the rest of the season, based on the past behaviour I suspect the AD will return. I don't think we will see a stall through the whole of August.

You're right, GFS shows persistent 1030 hPa over the Central Arctic. This is like a cage fight where the guy on the floor keeps getting punched. But we don't know how thick his skull is.
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jdallen

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Re: The 2015 melting season
« Reply #2417 on: July 23, 2015, 12:44:09 AM »
GFS shows high continuing with moderately tight isobar gradient over the Siberian coast by 30 July. AO ensemble shows moderate negative AO through to early June. But the AD is associated with low pressure dominance over the UK (-ve AO) and Western Europe according to one study. BBC News long term forecast shows two more lows coming into the UK, but the assertion of a blocking high was mentioned for early August as a distinct possibility

One can only guess for the rest of the season, based on the past behaviour I suspect the AD will return. I don't think we will see a stall through the whole of August.

You're right, GFS shows persistent 1030 hPa over the Central Arctic. This is like a cage fight where the guy on the floor keeps getting punched. But we don't know how thick his skull is.
... Or is getting smashed against the bars of the cage.  Looking at the next week in climate reanalizer, the pressure will set up a westerly/southwesterly flow which should shove Beaufort ice into water heated to well above zero.  It may push back ice into the Laptev that is similarly warmed up, and push other basin ice into the rather warm Barents.  (The sharp ice boundary we see on the Atlantic side is at least in part a result of high SSTs lurking just beyond the ice front...)

Meanwhile, we may see open water show up in the CAB from things being shoved around just in time to pick up insulation unleased by clear skies.

Interesting times ahead.
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Bob Wallace

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Re: The 2015 melting season
« Reply #2418 on: July 23, 2015, 12:46:29 AM »
If HYCOM is correct the very thick ice to the west of Queen Elizabeth Islands is about to take a sea cruise....


Buddy

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Re: The 2015 melting season
« Reply #2419 on: July 23, 2015, 01:46:13 AM »
WOW.....THAT was easy... :-[
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stackmaster

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Re: The 2015 melting season
« Reply #2420 on: July 23, 2015, 02:22:23 AM »
Nothing but cracked and shattered ice and open water from Baffin to Beaufort.

http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r04c02.2015203.terra.250m.jpg


weatherdude88

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Re: The 2015 melting season
« Reply #2421 on: July 23, 2015, 03:11:20 AM »
Air temperatures are plummeting above 80 north.


Tommy

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Re: The 2015 melting season
« Reply #2422 on: July 23, 2015, 03:23:35 AM »
Thanks for the answers everyone.
I appreciate the new info. and will go over those fully in the coming days, but before that last ice-bridge to Russia breaks through just one more random thought.

I don’t have a comparison for every year, but certainly those river watersheds involved in the western arctic had little impact on the region in 2012 compared to the same date in 2015. So did they get masses more rain this year or something, or is the Pacific Blob seeping in with warm water at the surface to make such a difference?

For many places in the world, what the main current is doing is not always the same as what the surface is doing.
The surface is the main thing here, maybe not the main ocean currents? The surface can flow in different directions than the main deep water currents, but maybe the Arctic Ocean is not deep enough for that to happen?

However, with the oceans becoming warmer the surface temps are becoming more homogenized even compared to 2012, so the differential in surface temperatures is not the same as it was even in 2012. With these more homogenized surface temperatures that the greenhouse effect will inevitably lead to, then the idea that the Pacific Blob warm water could flow over the surface of the Arctic more easily than in previous years, and in the hottest year on record so far for month to month, is not far-fetched. The main ocean currents will still be in play at depth (but weaker), but on the surface the homogeneity of temperatures between Pacific, Arctic, and Atlantic will have much less differential and therefore much less forced flow in any direction, that it could mean that the warm Blob spreads right over the surface of the Arctic no problem, despite underlying currents, and the ice on on the surface will be directly affected.

I don’t think the surface temps. in any ocean are the same as they were in even 2012, and now, in 2015, the warm water from the Pacific Blob can flow over the surface much more easily than the traditional models of ocean currents would suggest.

The Pacific Blob, and the worst Albedo reflection on record, as well as the warmest month globally every month this year so far, and the arctic ice being thinner than before anyway, could all mean that this year is nothing like previous years.

Have you never seen the beginning of Water World !   :)
.

PS. I may have missed it, but is there a site that does a daily update of North Atlantic/ Eastern Arctic SURFACE water temps?
Sorry if I missed it posted, just couldn’t find it.
Thanks

Tommy
« Last Edit: July 23, 2015, 03:35:53 AM by Tommy »

weatherdude88

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Re: The 2015 melting season
« Reply #2423 on: July 23, 2015, 03:36:19 AM »
One can only guess for the rest of the season, based on the past behaviour I suspect the AD will return. I don't think we will see a stall through the whole of August.

A prolonged arctic dipole is unlikely due to current AMO (American Multidecadal Oscillation) values being colder then previous melting seasons. It has been proposed that the AMO plays a significant role in forcing summer circulation anomalies. For example: Sutton and Dong, 2012

http://www.esrl.noaa.gov/psd/data/correlation/amon.us.data  (monthly AMO values)

slow wing

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Re: The 2015 melting season
« Reply #2424 on: July 23, 2015, 03:59:19 AM »
Tommy, a couple of years ago I wrote an article on Ocean Heat Flux in the Arctic. It contains a lot of info on what water goes where and how.
Thanks Neven! Very helpful blog on important topic.


U.Bremen has updated and the Beaufort ice is showing so much green and below that it may not be long of this world. The biggest floes will hold out for an extra week or two, as discussed above, but all of the region with greens is presumably condemned.

  The very thick ice in the sanctuary up against the Canadian Arctic coastline is also detaching, as predicted in one of the models and posted above.

http://www.iup.uni-bremen.de:8084/amsr2/arctic_AMSR2_nic.png


Click on the .gif for flashes back to yesterday's map...
EDIT: is it working? Doesn't seem to work for me this time. The original gif does
« Last Edit: July 23, 2015, 06:38:32 AM by slow wing »

greatdying2

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Re: The 2015 melting season
« Reply #2425 on: July 23, 2015, 06:16:57 AM »
Regarding heat entering via the Bearing Strait: this year the Bearing Sea melted out early, followed directly by the Chukchi, then the adjacent section of the ESS (and next the adjacent portion of the CAB?). But this supposedly has nothing to do with The Blob? Hmmm...  ???
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

sofouuk

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Re: The 2015 melting season
« Reply #2426 on: July 23, 2015, 06:26:24 AM »
greatdying, arguments from personal incredulity aren't very meaningful. the claim was well referenced - have you read them?

greatdying2

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Re: The 2015 melting season
« Reply #2427 on: July 23, 2015, 06:56:51 AM »
No, I didn't read them. Did you?

But I'm afraid that I read enough science in my day job to know that a paper or two aren't necessarily all that meaningful either. You are free to form and express your own opinions, as am I. My opinion, as I said, is that it seems fishy. I could easily be wrong.

I hope that I don't need to say this every time I state an opinion to avoid being scolded by random strangers...
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

sofouuk

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Re: The 2015 melting season
« Reply #2428 on: July 23, 2015, 07:09:05 AM »
http://onlinelibrary.wiley.com/doi/10.1029/2009JC005849/full#

it's not as if the speed of an ocean current is a difficult thing to measure, especially when it would need to be an order of magnitude faster to invalidate the point

ktonine

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Re: The 2015 melting season
« Reply #2429 on: July 23, 2015, 07:16:59 AM »
greatdying, arguments from personal incredulity aren't very meaningful. the claim was well referenced - have you read them?

This paper has been discussed on the forum at various  times and places.  The 2007 Bering Strait Oceanic Heat Flux and anomalous Arctic Sea-ice Retreat

The abstract:
Quote
To illuminate the role of Pacific Waters in the 2007 Arctic sea-ice retreat, we use observational data to estimate Bering Strait volume and heat transports from 1991 to 2007. In 2007, both annual mean transport and temperatures are at record-length highs. Heat fluxes increase from 2001 to a 2007 maximum, 5-6x1020J/yr. This is twice the 2001 heat flux, comparable to the annual shortwave radiative flux into the Chukchi Sea, and enough to melt 1/3rd of the 2007 seasonal Arctic sea-ice loss. We suggest the Bering Strait inflow influences sea-ice by providing a trigger for the onset of solar-driven melt, a conduit for oceanic heat into the Arctic, and (due to long transit times) a subsurface heat source within the Arctic in winter. The substantial interannual variability reflects temperature and transport changes, the latter (especially recently) being significantly affected by variability (> 0.2Sv equivalent) in the Pacific-Arctic pressure-head driving the flow.

Michael Hauber

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Re: The 2015 melting season
« Reply #2430 on: July 23, 2015, 07:26:43 AM »
Regarding heat entering via the Bearing Strait: this year the Bearing Sea melted out early, followed directly by the Chukchi, then the adjacent section of the ESS (and next the adjacent portion of the CAB?). But this supposedly has nothing to do with The Blob? Hmmm...  ???

I suspect that both the blob and the retreat of sea ice on the Pacific side are both responses to the same (or closely related) atmospheric conditions.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

jdallen

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Re: The 2015 melting season
« Reply #2431 on: July 23, 2015, 07:36:46 AM »
Nothing but cracked and shattered ice and open water from Baffin to Beaufort.

http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r04c02.2015203.terra.250m.jpg

What's really amazing is how *thoroughly* shattered the ices is, in just 2-3 days.  It will be end to end like that by tomorrow, most like.
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ChrisReynolds

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Re: The 2015 melting season
« Reply #2432 on: July 23, 2015, 07:55:19 AM »
One can only guess for the rest of the season, based on the past behaviour I suspect the AD will return. I don't think we will see a stall through the whole of August.

A prolonged arctic dipole is unlikely due to current AMO (American Multidecadal Oscillation) values being colder then previous melting seasons. It has been proposed that the AMO plays a significant role in forcing summer circulation anomalies. For example: Sutton and Dong, 2012

http://www.esrl.noaa.gov/psd/data/correlation/amon.us.data  (monthly AMO values)

Blaine has put the AMO forward as an explanation for 2013 and 2014.
http://neven1.typepad.com/blog/2015/06/ocean-circulation-and-arctic-sea-ice-retreat.html?cid=6a0133f03a1e37970b01bb084b578d970d#comment-6a0133f03a1e37970b01bb084b578d970d
The  bottom line for me though is that we have seen an AD with its attendent effects across the NH. I had been suspecting  it might have been a transient pattern limited to 2007 to 2012, it is not. However you may be right, it might not persist.

With regards temperatures north of 80. GFS is showing, for the first time in a while, temperatures in the 0 to -3 across the Pacific side of the pack at the end of this month. Temperatures pegged at zero indicate thaw limiting temperatures from going higher, as soon as temperatures drop below zero they indicate that is not happening. A stall could be iminent.

seaicesailor

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Re: The 2015 melting season
« Reply #2433 on: July 23, 2015, 09:05:41 AM »
Air temperatures are plummeting above 80 north.



Even when getting colder, Euro predicts 850mb above zero on the big high, which btw will keep moving air clockwise around the periphery and moderately in eurasian coast. So some action, but I am not competent on this. I dont know if experts here have something to add about next days conditions.

greatdying2

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Re: The 2015 melting season
« Reply #2434 on: July 23, 2015, 11:08:20 AM »
This paper has been discussed on the forum at various  times and places.  The 2007 Bering Strait Oceanic Heat Flux and anomalous Arctic Sea-ice Retreat

http://onlinelibrary.wiley.com/doi/10.1029/2009JC005849/full#

it's not as if the speed of an ocean current is a difficult thing to measure, especially when it would need to be an order of magnitude faster to invalidate the point
And do you think this paper you cite supports "the point"? Rather, like the paper cited by ktonine above, a quick skim suggests that it does the opposite:

Quote
This indicates that the warm Pacific waters ... accelerated, bringing warmer water farther into the Beaufort Gyre.
Quote
In summary, during the summer of 2007 the Pacific Sector of the Arctic Ocean experienced 250% higher surface heating, 175% higher ocean advective heating, and 210% = 1.51/(1.51 + 0.72) higher net ocean warming, relative to the mean summers of 2000–2006.
Quote
A broad area of high melt rates exists in the Pacific Sector, with values of nearly 1 m of melt over this month. Top melting Δhtop is relatively weak and uniform over the ice pack, in contrast to bottom melting, which reaches higher values but only near the ice edge. In particular, the dynamical ocean component of bottom melting ΔhbotO is large to the west and north of each open water area in the Pacific Sector. This is consistent with Figure 5, which shows that these open water areas are warming in response to atmospheric heat input (and northward ocean current advection near Alaska).
Easy to measure, eh? To me it looks rather difficult and complex.
« Last Edit: July 23, 2015, 11:15:16 AM by greatdying2 »
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

sofouuk

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Re: The 2015 melting season
« Reply #2435 on: July 23, 2015, 11:33:46 AM »
<yawn> measuring the relative contribution of surface and other forms of heating is not the same as measuring the speed of a current, etc, but carry on believing what you like

greatdying2

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Re: The 2015 melting season
« Reply #2436 on: July 23, 2015, 12:24:18 PM »
Yes, well sofouuk, I believe I'll let your words speak for themselves...

Back to something interesting, I find these images from Wipneus' "home brew" thread quite revealing about what may have happened to the ice near that giant hot Pacific blob early this summer:








Finally, here's another nice blog about the issue. 'Nuf said.

http://robertscribbler.com/2015/06/23/hot-blob-2-takes-aim-at-sea-ice-abnormally-warm-waters-invading-the-arctic-through-bering-and-chukchi-seas/ .

The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Nick Stokes

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Re: The 2015 melting season
« Reply #2437 on: July 23, 2015, 12:59:55 PM »
Tommy
"PS. I may have missed it, but is there a site that does a daily update of North Atlantic/ Eastern Arctic SURFACE water temps? "
 
 There is NOAA AVHRR SST data mapped here
http://www.moyhu.blogspot.com.au/p/blog-page.html, updated daily. Here is a screenshot, but you can choose date and region:
 


 
 There is an updated movie version http://www.moyhu.blogspot.com.au/p/sst-regional-movies-as-described-here-i.html?WxK=31.
 

BenB

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Re: The 2015 melting season
« Reply #2438 on: July 23, 2015, 01:42:27 PM »
At the risk of flogging a dead blob, even if the water from the blob cannot plausibly retain any of its original heat by the time it passes through the Bering Strait, isn't it possible that the blob *may* indirectly have been one of the factors that contributed to early melting in Chukchi.

The mechanism would be something like:

1. the blob reduced ice formation/contributed to early melt in the southern Bering Sea
2. this resulted in lower albedo and greater surface warming in the southern Bering Sea at the start of the melt season
3. these warmer surface waters then helped to melt the adjacent ice further north
4. this process continued up through the Bering Sea and into Chukchi

This would obviously only be part of the story, with this year's weather likely to be the main cause. Feel free to shoot the theory down in flames.

Laurent

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Re: The 2015 melting season
« Reply #2439 on: July 23, 2015, 01:56:18 PM »
Tommy
The tool in worldview may suit you ? http://1.usa.gov/1eiUrrm
In the tool menu select "+" then brightness temperature band, then click on active layer "left of "+"" then in the brightness layer click on the parameter (near "X"), select between 260°K and 295°K, color palette rainbow1, tick squash palette.

greatdying2

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Re: The 2015 melting season
« Reply #2440 on: July 23, 2015, 02:05:38 PM »
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

greatdying2

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Re: The 2015 melting season
« Reply #2441 on: July 23, 2015, 02:34:09 PM »
And here are 2012 and 2014, all July 21. (Guess which is which... ;) ).
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Tommy

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Re: The 2015 melting season
« Reply #2442 on: July 23, 2015, 03:26:51 PM »
Probably not a huge effect on Arctic, but I've seen this pattern many times lately, where warm air snakes all the way up from the Caribbean. Basically a continuous direct flow of wind from deep south to north that I've seen many times in the wind pattern. I put arrows to show the wind directions that are indicated on the wind map today.
Tommy

plinius

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Re: The 2015 melting season
« Reply #2443 on: July 23, 2015, 05:07:07 PM »
@Tommy: Apart from that the plotted ground layer does not remain in the ground layer in that path, please do me a favour and calculate the time you would need to hold this pattern stable so that at a grossly overestimated streaming velocity of 40km/h would need to reach the Canadian archipelago from the Carribean...

seaicesailor

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Re: The 2015 melting season
« Reply #2444 on: July 23, 2015, 05:11:34 PM »
Keeping the eye on our little friend (the floe closest to the Mckenzie river delta), I compare 7/20 image (top) with 7/22 made available today (bottom). These images are post-processed by Wipneus using AMSR2 uni-Hamburg data.
Size remains approx. the same, but it has darkened a bit. Not sure if that really means much. I also clumsily pasted today's MODIS visual (upper floe).

Anybody sees something interesting, holler out :)

seaicesailor

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Re: The 2015 melting season
« Reply #2445 on: July 23, 2015, 05:14:37 PM »
BTW, the huge thick chunk of ice that was attached to the coast (upper part of the images) seems to be hit pretty hard



oren

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Re: The 2015 melting season
« Reply #2446 on: July 23, 2015, 05:17:01 PM »
seaicesailor - thank you. Please keep up the watch on this floe. A very interesting micro-case.

Tommy

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Re: The 2015 melting season
« Reply #2447 on: July 23, 2015, 05:19:23 PM »
Quote
"Please do me a favour and calculate the time you would need to hold this pattern stable so that at a grossly overestimated streaming velocity of 40km/h would need to reach the Canadian archipelago from the Carribean..." --
plinius


Ok. Just did it n my head.
Answer: Not that long. Warm air is moving north along that pattern. No question about it.
The part at the north is taking warm air from the part from the south almost all the time in late spring and summer, the part south of that is taking warm air from the part from the south of it almost all of the time in late spring and summer, the part south of that is is taking warm air from the part from the south of it almost all of the time in late spring summer ... and so on...
« Last Edit: July 23, 2015, 05:24:51 PM by Tommy »

jdallen

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Re: The 2015 melting season
« Reply #2448 on: July 23, 2015, 05:56:14 PM »
Quote
"Please do me a favour and calculate the time you would need to hold this pattern stable so that at a grossly overestimated streaming velocity of 40km/h would need to reach the Canadian archipelago from the Carribean..." --
plinius


Ok. Just did it n my head.
Answer: Not that long. Warm air is moving north along that pattern. No question about it.
The part at the north is taking warm air from the part from the south almost all the time in late spring and summer, the part south of that is taking warm air from the part from the south of it almost all of the time in late spring and summer, the part south of that is is taking warm air from the part from the south of it almost all of the time in late spring summer ... and so on...
Answer:  About 4 days.

Here's the problem - the pattern will not persist long enough for the air currently at the bottom of the "hose" to make it to the top, before the top moves.

I've seen this before, *and* initially had the same conclusion, Tommy.  But on reflection and further observation it became clear to me the conclusion didn't apply.

*Now* contrary-wise, the flow does demonstrate that there is exchange running from the tropics all the way to the Arctic, which does imply changes to the previously typical Hadley-Ferrel-Arctic cell circulation of the atmosphere.

Similarly contrary, we have had serious blocking patterns (e.g. the "RRR" off of the Pacific coast of North America and what I call the "cyclone cannons" on the Eastern Seaboard of the US and Asia).  With those, the flow was still very chaotic.

Now, as to what the transitory flow off of the continent into the CAA *will* do...  on a daily basis, net insolation in sub-arctic Canada right now is as high as that in the tropics.  The heat which is landing on the tundra is what will be exported north, not what's currently in the Caribbean.

The direct effect of this will still be nominal; heat uptake by ice from atmosphere is quite low.  The heavy lifting for melt is from surface water and sunlight.

Now, when we shift from melt season to refreeze, the dynamic and the effects will change again.  The heat imported instead of going into the ice, will exit the atmosphere.  In doing so, it will *replace* heat which normally would be lost by ocean during the refreeze.  It's my hypothesis that the extraordinary heat flows we saw moving into the arctic last winter did exactly this... and caused the record low maxima we saw.  That heat last winter did originate in the tropics or subtropics - much of it coming again from conga lines of storms along the west side of both the Atlantic and Pacific.

So my conclusion, flow from the tropics to Arctic in July, not that big a deal.  Flow from tropics to Arctic in January - definitely a big deal.
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Tommy

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Re: The 2015 melting season
« Reply #2449 on: July 23, 2015, 06:15:52 PM »
Quote
So my conclusion, flow from the tropics to Arctic in July, not that big a deal.  Flow from tropics to Arctic in January - definitely a big deal.
- jdallen.

Interesting post. Makes sense. Like I said when I posted it, probably not a big effect at this time, but just interesting to see. I'll keep a daily eye/screenshot on it.
Been watching the RRR for over a year now, on the same wind map. Unbelievably resilient most of the time.
Tommy.