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Jim Hunt

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Re: The 2015 melting season
« Reply #500 on: April 14, 2015, 03:47:26 PM »

Hmm, correct me if I'm wrong but you wouldn't really expect to see the temperatures rise much above that regardless whilst there is enough ice to act as a heatsink and cause a temperature inversion would you?

I was seeking to contrast the anomaly map I posted yesterday with the absolute temperatures. Here's today's version. At this time of year a deep red anomaly at the Pole translates to --17.25 °C on the ground.

In the Kara temperatures at Troynoy Island have been much closer to -1.8, but nonetheless still below:


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Jim Hunt

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Re: The 2015 melting season
« Reply #501 on: April 14, 2015, 03:53:11 PM »
That temperature is only at 2 metres, so isn't that around the temperature of the top of the ice as  well?

More like the temperature at the top of the snow, which is generally still blanketing the ice at this time of year. I'm rather hoping that the numbers from the  ice mass balance buoy installed near ITP 83 will become available shortly, in order to illustrate that point. In the meantime here's the state of IMB 2014E from around this time last year:

P.S. 2015D has now appeared on my screen. Bear with me for a bit.......
« Last Edit: April 14, 2015, 04:57:13 PM by Jim Hunt »
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Siffy

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Re: The 2015 melting season
« Reply #502 on: April 14, 2015, 04:14:45 PM »

Hmm, correct me if I'm wrong but you wouldn't really expect to see the temperatures rise much above that regardless whilst there is enough ice to act as a heatsink and cause a temperature inversion would you?

I was seeking to contrast the anomaly map I posted yesterday with the absolute temperatures. Here's today's version. At this time of year a deep red anomaly at the Pole translates to --17.25 °C on the ground.

Ahh, okay I understand where you are coming from a bit better now.

For myself I don't expect to see insitu melting in the pole for a good while yet. I'm more thinking that the heat spike around the Barents sea at between the 75-80th parallel north which has persisted for a good deal of time will be influential as it seems to already be starting to melt out there well ahead of the previous year for instance.


If you compare todays asmr2



Against the same date last year



Perhaps that isn't a fair comparison though, I'll admit that I've not been eyeballing absolute temperature charts to much but the GFS forecast i've seen puts the barents area at or close to 0 for most of the last week and continues in that vein for a while.

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Re: The 2015 melting season
« Reply #503 on: April 14, 2015, 04:53:33 PM »
Hot off the presses, temperature profiles for ice mass balance buoy 2015D. The buoy is currently situated just south of the North Pole. A brief explanation of the charts can be found at:

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/

Air temperatures reached a maximum of -9.16 °C on the 12th. The snow depth is currently guesstimated at 5 cm. Last year at this time 2014E proclaimed a snow depth of 20 cm.
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Jim Hunt

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Re: The 2015 melting season
« Reply #504 on: April 14, 2015, 05:12:20 PM »
I'm more thinking that the heat spike around the Barents sea at between the 75-80th parallel north which has persisted for a good deal of time will be influential as it seems to already be starting to melt out there well ahead of the previous year for instance.

Last year the Laptev Sea was receiving some warmth about this time, as shown by your 2014 map and temperatures in Tiksi:

http://www.meteociel.lu/temps-reel/obs_villes.php?code2=21824&jour2=10&mois2=3&annee2=2014&envoyer=OK

Later in the season open water in that sector reached north of the 85th parallel, so it will undoubtedly be interesting to see how the Atlantic side of things progresses this year.

Will open water reach 90 degrees north this summer?!
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Neven

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Re: The 2015 melting season
« Reply #505 on: April 14, 2015, 05:19:15 PM »
Will open water reach 90 degrees north this summer?!

Jim, you're getting me all excited! And it's only April.  ;D
« Last Edit: April 14, 2015, 05:44:16 PM by Neven »
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Re: The 2015 melting season
« Reply #506 on: April 14, 2015, 05:39:28 PM »
Hot off the presses, temperature profiles for ice mass balance buoy 2015D. The buoy is currently situated just south of the North Pole. A brief explanation of the charts can be found at:

Looking pretty hot for ice that north (can't find the proper emoticon for this one).

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Re: The 2015 melting season
« Reply #507 on: April 14, 2015, 05:46:13 PM »
to see how the Atlantic side of things progresses this year.

Will open water reach 90 degrees north this summer?!

It's a wild ass guess on my part but I'm quietly expecting that we will see open water all the way into the pole by the end of the melt season and not just a channel into from the leptev as we saw last year but an empty pole.

Ofcourse it's rather exceptionally early to speculate as I am hence the wild ass guess part but a number of factors look to be lining up to make it a possibility including the hot El Nino.

Edit: Actually has any one ever tried to check the correlation between El nino/la Nina on seasonal melt refreeze?

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Re: The 2015 melting season
« Reply #508 on: April 14, 2015, 06:03:57 PM »
to see how the Atlantic side of things progresses this year.

Will open water reach 90 degrees north this summer?!

It's a wild ass guess on my part but I'm quietly expecting that we will see open water all the way into the pole by the end of the melt season and not just a channel into from the leptev as we saw last year but an empty pole.

Ofcourse it's rather exceptionally early to speculate as I am hence the wild ass guess part but a number of factors look to be lining up to make it a possibility including the hot El Nino.

Edit: Actually has any one ever tried to check the correlation between El nino/la Nina on seasonal melt refreeze?
Iirc El Niño is actually favorable to ice, oddly. I'm not sure the behavior will be the same however, because of how different conditions are, and the fact there is much warmer water further north along the coast of North America.

As others have mentioned, the early heat in the arctic has cognates to last year. The heat over the Kara and Barents I do think will be significant.  The ice in the Laptev is not much better off. Export through the Fram has shifted thicker ice away from the coast there.  It will be at risk even without the heat of last season.

This year will be volatile, dynamic and I think damn near impossible to predict.
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Re: The 2015 melting season
« Reply #509 on: April 14, 2015, 06:26:25 PM »
My own thoughts are that El Nino is favorable to colder summers in the Arctic, and warmer winters. La Nina the opposite. So if there's no record melt this summer, it's lurking behind the corner for 16/17.

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Re: The 2015 melting season
« Reply #510 on: April 15, 2015, 06:20:52 AM »
re: el nino and arctic :

My thoughts are the el Nino years look quite normal (with the overall decreasing trend), but the arctic abnormality would start in 1 - 1½ years  (divided about like this: 6 months for the normal Nino effect in tropics&subtropics + 6 months for the el Nino warmed water cycle to pass Ferrel cell + some odd months for oceanic circulation to get to the Arctic) That would be late 2016, in this case, or if the Nino of 2015 is delayed 2017)

Mind you, in records 2014 was a very mild el Nino year. In addition, I'd say the destruction of the polar vortex (creating the boundary for the polar atmospheric cell) could speed up things a bit, so given the prediction of late June 2015 Nino realizes, July-August 2016 would be sort of 'go brown'-months for polar bears.

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Re: The 2015 melting season
« Reply #511 on: April 15, 2015, 07:39:35 AM »
There are some years that shows a correlation, escpecially after a large El Nino.
http://forum.arctic-sea-ice.net/index.php/topic,778.msg33860.html#msg33860

My way into all of this was actually interest in how our winters in Scandinavia were affected by ENSO. And there are correlations, not direct and obvious though. Here's a collection of older papers regarding that from another Scandinavian.
https://agwobserver.wordpress.com/2010/12/02/papers-on-enso-effects-in-europe/

Jim Hunt

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Re: The 2015 melting season
« Reply #512 on: April 15, 2015, 11:28:44 AM »
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Jim Hunt

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Re: The 2015 melting season
« Reply #513 on: April 15, 2015, 11:36:43 AM »
Jim, you're getting me all excited! And it's only April.  ;D

If you'd like a more up to date video for your forthcoming article on the subject let me know. Here's one I somewhat hastily prepared earlier:

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viddaloo

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Re: The 2015 melting season
« Reply #514 on: April 15, 2015, 12:13:02 PM »
Estimated Week 16 melt: 11% less than 2011.


[chart faq]

After Week 16 (Week 12–16 total estimate): 118204 km² less melt than 2011
Week 15: 79930 km² less melt than 2011
Week 14: 110128 km² more melt than 2011
Week 13: 129443 km² more melt than 2011
Week 12: 289745 km² less melt than 2011

118 k km² less melt than 2011 by Sep 10 would imply a seasonal melt of 10 million km² and an ice extent of 4 m km² in September. A minimum that low would secure 2015 the 2nd position — after 2012 but before 2007 & 2011.
[]

JayW

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Re: The 2015 melting season
« Reply #515 on: April 15, 2015, 12:25:11 PM »
I thought I would try plot some composites based on the +ve PDO, for the period May-SeptemberI went over the monthly numbers from JMA http://www.data.jma.go.jp/gmd/kaiyou/data/db/climate/pdo/pdo.txt  and JISAO http://research.jisao.washington.edu/pdo/PDO.latest, and put together a quick and dirty list of years.  I had to make choices, so if anyone has issues with the years I used, one can plot their own correlations here http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl

Years are listed on the bottom of the plot

First attachment is surface temps, second is 500mb geopotential heights, third is sea level pressure

« Last Edit: April 15, 2015, 12:34:46 PM by JayW »
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Re: The 2015 melting season
« Reply #516 on: April 15, 2015, 12:28:20 PM »
I also made the same plots using a +ve PDO and El Niño years. Again, years listed at bottom, apologies if I'm in error. 

May-September

First attachment surface temps, second 500mb geopotential heights, third sea level pressure
« Last Edit: April 15, 2015, 12:49:20 PM by JayW »
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Neven

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Re: The 2015 melting season
« Reply #517 on: April 15, 2015, 12:37:29 PM »
If you'd like a more up to date video for your forthcoming article on the subject let me know. Here's one I somewhat hastily prepared earlier:



You could speed it up slightly, but that's a very nice animation, Jim. It's fascinating to focus on just one area (Beaufort, North Pole, Kara/Barentsz) and see how the ice moved in these past couple of months.
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Jim Hunt

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Re: The 2015 melting season
« Reply #518 on: April 15, 2015, 12:38:52 PM »
I also made the same plots using a +ve PDO and El Niño years.

May-September

The plots say January?
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JayW

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Re: The 2015 melting season
« Reply #519 on: April 15, 2015, 12:49:51 PM »
I also made the same plots using a +ve PDO and El Niño years.

May-September

The plots say January?

Grr, sorry bout that Jim,  forgot to change that part, fixed now. Thanks for catching that!
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Re: The 2015 melting season
« Reply #520 on: April 15, 2015, 06:22:30 PM »
The Kara Sea has started to refreeze today:
Doubt it will get far; it's close to freezing, and heat is due in force in a couple of days.
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Re: The 2015 melting season
« Reply #521 on: April 15, 2015, 10:45:54 PM »
If you'd like a more up to date video for your forthcoming article on the subject let me know. Here's one I somewhat hastily prepared earlier:



You could speed it up slightly, but that's a very nice animation, Jim. It's fascinating to focus on just one area (Beaufort, North Pole, Kara/Barentsz) and see how the ice moved in these past couple of months.
Yes, that's a fascinating animation. Thanks Jim, much appreciated

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Re: The 2015 melting season
« Reply #522 on: April 16, 2015, 12:33:45 AM »
Siffy, if you want to compare sea ice I suppose it is better to do an animation, or maybe something like this ;).

Certainly less ice in Barents and Kara now compared to one year ago, but its still April and we are just getting started way out there on the edges, so I personally don't see very much useful information in such comparisons right now. Better have the patience to wait another month at least.

And yes; that thing in Hudson is mainly an artifact.

viddaloo

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Re: The 2015 melting season
« Reply #523 on: April 16, 2015, 05:02:39 AM »
Icelook apr15: Average extent 6th lowest in 9 weeks, average volume will be 6th in 16 days, and p1k (Piomas minus 1000) will be 5th in 7 weeks. Once again I find myself in a chair with coffee within my reach: Annual average extent continues to be the most exciting graph to follow this time of year, with sea ice in peripheral oceans still pulsing back and forth. For the first time since leaving the 'Plateau' of 200 k km² from the yearly maximum, JAXA's reported increases in extent last week may cause an uptick in annual average extent. For this graph to turn upwards, the daily extent would have to be higher than last year on the same day, which seems possible during this week. The 10.27 million line in any case will take longer to cross because of this slowdown in the melt, with April 2015 as the slowest melting April to date. Per the estimate graph 10.27 will never be crossed, but per the weekly delta of 3700 km² we will be lower by Apr19. Currently, the forecast graph says we'll be higher than 2014 and thus 6th lowest by June 20th.


[chart faq]

Average volume is based on the Piomas data model, and therefore considerably more uncertain, and it now once again seems somewhat likely we *will* cross the 2008 graph someday in May. We will thus be 6th lowest in annual average volume. If about 1000 km³ lower than official Piomas figures suggest, however, the p1k assumption, average volume could go higher than 2014 and be 5th lowest around Jun6.

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seaicesailor

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Re: The 2015 melting season
« Reply #524 on: April 16, 2015, 06:57:42 AM »
Vid,
Just by eyeballing the extent evolution in recent years:

http://meteomodel.pl/klimat/arcticice_nsidc.png

it has been observed before by other contributors that the rate of extent reduction becomes very similar in June for many different years. I believe that this is the reason why the annual average extents 2011 2008 and 2012 gradually reach a plateau on early June (moving average is losing at one extreme of the range the same that it gains at the other).

Per this other plateau hypothesis ;-) my feeling is that 2015 will flatten out closer to 10.20 M km2, somewhere between values of 2011, 2008, 2012. Anyways soon we'll see how good or bad this is.

Extent Jun - to - Jun average may end up much lower than 2014 and back to earlier years, a notable result in my opinion. Thx for the plot

viddaloo

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Re: The 2015 melting season
« Reply #525 on: April 16, 2015, 01:58:11 PM »
I noticed while I wrote this that per Apr 14 the two slowest April melters were 2011 and 2015 — ie exactly the two years with the longest & lowest ice extent plateaus around the winter maximum. I'd say not melting very fast because not so much ice to melt, but what do I know? If you ask politely there's hardly ever an answer, and I'm probably the only one interested in sea ice on this planet, or at least that is the impression I'm given here. Would be nice to find another person that I could talk to!
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Jim Hunt

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Re: The 2015 melting season
« Reply #526 on: April 16, 2015, 02:04:44 PM »
According to 2015D the air temperature at the North Pole is now -4.99 °C. Here's the updated temperature profile:
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Jim Hunt

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Re: The 2015 melting season
« Reply #527 on: April 16, 2015, 02:07:33 PM »
And yes; that thing in Hudson is mainly an artifact.

According to Wipneus:

Quote
The "torch" is on over the Hudson bay.

http://forum.arctic-sea-ice.net/index.php/topic,382.msg50238.html#msg50238
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Jim Hunt

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Re: The 2015 melting season
« Reply #528 on: April 16, 2015, 02:11:05 PM »
You could speed it up slightly, but that's a very nice animation, Jim. It's fascinating to focus on just one area (Beaufort, North Pole, Kara/Barentsz) and see how the ice moved in these past couple of months.

OK - I'll endeavour to produce an up to date and slightly more "professional" version.

BTW, it seems the NSIDC have now produced a March 2015 version of their ice age breakdown:
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Jim Hunt

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Re: The 2015 melting season
« Reply #529 on: April 16, 2015, 02:17:32 PM »
I'm probably the only one interested in sea ice on this planet, or at least that is the impression I'm given here. Would be nice to find another person that I could talk to!

Is your "probably" frequentist or Bayesian?

I'm interested in sea ice. What do you make of my sea ice temperature profiles?
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Re: The 2015 melting season
« Reply #530 on: April 16, 2015, 02:22:11 PM »
According to 2015D the air temperature at the North Pole is now -4.99 °C.

Nullschool.net is predicting the North Pole to hover just above freezing from 9am BST on 17 April 2015, and staying at or above 0oC for 9 hours thereafter. http://earth.nullschool.net/#2015/04/17/0300Z/wind/surface/level/overlay=temp/orthographic=-17.53,81.70,1094

Obviously the air above the ice is slightly warmer (0.5C at 1000 hPa)

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Re: The 2015 melting season
« Reply #531 on: April 16, 2015, 02:40:13 PM »
BTW, it seems the NSIDC have now produced a March 2015 version of their ice age breakdown:

After 2007 shock, the minimums are occur close to where you would expect. I would have expected 4 and 5 year ice to take some time to recover and not long enough has passed yet. 1, 2, and 3 year ice should recover more quickly. Seems surprising these are still tending upwards so long after the 2007 shock? Maybe 2013 and 2014 are just unusual poor melt seasons and just give the impression of continuing 'recovery' in ice age proportions from 2007 shock? (I wish they would do those diagrams in million Km^2 instead of % of ice because proportion could give impression of recovery when area is actually declining.)

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Re: The 2015 melting season
« Reply #532 on: April 16, 2015, 02:47:40 PM »
I wish they would do those diagrams in million Km^2 instead of % of ice because proportion could give impression of recovery when area is actually declining.

Quite so. And what about the volume?  ;)
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Re: The 2015 melting season
« Reply #533 on: April 16, 2015, 02:53:12 PM »
Nullschool.net is predicting the North Pole to hover just above freezing from 9am BST on 17 April 2015

Quite so:
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Re: The 2015 melting season
« Reply #534 on: April 16, 2015, 03:36:22 PM »
According to 2015D the air temperature at the North Pole is now -4.99 °C. Here's the updated temperature profile:

Concerning the specific temperature profiles: Is the steep temperature decrease on top just a matter of the time evolution, or is this actually the insulating effect of the snow cover?

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Re: The 2015 melting season
« Reply #535 on: April 16, 2015, 03:51:01 PM »
Quite so. And what about the volume?  ;)


Well volume has increased these last few years while area and extent is at near record low so the thickness has increased. ;) And then there is what about the proportion of the volume?  ;)

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Re: The 2015 melting season
« Reply #536 on: April 16, 2015, 04:01:34 PM »
Concerning the specific temperature profiles: Is the steep temperature decrease on top just a matter of the time evolution, or is this actually the insulating effect of the snow cover?

I've never watched temperatures of an ice floe change so far so fast. At this time of year I generally check what's going on once a month or so. Ask me again after the excitement is over and the report from the field has arrived!

According to the preliminary information there is only 5 cm of snow. If that is indeed the case then the drop between thermistors 6 & 7 is down to snow, then everything down to 30 is what's happening inside the ice. There's also the diurnal cycle to consider, which that graph doesn't address. Here's what ITP 83 has to say on that matter:


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Re: The 2015 melting season
« Reply #537 on: April 16, 2015, 04:40:23 PM »
MetOp2 has been down for about a week, but through its sister MetOp1 I've been able to piece together an Ersatz graph for April.

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Re: The 2015 melting season
« Reply #538 on: April 16, 2015, 05:10:41 PM »
Concerning the specific temperature profiles: Is the steep temperature decrease on top just a matter of the time evolution, or is this actually the insulating effect of the snow cover?

I've never watched temperatures of an ice floe change so far so fast. At this time of year I generally check what's going on once a month or so. Ask me again after the excitement is over and the report from the field has arrived!

According to the preliminary information there is only 5 cm of snow. If that is indeed the case then the drop between thermistors 6 & 7 is down to snow, then everything down to 30 is what's happening inside the ice. There's also the diurnal cycle to consider, which that graph doesn't address. Here's what ITP 83 has to say on that matter:

Well knowing the time evolution of the air temperature, actually that has the potential for a textbook example for thermodynamics/physics students ;-), finally getting away from iron bars in a heat bath... An interesting question (see diurnal cycle) is also: could we neglect the radiation balance/light absorption of the ice itself?

Jim Hunt

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Re: The 2015 melting season
« Reply #539 on: April 16, 2015, 07:32:14 PM »
Could we neglect the radiation balance/light absorption of the ice itself?

There's currently still that layer of shiny snow on top of the ice. Then we'd need to start worrying about clouds wouldn't we? Long wave versus short wave?
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Re: The 2015 melting season
« Reply #540 on: April 16, 2015, 08:47:29 PM »
We're down .2 million since the start of the month, yet 2007 is down .5 and 2012 .4 million km². 2015 april ice has been melting slower than any other first half of April, save 2006, probably because of an already low ice extent at the end of March. For 'centuries', 2012 has had one new century drop, while the two other years are unchanged. Based on these indicators alone, 2015 currently looks like the last or middle year among the 3 in overall melt.

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Neven

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Re: The 2015 melting season
« Reply #541 on: April 17, 2015, 12:05:49 AM »
For those not following the Plateau Hypothesis topic:

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I've banned Viddaloo. I want to thank you for your patience with my patience, and apologize for taking so long. I prefer to keep folks on board as much as I can (except for climate risk deniers), and so this was a useful experience for me. Next time I'll do it differently.
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Neven

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Re: The 2015 melting season
« Reply #542 on: April 17, 2015, 12:08:53 AM »
On a more positive note: crandles and others, I've solved the temperature vs anomalies dilemma on the new ASIG Forecasts page! I've made a second, identical Forecasts page with the actual SATs, and via small links you can switch between actual temps and temp anomalies.

Pretty elegant solution, if I say so myself. Must be because I spent time with actual scientists at EGU today.  ;)
« Last Edit: April 17, 2015, 10:39:25 AM by Neven »
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Rubikscube

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Re: The 2015 melting season
« Reply #543 on: April 17, 2015, 12:11:52 AM »
According to Wipneus:

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The "torch" is on over the Hudson bay.

Hm, I see its there today as well. It is just wet snow I suppose and not full melt ponding? Either way, I'll try to be more careful next time :).

sedziobs

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Re: The 2015 melting season
« Reply #544 on: April 17, 2015, 12:34:01 AM »
Currently 39F in Churchill according to wunderground.  Doesn't seem to be any ponding on the webcam here:
http://hdontap.com/index.php/video/stream/port-of-churchill-live-stream

crandles

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Re: The 2015 melting season
« Reply #545 on: April 17, 2015, 12:38:50 AM »
On a more positive note: crandles and others, I've solved the temperature vs anomalies dilemma on the new ASIG Forecasts page! I've made a second, identical Forecasts page with the actual SATs, and via small links you can switch between actual temps and temp anomalies.

Pretty elegant solution, if I say so myself. Must be because I spent time with actual scientists at AGU today.  ;)

Nice  :)

sedziobs

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Re: The 2015 melting season
« Reply #546 on: April 17, 2015, 12:57:01 AM »
The new forecasts page looks great!  Very clear and useful.  Thanks!

Jim Hunt

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Re: The 2015 melting season
« Reply #547 on: April 17, 2015, 01:59:52 AM »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Michael Hauber

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Re: The 2015 melting season
« Reply #548 on: April 17, 2015, 04:09:32 AM »
Some hints in the forecast that their may be some melt on the edges of the Beaufort.  2008 was the earliest melt in this region with significant open water starting to open up in the 2nd week of May (I've checked back to 2007).  While I don't think current conditions are enough to get any sustained melting happening it will be interesting to see if the warmth builds further as we approach the start of May.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

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Re: The 2015 melting season
« Reply #549 on: April 17, 2015, 07:02:52 AM »
I wish they would do those diagrams in million Km^2 instead of % of ice because proportion could give impression of recovery when area is actually declining.

Quite so. And what about the volume?  ;)
Thanks for these comments. Was thinking the exact same thing.