Arctic Sea Ice : Forum

Cryosphere => Arctic sea ice => Topic started by: BornFromTheVoid on September 22, 2014, 07:59:57 PM

Title: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on September 22, 2014, 07:59:57 PM
Looks like it's time for a new thread. Seems most measures have hit their minimum and are now on the way up.
The ECM shows colder than average uppers over the next 5 days, so an opportunity for some above average ice growth.

T0
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FzenQgYg.png&hash=ba67a8dfc10699dd43cf0368ffa890c1)

T72
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FZO3lKbO.png&hash=141d7fff034f51d2e5b07ebea1303678)

T120
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FRvD4gh0.png&hash=fa833da941e282f59e4db2988f147eab)

As the ocean releases its heat, we will likely see above average surface temps persisting for a while though, as has been the case in most recent autumns.

Based off the NSIDC extent (using a 5 day running average), below is a graph of the largest 7 day extent increases recorded for each year since 1979

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FNpO9Imh.jpg&hash=e885a0d06d50510929fa3ee5b1fe86e7)

It will be interesting to see where 2014 ends up!
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on September 22, 2014, 09:51:49 PM
Void, my gut feeling tells me people are reluctant to comment because they'd rather have Summer linger on for a few more weeks :)

The 7 day increases you graph, are they from September/October, or any time of the year? I thought November was the best month for refreeze, but that is perhaps only for volume?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on September 23, 2014, 02:05:11 AM
This is now the official freezing season thread. Thanks for opening, BFTV.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on September 23, 2014, 02:19:00 AM
Lord M Vader had already posted a freezing season thread a month ago, but he was so early that I forgot.  :-[ ::)

To make it up I post his latest comment here:

So, now when we have reached the minima we can put our attention to the Arctic weather winter 2014/2015.. The last couple of years the SIE per JAXA have been more than 8 Mn km2 at October 31 (except for 2012).

Given the rather high sea ice extension in Barents Sea I won't be too surprised if the SIE may be close to 9 Mn km2 by October 31. Last time that happened was 2008.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on September 23, 2014, 07:56:37 AM
Void, my gut feeling tells me people are reluctant to comment because they'd rather have Summer linger on for a few more weeks :)

The 7 day increases you graph, are they from September/October, or any time of the year? I thought November was the best month for refreeze, but that is perhaps only for volume?

Yes it is. Early freeze season extent gains are very rapid as thin ice spreads very fast.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on September 23, 2014, 11:20:57 AM
Void, my gut feeling tells me people are reluctant to comment because they'd rather have Summer linger on for a few more weeks :)

The 7 day increases you graph, are they from September/October, or any time of the year? I thought November was the best month for refreeze, but that is perhaps only for volume?

Unfortunately, my laptop is on the way out. So I've lost all the data that went into that graph!
As far as I can remember, the date range of fastest gains went from something like the week up to October 6th for the earliest, and to December 8th for the latest. The majority of them occur in mid to late October.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on September 23, 2014, 12:14:13 PM
Unfortunately, my laptop is on the way out. So I've lost all the data that went into that graph!

Tell me about it, my second HD died a couple of days ago. It was more or less my back-up HD, but there was some stuff I hadn't copied to my laptop (my double back-up), like my Arctic Archives! All those animations, graphs, etc, lost.

I'm so stupid...  >:( :'(

But that was the first and last time this happens to me.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: iceman on September 23, 2014, 03:00:35 PM
That's quite a setback, Neven.  Fortunately the ASIF community has a collective memory that will offset the loss of data to some extent.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on September 23, 2014, 05:09:02 PM
Unfortunately, my laptop is on the way out. So I've lost all the data that went into that graph!

Tell me about it, my second HD died a couple of days ago. It was more or less my back-up HD, but there was some stuff I hadn't copied to my laptop (my double back-up), like my Arctic Archives! All those animations, graphs, etc, lost.

I'm so stupid...  >:( :'(

But that was the first and last time this happens to me.

Makes my 40 minutes of lost work seem like so little now! I think you always have to lose something big before backing up data consistently becomes a priority.

Anywho, I re-did the stuff from yesterday. Below is a graph showing the day of the year that the fastest 7 day extent increase finished on. There's a slight trend toward an earlier maximum date, which is to be expected. The range is from October 7th to December 8th, so my memory wasn't too far off yesterday.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FZ5anyTA.jpg&hash=f493384fe86e827d1c3e241755494193)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on September 23, 2014, 06:01:09 PM
My macbook served itself to some red wine a week ago, while I was sleeping innocently. Luckily, only the Return key stopped working, and I finally found a (software) fix for that. Use memory sticks for backup, guys. The cheapest (bytes/cost) sticks store 128 GB these days. (Note to self: Employ daily or at least weekly backups from now on!)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on September 24, 2014, 07:00:26 AM
This IJIS Yearly Mean Extent graph may look a bit messy, but there is a pattern here — a 5–year cycle — if you look closely: In both 2007 and 2012 you have steep descents down to record Autumn minima. Then in 2008 and 2013 follow steep ascents, packing a lot of ice to the yearly mean. The 3rd year of the cycle, 2009 and 2014, are fairly uneventful years with only a slight descent in mean extent.

The 4th year of the cycle is 2010 and 2015, where a major descent is starting. The descent continues with year 5 of the cycle, 2011 and 2016, perhaps. And by now you've had 1 record extent minimum (2007) and 3 record volume minima (2007, 2010, 2011) in the first cycle, and 1 record extent and volume minimum (2012) in the second cycle. But 3rd year 2014 is .303 million km² below 2009 for September 23rd, so if the 4th and 5th year — 2015 and 2016 — resemble 2010 and 2011 in any way, we may see huge drops in average extent and volume that go beyond even 2010 and 2011, and also impressive new minimum records for PIOMAS ice volume, before 2017, the first — and possibly record — year of yet another 5–year cycle.

If correct, the Yearly Mean Extent graph will likely start a descent as early as October 2014 and continue all the way through a 'Perfect Storm' 2015 until we have a new record minimum volume in September. This means that the Arctic Refreeze of 2014 will be very exciting indeed. Though maybe a bit confusing: The sea ice extent will of course increase, but the speed and size of the refreeze will determine whether this Yearly Mean Extent graph will sport an October descent or not.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on September 24, 2014, 11:02:02 AM
I for one will start tracking 2 meter temps more closely; temperatures bottom to top in fact.  Perhaps it can give us a sense of the heat leaving the system, and by inference, an idea of how volume is rising.

Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Rubikscube on September 24, 2014, 08:07:44 PM
2014 was a year which appeared at first to become the ultimate comeback, but then everything went wrong. In fact in March, at the very beginning of melt, I thought chances of record where vast. Not only because volume has caught up with 2012, but because there was so much volume stacked up along CAA and so little was left in more crucial places such as Laptev and ESS.

In March though, the polar vortex came back together, and ice started flowing into Barents once more. Without this export taking place throughout the spring I think extent could have been at least 0,5M lower at minimum. Then in late April, May things started to go wrong when snow cover deficits failed to keep up with other post-2007 years and lack of heat import brought 80N temps below normal, and despite indications of the opposite, propper melt conditions never materialized in early June. HP-systems did appear, but no propper heat nor any winds to speak of, only crisp sunshine on what seems to have been too much snow. Super bad melting conditions for June it appears, so bad that volume couldn't even keep up with 2013.

July weather this year was boring and uneventful, LP-dominated and too cold, it kind of resembled that of July 2012 I would claim, but the difference was that in 2012 there were more ponds, more heat lingering around and in general more weak ice to melt, nevertheless July was no good month in 2012 either.

I would also maintain that if the weather in August had occurred 2 months earlier, then 2014 would have rivaled 2012 almost regardless of what would happen next, but as "August weather", and with such limited amounts of ponds and slush to work with, massive HP-systems without a proper dipole setup seems to do the ice more good than harm, hence the historic bad volume melt.

Looking back with hindsight, I can hardly imagine that it could have become any worse than this, taking into account conditions in March. And as a result of all this, I would argue that the virtually ice free date may have been postponed with 2 years, perhaps more. Before 2017 seems less plausible every day. Though, I'm really looking forward to see whether we can see yet another "volume catch up" this winter, and I will be left speechless if 2012 is caught at maximum like it was this year.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on September 24, 2014, 09:19:55 PM
It will mean more when the September data is used. But looking at August PIOMAS volume.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F1.bp.blogspot.com%2F-h3SrmoCC8kI%2FVAvyVQ2V94I%2FAAAAAAAAA8c%2FYrHJ8229bdo%2Fs1600%2FPIOMAS%252BVolume%252Bby%252Bregion.png&hash=533b36c7e94dcfcbb18d2a4678a11db4)

Note that the only region with unusually high volume for recent years is the Central Arctic, CAA not shown also has a high volume in comparison to recent years. I've not yet formed a firm opinion about what this means for peak volume, but my suspicion is peak volume may be around 24.5k km^3, that's the average for April 2011 to 2014 with an extra 2k km^3 added on (the current excess over recent years).

I'll be watching what happens to the extra mass in the Central Arctic.

ASCAT
http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/ (http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/)

Drift Age Model
ftp://ccar.colorado.edu/pub/tschudi/iceage/gifs/ (http://ftp://ccar.colorado.edu/pub/tschudi/iceage/gifs/)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: iceman on September 25, 2014, 03:18:14 PM
The peak volume question merits some thought.  I suppose the actual peak (freeze season maximum) mainly reflects ice dynamics, while the "high minimum" during recent and upcoming years (near end of melt season) says more about spring and summer weather.  Given that atmospheric conditions were mixed during this past melt season, I wouldn't necessarily expect that 2014 marks the "high minimum" for, say, 2008-2017.  But any weather-related variability in ice volume loss will be against a gradually dropping trendline, as Chris R has shown on Dosbat.
      If I find any good articles or data that bear on this question, I will find a suitable PIOMAS thread to post to.
     
Side note, I'm sticking with my earlier guess of a net volume loss for this September.  We'll see what PIOMAS says in a couple weeks.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on September 27, 2014, 09:09:32 PM
It seems the Arctic is about to switch from mainly negative upper air temperature anomalies to positive over the weekend, which may slow the rate of increase.

Tomorrow
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FWHcFE36.png&hash=864f3dd27b3f7e68b1a0812ec01dafc6)

4 days ahead
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FXtNZ6Zd.png&hash=0465c1f7d73f60e5064467972117addd)

EDIT: stats were wrong...
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on September 28, 2014, 05:34:27 AM
Extent 5th lowest by Sunday September 28th?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on September 29, 2014, 07:26:06 AM
2% of 2014 max extent refrozen. 5th lowest as of September 28th, but with a Sunday margin of just 41k km² back to 2010.

Next target is 2008, 350k km² below 2014. 4th lowest by Thursday October 30th?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Comradez on September 29, 2014, 05:14:03 PM
I just wanted to point out that the Northern Hemisphere snowcover is way above normal right now on Rutgers Global Snow Lab.  Negative albedo feedback much?  Does this foreshadow the start of a cold winter season?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: crandles on September 29, 2014, 06:40:44 PM
I just wanted to point out that the Northern Hemisphere snowcover is way above normal right now on Rutgers Global Snow Lab.  Negative albedo feedback much?  Does this foreshadow the start of a cold winter season?

The departure looks similar to this time last year and way different than 2012. However by Jan 2014 the anomaly was negative while Jan 08-13 had positive anomalies. 2014 was a warm winter.

So I suggest we would need the positive anomaly to last quite a bit longer before we should expect a cold winter
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on September 29, 2014, 07:35:08 PM
I just wanted to point out that the Northern Hemisphere snowcover is way above normal right now on Rutgers Global Snow Lab.  Negative albedo feedback much?  Does this foreshadow the start of a cold winter season?

The departure looks similar to this time last year and way different than 2012. However by Jan 2014 the anomaly was negative while Jan 08-13 had positive anomalies. 2014 was a warm winter.

So I suggest we would need the positive anomaly to last quite a bit longer before we should expect a cold winter

Also relevant is the location of that snow cover.

 If it is at high enough latitude, it in fact will decrease rather than increase heat loss.  If on the ice, it will actually retard thickening of the ice.

High albedo in areas with low incident insolation and short days doesn't strike me as likely to make weather particularly cooler.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on September 29, 2014, 10:20:43 PM
More food for thought regarding snow cover.

Snow has approximately 1/4 the insulative value of fiberglass insulation; by extension,  40CM of snow reduces heat flow to the same degree ~10CM of fiberglass would.

Further, the elimination of prompt transfer of heat from ice directly to air via convection will be reduced considerably.  Reduced convective flow should decrease the rate at which heat is *physically* transported to where it can be lost.

QED, snow on the pack  ice acts like an "inverse melt pond", considerably reducing the rate at which new ice can form. Early season positive snow cover anomalies are not good for the ice.

Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Rick Aster on September 30, 2014, 12:42:00 AM
The area of high-concentration ice I was following has not done much, and my guess is this could be the last day it remains a recognizable feature on the Bremen map. It has drifted slightly west, possibly moving it toward warmer water — though really, movement in any direction but north would be into an area of open water. If this is thicker ice it must still be affected by bottom melt even though surface refreezing is occurring around it.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Comradez on September 30, 2014, 05:51:10 PM
It is true that snow on top of ice will reduce melt.  However, that's not what we are seeing right now.  At least, that's not what Rutgers Global Snow Lab shows.  Granted, they don't show snow cover on top of the ice.  Is there any product on the Internet that actually shows that?

Rutgers Global Snow Lab shows snow over land.  Aside from insulating the permafrost from the cold somewhat over the winter, snowcover over the lower latitude land areas can only make the winter colder - partly by reducing albedo, and partly by causing more release of heat to the open sky at night. http://www.theweatherprediction.com/habyhints/207/ (http://www.theweatherprediction.com/habyhints/207/)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: crandles on September 30, 2014, 07:30:46 PM
Is there any product on the Internet that actually shows that?

PIOMAS is a model rather than a measurement but Chris Reynolds mentioned there was snow on ice data up to Aug 2014. I assume that is a monthly average that is available for each grid point within a week of the month end rather than daily figures for each grid point.

As PIOMAS is driven in part by atmospheric reanalysis data, it might not be too bad?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on September 30, 2014, 11:09:36 PM
It is true that snow on top of ice will reduce melt.  However, that's not what we are seeing right now.  At least, that's not what Rutgers Global Snow Lab shows.  Granted, they don't show snow cover on top of the ice.  Is there any product on the Internet that actually shows that?

Rutgers Global Snow Lab shows snow over land.  Aside from insulating the permafrost from the cold somewhat over the winter, snowcover over the lower latitude land areas can only make the winter colder - partly by reducing albedo, and partly by causing more release of heat to the open sky at night. http://www.theweatherprediction.com/habyhints/207/ (http://www.theweatherprediction.com/habyhints/207/)

Quibble - snow will increase albedo, not reduce it.  Second,  it doesn't cause more heat loss, it reduces it by reducing additional thermal transfer from earth or ocean.  The rate of radiative loss doesn't increase.

What changes is the source of the heat - the atmosphere -  which is a much smaller reservoir of heat.  It declines faster and reaches equilibrium - a balance between outgoing radiation and incoming heat sources - at a lower temperature.

Loss from the 500lb gorilla - earth and ocean - is actually slowed down.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: crandles on October 01, 2014, 01:08:37 AM
Quibble - snow will increase albedo, not reduce it.  Second,  it doesn't cause more heat loss, it reduces it by reducing additional thermal transfer from earth or ocean.  The rate of radiative loss doesn't increase.

What changes is the source of the heat - the atmosphere -  which is a much smaller reservoir of heat.  It declines faster and reaches equilibrium - a balance between outgoing radiation and incoming heat sources - at a lower temperature.

Loss from the 500lb gorilla - earth and ocean - is actually slowed down.

I'll quibble your quibble.

>snow will increase albedo, not reduce it.

Note that Comradez preceded the reducing albedo comment by "Rutgers Global Snow Lab shows snow over land. Aside from insulating the permafrost..."

Therefore we are talking albedo/emissivity of Long-wave radiation from Earth not ocean or sea ice. Snow has quite low albedo and therefore high emissivity for long-wave radiation.

Snow has high albedo to short (solar) wavelengths but not for infra red wavelengths.

.

"Aside from insulating the permafrost" seems to indicate we are all agreed there in an insulating effect of snow. Not sure we are recognising all the effect though:

Atmosphere radiates to ground effeciently, causing some melt and the water trickles though the snow where the permafrost freezes the water to form part of the active layer freezing. This will warm the permafrost. While snow insulates reducing the permafrost sensible heat loss, the heat flow is increased by such latent heat transfer.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on October 01, 2014, 07:26:02 AM
<snippage of redundancy>

I'll quibble your quibble.

Fair enough ;)


>snow will increase albedo, not reduce it.

Note that Comradez preceded the reducing albedo comment by "Rutgers Global Snow Lab shows snow over land. Aside from insulating the permafrost..."

Therefore we are talking albedo/emissivity of Long-wave radiation from Earth not ocean or sea ice. Snow has quite low albedo and therefore high emissivity for long-wave radiation.

Snow has high albedo to short (solar) wavelengths but not for infra red wavelengths.

Excellent education and correction.

Can we quantify the distribution?  Would the difference in albedo render the snow more effective at capturing IR emitted by atmosphere directly rather than just via sunlight?  What sort of heat content do you think we are looking at, fractionally, by way of the sunlight on the snow?  You can just point me at references, or suggest a direction.


"Aside from insulating the permafrost" seems to indicate we are all agreed there in an insulating effect of snow. Not sure we are recognising all the effect though:

Atmosphere radiates to ground effeciently, causing some melt and the water trickles though the snow where the permafrost freezes the water to form part of the active layer freezing. This will warm the permafrost. While snow insulates reducing the permafrost sensible heat loss, the heat flow is increased by such latent heat transfer.

Permafrost can still be a net reservior of heat, if the atmosphere is cold enough ;)

I'm not sure the scenario you describe isn't zero sum.  I'm also somewhat skeptical of the scale of transfer. 

Heat taken up in the snow will remain there longer than heat radiated or convectively transferred from ground directly to atmosphere. The direction of movement is stochastic, and all in the gradient.  The snow tends to fight the movement of heat regardless of direction.

I'd be less skeptical of the effect of IR through snow if we were on the "hot" side of the equinoxes.  At this point, I'm not sure the incident sunlight would produce significant enough heating to cause the kind of melt/refreeze transfer you are talking about.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on October 01, 2014, 08:24:14 AM
This week, we see the Yearly Mean Extent descent increasing in daily drops — down 507 km²/d — and weekly we're now down 1116/w. For the past 30 days the net change is still up 5882 km²/m.

The Five Year Cycle hypothesis (http://forum.arctic-sea-ice.net/index.php/topic,994.0.html) is now strengthened 27.9% since Sep 24 — and the Big Descent is 32 days ahead of schedule. Even with 0% and 0 days the prognosis would be dramatic for the ice; the added strength just makes the descent even steeper than what the Five Year Cycle hypothesis expects, statistically. Next week we'll probably go below the 10.3 mill line, plus we'll see whether this dramatic strengthening actually continues or was just beginner's luck.

PS: Note also that the prognosis is sharpened slightly for each day of new data, so that the forecast for October 2016 is now for 9.3 mill — which would be a million km² gone from the average extent in just 2 years — whilst October 2016 was set for 9.5 mill just 2 days ago.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fguymcpherson.com%2Fforum%2Findex.php%3Faction%3Ddlattach%3Btopic%3D800.0%3Battach%3D229%3Bimage&hash=9e25680490005b7835c3b59f084d5cee)

2014 has gone purple since last week, automatically getting that colour from Google after overtaking 2013 (light green) on the 27th of September and 2010 on the 28th, so that 2014 is now 5th lowest extent-wise. At the same time, and because of this, purple is now descending at a rate of about 3000 km² per week since the start of the descent, and the strength of the 5-year cycle hypothesis is up almost 30%.

This also means that the chance of a new record minimum in 2015 is up 30% since September 24th, or maybe rather that the coming minimum will be 30% more extreme? The figure anyway measures the delta of 2013 and 2014 compared to that of 2008 and 2009. This graph gives a little more detail to 2014, while losing some of the context and easyness of the first graph:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fguymcpherson.com%2Fforum%2Findex.php%3Faction%3Ddlattach%3Btopic%3D800.0%3Battach%3D231%3Bimage&hash=6b095247c4f694e772e7498f450494bc)

Finally, a prediction that 2008 will be overtaken by next Friday:

3% of 2014 max extent refrozen. 5th lowest as of September 28th, but with a Tuesday margin of just 69k km² back to 2010.
Next target is 2008, 239k km² below 2014. 4th lowest by Friday October 10th?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: crandles on October 01, 2014, 10:40:22 AM
Permafrost can still be a net reservior of heat, if the atmosphere is cold enough ;)

Sure I was trying to say we all appeared to agree on this.

Quote
I'm not sure the scenario you describe isn't zero sum.  I'm also somewhat skeptical of the scale of transfer. 
...
At this point, I'm not sure the incident sunlight would produce significant enough heating to cause the kind of melt/refreeze transfer you are talking about.

I meant to leave it vague as to scale of these transfers as I don't know. Sorry if I gave the impression that latent transfer was outweighing or balancing the slow down of sensible heat flow

Quote
Can we quantify the distribution?  Would the difference in albedo render the snow more effective at capturing IR emitted by atmosphere directly rather than just via sunlight?  What sort of heat content do you think we are looking at, fractionally, by way of the sunlight on the snow?  You can just point me at references, or suggest a direction.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fclimateknowledge.org%2Ffigures%2FWuGblog_figures%2FRBRWuG0086_Trenberth_Radiative_Balance_BAMS_2008.GIF&hash=1b2f8cac350f652ae5552a139247968a)

Back radiation from atmosphere (333 in image) is larger than solar radiation absorbed (161) already and that is just on average. When you look at high latitudes during winter when there is few hours of sunlight at a low angle, the back radiation from atmosphere is going to be much larger than incoming solar absorbed.

The above is before mentioning the difference in albedo for snow for short wavelength and long wavelengths.

For a more quantitative answer you would presumably want formulas that deal with latitude, time of year, typical atmospheric temperature profile for time of year for a snow covered location. Sorry I am struggling to find a reference or link that would cover that sort of detailed information. Maybe someone else knows one? A public source climate model might have it but it is a bit large to go through and pick out the required information.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on October 01, 2014, 06:56:58 PM
Great graphic, Crandles.  I'm a visual thinker, so the images give my imagination something to chew on.  There's a lot there I can extrapolate on.  It ( and your commentary) give me ideas as to what to hunt for.

I apologize if I come off as abrasive.  No value judgement is intended.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Rubikscube on October 01, 2014, 11:06:00 PM
Comparison maps with 2007, 2012, 2013 and 2010 (29th Sep) show that the situation is a little bit different from a couple of weeks ago. There is for example less ice than 2013 all the way from Beaufort to Kara, while CAA seems to be filling up very fast. Barents still has more ice than any other year, but the gap appears to be shrinking.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Rubikscube on October 05, 2014, 12:31:15 PM
From a statistical point of view, there seems to be little or no correlation between autumn snow cover extent in the high (or lower) latitudes and snow (or ice) melt during the following spring and summer. Of the two recent years that saw the snow cover in Siberia settle down latest (2008 and 2009), one saw a slow melt in this area the following spring, while the other saw a very rapid one. This also seems to be the case for most other years, resulting in the overall picture being rather inconclusive.

If one looks very hard, one can possibly draw the conclusion that late snow gives a marginally higher chance of an early melt, something I would attribute to the simple fact that more snow is harder to melt than less snow. Apart from that, no feedbacks from autumn snow seem have any effect on the following summer, and probably not in the longer term either. To me, October snow is more a "symptom" than a cause.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on October 08, 2014, 10:43:16 AM
Have a look at the jet stream over the arctic right now:

http://earth.nullschool.net/#current/wind/isobaric/250hPa/orthographic=-59.77,80.92,257 (http://earth.nullschool.net/#current/wind/isobaric/250hPa/orthographic=-59.77,80.92,257)

Weird looking flow.

SST temp bands in the North Pacific are 3-500 KM further north than average - 2c or more above average.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on October 08, 2014, 01:42:16 PM
Last week I predicted that 2014 IJIS extent would be lower than 2008 by Friday 10th October. It was lower Tuesday 7th (but 2009 has now come back even lower than 2014 so we're still 5th lowest).

Yearly Mean Extent is down 985 km²/day, down 4677 km²/week and down 1954 km²/month.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on October 08, 2014, 04:05:53 PM
Quite a slow start to the refreeze this year. In fact, the -ve anomaly compared to the 81-10 average is current the largest it's been all year, at -1.42 million km2 for the NSIDC extent (with 5 day average).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Rubikscube on October 14, 2014, 07:33:03 PM
There is still way more ice on the Atlantic side than during all the other years of particular interest (12. Oct 2007, 2012 and 2013), although compared to the very low years, the Pacific still makes up most of the difference. The additional year this week is 2009 which is tracing very close to 2014 on SIE, and one can perhaps see why. Notice that I have taken extra care to remove the false ice this week, so the smaller patches along the coasts should largely be counted as real.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on October 15, 2014, 09:52:24 AM
This week we see the Yearly Mean Extent descent stabilizing at about 1100 km²/day — and weekly we're now down 7438. For the past 30 days the net change is now down 11 970 km².

The Five Year Cycle hypothesis (http://forum.arctic-sea-ice.net/index.php/topic,994.0.html) is now strengthened 67% since Sep 24 — and the Big Descent is 47 days ahead of schedule. (Even with 0% and 0 days the prognosis would be dramatic for the ice; the added strength just makes the descent even steeper and the gap even bigger than what the Five Year Cycle hypothesis expects, statistically.) The Yearly Mean Extent is now very close to the 10.3 mill line, and also very close to the July 14th yearly low–point of 10.2978. Today we will most likely cross and go lower than 2013 for the same day (Oct 15th). For 5YC reference, 2009 yearly extent went lower than 2008 on December 3rd, meaning the descent will be 49 days ahead of the corresponding descent 5 years ago.

Note also that the prognosis is sharpened slightly for each day of new data, so that the forecast for October 2016 is now for 9.28 mill (yearly average extent) — which would be a million km² gone from the average extent in just 2 years — whilst October 2016 was set for 9.5 mill just 16 days ago.

As per September 30th in Piomas' data, no Yearly Mean descent has yet started in (modeled) sea ice volume.

The second graph below gives more detail to the 2014 descent in Yearly Mean Extent, while losing the overview of the first 5–Year Cycle graph:
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Pmt111500 on October 16, 2014, 05:41:21 AM
Quite a slow start to the refreeze this year. In fact, the -ve anomaly compared to the 81-10 average is current the largest it's been all year, at -1.42 million km2 for the NSIDC extent (with 5 day average).

Salts from Bardarbunga (or rather, the new shield volcano forming in Iceland, the high intensity fissure eruption that's been going on now for 1,5 months) are possibly having an effect, as these have been keeping at low altitudes and depositing most of sulfates to arctic ocean and not going to stratosphere. It'll be interesting to see the analysis of this. Are springtime eruptions much different in this respect as there's plenty of light as opposed to now? When, during a year, should a phreatic-phreatomagmatic eruption happen for it to have a maximum effect on arctic sea ice?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on October 16, 2014, 12:17:11 PM
13% refreeze now. Notice how gaps to esp. 2012 and 2008 are narrowing and widening, respectively.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Michael Hauber on October 20, 2014, 12:43:29 PM
Comparing to previous years there has been very little formation of ice along the coasts of Alaska and Siberia.  In contrast there has been more ice forming in the Kara sea area than most recent years, and the Barents sea remains much higher than other recent years.

Will we see another low ice amount in the Bering sea this winter?  Is there any connection between the high sea ice amounts in the Bering sea from 07 to 12 and the low summer ice minimums over that period?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on October 20, 2014, 08:03:59 PM
Michael,

I've attached a plot of Bering Sea March Extent. Not sure it looks like a good predictor of summer sea ice. 2011 was a tie with 2007, yet had a low March extent. However it is striking that post 2007 years have high extent, I'd not noticed it until now.

In some work a couple of years ago I noticed that the Aleutian low was unusually low in recent years (if I recall correctly). But all that year's stuff has been archived and I can't put my hands on the drive right now.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on October 20, 2014, 08:05:51 PM
ASCAT is starting to reveal the large central white mass of thicker ice from this year.
http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2014292.sir.gif (http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2014292.sir.gif)

More here:
http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/ (http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on October 22, 2014, 05:47:33 AM
This week we see the Yearly Average Extent drop falling all the way to just 208 km²/day — and weekly we're now down 5447. For the past 30 days the net change is down 18 455 km². We're also finally below 10.3 mill km² — exactly 8 months after we fell below 10.4 on February 21st. Only 4 previous years have ever been this low, and 2014 will be the 4th year with a calendar year YAE below 10.3, but the first of those to not set an Autumn all–time low. This means the general level is now extremely low, when even a slow non–record year is stumbling around in 10.2 territory.

The current Big Descent that began on January 5th 2014 has already removed 120 283 km² from yearly averages. During the week we will probably pass the July 14th yearly low–point of 10.2978. Today's YAE is 27 828 km² lower than 2013 for the same day (Oct 21st), and it will be another 53 days before 2009 is that low compared to 2008.

The forecast has settled on October 24th 2016 as the low–point of this descent, and a current estimate for this date of 9.35 m km² — a loss of 1.07 m km² of Arctic sea ice since the beginning of the descent, on January 5th of this year. If correct, this will be the biggest descent in IJIS history.

First graph below shows 2014 + 2009 detail. The second presents the general overview.

QUESTION: If the 2 first years after 2007 and 2012 are in some sort of 'after–shock' after the record lows, what could be the physical cause of this?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Rubikscube on October 22, 2014, 04:09:31 PM
Since the snow cover extent has been soaring lately, I made a snow cover comparison similar to those I made earlier this spring. Though, I'm not sure how informative they are since I personally find them a little bit messy and chaotic this time.

The pics are 2014, 2013 and 2012 respectively, I believe the date is October 19th, but since CT labels the maps in its compare tool with different dates than those in its archive, it is hard to be sure (the CT archive appears in general quite flimsy, as random dates and entire section are missing everywhere). Reds are decrease, blues are increase.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on October 22, 2014, 05:32:35 PM
QUESTION: If the 2 first years after 2007 and 2012 are in some sort of 'after–shock' after the record lows, what could be the physical cause of this?
I'm thinking maybe something to do with the freshwater in the Gyre, or upwelling of warmer water from the deep. To quote Wikipedia on the Gyre:

Quote
The Beauford Gyre is a clockwise rotating system, flowing the same direction as the high pressure area over the Arctic which in turn is caused by falling dense air spreading southward with Coriolis turning the south flowing wind to the West. Lighter surface water piles up in the centre of the gyre due to Coriolis which sends surface water to the centre of the system. In so far as counter clockwise atmospheric systems such as the hurricane of Aug6, 2012 cause the rotation of surface water to reverse, this surface water will be "flung" outward and replaced by upwelling of the deep, saltier, warmer Atlantic water which underlies the fresher colder Arctic water. This mixing would be expected to lead to accelerated melting.

Maybe a Gyre reversal as that of August 6th 2012 did 2 things: 1) cause hot upwelling and further Aug/Sep melt in 2012, and 2) fling so much freshwater south that the refreeze goes into hyperdrive? In any case, the Yearly Average Extent for 2013 and 2014 is way up compared to that of 2012.

And from mtkass.blogspot.com (http://):
Quote
The Beaufort Gyre Exploration Project reports that the amount of fresh water stored on the surface of the Arctic Ocean is equal to a number of years flow of rivers emptying into the Arctic ocean.  However, the Beauford Gyre can reverse direction.  As reported by the BGEP, the cycle is from 4 to 8 years in each direction.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Shared Humanity on October 24, 2014, 07:31:57 PM
Could the snow cover over Asia be due to the large expanse of open water on the northern coast, certainly the Laptev but the ESS and Chukchi as well. The cold coming from the pole over Asia should be picking up a lot of moisture off this open water.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on October 24, 2014, 09:50:18 PM
Could the snow cover over Asia be due to the large expanse of open water on the northern coast, certainly the Laptev but the ESS and Chukchi as well. The cold coming from the pole over Asia should be picking up a lot of moisture off this open water.

http://earth.nullschool.net/#current/wind/isobaric/850hPa/orthographic=-332.96,91.40,483 (http://earth.nullschool.net/#current/wind/isobaric/850hPa/orthographic=-332.96,91.40,483)

At 850mb this suggests there is entrainment of air from the open Arctic Ocean over Asia. Research indicates a role for open water in recent year's large snow advances over Eurasia.

Rutgers data has stopped as of 20 Oct due to the NCEP/NCAR data outage, which is still not resolved. However as of 19 Oct there is a substantial positive snow area anomaly over Eurasia.
http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2014&ui_day=292&ui_set=2 (http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2014&ui_day=292&ui_set=2)

On that page use the single '<' for YEAR to step back to see snow cover anomalies for that date on different years. Currently the anomaly is large.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Nightvid Cole on October 24, 2014, 10:12:21 PM
DMI seems to be showing that the North of 80 temperatures are one of the hottest autumns on record, I'm expecting to see volume anomaly drop significantly on the next PIOMAS update but time will tell...
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on October 25, 2014, 12:13:13 AM
DMI seems to be showing that the North of 80 temperatures are one of the hottest autumns on record, I'm expecting to see volume anomaly drop significantly on the next PIOMAS update but time will tell...
It would certainly make things more normal compared to extent. Average volume has been up all year, while average extent has been down.

Edit: 9% volume refreeze versus 21% extent refreeze, if my estimates are correct. Seems normal, as these figures were 10% and 22% for 2013.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on October 25, 2014, 03:50:42 AM
I could look in the Melt Season thread, but does anyone know if the Gyre changed direction 2–3 times this year?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on October 25, 2014, 08:15:20 AM
I could look in the Melt Season thread, but does anyone know if the Gyre changed direction 2–3 times this year?

The Gyre is driven by winds, so you'd need to start with the atmosphere. However this summer the conditions have been largely anticyclonic which favours the gyre and retention of fresh water in the gyre. Whether transient summer lows passing over Beaufort would persist for long enough to reverse the gyre and releaase the fresh water dome I do not know.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on October 28, 2014, 04:25:26 PM
Looks like we've passed the period of maximum growth rate, topping out at 1.06million km2.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fllq4LxG.jpg&hash=f288ab7d5c4dae81cadd5b741f1f3b9f)

This is slightly above the long term average (81-10) of 981k, but below the average of the last 10 years, of 1.139m

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2F5VZPkvh.jpg&hash=65a912b5c34a4f9e21a422316c49f02c)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Rubikscube on October 28, 2014, 05:27:11 PM
The amount of ice in Kara is really standing out at the moment, continuing this seasons trend of above normal amounts of "Atlantic ice". On the other end of the scale, the ESS is now lagging behind three out of the four years and there is still an apparent lack of export through farm. Refreeze has also begun in Baffin where the amounts of ice seems on pair with those of recent years.

In addition to 2007, 2012 and 2013, I've this week added a comparison with 2010.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on October 29, 2014, 11:05:30 PM
This week we saw the Yearly Average Extent go from decreasing daily drops to slowly increasing gains, the last one up 234 km²/day — and weekly we're now down only 298. For the past 30 days the net change is down 18 760 km². We're still below 10.3 million km², and only 4 previous years have ever been this low. (2014 will be the 4th year with a calendar year YAE below 10.3, but the first of those to not set an Autumn all–time low.)

The current Big Descent that began on January 5th 2014 has removed 120 581 km² from yearly averages. During November we will probably pass the July 14th yearly low–point of 10.2978. Today's YAE is 49 314 km² lower than 2013 for the same day (Oct 28th), and it will be another 85 days before 2009(10) is that low compared to 2008(9), on January 21st.

The forecast has changed to October 21st 2016 as the low–point of this long descent, and a current estimate for this date of 9.4 m km² — a loss of 1.02 m km² of Arctic sea ice since the beginning of the descent, on January 5th of this year. If correct, this will be the biggest descent in IJIS history.

First graph below shows 2014 + 2009 detail. The second presents the general overview.

Next week we'll likely have the PIOMAS data for October, but estimates show the Yearly Average Volume is still up, and that no descent, small or big, has yet started for average volume. Instead, the Yearly Average Volume has interestingly gone from 3rd lowest to 5th lowest during a 2014 where Yearly Average Extent has gone the other way, from 6th lowest to 4th lowest in October.

My question to all of you is thus why average volume is rising in a year where average extent is falling and losing more than 120 000 km². And for the really adventurous out there: Will average volume follow extent and start a Big Descent (my bet), or will average extent instead turn around to follow volume and start an ascent?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: iceman on October 30, 2014, 01:11:50 PM
  ....
My question to all of you is thus why average volume is rising in a year where average extent is falling ....

Good question, partially answered in Neven's latest PIOMAS blog post and elsewhere.  Most of the volume rebound has been in the central region of the ice pack, where it is not directly affected by area/extent except near the minimum.
     If you look a the volume anomaly chart, the departure from recent years' trends began in early June and persisted through mid-August.  Various explanations have been mooted that would be consistent with that time interval.  If we could unpick the causal chain among them, we'd be a lot farther toward a physical basis for predictions.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on October 30, 2014, 07:23:48 PM
You're probably right about the CAB being central to this minor paradox, but through the year the story is a bit more complex (see graph below). While average extent deltas have been around and mostly below zero (2013s data) for the entire year, volume deltas have been way over zero all year except March, April and May.

There's also a fairly recent trend that 2014 is strengthening and extending, and that is the slow July–August melt, explored in this thread (http://forum.arctic-sea-ice.net/index.php/topic,980.0.html).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on November 04, 2014, 04:10:49 PM
A massive jump of 259.8k on the NSIDC extent puts 2014 up to the highest since 2001.

Don't think that's happened since the end of May last year.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: DavidR on November 06, 2014, 08:12:52 AM
     If you look a the volume anomaly chart, the departure from recent years' trends began in early June and persisted through mid-August.  Various explanations have been mooted that would be consistent with that time interval.  If we could unpick the causal chain among them, we'd be a lot farther toward a physical basis for predictions.
If you look at Arctic temperatures over summer http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries.pl?ntype=1&var=Air+Temperature&level=1000&lat1=90&lat2=67&lon1=0&lon2=360&iseas=0&mon1=0&mon2=11&iarea=0&typeout=1&Submit=Create+Timeseries (http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries.pl?ntype=1&var=Air+Temperature&level=1000&lat1=90&lat2=67&lon1=0&lon2=360&iseas=0&mon1=0&mon2=11&iarea=0&typeout=1&Submit=Create+Timeseries) its fairly  clear that a major factor was that the Arctic summer was comparatively cool.  June in particularly  cool rating at 44th warmest  in the last 66 years a full 1.5 degrees colder on average than 2012. 
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 06, 2014, 08:47:35 AM
Any idea as to why June was so cold? Maybe too much wildfire smoke for the sun to warm it?

Here's June compared to the 1979–1999 average:
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on November 06, 2014, 09:08:40 AM
A massive jump of 259.8k on the NSIDC extent puts 2014 up to the highest since 2001.

Don't think that's happened since the end of May last year.

Lots of false ice in Sea of Okhotsk (Nuri?). Some has disappeared again in yesterdays update, with a drop in total extent of -22k, Okhotsk contribution -75k.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 06, 2014, 06:08:59 PM
Any idea as to why June was so cold? Maybe too much wildfire smoke for the sun to warm it?

Here's June compared to the 1979–1999 average:

Cloud cover more likely, IIRC.

Tangent - does the Refreeze of the Hudson and central/southern Baffin bays seem behind schedule?  Seems a lot of open water approaching mid November.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on November 07, 2014, 02:11:17 PM
A massive jump of 259.8k on the NSIDC extent puts 2014 up to the highest since 2001.

Don't think that's happened since the end of May last year.

Lots of false ice in Sea of Okhotsk (Nuri?). Some has disappeared again in yesterdays update, with a drop in total extent of -22k, Okhotsk contribution -75k.

I hadn't considered Nuri. Yeah, it's grown to a 2 day pause now and the 5 day mean remains below 2008.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Michael Hauber on November 07, 2014, 11:14:33 PM
Wow at the latest GFS.  +4 850hp temps in the Beaufort sea?  It may not yet be officially winter yet, but DMI 80n shows that average temps this year are about 80% of the way towards

The worst of it is at the end of the 7 day run, but even with significant downgrades we could see near freezing temps along the Beaufort coast, and a week of offshore winds could open up some noticeable water.

Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 08, 2014, 08:29:05 AM
Wow at the latest GFS.  +4 850hp temps in the Beaufort sea?  It may not yet be officially winter yet, but DMI 80n shows that average temps this year are about 80% of the way towards

The worst of it is at the end of the 7 day run, but even with significant downgrades we could see near freezing temps along the Beaufort coast, and a week of offshore winds could open up some noticeable water.
I'm not following you Michael.  What are you getting at?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: JayW on November 08, 2014, 11:17:57 AM
Wow at the latest GFS.  +4 850hp temps in the Beaufort sea?  It may not yet be officially winter yet, but DMI 80n shows that average temps this year are about 80% of the way towards

The worst of it is at the end of the 7 day run, but even with significant downgrades we could see near freezing temps along the Beaufort coast, and a week of offshore winds could open up some noticeable water.
I'm not following you Michael.  What are you getting at?

I don't want to speak for Michael, but I do watch weather models a lot because I like snowstorms  :)

I I think he's suggesting the north shore of Alaska could get above freezing.  I've been curious about this too.
 
The flow over north America is expected to become very blocky with a large amount of warm air forced into Alaska and north.  Coinciding with the large chill over the central-eastern US. Lasting a week+

GFS ensembles 850mb temp anomalies
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.esrl.noaa.gov%2Fpsd%2Fmap%2Fimages%2Fens%2Ft850anom_f144_nhsm.gif&hash=fdf69faae304caec8ec63eaeeae3b3e3)

850 temp std. dev.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.esrl.noaa.gov%2Fpsd%2Fmap%2Fimages%2Fens%2Ft850nanom_f144_nhsm.gif&hash=20a73c1c999d61510d23603e67e77aa3)

http://www.esrl.noaa.gov/psd/map/images/ens/t850anom_f144_nh.html (http://www.esrl.noaa.gov/psd/map/images/ens/t850anom_f144_nh.html)




Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Rubikscube on November 08, 2014, 11:53:14 AM
The euro is also quite harsh, it seens that an initial wave of warm air from the masive bering storm eventually will result in a cutoff system over Alaska, (120-144h range), then in the 168h+ range this cutoff high meanders deep into the arctic, basically pushing all the cold down Canada and Siberia. The Pacific refreeze will certainly be delayed quite a bit, and if the forecast go all the way (which is of course a bit unlikely), some seriously high 80N temps should be expected.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 08, 2014, 06:54:05 PM
The euro is also quite harsh, it seens that an initial wave of warm air from the masive bering storm eventually will result in a cutoff system over Alaska, (120-144h range), then in the 168h+ range this cutoff high meanders deep into the arctic, basically pushing all the cold down Canada and Siberia. The Pacific refreeze will certainly be delayed quite a bit, and if the forecast go all the way (which is of course a bit unlikely), some seriously high 80N temps should be expected.

Thank you Jay and Rubic.

That makes sense, considering the huge volume of "warm" moist air Nuri is dragging along.  It is in line with what I've been imagining; nice to have that thinking confirmed.

Most people who experience arctic breakouts don't think as deeply about them as to realize the air that came from the arctic, had to be *replaced* in the arctic.  In this case, the replacement will be air as much above normal as the arctic breakout is below. 

Time to start tracking freezing degree days, I think.  I also think I may want to see what I can find about precipitation over the pack.  Significant snowfall on it this early is not likely to be good for later thickening.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: flyoverice on November 09, 2014, 02:40:39 AM
In watching the nsidc SIE data I just noticed that total NH and SH area is as high as 1984 for day 311 of 2014. Is this a sign of recovery of sea ice globally? Arctic being 380k sq km below 1984 and the Antarctic being 420k sq km above 1984 level. Or is the volume still extremely depleted at the Arctic?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: OSweetMrMath on November 09, 2014, 05:12:23 AM
I have been posting regular updates on my predictions for the minimum NSIDC extent and PIOMAS volume on the appropriate prediction threads. Since we've passed this year's minimum, I've started predicting maximum values. In the absence of another obvious place to post, I'm posting my predictions here.

Last month's prediction for the October average PIOMAS volume was 8000 cubic km. The reported value was 8159 cubic km, high but inside my confidence interval. This increases my prediction for the April average volume to 23,800 cubic km, with 95% confidence interval of 22,100-25,600 cubic km.

Last month's prediction for the October average NSIDC extent was 7.8 million sq km. The reported value was 8.06 million sq km, again high but inside my confidence interval. This increases my prediction for the March average extent to 14.8 million sq km, with 95% confidence interval of 14.1-15.5 million sq km.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: JayW on November 09, 2014, 02:09:14 PM
The euro is also quite harsh, it seens that an initial wave of warm air from the masive bering storm eventually will result in a cutoff system over Alaska, (120-144h range), then in the 168h+ range this cutoff high meanders deep into the arctic, basically pushing all the cold down Canada and Siberia. The Pacific refreeze will certainly be delayed quite a bit, and if the forecast go all the way (which is of course a bit unlikely), some seriously high 80N temps should be expected.

Thank you Jay and Rubic.

That makes sense, considering the huge volume of "warm" moist air Nuri is dragging along.  It is in line with what I've been imagining; nice to have that thinking confirmed.

Most people who experience arctic breakouts don't think as deeply about them as to realize the air that came from the arctic, had to be *replaced* in the arctic.  In this case, the replacement will be air as much above normal as the arctic breakout is below. 

Time to start tracking freezing degree days, I think.  I also think I may want to see what I can find about precipitation over the pack.  Significant snowfall on it this early is not likely to be good for later thickening.

I have seen a lot of talk about the Siberian snow cover and the SAI and OPI causing the Arctic oscillation to tank this winter, making it a cold winter. And I will note that this is different than last year which featured a predominately positive AO .

As a Mainer, these Teleconnections often don't line up with the rest of the east coast.  ;)

Attached are the temperature linear correlations with regard to AO for DJF

http://www.esrl.noaa.gov/psd/data/usclimdivs/correlation/ (http://www.esrl.noaa.gov/psd/data/usclimdivs/correlation/)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Michael Hauber on November 09, 2014, 08:11:57 PM


I I think he's suggesting the north shore of Alaska could get above freezing.  I've been curious about this too.
 
The flow over north America is expected to become very blocky with a large amount of warm air forced into Alaska and north.  Coinciding with the large chill over the central-eastern US. Lasting a week+


Its not just the warmth, but the offshore wind which will push ice away from the Alaskan coast.  With the temps close to freezing - even if its not high enough to melt ice I doubt it will be cold enough to freeze back over until the pattern ends.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: JayW on November 10, 2014, 12:01:22 PM

Its not just the warmth, but the offshore wind which will push ice away from the Alaskan coast.  With the temps close to freezing - even if its not high enough to melt ice I doubt it will be cold enough to freeze back over until the pattern ends.

When does the pattern end?  This block is looking tough. And, you are right about the winds. Also, with the AO going negative, and likely to remain there, won't Fram export be on the increase.  Looking at Wipneus' PIOMAS update for October, a decent fraction of areas that increased in thickening from 2013-2014 is in close proximity to the Fram.

I know these forecasts are for 10 days out, so the normal caveats apply, but it's quite a blocky pattern, it should persist.

Attachment 1 GFS ensemble 850hpa temp anomalies hr 240
http://www.esrl.noaa.gov/psd/map/images/ens/t850anom_f240_nh.html (http://www.esrl.noaa.gov/psd/map/images/ens/t850anom_f240_nh.html)

Attachment 2 EURO ensembles 850hpa temp anomalies hr 240 (the deterministic has 20°C+ anoms north of Alaska)
http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=100&map=1&type=1&archive=0 (http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=100&map=1&type=1&archive=0)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 10, 2014, 05:34:35 PM
Don't think Nuri is the only one to blame here: Notice the sharp increase in mean CH4, and the subsequent decrease in refreeze (both extent and volume). Also note the sharp fall in 2013 extent and volume, following a 2600 ppb CH4 (http://arctic-news.blogspot.no/2013/11/methane-levels-going-through-the-roof.html) event last year.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 10, 2014, 09:27:30 PM
A relevant October/November blog post is now available.

http://dosbat.blogspot.co.uk/2014/11/mid-november-status.html (http://dosbat.blogspot.co.uk/2014/11/mid-november-status.html)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 10, 2014, 09:38:30 PM
Don't think Nuri is the only one to blame here: Notice the sharp increase in mean CH4, and the subsequent decrease in refreeze (both extent and volume). Also note the sharp fall in 2013 extent and volume, following a 2600 ppb CH4[/url] event last year.

I really don't think the CH4 release would have that prompt an effect, even with a temporary 30% increase in concentration.  It's not being pumped fast enough, high enough into to the atmosphere, nor do I think it is remaining concentrated long enough to seriously impede energy exiting the atmosphere.

I'll offer an additional observation - the block of atmosphere that CH4 got injected into, most likely is no longer over the arctic.  The displacements from the storms with almost complete certainty have driven that air out of the Arctic, and over the continents in the breakouts we currently are watching.  If there is a prompt effect, it would most likely  be to ablate the severity of the breakout(s).

http://chriscolose.wordpress.com/2008/11/10/methane-and-co2/ (http://chriscolose.wordpress.com/2008/11/10/methane-and-co2/)

*Long* term, as overall concentrations increase steadily, it will have more of an effect.  Physics doesn't support prompt releases over what are relatively "small" areas having a dramatic direct effect on the ice or the weather.

There are other very clear sources - tropical moisture, wind, sensible heat in direct transfer of atmosphere from temperate latitudes to the arctic - for the extra energy to produce the observed changes (or lack there of), which frankly dwarf the short term effect of a methane release.

I'll add an observation: the blocks of atmosphere which picked up that methane most likely are no longer over the arctic.  The air displaced by Nuri et. al. has no doubt driven down over the continents.  The prompt effect of the methane at most might take some of the edge off of the cold they are starting to feel over the Mississippi valley.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 10, 2014, 09:45:49 PM
For sure, the graph doesn't say CH4 caused the slow refreeze (in November 2013 or this year), there could just as well be a common cause of both the CH4 release and the refreeze change (eg wind, waves).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 11, 2014, 01:46:04 AM
However, CH4 from submarine permafrost is also transformed by bacteria into CO2, which we do know has a blanket effect, even in Winter. So parts of the hydrates cause spikes in the measured CH4 levels, while other parts cause increased CO2, that melts ice, or prohibits ice refreeze.

The Arctic Ocean also emits CO2 these days, as verified by eg the Swerus expedition this summer. I know warmer oceans emit more CO2, but I don't know to what extent warmer Winter waters or Autumn storms in Arctic will actually put out more CO2?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 11, 2014, 05:22:22 AM
However, CH4 from submarine permafrost is also transformed by bacteria into CO2, which we do know has a blanket effect, even in Winter. So parts of the hydrates cause spikes in the measured CH4 levels, while other parts cause increased CO2, that melts ice, or prohibits ice refreeze.

The Arctic Ocean also emits CO2 these days, as verified by eg the Swerus expedition this summer. I know warmer oceans emit more CO2, but I don't know to what extent warmer Winter waters or Autumn storms in Arctic will actually put out more CO2?
Not enough to cause significant (greater than 0.1C) increases in local temperature.  You are starting to sound silly, or argumentative, I'm not sure which, or both.

At the very least, your sense of scale is off. CH4 release is a huge problem, but one which will evolve over a time scale of decades, not days.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 11, 2014, 05:34:04 AM
JD, it's a simple yes-or-no question, so no reason to go into full personal attack mode.

With the mentioned 2600 ppb CH4 event in early November 2013, there was a first ever net melt from one day to the next. That was the only November day of net melt of Arctic sea ice in the whole 1979—2014 time series.

Silly to me would be to automatically assume this to be mere coincidence.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 11, 2014, 06:41:42 AM
JD, it's a simple yes-or-no question, so no reason to go into full personal attack mode.

With the mentioned 2600 ppb CH4 event in early November 2013, there was a first ever net melt from one day to the next. That was the only November day of net melt of Arctic sea ice in the whole 1979—2014 time series.

Silly to me would be to automatically assume this to be mere coincidence.
It is not a personal attack.  It *is* a reaction to persistent misinterpretation of facts and events. You ask a lot of good questions, and make some good connections.  Other times, even in the face of pretty clear evidence that undermines an assertion you make, you persist in digging yourself in deeper.

That's what I'm reacting to.

I assure you, you are getting nothing like what I'd deliver in "full personal attack mode".  It has been known to blister paint (never in this venue), and reserve it for those who truly deserve it.  You're not on that list.

;)

Best regards...
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 11, 2014, 06:53:30 AM
I just believe we all learn more if we can think out loud and ask questions without the fear of ridicule and recreational comments about certain questions being silly. I come from a (mainly) non–religious family and culture and don't particularly appreciate taboos or dogmas when physics and chemistry are involved. To me you can believe whatever you want happens to the CH4 molecules before they 'go to heaven', but please keep it to yourself if it's only based in some sort of organized religion.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 11, 2014, 06:48:56 PM
I just believe we all learn more if we can think out loud and ask questions without the fear of ridicule and recreational comments about certain questions being silly. I come from a (mainly) non–religious family and culture and don't particularly appreciate taboos or dogmas when physics and chemistry are involved. To me you can believe whatever you want happens to the CH4 molecules before they 'go to heaven', but please keep it to yourself if it's only based in some sort of organized religion.

Requiring you to present a substantive case is not dogma.

1) November? One Day melt? Was this really melt?

2) Given temperatures at that time, is it reasonable to suspect actual melt of ice? i.e. was temperature significantly above zero degC.

3) Where did the reduction in extent/area occur? Can this be supposed to be linked to a localised methane source?

4) What is the probability of these two events occurring simultaneously (by random chance)?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 11, 2014, 09:48:56 PM
NSIDC Extent, number of days from 1979 to 2013 in November that have a decline in extent from preceding day.

01-Nov   0
02-Nov   1
03-Nov   4
04-Nov   3
05-Nov   6
06-Nov   4
07-Nov   8
08-Nov   4
09-Nov   5
10-Nov   4
11-Nov   3
12-Nov   5
13-Nov   3
14-Nov   4
15-Nov   2
16-Nov   3
17-Nov   4
18-Nov   5
19-Nov   4
20-Nov   3
21-Nov   5
22-Nov   1
23-Nov   2
24-Nov   1
25-Nov   1
26-Nov   1
27-Nov   6
28-Nov   2
29-Nov   2
30-Nov   0
   
Sum   96
Count   1050
Prob   9%

Probability of 9% of any day in November showing a decline in volume.

PIOMAS is more monotonic. Only 7 November 2013 shows a decline on previous day, but the decline is so small (-0.004k km^3) that considering PIOMAS uncertainty the most favourable conclusion is that it is a levelling. The next four days have an average decline of 0.060k km^3, average decline from 1979 to 2013 being 0.090k km^3 for those four days (8 to 11 Nov).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 12, 2014, 01:08:10 AM
PIOMAS volume is what we're talking about, so I can only guess why you choose to list the extent deltas instead. Is it really melt if it melts? Well, yes. Even if it's a small melt, it's still a melt, and singular in this case. It was the only November day that had a decline in volume from the previous day, and it happened during a period of high methane.

As I already pointed out it is a single day, so listing the following days and saying they had no melt, surprises no–one, really.

You see dogmas and taboos when someone is fighting rigorously against even the notion that two phenomena could be related, and when words are intentionally twisted beyond recognition («Requiring you to present a substantive case is not dogma.»). Dogmatic religion or group–think is then to be assumed, if not outright hatred of the messenger, for whatever reason. The important function of the attacks is to prevent others reading them from thinking undogmatically, inducing in them the fear of getting a similar response from dogmatic haters.

This is basic psychology, folks.

«1) November? One Day melt? Was this really melt?»

Yes, November is a month, the 11th in the year, yet I can see the need for even questioning this, given the level of taboo here. And yes, there was melt one day. Yes, really melt. Why is it so hard to accept?

«2) Given temperatures at that time, is it reasonable to suspect actual melt of ice? i.e. was temperature significantly above zero degC.»

Feel free to suggest other ways of making ice disappear other than through melting, if it's that important to you.

«3) Where did the reduction in extent/area occur? Can this be supposed to be linked to a localized methane source?»

Again, if you read my actual words, I'm not saying CH4 caused it directly, only that it happened simultaneously. There are a number of ways in which this may happen.

«4) What is the probability of these two events occurring simultaneously (by random chance)?»

Very close to zero. You have 35*30+10 = 1060 days and it happened once. That once was in a high CH4 period.

Basically, your attacks are strawman attacks, challenging a notion that was never actually suggested. They're also anti–scientific in the sense that you wish to limit — through ridicule etc — the scope of scientific investigation using whatever recreational pseudo–arguments that come to mind («CH4 release is a huge problem, but one which will evolve over a time scale of decades, not days.»).

The lady doth protest too much, methinks.

In any case, here is todays graph. Go nuts! :)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 12, 2014, 06:03:21 PM
Don't think Nuri is the only one to blame here: Notice the sharp increase in mean CH4, and the subsequent decrease in refreeze (both extent and volume). Also note the sharp fall in 2013 extent and volume, following a 2600 ppb CH4 event last year.
It seems pretty clear to me from this, that is exactly what you are saying - that prompt release of CH4 had an immediate effect on the pack.  We are not mistaking you. No taboo nonsense.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Peter Ellis on November 12, 2014, 06:28:24 PM
«1) November? One Day melt? Was this really melt?»

Yes, November is a month, the 11th in the year, yet I can see the need for even questioning this, given the level of taboo here. And yes, there was melt one day. Yes, really melt.
How do you know?  What is your evidence?

What you've posted so far is PIOMAS figures.  PIOMAS is a an estimate of what a computer program believes the volume to be, based on numerical modelling, and informed by satellite measurements of area and extent.  It is not actual data on volume.

We already know that the area and extent measurements are noisy, particularly during stormy weather, and can show quite large fluctuations from day to day, which will then be propagated into the PIOMAS model.

So, I repeat, what is your evidence that there really has been melt, and that this is in the same area and at the same time as the methane release?  And do you have any answer to the calculations showing that a release of methane cannot possibly have any localised effect on the local heat budget that's large enough to affect sea ice melting?

The local effect of methane at these concentrations is negligible - what matters is the aggregate effect over weeks/months/years in the atmosphere, at a global scale. You are, quite literally, claiming that farting in your garden will make your pond melt.

[Back of envelope calculation: average fart volume = ~1 litre per day, ~10% of which is methane. These supposed methane events in the Arctic involve concentrations changing by a few hundred ppb in one layer of the atmosphere.  That corresponds to diluting a fart into a volume ~10m x 10m x 10m, which is near enough the surface layer above a suburban garden pond.

So, I have an experiment for you.  Some time this winter, find a friendly neighbour whose pond has frozen over and spend a day farting above it, and see if it melts.]
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 12, 2014, 07:07:02 PM
Peter Ellis, your hateful ad hominem attacks are not appreciated.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 12, 2014, 08:00:05 PM
Viddaloo,

1) You have one day of actual PIOMAS volume reduction on a day to day basis. The rest you seem to base your claim of a volume loss is actually an anomaly of volume. In both graphs you present it is stated that volume is 'relative to 2002 to 2013 Volume and Extent'. So your claimed volume loss is not necessarily a loss of volume, it is actually a period where the autumn volume gain is less than the 2002 to 2013 average, and might have a real terms loss as a causal factor.

But as I show, only one day shows a day on day volume loss.

2) Meaningless.

3) You state in the above comment:
Quote
..if you read my actual words, I'm not saying CH4 caused it directly, only that it happened simultaneously.

Let me make clear what you actually said. Upthread various people were discussing cyclone Nuri. You then said:
Quote
Don't think Nuri is the only one to blame here: Notice the sharp increase in mean CH4, and the subsequent decrease in refreeze (both extent and volume). Also note the sharp fall in 2013 extent and volume, following a 2600 ppb CH4 event last year
From the available evidence it is clear that you were drawing a causal link between the CH4 and ice loss.

4) And there have never been other blips of high methane? The coincidence of two factors once is not proof.


I have made available the volume data you needed to address where the volume loss came from.
http://dosbat.blogspot.co.uk/2013/12/regional-piomas-volume-data.html (http://dosbat.blogspot.co.uk/2013/12/regional-piomas-volume-data.html)
Rather than use this resource you choose to launch a barrage of insults against me. Insults I can take, but your laziness in doing the ground work for your own theory means I have to make time available to do your work, that I find very annoying.

So here it is.

Using the regional breakdown of daily PIOMAS gridded data here is the daily difference between 6th and 7th of November, in km^3.

Other   0.001
Okhotsk   -0.105
Bering   0.180
Beaufort   11.060
Chukchi   -7.784
ESS   1.846
Laptev   -9.457
Kara   -34.590
Barents   0.741
Greenland   2.550
Central   8.091
CAA   10.474
Baffin   8.826
Hudson   3.451

Most of the drop comes from Kara, at which point you're probably jumping up and down saying 'Yes I was right, it is methane!!!!' and then you'd stop.

Knowing that NCEP/NCAR data is used to drive PIOMAS I look at NCEP/NCAR data for 7th November.

(https://farm8.staticflickr.com/7545/15588737179_ffbd3085c5_o.gif)

And I find a warm tongue of air that is indeed warmer than freezing thus makes actual melting possible. So I have identified that export and melt through Fram or Bering is not at play, and that actual melting was involved.

Had you got this far you'd have stopped, being satisfied that the warming was due to methane. I dig deeper, because I have had my own fingers burnt before by jumping to conclusions (which doesn't guarantee that won't happen again!).

I look at that tongue of warming over Kara and immediately suspect a dipole. So I look at pressure.

(https://farm8.staticflickr.com/7551/15750860546_605e0a180a_o.gif)

And yes indeed, we see a strong dipole with high pressure over western Siberia and a low over Barents, that draws in warmer air from outside the Arctic and is a reasonable candidate as the main cause of the volume loss that is the only day to day November volume loss in the PIOMAS data record.

The irony of it all is that had you approached my list in a constructive manner, even being humble enough to ask for help, I'd have gladly given such help to the best of my meagre amateur abilities. Asking proper professional scientists for help when I need it is one of the techniques I use for learning, and it works. If I approach a scientist with questions, ideally phrased from the point of view of 'how can I sort this out', showing I am not wanting to be spoon-fed but am prepared to work for my knowledge, I have found on every occasion that help has been willingly given. And the scientists I am in regular contact with are pleased to see amateurs with enthusiasm for their work.

But were I to storm in telling them how they're wrong and I'm right, and answering every attempt to guide with beligerence and abuse I would get nowhere.

And nowhere is where you are with me. I have had enough of you. I hope the moderators don't get twitchy with the 'ban button'. Feel free to stick around here, you might learn, both about sea ice and human interaction. But please understand that my patience is now stretched beyond its limit. I have no interest in any interaction with you from now on.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 12, 2014, 08:34:01 PM
[Snip]

This is Neven chiming in: viddaloo, you need to read up on what an argumentum ad hominem (http://en.wikipedia.org/wiki/Ad_hominem) is. It is when something says you're wrong because you're ugly, or because you travel by train, or because you work for the GWPF. Nobody has done this here. Everyone has explained why your theory is most probably wrong.

You don't like their wording (fart near a melt pond)? IT'S THE INTERNET! People aren't necessarily nice. You can't posit an extraordinary claim, and when people explain to you that there is no extraordinary evidence (because there isn't), accuse them of attacking you personally. It's childish and stifles all discussion.

When someone disagrees with you, he/she is not automatically using ad hominems to attack you. I've known everyone who has responded to you for years, and they're all courteous, intelligent people I highly respect. In other words, you're out of line. And it's the second time this happened.

There's room for almost everything here, except for this. I don't want to see it happen a third time.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Peter Ellis on November 13, 2014, 01:06:44 AM
That really wasn't intended to be rude.  I often find that the sheer scale of the numbers involved in the Arctic makes things hard to intuit, so I find that kind of "downscaling" thought experiment incredibly useful as a sanity check for "Is what I'm saying remotely physically plausible?"

To bring the methane scenario down to a common-or-garden day-to-day understandable scale, I needed an example of small scale localised methane release, and really only one candidate mechanism came to mind :-)

In a similar "downscaling" exercise, around the time of the Tohoku tsunami, I remember calculating that the relative thickness of sea ice compared to ocean depth is about the same as gluing Pringles to a cat - from which we can conclude that while ice may have a dampening effect on sea surface waves, it's not going to have any effect whatsoever to dampen tsunami waves that involve the whole water column
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Rubikscube on November 13, 2014, 02:02:44 AM
Delta maps for the 10th of November reveals that the refreeze in eastern ESS appears rather slow this year, the same also seems to be the case in Baffin. Though, as one might expect, Barents/Kara is still quite a bit ahead of most years (I'm amazed by how much 2012 refreeze was postponed in this region, didn't remember it was that bad).

The forth year of comparison this week is 2008 (in addition to 2007, 2012 and 2013 respectively). A year which in general saw abnormally much SIA and SIE around this date.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Atomant on November 13, 2014, 12:19:56 PM


It is not a personal attack.  It *is* a reaction to persistent misinterpretation of facts and events. You ask a lot of good questions, and make some good connections.  Other times, even in the face of pretty clear evidence that undermines an assertion you make, you persist in digging yourself in deeper.

That's what I'm reacting to.

I assure you, you are getting nothing like what I'd deliver in "full personal attack mode".  It has been known to blister paint (never in this venue), and reserve it for those who truly deserve it.  You're not on that list.

;)

Best regards...

Well, I think you're dismissing and underestimating CH4 in the Polar atmosphere

CH4 can, and does hang around the Arctic atmosphere throughout the winter, and only with the return of sunlight does some CH4 'washed' away. Hydroxyl radicals get to work with UV and as a result of this process Noctilucent Clouds make their appearance from May. Of course other chemicals result from the process but to prove how certain I am about CH4 and  NLC's, I will predict here and now, based on the CH4 readings we're seeing, that 2015 will bring another spectacular show, more intense (and perhaps for longer) that 2014. :)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 13, 2014, 07:49:10 PM

Well, I think you're dismissing and underestimating CH4 in the Polar atmosphere

CH4 can, and does hang around the Arctic atmosphere throughout the winter, and only with the return of sunlight does some CH4 'washed' away. Hydroxyl radicals get to work with UV and as a result of this process Noctilucent Clouds make their appearance from May. Of course other chemicals result from the process but to prove how certain I am about CH4 and  NLC's, I will predict here and now, based on the CH4 readings we're seeing, that 2015 will bring another spectacular show, more intense (and perhaps for longer) that 2014. :)
A not unreasonable challenge, which can be evaluated.

So, key factors to examine..

Starting CH4 and distribution
Modified CH4 and distribution

Challenges to getting apples-to-apples includes
- Differences in heat input
   - inflow via weather
   - humidity changes
   - thermal transfer from the ocean
   - insolation input (or lack thereof)

Key elements to capture
- heat transfer between layers of atmosphere
- heat exiting the troposphere
- heat exiting the stratosphere

These would need to be normalized for the differences in heat input.

I'd say there's probably an even dozen scientific papers waiting to be written in that list...
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 14, 2014, 01:05:19 PM
So, key factors to examine..

Starting CH4 and distribution
Modified CH4 and distribution

Challenges to getting apples-to-apples includes
- Differences in heat input
   - inflow via weather
   - humidity changes
   - thermal transfer from the ocean
   - insolation input (or lack thereof)

Key elements to capture
- heat transfer between layers of atmosphere
- heat exiting the troposphere
- heat exiting the stratosphere

These would need to be normalized for the differences in heat input.

I'd say there's probably an even dozen scientific papers waiting to be written in that list...

Cool! I'll go ahead and do that work plus write those scientific papers (seems quicker and easier, anyway, than explaining to certain people what a "common cause" means and not means).

A happens. B and C follows from A. <-- This does *NOT* mean C follows from B. Only that B and C appeared at the same time.

In other words: I'm not saying what you all think I'm saying. I'm not as stupid as I would be if I was saying what you all think I was saying. Because I never said that, I'm smarter than stupid.

(I know, you were in a hurry and read it wrong and you don't feel like going back to reread because you've decided I'm stupid and said that anyway. Feel free to go on thinking about me as stupid and correcting stupid things I did *NOT* say.)

PS: I guess *I* should apologize. Because the social world is not a logical place.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 14, 2014, 01:20:20 PM
«1) November? One Day melt? Was this really melt?»

Yes, November is a month, the 11th in the year, yet I can see the need for even questioning this, given the level of taboo here. And yes, there was melt one day. Yes, really melt.
How do you know?  What is your evidence?

Well, Chris confirmed (eventually) that there was a melt.

What you've posted so far is PIOMAS figures.  PIOMAS is a an estimate of what a computer program believes the volume to be, based on numerical modelling, and informed by satellite measurements of area and extent.  It is not actual data on volume.

How do you suggest I get actual data on volume, Peter Ellis?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 14, 2014, 01:40:57 PM
Most of the drop comes from Kara, at which point you're probably jumping up and down saying 'Yes I was right, it is methane!!!!' and then you'd stop.

No. I don't care where in the Arctic the November 2013 melt was. I just said there was a one–day melt in the totals. I don't have to know where that melt was to know that there was a one–day melt. Finding where that was was your idea, and thus you felt you had to do your own work for yourself.

People mostly think of CH4 and ice–loss as a one–way street: Ice melts, and CH4 is released from hydrates. As already pointed out, it can go the other way. Hydrate thaws will release potent greenhouse gases like CH4 and CO2, and these *will* warm the Arctic Ocean area — probably CO2 more than CH4, at least in Winter. In a few rare examples we've had midwinter volume setbacks — melts — and finding the cause of these is *interesting*.

In no way does that mean one should be «jumping up and down saying 'Yes I was right, it is methane!!!!'». But finding the CH4 levels around those events is key to understanding whether hydrates were melted because of ice–loss or the other way around (or, of course, if other causes were more likely, eg storms, heatwaves).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 14, 2014, 06:22:37 PM
Viddaloo;

You cut off the top of my quote, which was..
Quote
A not unreasonable challenge, which can be evaluated.
The rest is a highly abbreviated list of requirements which not just you, but any researcher would need to address in order to support the assertion it appeared you were making - that prompt increases of CH4 have an immediate visible effect on Arctic Sea ice via changes in heat transfer.

It perhaps would benefit us to reflect briefly on two facets of argument here.

First is burden of proof. When drawing a conclusion, the quality of your conclusion is directly related to the quality and reliability of your supporting evidence.

Second is Hitchen's Razor - what is asserted without evidence can be dismissed without evidence.

Guided by these, it is pretty clear what you were doing was speculating about the impact of CH4.  Where you went off the rails and found yourself being challenged was when you tried to use that speculation as the foundation for further argument.

It is fine, actually encouraged, for people to speculate here. That mechanism leads us to all sorts of interesting avenues of investigation and understandings. Where you will draw criticism here (as most of us have on occasion) is when you let your arguments get ahead of fact. That includes persisting in defending speculation in view of fact which provides reasonable, supportable counter to that speculation. 

Counter fact in an argument does not preclude a hypothesis. Rather it sets the bar which must be reached in order to support it.  I just gave you a list you could use to prove yours.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 14, 2014, 06:32:18 PM
«1) November? One Day melt? Was this really melt?»

Yes, November is a month, the 11th in the year, yet I can see the need for even questioning this, given the level of taboo here. And yes, there was melt one day. Yes, really melt.
How do you know?  What is your evidence?

Well, Chris confirmed (eventually) that there was a melt.

In the interests of accuracy. I did the work you couldn't be bothered to do, so don't go crowing over others about your inadequacies.

Absolutely unbelievable.  ::)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 14, 2014, 06:43:53 PM
«1) November? One Day melt? Was this really melt?»

Yes, November is a month, the 11th in the year, yet I can see the need for even questioning this, given the level of taboo here. And yes, there was melt one day. Yes, really melt.
How do you know?  What is your evidence?

Well, Chris confirmed (eventually) that there was a melt.

In the interests of accuracy. I did the work you couldn't be bothered to do, so don't go crowing over others about your inadequacies.

Absolutely unbelievable.  ::)

I'm not saying you confirming it amounts to evidence, Chris. The good Peter Ellis here rejects PIOMAS as actual data, and what I did was to look for volume reductions in the (whole Arctic) PIOMAS data, before you went ahead and did exactly the same in the regional PIOMAS data.

For a guy who rejects PIOMAS altogether as not actual data, this isn't good enough, but I figured «appeal to authority» might work in this case (your name rather than what you're saying).

As we all know, you don't have to go to the regional data to prove there was overall net melt from a day to the next. That is absolutely redundant, but no–one can stop you from doing it, of course.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 14, 2014, 07:08:03 PM
Guided by these, it is pretty clear what you were doing was speculating about the impact of CH4.  Where you went off the rails and found yourself being challenged was when you tried to use that speculation as the foundation for further argument.
JD, you persist, so I've made a new thread for your assumptions off this 'official' thread:

http://forum.arctic-sea-ice.net/index.php/topic,1065.0.html (http://forum.arctic-sea-ice.net/index.php/topic,1065.0.html)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 14, 2014, 08:53:46 PM
Guided by these, it is pretty clear what you were doing was speculating about the impact of CH4.  Where you went off the rails and found yourself being challenged was when you tried to use that speculation as the foundation for further argument.
JD, you persist, so I've made a new thread for your assumptions off this 'official' thread:

http://forum.arctic-sea-ice.net/index.php/topic,1065.0.html (http://forum.arctic-sea-ice.net/index.php/topic,1065.0.html)

I suppose I should be gratified you consider me sufficiently important that you need a completely separate thread to excoriate me.  I'm sorry you misinterpreted the intent of my last note.  Be aware, beyond this reply, I've no intention of engaging in any further personal exchange with you.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on November 14, 2014, 10:42:30 PM
Great. Back to the Arctic, everyone.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: mark on November 15, 2014, 12:18:10 AM
I wish he wasnt so touchy he brings up some good topics of conversation (hes cut off talking to me as well!).

On the november extent (its on your graph) and piomass data isnt it possible that there may not have been a melt but changing systems and wind directions caused the ice to compact and reduce extent over a short period. Personally I dont know how PIOMAS calculates the volume but being a model it may have equated loss of extent with a loss of volume when in fact thickness may have gone up.

As usual in speculation like this over a short period there are several ways of looking at the data and a safer bet is over a slightly longer period to see if the change was consistent. Without all the possible forcings on view taking data in isolation is risky if you want to confirm a point of view.

Cheer up Vid, I've been lurking along with this and other threads you post on and if you werent so touchy and convinced everyone is against you, you may have made a few friends here instead of foes!
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Peter Ellis on November 15, 2014, 12:19:21 AM
I'm not saying you confirming it amounts to evidence, Chris. The good Peter Ellis here rejects PIOMAS as actual data, and what I did was to look for volume reductions in the (whole Arctic) PIOMAS data, before you went ahead and did exactly the same in the regional PIOMAS data.

For a guy who rejects PIOMAS altogether as not actual data, this isn't good enough, but I figured «appeal to authority» might work in this case (your name rather than what you're saying).

It doesn't, and I'm still not convinced that there's been any melt in the Arctic this time of year.  I can see the white pixels marching backwards in the IJIS map, of course - and that will doubtless propagate through to the PIOMAS model. However, that could be ice compaction, differential snowfall making areas more/less visible to the satellite, cloud interference, wave interference, etc.

It's possible there was some melt, of course, but the evidence just isn't strong enough to stand up and say "here is an unprecedented event which we must explain".

If I understand your other posts, you're not claiming that the methane directly caused the putative melt (which is good, because as covered previously this just doesn't make physical sense), but that they  may be due to a common cause - e.g. an influx of warm air melting some ice and releasing some of the underlying hydrates.

To which I would point out that this water was ice-free a few weeks ago, and the waters were warmer then.  Right now, they are cooling and the ice edge is advancing. Even if that advance has stalled or reversed for a few hours, why would that suddenly destabilise the hydrates many metres below, when fully open water a few weeks ago did not?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 15, 2014, 01:38:53 AM
From my setbacks.php script, looking for days of melt in the refreeze season in PIOMAS volume data during the month in question:

Code: [Select]
October:

1981/277 (13380/13372)
2006/282 (9386/9383) 2006/283 (9383/9374)
2009/281 (7039/7038)

November (thoroughly discussed here):

2013/311 (9249/9245)

December:

2008/351 (15210/15155)

January:

1981/8 (24666/24634)
1984/11 (24414/24398)
2004/24 (20878/20864)
2007/29 (19639/19497)

February:

1989/46 (27882/27876)
1992/40 (26481/26476)
1998/57 (27364/27362)
2007/53 (21550/21521)

March:

1987/90 (31427/31410)
1989/66 (29057/29039) 1989/90 (29949/29945)
1995/72 (27852/27847)
2000/79 (26404/26402) 2000/80 (26402/26391)
2007/77 (23163/23122) 2007/88 (23663/23654)
2008/70 (23450/23420) 2008/88 (24669/24581)
2011/68 (21139/21073)
2014/89 (22604/22602)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 15, 2014, 08:16:50 AM
.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 15, 2014, 09:58:26 AM
For information of the board. A drop relative to the average of a past baseline  period does not necessarily mean there was an actual drop over that period. There might be an actual drop, but in the cas of a period of dominant increase the most likely explanation is merely that the drop relative to the past period is caused by an increase that is less than the average for the past period.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Richard Rathbone on November 15, 2014, 09:23:22 PM
It would be interesting if the anomaly changes were all  in the same direction at a particular time of year (which was happening 2007-12, but has faded away with the 13-14 rebound). Sometimes up and sometimes down is what anomalies normally do and isn't remarkable.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 16, 2014, 05:59:43 AM
.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on November 16, 2014, 11:40:39 AM
Now there's a nice little hot spot  in the Beaufort and Chukchi:

(https://lh6.googleusercontent.com/-svBhAQRyzqY/VGh-fwTawXI/AAAAAAAAB-g/fvip3kkzMQs/w800-h618-no/sfctmpmer_01a.fnl.gif)

Is that all from Nuri?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 16, 2014, 02:15:03 PM
.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 16, 2014, 05:51:43 PM
Now there's a nice little hot spot  in the Beaufort and Chukchi

Is that all from Nuri?

Not any more; however, there is a strong high pressure system in SE Alaska and the gulf which established itself in Nuri's wake, which is pulling heat into the region. As you can see, the Arctic is as much above normal as the U.S. is below.

The cold we are currently seeing across the central part of the continent is the cold air displaced by that flow.

A pattern appears to be settling in where warm low pressure systems are being swept through the western an central Bering across Alaska followed by Gulf of Alaska ridging.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 16, 2014, 06:07:07 PM
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fcci-reanalyzer.org%2FDailySummary%2Foutput%2FT2_anom_satellite1.jpg&hash=2fc8ffe732451a7cf22d128be46b729c)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 16, 2014, 07:21:02 PM
Neven, JD,

Do you have a source of current temperatures from NCEP/NCAR operational at various atmospheric levels?

Taking NCEP/NCAR reanalysis the latest data available is 13 November. Looking at atmospheric cross section north of 60degN, and between 180degE and 240 degE reveals the sort of low lying warming (15degC above average!) associated with open water or thin ice. However on that date the winds were from Alaska into the Arctic, whereas looking at the latest HRPT IR from Environment Canada shows winds from the Arctic Ocean to Alaska.

(https://farm6.staticflickr.com/5613/15619408440_8915488650_o.gif)

Notably, along with the low lying intense warming there is also warming aloft, this higher warming is indicative of warm air influx from outside the Arctic, and at 500/850mb there's a strong northwards flow over the Bering Straits.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: plinius on November 17, 2014, 01:34:03 AM
sure it is an open water signature? Goes pretty much inland (Barrow is at 71 degrees) and you will see the same anomaly when strong winds break up the inversion.
Wind turned quickly because of a high pressure ridge forming quickly north of the coast, also because of the WLA.

Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 17, 2014, 01:38:03 AM
Neven, JD,

Do you have a source of current temperatures from NCEP/NCAR operational at various atmospheric levels?

Nothing that sophisticated, Chris; just watching NOAA and the U of Maine models like Reanalyzer and the like.

Your are correct to point out the different source of heat - the open water in the Beaufort and Chukchi.  Not just the circulation producing the increases in temperature.  All in all, a lot of heat to dump.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 17, 2014, 04:25:01 AM
.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 17, 2014, 02:50:14 PM
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D1059.0%3Battach%3D11929%3Bimage&hash=b36dd1fad3eb225f827dec7f47c53e8f)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 17, 2014, 07:50:53 PM
sure it is an open water signature? Goes pretty much inland (Barrow is at 71 degrees) and you will see the same anomaly when strong winds break up the inversion.
Wind turned quickly because of a high pressure ridge forming quickly north of the coast, also because of the WLA.

Plinius,

A reasonable point. I just understand the climatological inversion to be thinner than this warm feature. See attachment. So disruption of the inversion shouldn't IMO produce a low lying warming to 850mb. My meteorology isn't strong enough to decide whether an influx of warmer air breaking down the inversion would be low level biassed as seen.

Rather than open water I see thin ice.
http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictn/nowcast/ictn2014111212_2014111300_923_arcticictn.001.gif (http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictn/nowcast/ictn2014111212_2014111300_923_arcticictn.001.gif)
However there seems to be greater extent of thin ice over Siberia/Atlantic sector, that there is no such low level warming there might support the interpretation of wholly atmosphere driven with no ice role. However the above image (HYCOM) suggests thinner ice in Beaufort/Chukchi which might go some way to explaining the difference.

That said now I'm starting to think it is a wholly atmospheric feature with negligible ice role. But I don't know enough to cut through the matter and provide a totally convincing answer.

Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 17, 2014, 08:19:03 PM
Related to the above. In my most recent blog post I graphed air temperature (NCEP/NCAR reanalysis) at three different levels for an area north of 70degN and from 90degE to 240degE, an area preferring the peripheral seas of the Arctic Ocean.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F2.bp.blogspot.com%2F-vABiGwIxBIs%2FVGEMKfOEx-I%2FAAAAAAAABKc%2Fs0Eprv-REoU%2Fs1600%2FTemperature%252BProfile.png&hash=ee1cfd6a113e373973da77652006ac34)

I've just re-done that for November same area etc (had the numbers in a spreadsheet).

(https://farm8.staticflickr.com/7513/15811741601_241cb1e3bb_o.png)

What's odd there is how in November the low level warming kicks off in around 1995 (the start of the recent period of rapid volume loss in PIOMAS - coincidence?), whereas in October there's more of an exponential warming behaviour which seems to be related to ice loss in the summer.

I'll update that graph when November data is in.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: plinius on November 17, 2014, 08:31:29 PM
hi Chris,

I am not certain that we could quantify that effect. Killing the inversion in my wider sense of use implied that you move towards a dry adiabatic vertical gradient, as usual for a breaking through Foehn/Chinook wind. As you can see from your plot, the climatology is at least near isothermal, so it is easy to produce a lower level hot spot of >5K, when such Foehn winds happen to blow north over the Alaskan mountain ranges. I do fully agree with you that the thin ice plays it's role (though cannot be all, as models now play temperatures below freezing, since the "Foehn" has stopped), but quantification would only be possible by looking at full spatial resolution and the dynamics.

Concerning last post - fully agree and this is also my main reason for doubt that an ice free arctic would easily return to a fully covered state nowadays. Large open water area would massively shield itself with WV and local heat bubble and reduce the number of freeze days. Don't trust that the current models can fully handle the changes in circulation playing in there.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 17, 2014, 08:46:45 PM
Well Plinius,

There's often two ways to look at things...

When I look at those graphs I see massive venting of ocean heat which will assist the sea ice in recovering from loss events and act as a negative feedback on ice loss.  ;D
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Laurent on November 17, 2014, 09:00:32 PM
Do you know why there is so much thickness differences between Hycom and Hycom+cice ?
http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictn_nowcast_anim30d.gif (http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictn_nowcast_anim30d.gif)
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim30d.gif (http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim30d.gif)

Wich one to trust ?

In case you wonder where is the root :
http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/skill.html (http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/skill.html)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 17, 2014, 09:30:31 PM
PIOMAS estimates (http://forum.arctic-sea-ice.net/index.php/topic,119.msg39769.html#msg39769) medio November

Code: [Select]
2014 305   9.782
2014 306   9.883
2014 307  10.030
2014 308  10.092
2014 309  10.249
2014 310  10.344
2014 311  10.512
2014 312  10.672
2014 313  10.683
2014 314  10.705
2014 315  10.830
2014 316  11.000
2014 317  11.222
2014 318  11.230
2014 319  11.154
2014 320  11.191

And as corrected on November 19th:

Code: [Select]
2014 305   9.782
2014 306   9.889
2014 307   9.984
2014 308  10.070
2014 309  10.158
2014 310  10.239
2014 311  10.321
2014 312  10.403
2014 313  10.490
2014 314  10.583
2014 315  10.674
2014 316  10.761
2014 317  10.851
2014 318  10.934
2014 319  11.011
2014 320  11.076
2014 321  11.106
2014 322  11.168
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: P-maker on November 17, 2014, 10:42:37 PM
Chris & Plinius

Before both of you go off on various tangents, please consider actual observations from the North shore of Alaska - such as these: http://pafg.arh.noaa.gov/wmofcst_pf.php?wmo=FPAK51PAFG&type=public (http://pafg.arh.noaa.gov/wmofcst_pf.php?wmo=FPAK51PAFG&type=public)

It appears to me, that the dominant weather these days is "freezing drizzle".

Comparing these observations to the last three weeks of drizzle on end in this country, just makes me wonder wether we are now entering the new phase of equi-thermal NH autumns.

As far as I reckon, this type of drizzle weather is just the way a warm and moist atmosphere would most efficiently get rid of it's surplus energy before the winter. A slow condensation process in a weak southerly air flow regime would give drizzle on the ground and positive temperature anomalies aloft.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 18, 2014, 12:47:08 AM
What's odd there is how in November the low level warming kicks off in around 1995 (the start of the recent period of rapid volume loss in PIOMAS - coincidence?), whereas in October there's more of an exponential warming behaviour which seems to be related to ice loss in the summer.

It seems if you're going to "lose weight" during the Arctic winter, November is the month to do it. 1996 is the all–time leader in this game, putting off an impressive 778 km³ in the course of the month. (That's growing slower, mind you, and not actual melt.)

I bet we'll see this 778 km³ record broken before the end of this decade.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 18, 2014, 09:25:37 AM
I have to post this update, as the already biggest November drop in sea ice gain anomalies this century just keeps getting bigger, day by day. True, the volume figures are based on my own algorithm, so we won't know for sure how big the drop was till PIOMAS data arrive. But the smoothing algorithm I made after October's data were in actually makes the drop even more severe, so I think we've got something here.

You could of course say that because this appears to be a record for the new century, the odds are the real picture is somewhere between this graph and no drop at all. But the smoothing function that made the October estimates more precise, says otherwise, and predicts a more extreme drop than in this graph. Wish I could Fast Forward to December 8th–ish!
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 18, 2014, 02:18:28 PM
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D1059.0%3Battach%3D11968%3Bimage&hash=26392c7cecf0b933da86640e3a804d74)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Peter Ellis on November 18, 2014, 04:48:28 PM
It seems if you're going to "lose weight" during the Arctic winter, November is the month to do it. 1996 is the all–time leader in this game, putting off an impressive 778 km³ in the course of the month. (That's growing slower, mind you, and not actual melt.)

I bet we'll see this 778 km³ record broken before the end of this decade.

Surely the causality is the other way round?  In recent years we tend to have faster re-freeze across the board in Oct/Nov, because we're starting from a lower base.  In 1996, the Arctic Basin was already pretty full of ice by the start of November, so there wasn't so much scope for growth.  Ergo slower growth in 1996 than in more recent years.

Accordingly I don't think we'll see the 778 km³ record broken ever again (well not until we get near to ice-free winters, by which time I doubt there'll be much human life around to comment! Rather, we'll keep setting ever higher and higher record for more ice growth in November.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: crandles on November 18, 2014, 05:39:46 PM

Surely the causality is the other way round?  In recent years we tend to have faster re-freeze across the board in Oct/Nov, because we're starting from a lower base.  In 1996, the Arctic Basin was already pretty full of ice by the start of November, so there wasn't so much scope for growth.  Ergo slower growth in 1996 than in more recent years.

Accordingly I don't think we'll see the 778 km³ record broken ever again (well not until we get near to ice-free winters, by which time I doubt there'll be much human life around to comment! Rather, we'll keep setting ever higher and higher record for more ice growth in November.

I agree we 'have faster re-freeze across the board in Oct/Nov, because we're starting from a lower base', at least so far.

But if there is much more heat built up over summer as we approach virtually ice free summer, might the heat being vented last into Nov so growth is then slow during October and at start of Nov before speeding up?

(https://sites.google.com/site/arctischepinguin/_/rsrc/1415431943124/home/piomas/grf/piomas-trnd4.png?height=360&width=480)

In addition to the mainly downward movement, the bottom is getting flatter and the sides steeper.
Hence the trend towards more ice growth in October certainly could reverse (quite soon?) but perhaps November is less clear and likely will take a long time before the trend could reverse but not quite as long as you suggest.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Steven on November 18, 2014, 06:03:27 PM
I have to post this update, as the already biggest November drop in sea ice gain anomalies this century just keeps getting bigger, day by day. True, the volume figures are based on my own algorithm, so we won't know for sure how big the drop was till PIOMAS data arrive. But the smoothing algorithm I made after October's data were in actually makes the drop even more severe, so I think we've got something here.

I don't think so.

Your estimates of daily PIOMAS volume for November 2014 are based on IJIS sea ice extent.

Your assumption is that the volume to extent ratio follows basically the same trajectory as 5 years ago, i.e. November 2009.

So I looked at the November 2009 data.  It turns out that the volume/extent ratio has an unusual drop from 13 to 17 November 2009.  This drop propagated through your calculation and it resulted in a spurious drop in your calculated 2014 curve.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Peter Ellis on November 18, 2014, 07:31:39 PM
In addition to the mainly downward movement, the bottom is getting flatter and the sides steeper.
Hence the trend towards more ice growth in October certainly could reverse (quite soon?) but perhaps November is less clear and likely will take a long time before the trend could reverse but not quite as long as you suggest.

I agree the bottom's getting flatter and wider, but that I think really only compounds the issue in November - a wide flat bottom to the curve through October only means that November starts from even lower, meaning there will be a faster catch-up freeze.

Even in Hudson Bay (much lower latitude, ice free all summer, and soaking up mid-day sun non-stop from ~July onward) shows an end to the trough and a steep upward climb through November.  To shift the curve so profoundly that November is in the shallow part of the immediate post-trough growth period, you'd need there to be substantial open water right across the Arctic for multiple months, right up to the end of October or nearly so.

i.e. you'd need the entire Arctic to have a yearly profile that looks much more like the Baffin sea or the northern Bering sea.  And by that point, as with those areas, you're into a regime where you have declining winter maxima as well as summer minima.  Not going to happen for multiple decades yet.  Winter in the land of 24 hr darkness is just too cold.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 19, 2014, 08:11:29 AM
Steven,

So I looked at the November 2009 data.  It turns out that the volume/extent ratio has an unusual drop from 13 to 17 November 2009.  This drop propagated through your calculation and it resulted in a spurious drop in your calculated 2014 curve.

Edit: I've added a smoothing function for the IJIS *and* PIOMAS 2009 data. Hopefully that will yield more precise estimates.

Edit2: You are right, of course. There was a huge natural variation rise in ext/vol for November 13 to 17, resulting in an unnatural false drop in 2014 gain for those same days. I'm thankful for the correction, Steven. Attached you'll find the graph for real Nov 2009 ext/vol versus smoothed.

Edit 3: And today's updated abrupt drops graph with smooth data! :)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 19, 2014, 08:48:13 AM
It seems if you're going to "lose weight" during the Arctic winter, November is the month to do it. 1996 is the all–time leader in this game, putting off an impressive 778 km³ in the course of the month. (That's growing slower, mind you, and not actual melt.)

I bet we'll see this 778 km³ record broken before the end of this decade.

Surely the causality is the other way round?  In recent years we tend to have faster re-freeze across the board in Oct/Nov, because we're starting from a lower base.

It's not that simple, I'm afraid. If you look at this graph for November:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D997.0%3Battach%3D11967%3Bimage&hash=7cfd9eb84e70fc1d482624e64a281ab0)

then the yellow line being lower than the black and green line, tells you the trend is for lower and lower November ice gains. The black 2007–2013/14 line tells you gains are higher than for the 1979–1999 average, but the trend has since turned towards slower gains again.

For October it's a whole different story, as October's gains are more and more determined by summer melt:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D997.0%3Battach%3D11912%3Bimage&hash=4072337ade679ee0a88e9b47e73d3020)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: crandles on November 19, 2014, 05:29:39 PM

It's not that simple, I'm afraid. If you look at this graph for November:


then the yellow line being lower than the black and green line, tells you the trend is for lower and lower November ice gains. The black 2007–2013/14 line tells you gains are higher than for the 1979–1999 average, but the trend has since turned towards slower gains again.


Sorry no, you are fooling yourself by looking at just a few comparisons in the last few years and deducing the trend for November is downwards.

(https://farm6.staticflickr.com/5615/15642349207_47369362c7_z.jpg) (https://flic.kr/p/pQg8rZ)PIOMASONDGains (https://flic.kr/p/pQg8rZ) by crandles2011 (https://www.flickr.com/people/67566729@N07/), on Flickr

The trend for the gain in each of the three months is similar generally upward. Looking at the last few years and saying the trend is downwards is highly likely to be noise giving a spurious result. (You can see the large amounts of noise in this graph.) Last couple of years having higher minimum against the trend also makes looking at just a few comparisons to deduce the trend dangerous.

The graph I posted earlier with discussion of main movement being downwards but also a wider bottom and steeper sides gives much better understanding of the situation.

Just because the trends are similar so far does not stop us understanding that it is October that is going to turn downwards first and it might not take much lower minimums to cause that to occur.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 19, 2014, 10:49:27 PM
The trend for the gain in each of the three months is similar generally upward. Looking at the last few years and saying the trend is downwards is highly likely to be noise giving a spurious result. (You can see the large amounts of noise in this graph.) Last couple of years having higher minimum against the trend also makes looking at just a few comparisons to deduce the trend dangerous.

Not sure I agree with you there, if we are to let the numbers themselves decide.

There seems to be a sea change at or just before 2007, from which year the first half of the X to 2014 years will have more rapid ice gain than the second half. That looks like a trend to me.

That means November 2007–2010 will have more ice growth than November 2011–2014, 2008–2010 more than 2011–2014, 2009–2011 more growth than 2012–2014, 2010–2012 more than 2013–14 and finally 2011–2012 more rapid ice gain than 2013–2014.

If you include more than 8 years, the trend is the opposite (last half of the selection will have quicker growth).

The graph I posted earlier with discussion of main movement being downwards but also a wider bottom and steeper sides gives much better understanding of the situation.

Just because the trends are similar so far does not stop us understanding that it is October that is going to turn downwards first and it might not take much lower minimums to cause that to occur.

This doesn't seem to be based in the data, Crandles. The trend is for faster melt in May and June, slower melt in July, August and September, continuing in faster refreeze in October, turning to slower refreeze in November, then back again to faster refreeze in December and April (with January to March in the 'Undecided' category).

My guess is that January to March will be the first to tip over into predominantly slower growth than the earlier years in the data, while October will keep growing ever faster until the summer crash expands into October 1st. Data suggest August will crash before October, though.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: crandles on November 19, 2014, 11:23:06 PM

Not sure I agree with you there, if we are to let the numbers themselves decide.

Trouble is this years data does help decide. I say the trend to lower minimums are causing faster refreeze. But this year has a high minimum therefore I expect low refreeze this year. You expect low refreeze this year because you think the trend is down. So if the refreeze is low we both claim the data supports our position. So we need to wait for a low minimum year to decide the matter and even then 2 or 3 low minimum years is better than one.

Quote
My guess is that January to March will be the first to tip over into predominantly slower growth than the earlier years in the data, while October will keep growing ever faster until the summer crash expands into October 1st. Data suggest August will crash before October, though.

Interesting maybe. For this year I expect the regrowth in Jan to March to be slow and that could well be by a larger amount than the trend which I agree could emerge as downward.

I don't think it will take minimums much below the current minimum for slow growth to extend into early October, as 2007 and 2009 have already had pretty slow growth in the early part of October.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 19, 2014, 11:57:05 PM
I think I've shown in the Transition thread how the first half of October is trending towards lower refreeze (ending in zero refreeze somewhere in the 2020s when there is no ice at all before medio October). Here it is:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D1017.0%3Battach%3D11621%3Bimage&hash=4de2c993d450e38cd882d7c2b82af8c3)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 20, 2014, 04:34:51 AM
I think I've shown in the Transition thread how the first half of October is trending towards lower refreeze (ending in zero refreeze somewhere in the 2020s when there is no ice at all before medio October). Here it is:
To my eye, that has the appearance of serious volatility.  I suspect  that the refreeze in the peripheral seas is at the root of that.  What does the scatter look like when we isolate it by region?  The CAB might be less subject to the variations we're looking at.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 20, 2014, 02:30:49 PM
New methane peak yesterday, 2495 ppb.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 20, 2014, 08:45:52 PM
Using:
1) PIOMAS gridded data for the Arctic Ocean, the difference December and September volume is used to calculate the autumn volume gain.
2) NCEP/NCAR surface temperature for the region 90 to 240degE north of 70degN.
3) NSIDC sea ice extent on 31 August, known as Late Summer Extent.

A)
(https://farm8.staticflickr.com/7546/15650243428_98b5131f17_o.png)

B)
(https://farm6.staticflickr.com/5608/15650243388_5d22bde9dd_o.png)

C)
(https://farm6.staticflickr.com/5616/15650534597_64c2f66600_o.png)

The conclusion I draw is that:

There is a moderate to strong relationship (R2=0.6) between sea ice volume gain in the autumn and the late summer extent of sea ice, such that as late summer extent goes down autumn volume gain goes up.

Temperature has a weak effect on autumn volume gain (R2=0.195), and would seem to act against what one would expect, as autumn warming occurs so autumn volume increase increases.

However temperature is seen to be moderately to strongly affected by late summer sea ice extent (R2=0.5), this can be explained by increasing open water leading to more heat being vented to the atmosphere in the autumn.

Therefore the increase in autumn volume gain is due to larger open water in summer and happens in spite of the heat gained in summer which is vented to the atmosphere in the autumn. This venting of heat does nothing to reduce autumn volume gains.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: crandles on November 20, 2014, 11:46:33 PM
Using:
1) PIOMAS gridded data for the Arctic Ocean, the difference December and September volume is used to calculate the autumn volume gain.
Is that difference between average of September and average of December?


Therefore the increase in autumn volume gain is due to larger open water in summer and happens in spite of the heat gained in summer which is vented to the atmosphere in the autumn.

Seems a sensible conclusion.

This venting of heat does nothing to reduce autumn volume gains.

I wonder if that is too absolute a statement from the evidence provided.

If you looked at piomas gains from say ~25 Sept to ~10 Oct, I think it may be possible to arrive at a slightly different nuanced conclusion: It might be that this brief initial period does see a delay but the amount is made up for by faster gains later in the Autumn in order to reach the results you have given.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 21, 2014, 07:49:24 AM
Crandles,

Yes, PIOMAS monthly, average is close to that.

Perhaps the suggestion that heat loss does nothing to stem volume gain is too strong. But I don't really think so. Yes there is a delay as heat is vented until the ocean cools, yet despite this the overall tendency is for lower summer extents to cause greater autumn volume gain.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: OSweetMrMath on November 22, 2014, 03:05:32 AM
Chris,

This is consistent with your previous evidence that ice grows fastest when it's thin. Years with low extent will start fast ice growth when the temperature falls below freezing. Also, it's easier for open water to transfer heat to the atmosphere, so it's not surprising that years with low extent have both higher air temperatures in the fall and greater volume growth in the fall.

Eventually the ocean will get warm enough to prevent ice formation, but that's a second order effect and is probably a long way out.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 22, 2014, 06:08:54 AM
Flat–out normalized: The past 2 Novembers have normalized the big post–2007 increase in November ice gain down to an anomaly of zero.

This could mean we can now have 5th lowest ice levels (annual average volume, or 4th for extent) and still have no higher ice growth in November than the 1979–1999 average.

It could also mean that a compensating "quicker growth to make up for a larger melt" is really a short–term effect, lasting only a few years, until things normalize on a new level.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 22, 2014, 08:42:19 AM
It could also mean that a compensating "quicker growth to make up for a larger melt" is really a short–term effect, lasting only a few years, until things normalize on a new level.

Indeed it could be.  We will have to see how the energy balance in the ocean plays out.

I've been watching the Bering, Chukchi and Beaufort with increasing alarm.  The region is still extraordinarily hot, and has been for weeks. 

Chris, where was it you were getting your degree day information?

-J
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: wili on November 22, 2014, 01:14:42 PM
"I've been watching the Bering, Chukchi and Beaufort with increasing alarm.  The region is still extraordinarily hot, and has been for weeks."

That further tips the 'cold pole' towards GIS and CAA, doesn't it?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 22, 2014, 02:33:16 PM
The drop in anomalies from the 79–99 average has ended, and the drop from 2002–2013 looks set to do the same in the near future. The first drop ended at –178 km³ and was the 3rd biggest such November drop since 2007, and the 5th biggest this century (with 2006' –323 km³ as #1). In the 20th century, 1981 was bigger with –343 km³ and 1996 with a drop of –778 km³ in November.

The volume deviation from the 2002–13 gain average is currently at –518 km³, but looks destined to narrow towards the end of the month. Final PIOMAS data in 2 weeks' time will hand us the official tally. Thereafter, December will be an interesting month to follow through these graphs, as 2013 volume shows a big rise and 2013 extent an even bigger drop, compared to the 2002–13 December gain average.



Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 22, 2014, 03:48:16 PM
It could also mean that a compensating "quicker growth to make up for a larger melt" is really a short–term effect, lasting only a few years, until things normalize on a new level.

Indeed it could be.  We will have to see how the energy balance in the ocean plays out.

I've been watching the Bering, Chukchi and Beaufort with increasing alarm.  The region is still extraordinarily hot, and has been for weeks. 

Chris, where was it you were getting your degree day information?

-J

What? Freezing degree days?

Ncep/ncar reanalysis time series. I can post a link if needed, but am on my phone right now. That data does reveal such warnings so they're taken into account, but I was using the average for the ESS and haven't got round to dealing with daily gridded data.

Edit- just been looking at earth nullschool and GFS at Wetterzentrale. It is warm there but that's relative to climatology, i.e. Only a little above freezing but enough to explain what looks like late freeze in chuckchi/bering, not checked the numbers on that. What I don't get is that earthnullschool is showing winds blowing south through Bering. Whereas gfs pressure suggests a high ridge drawing air broadly northwards.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 22, 2014, 04:35:14 PM
I've attached a graph of Chukchi extent from 1979 to 2014 for 19 November, current Chukchi extent is not low in the context of recent years despite being low in the longer term context.

Image removed as it is wrong.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 22, 2014, 08:40:52 PM
I've attached a graph of Chukchi extent from 1979 to 2014 for 19 November, current Chukchi extent is not low in the context of recent years despite being low in the longer term context.
So, it is safe to conclude, ice conditions are not a primary factor in the increase in temperature.

I also note, SSTs are high, but not remarkably so.

http://www.ospo.noaa.gov/data/sst/anomaly/2014/anomnight.11.20.2014.gif (http://www.ospo.noaa.gov/data/sst/anomaly/2014/anomnight.11.20.2014.gif)

So, most probable primary cause is increased circulation from lower latitudes.  I'd offer overturning circulation from depth being a second possibility, considering the gales we've seen, but as I think of it, moderately remote.

Weather keeping temperatures consistently high implies heat isn't getting dumped out of the Chukchi, and where there is ice, it won't be thickening (Thus my query about freezing degree days). When the freeze does take hold, it may not be material.  Depending on cold, it may dump heat fast enough to catch up during the deepest part of the season to come back to a more "normal" state.

My over all concern is heat retention in the ESS, Chukchi and Beaufort.  More is not good, of course, and might lead to earlier melt next spring.  Flip side, the additional heat and early melt could produce feedback which increases albedo and slows the melt. 

Seems the Refreeze will be as interesting to watch as the Melt.

Edit:  Boiled down to its most simple, the question I'm pondering here is - the Arctic refreeze is well underway, and volume is increasing, and will expand to its typical winter extents - but is it freezing fast enough?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 22, 2014, 08:52:08 PM
Seems the Refreeze will be as interesting to watch as the Melt.
I second that. The problem for the tabloids (and the 'tabloid thinkers') would be the unsexiness of 'not refreezing quite as fast' versus the headline–grabbing 'melts more and faster than ever'.

But I think the new major area where ice collapse will be seen is exactly in the slower growth.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 22, 2014, 09:22:10 PM
I've attached a graph of Chukchi extent from 1979 to 2014 for 19 November, current Chukchi extent is not low in the context of recent years despite being low in the longer term context.
So, it is safe to conclude, ice conditions are not a primary factor in the increase in temperature.

I also note, SSTs are high, but not remarkably so.

http://www.ospo.noaa.gov/data/sst/anomaly/2014/anomnight.11.20.2014.gif (http://www.ospo.noaa.gov/data/sst/anomaly/2014/anomnight.11.20.2014.gif)

So, most probable primary cause is increased circulation from lower latitudes.  I'd offer overturning circulation from depth being a second possibility, considering the gales we've seen, but as I think of it, moderately remote.

In the specific case of Chukchi at present it may be mainly atmospheric, but the presence of open water will warm the atmosphere. To look at that you'd have to look at the atmospheric cross section. In terms of the longer term trend of Chukchi low extent, a similar method to my earlier scatter plots would seem reasonable. I haven't the time to do either right now
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 22, 2014, 09:31:44 PM
Chris,

This is consistent with your previous evidence that ice grows fastest when it's thin. Years with low extent will start fast ice growth when the temperature falls below freezing. Also, it's easier for open water to transfer heat to the atmosphere, so it's not surprising that years with low extent have both higher air temperatures in the fall and greater volume growth in the fall.

Eventually the ocean will get warm enough to prevent ice formation, but that's a second order effect and is probably a long way out.

Sorry, nearly missed your comment.

Yes, I agree. From my understanding of Eisenman, also other work on cloud radiative forcing, things seem likely to get really interesting after an ice free summer becomes regular. It is then that an abrupt transition to perennial ice free might occur, when autumn water vapour from open ocean forms a cloud base that severely limits winter ice growth.

If you want the references just ask.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Steven on November 22, 2014, 10:26:27 PM
I've attached a graph of Chukchi extent from 1979 to 2014 for 19 November, current Chukchi extent is not low in the context of recent years despite being low in the longer term context.

Chris, your graph seems to show the total Arctic sea ice extent, rather than the Chukchi Sea regional extent?

Using the data on Wipneus website (https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data), I plotted regional extent data for 21 November: see the graph below.  The blue line in the graph shows the sea ice extent in Chukchi + Bering + East Siberian Seas (I lumped these 3 regions together). 

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FILfuRak.png&hash=010e62349a7b8a5f3042953b07a76d8c)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 23, 2014, 12:14:05 PM
A big bubble of hot air (http://www.theecologist.org/Interviews/2636775/global_warming_you_must_be_joking_how_melting_arctic_ice_is_driving_harsh_winters.html):
Quote
"So what we're finding is that there's an area, north of Scandinavia in the Arctic, where the ice has been disappearing particularly rapidly. When that ice disappears ... there is unfrozen ocean underneath, and that ocean absorbs a lot more energy from the sun through the summertime. So it becomes very warm there.

"Then as the fall comes around, all that heat that's been absorbed all summer long, where the ice has retreated, is put back in the atmosphere and that creates a big bubble of hot air ... over that region where the ice was lost."
Probably not so new or shocking, but I thought I'd post it anyhow. Apart from this, the article mostly covers the jet stream and moving polar vortex.

PS: I guess my question then is whether the creation of the hot air bubble, caused by summer melt, and the changes it brings to the jet stream, and thus the removal of very cold air from the Arctic during autumn and winter, can properly be called another positive feedback? If frequent, it certainly makes it easier for the ice to melt faster, or for the refreeze to slow down considerably.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 23, 2014, 12:19:09 PM
Steven,

That's really weird, here's the graph as it looks in the spreadsheet, the graph above is showing the wrong data. What's weird is I opened the sheet without changing anything and the graph was different, I've never seen Excel fail to update like that. Thanks for catching this.

My impressions were right after all, Chukchi is near the lowest on record.

Viddaloo,

You'll find this of interest.
http://www.realclimate.org/index.php/archives/2010/12/cold-winter-in-a-world-of-warming/ (http://www.realclimate.org/index.php/archives/2010/12/cold-winter-in-a-world-of-warming/)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 23, 2014, 12:28:12 PM
Steven,

That's really weird, here's the graph as it looks in the spreadsheet, the graph above is showing the wrong data, something changed when copying and saving the image. Thanks for catching this.

My impressions were right after all, Chukchi is near the lowest on record.

Viddaloo,

You'll find this of interest.
http://www.realclimate.org/index.php/archives/2010/12/cold-winter-in-a-world-of-warming/ (http://www.realclimate.org/index.php/archives/2010/12/cold-winter-in-a-world-of-warming/)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 23, 2014, 01:00:14 PM
Thanks, Chris. I also recall reading about findings in the paleo archives that a breakthrough of Pacific ocean temperature regimes into the Arctic preceded severe abrupt Arctic warming and meltdown events. Does this sound familiar? I'm thankful for links/articles about this.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Gray-Wolf on November 23, 2014, 01:41:33 PM
I'm still mulling the implications of low ice and winter weather? The post 07' years saw the jet Ridge over the U.S. and have the UK plagued by a trough. Post 2012 there appears to have been a tweak to the jets wave positioning with the amplitude extremes appearing unchanged? Could the long term ice loss over Kara/Barentsz now be being augmented by long term losses over Beaufort/Baffin or did the record low of 2012 alone drive the 'tweak' in wave patterns?

Then I also can't ignore the changes to the tropical oceans and impacts they might also drive in positioning the jets positioning?

My final concern is what we ought to expect when the amplitude of the polar Jet becomes so extreme as to run into the sub tropical jet? In the same way we are seeing Arctic airs head due south and bring max impact could we expect rapid northward plunges of moist tropical air once a corridor is opened by the Jets touching?

We worry about the polar plunges and the disruption this brings to regions but when I see tropical air meet fridged  over the great plains I see a different set of issues in the making?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: JayW on November 23, 2014, 01:46:20 PM
Warning: my knowledge on these subjects are very superficial, criticisms and comments are encouraged.


Attached is the 10hPa circulation and temperatures.  From my understanding, we are seeing warm air in the stratosphere heading poleward. This began as a Wave 1 response (one warm, one cold cell) and evidenced in the recent -AO, and a displaced polar vortex.  Perhaps even associated with Nuri.


(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.cpc.ncep.noaa.gov%2Fproducts%2Fstratosphere%2Fstrat-trop%2Fgif_files%2Ftime_pres_WAVE1_MEAN_OND_NH_2014.gif&hash=abcf7c21a05a73b8ec43c01f916cb86b)

But it could be that the cold area is beginning to split into two areas, likely allowing a second warm area to form, initiating a Wave 2 response (two warm, two cold cells), splitting the polar vortex.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.cpc.ncep.noaa.gov%2Fproducts%2Fstratosphere%2Fstrat-trop%2Fgif_files%2Ftime_pres_WAVE2_MEAN_OND_NH_2014.gif&hash=2791aecb2cb8f4829df91285e4694160)

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/ (http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/)

I believe that the QBO has moved into neutral and negative territory, and this can increase the chance for stratospheric warming events.  This is also consistent with the many forecasts I have seen for a generally - AO for the DJF period.  Thus I'm expecting many intrusions of cold into the mid-latitudes, and chunks of warmth shoved poleward this boreal winter.

All these thoughts are from the mind of an amateur, hack, armchair weatherman  :)  feel free to rip me apart.

http://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-89.51,87.41,426 (http://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-89.51,87.41,426)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 23, 2014, 02:36:03 PM
The gap in November extent gain widens up to 2013, as daily extent is also for the first time since November 2 lower than last year. Also, no CH₄ release drama thus far this winter, despite cyclones and open water on the Pacific/ESS side.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 23, 2014, 05:10:49 PM
Jay,

Over Eurasia October  snow exten is substantially above normal (Rutgers snow lab). I suspect this might be enough to bring Cohen's hypothesis linking Eurasian snow advance to extreme winters. Part of that process would be SSW event.

Can you give a link to those wave activity plots - where they come from. Can you explain what they show?

The earth.nullschool plot is strato flow, right? I may be wrong, but I seem to recall a similar dumbell between barents and Canada during the 'polar vortex' freeze of last winter. Is such a pattern common?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: JayW on November 23, 2014, 08:58:43 PM
Chris,
    I'm afraid my knowledge of these things isn't very extensive.  I'm still learning how these processes work, even just learning the terminology and how to read the plots has been difficult at times.  So be a bit more than skeptical of what I say  :).  The plots show the temperature of wave(s).  Wave 1 is a singular bubble of warmth invading the polar stratosphere.  The wave 1 plot shows that we had a small SSW mid-late October, and another currently occurring.

Edit: looking closer, technically the plots are showing the height of the wave(s), but I believe that the increase in heights can be attributed to warm air expanding, creating a bulge.  Hope my thoughts make sense, my brain moves faster than my fingers.  I'll gladly attempt to clarify any of what I say.

Thos animation illustrates it nicely.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.cpc.ncep.noaa.gov%2Fproducts%2Fintraseasonal%2Ftemp10anim.gif&hash=8efff003c484ca43641f25874fda9814)

A wave 2 response would involve two separate warm intrusions at the same time, and wave 3, 3 areas.  My very limited knowledge is that wave 1+2 are the most important.  With warming that begins at the top of the stratosphere and propagates downward being the most disruptive.

The earth.nullschool image is the 10hPa winds and temps.  It shows just how anomalous the temps are with these SSW events.  It's in the vicinity of +45°C !  I think the stratosphere begins at about 100hpa, so despite no real sensible weather in the stratosphere, much can happen there that effects the big picture.

I agree that this is likely related to the strong Siberian snow advance this past October.  Interestingly, the snow cover has actually stalled in Siberia for most of November and expanded in North America recently.
(https://www.ccin.ca/home/sites/default/files/snow/snow_tracker/eu_sce.png)
https://www.ccin.ca/home/ccw/snow/current (https://www.ccin.ca/home/ccw/snow/current)

But my understanding is that the events are set in motion in October.  I believe last winter we saw a largely +AO, just displaced.  I can't really speak about how common these events are, I've only really been trying to educate myself on all matters meteorological in the past 12-18 months, full disclosure, I was hoping some folks more knowledgeable about this stuff would correct me or expand.  :) I don't mind taking a stab at things and being wrong, it's how I learn.

Hope that helps a little. If I'm in error anywhere I apologize, I'm just a carpenter, weather is a hobby.  :D

 The wave activity plots from the CPC are available here http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/ (http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/)


This is a great resource for ECMWF stratospheric output.
http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html (http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fusers.met.fu-berlin.de%2F%7EAktuell%2Fstrat-www%2Fwdiag%2Ffigs%2Fecmwf1%2Fecmwfzm_ta1_a12.gif&hash=2557539771429c5fe9f24ee629ffcdae)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 24, 2014, 09:38:08 AM
<snippage>

The earth.nullschool plot is strato flow, right? I may be wrong, but I seem to recall a similar dumbell between barents and Canada during the 'polar vortex' freeze of last winter. Is such a pattern common?

I can't speak to "common", but you are correct, we saw that 10hPA dumbell multiple times last winter, both in its current position, and shifted around on various compass angles across the arctic.  That said, I recall Greenland was a "popular" location for one of the loops to anchor.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 25, 2014, 07:10:55 PM
Jay,

Thanks for the extra detail. The stratospheric warnings aren't due to air moving in, as I understand it. They're caused by waves breaking against the stratosphere, as the wave breaks the pressure goes up, this warms the air (like a bicycle pump getting warm). With regards the waves, they're not mass movement any more than ocean waves transport water. I'm just an amateur too, but someone posted at Neven's saying the strato warming was mass transport and an actual meteorologist took exception to it.

I'll follow up your links when I'm on my laptop and have time to consider. What is interesting is that the Eurasian warming actually seems to start in China, that did surprise me.

JD Allen,

I'll have to look into how common that pattern is. So far the UK has had a high pressure dominant autumn, if we were to have a repeat of the American/Canadian cold and extreme UK  winter storminess this winter, I'd start suspecting a link with the last two arctic summers. Buy we're a long way from that now.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on November 26, 2014, 09:45:39 AM

JD Allen,

I'll have to look into how common that pattern is. So far the UK has had a high pressure dominant autumn, if we were to have a repeat of the American/Canadian cold and extreme UK  winter storminess this winter, I'd start suspecting a link with the last two arctic summers. Buy we're a long way from that now.
Definitely. Two seasons does not a trend make.

At this point I'm mostly interested at watching how the winter circulation plays out.  Over much of the last two years, we have had a powerful high pressure system parked over the Gulf of Alaska.  That's been displaced this fall by cannon shots of powerful lows shooting up along the East Asian margin, driving heat into the arctic, and displaced cold south along the east side of the Rockies.  It will be interesting to see how that affects ice thickening, presuming it persists.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Gray-Wolf on November 26, 2014, 10:38:57 AM
After seeing the changes 2012 appeared to wrought in the positioning of troughs and ridges of the Jet I have to think that some kind of forcing did arise ? Post 07' saw the UK with an unkind Jet positioning ( hence its washout summers and winter trending toward cooler/cold. Then 2012 appeared to break that trend? The U.S. , post 07, had a Jet ridge positioned over the center the country which reversed in 2012 bringing the central jet trough ( and potential polar outbreaks). What caused this 'shift' in pattern?

I'm pretty convinced that the post 07' positioning was tempered by the long run of low ice over Barentsz/Kara from the early noughties on but then , later in the noughties, we saw other areas lose ice over the summer months and so maybe it was the forcing that the autumn output of warmth from the cooling ocean that sets up and reinforces current jet positioning?

The only other thing that my tiny mind can come up with is that the naturals are now switching to their positive states ( PDO/IPO) and that this extra energy entering the climate system has engaged with the polar anomalies and both are now forcing the post 2012 jet positioning?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on November 26, 2014, 07:11:59 PM
Gray Wolf,

2012 was an unusually wet UK summer, I know from a personal angle, in July of that year the river near my flat broke its banks after weeks of heavy rain and my pleasant basement flat was flooded. I now live on a hill.  ;D

I've just remembered I blogged on the event, it just gave me a laugh...
http://dosbat.blogspot.co.uk/2012/06/on-difference-between-knowing-and.html?m=1 (http://dosbat.blogspot.co.uk/2012/06/on-difference-between-knowing-and.html?m=1)


JD Allen,

I'll be watch
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: JayW on November 27, 2014, 12:24:04 PM
Chris,
  Thanks for that info.  The warming that began over China coincided with super typhoon Nuri.  I can't say that there is a cause and effect there, or if it's purely coincidental, but it's explosive cyclogenesis did make it the deepest Bering sea storm ever recorded.  I've just learned about a tropopause fold, where the stratosphere can get drawn under the troposphere in storms with very strong jet steaks. I'm led to believe that the current -QBO will increase the chances of more wave breaking events, through tropical eddies that propagate waves poleward.  I suspect we will see more events this winter, I'll do my best to learn more and share.  I like this crowd sourced  learning.  :)



I will make zero comparisons to last winter. A displaced polar vortex characterized winter 13-14' for me. Which meant persistent cold and a suppressed storm track.  All the moisture for my snowstorms had to come from the Atlantic ocean.  As I sit here, I'm looking at about 15" of fresh snow whose moisture had origins in the tropical Pacific and tropical Atlantic, I don't think I had a single storm last winter with moisture from the subtropical jet steam.  Oh the funniest part of my snowfall, we had record warm temperatures for the 2 days prior to the snow, one set just 18 hours before the first flake flew, didn't see a single rain drop.  8)   

I expect my Winter to be a mix of extremes do to a persistent -AO, huge warm ups, huge cool downs, powerful storms.  Sorry to go on a tangent, but I watch lots of storms head up towards Greenland and beyond, and they tend to drag warmth with them.  Seems like there is always a sub 960 low near the southern tip of Greenland. So it's kinda relevant.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on November 30, 2014, 12:42:04 PM
4th lowest November extent gain since 2002 (IJIS).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 02, 2014, 06:42:28 PM
Sea ice north of Svalbard melts more during winter than summer:

Reduced sea ice area also in winter (http://www.unis.no/60_NEWS/6090_Archive_2014/14_06_12_reduced_seaice/reduced_seaice_news_12062014.htm)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Michael Hauber on December 02, 2014, 09:52:11 PM
The ice in that area does funny things.  It was very low in January, and increased somewhat to be higher from April to June, with only a very slight decrease from July to September.  There was slightly more ice in this area in September than their was in March.  Since September it has pretty much held the same position.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on December 03, 2014, 10:52:18 AM
The ice in that area does funny things.  It was very low in January, and increased somewhat to be higher from April to June, with only a very slight decrease from July to September.  There was slightly more ice in this area in September than their was in March.  Since September it has pretty much held the same position.
Just SW of the islands seems to be a persistent upwelling that keeps SST's about 3-5C.  The Fram flow will occasionally over run it, but is a persistent regional feature.

It may be a driver behind the other behavior.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: crandles on December 03, 2014, 11:31:33 AM
It may be a driver behind the other behavior.

I think that is exactly what the above link is saying with

Quote
Warm and saline water from the Atlantic dominates the area west of Svalbard. Parts of the warm water continue northwards, transporting heat towards the Arctic Ocean. In the opposite direction, winds drive sea ice from the Arctic Ocean into the area. As the warm water from the south encounters the sea ice from the north, the oceanic heat both melts the ice from below and inhibits ice growth during winter.

The study shows that the sea ice has retreated above the pathway of the Atlantic water north of Svalbard. This indicates a direct influence from the Atlantic water on the sea ice conditions.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 03, 2014, 12:12:10 PM
December 2014 starts out with a little drop in Sea Ice Gain Anomalies, but nothing much to write about, yet.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 03, 2014, 05:32:21 PM
Nothing much to say at this early stage, apart from the fact that December 2014 starts out the opposite of last year, with extent anomalies being up and volume anomalies down this year, instead of the opposite throughout the month of December last year.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on December 03, 2014, 09:28:50 PM
It may be a driver behind the other behavior.

I think that is exactly what the above link is saying with

Quote
Warm and saline water from the Atlantic dominates the area west of Svalbard. Parts of the warm water continue northwards, transporting heat towards the Arctic Ocean. In the opposite direction, winds drive sea ice from the Arctic Ocean into the area. As the warm water from the south encounters the sea ice from the north, the oceanic heat both melts the ice from below and inhibits ice growth during winter.

The study shows that the sea ice has retreated above the pathway of the Atlantic water north of Svalbard. This indicates a direct influence from the Atlantic water on the sea ice conditions.

Indeed it does.  I was referencing not that Atlantic flow was the cause; rather, what is bringing the heat to the surface. Mostly that heat stays below a couple hundred meters of depth because of differences in salinity. The hot spot is unusual, at least in my estimation.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: OSweetMrMath on December 06, 2014, 10:20:05 PM
With the updates to the monthly PIOMAS volume and NSIDC extent numbers, I can update my predictions for the winter maxima.

My predicted value for the November average PIOMAS volume was 11.2 thousand cubic km. The actual reported value was 11.481 thousand cubic km, so my prediction was low, but within my confidence interval. This updates my prediction for April from 23.8 thousand cubic km to 24.1 thousand cubic km, with 95% confidence interval of 22.5 - 25.8.

My predicted value for the November average NSIDC extent was 10.3 million sq km. The actual reported value was 10.36 million sq km, nearly identical to my prediction. My prediction for March is unchanged at 14.8 million sq km, with 95% CI of 14.1-15.5.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on December 07, 2014, 09:27:26 AM
With the updates to the monthly PIOMAS volume and NSIDC extent numbers, I can update my predictions for the winter maxima.

My predicted value for the November average PIOMAS volume was 11.2 thousand cubic km. The actual reported value was 11.481 thousand cubic km, so my prediction was low, but within my confidence interval. This updates my prediction for April from 23.8 thousand cubic km to 24.1 thousand cubic km, with 95% confidence interval of 22.5 - 25.8.

My predicted value for the November average NSIDC extent was 10.3 million sq km. The actual reported value was 10.36 million sq km, nearly identical to my prediction. My prediction for March is unchanged at 14.8 million sq km, with 95% CI of 14.1-15.5.
I will be very keen to see how close you are. I must confess to slacking the last few weeks. That said, the heat in the arctic right now is impressive. It will need to persist to have a real effect. It will be interseting to see if it throws predictions off.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 07, 2014, 02:50:35 PM
Speaking of predictions, my new roadmap for the Arctic predicts annual extent will first move from 4th to 5th lowest on about January 18th. Then annual volume will take us from 5th to 6th lowest on about April 24th (though more likely somewhere in May). Theoretically, at least, that takes us to a somewhat safer place.

From 4th/5th lowest to 5th/6th lowest in just half a year. Before this, 2014 has taken us from 6th/3rd lowest to 4th/5th, so there has been a leveling where extent has caught up with volume, or the other way around  ;D

Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: OSweetMrMath on December 07, 2014, 09:15:22 PM
jdallen,

I started doing these predictions in April. My plan is to run the predictions for a full year and then post some analysis on the quality of my predictions. So far, my predictions seem to be reasonably accurate on a month-to-month basis. However, the model assumptions that go into the predictions assume that each month my predictions are equally likely to be too high or too low. So far, every single prediction for PIOMAS has been too low, which suggests a problem with my prediction scheme. If we have a couple of hot months in the Arctic and corresponding low ice growth, that could be interpreted as improving the overall quality of my predictions.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on December 08, 2014, 12:52:07 AM
jdallen,

I started doing these predictions in April. My plan is to run the predictions for a full year and then post some analysis on the quality of my predictions. So far, my predictions seem to be reasonably accurate on a month-to-month basis. However, the model assumptions that go into the predictions assume that each month my predictions are equally likely to be too high or too low. So far, every single prediction for PIOMAS has been too low, which suggests a problem with my prediction scheme. If we have a couple of hot months in the Arctic and corresponding low ice growth, that could be interpreted as improving the overall quality of my predictions.

Again, will be interested to see.

One of the implications of a lack of effect on the refreeze would be that the heat loss at the top of the atmosphere is still sufficient to permit ice formation.  My question then is, will the increased temperatures translate into heat retained in the ocean proper, which will express itself later in the refreeze, or next spring when the melt starts back up again.

I'm particularly interested in what happens in the Chukchi, ESS and Beaufort.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on December 09, 2014, 09:45:50 PM
jdallen,

I started doing these predictions in April. My plan is to run the predictions for a full year and then post some analysis on the quality of my predictions. So far, my predictions seem to be reasonably accurate on a month-to-month basis. However, the model assumptions that go into the predictions assume that each month my predictions are equally likely to be too high or too low. So far, every single prediction for PIOMAS has been too low, which suggests a problem with my prediction scheme. If we have a couple of hot months in the Arctic and corresponding low ice growth, that could be interpreted as improving the overall quality of my predictions.

I don't think so, the scheme is probably fine, conditions are abnormal. It seems to me you're using past behaviour (in a period of rapid loss) when we're in a period of very unusual gain, so you'll get low every time. I got hit by this badly in my April SIPN prediction network this year.*

I need to seriously ponder what I'm going to do next year.

*just say if I've totally forgotten what your method is, but this is the impression I have while not recalling the details.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: OSweetMrMath on December 10, 2014, 11:20:26 PM
In theory, my time series model should correct for the ice being much higher or lower than predicted. That is, if the actual value for November is higher than the predicted value, the predicted value for December (and all future months) is adjusted upward, so the new prediction should be too high 50% of the time.

In practice, this year the adjustments haven't been big enough, so my predictions are always too low even after adjusting for the fact that my predictions are too low.

My model assumptions are being violated, and whether you want to blame that on the model or on the ice, it's still a problem for my model.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 11, 2014, 12:18:48 AM
A third option is — at least theoretically — possible: Geo data engineering.

Just as there's much talk about 'geo engineering' — physical attempts to compensate for the regular geo engineering carried out by the 'wise ape' since the 18th century — the cheaper version of this concept is simply to hack the data so they look better.

Whether or not someone is doing that per now is not known, of course. But will it be done somewhere down the line by future governments? No doubt!
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 14, 2014, 04:30:12 AM
2014 has finally started competing for the biggest abrupt December drop in refreeze anomalies, and is currently second, since 2007, after 2010.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on December 15, 2014, 09:31:15 PM
In theory, my time series model should correct for the ice being much higher or lower than predicted. That is, if the actual value for November is higher than the predicted value, the predicted value for December (and all future months) is adjusted upward, so the new prediction should be too high 50% of the time.

In practice, this year the adjustments haven't been big enough, so my predictions are always too low even after adjusting for the fact that my predictions are too low.

My model assumptions are being violated, and whether you want to blame that on the model or on the ice, it's still a problem for my model.

I still think any model not incorporating (and able to predict?) the role of the atmosphere would have failed this year.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 16, 2014, 12:05:28 AM
An increase to 212 km³ — from 166 the day before — and for the first time this month we are below zero, meaning the December 2014 refreeze is smaller than the late 20th century average.

It will be interesting to see how much lower we'll go before the drop is broken, and whether 2014 can beat 2010!
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 16, 2014, 03:47:27 AM
In theory, my time series model should correct for the ice being much higher or lower than predicted. That is, if the actual value for November is higher than the predicted value, the predicted value for December (and all future months) is adjusted upward, so the new prediction should be too high 50% of the time.

In practice, this year the adjustments haven't been big enough, so my predictions are always too low even after adjusting for the fact that my predictions are too low.

My model assumptions are being violated, and whether you want to blame that on the model or on the ice, it's still a problem for my model.

Maybe your model isn't so wrong after all?

Quote from: BBC
The spacecraft observed 7,500 cu km of ice cover in October [2014] when the Arctic traditionally starts its post-summer freeze-up.

This was only slightly down on 2013 when 8,800 cu km were recorded.

Quote from: ESA link=http://earth.esa.int/web/guest/missions/esa-operational-eo-missions/cryosat/news/-/article/cryosat-extends-its-reach-on-the-arctic
Measurements made during October and November [2014] show that the volume of Arctic sea ice now [15 December 2014] stands at about 10,200 cubic km - a small drop compared to [2013]'s 10,900 cubic km
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 17, 2014, 12:32:20 AM
The average for the past 7 days is now 2374 ppm. Has this ever happened before during the Arctic refreeze season?

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D1059.0%3Battach%3D12415%3Bimage&hash=7c4a22152bbf0c86b2bb4acd0c4bdb15)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 17, 2014, 10:33:54 PM
With no objections in almost 24 hours, I think we can safely use 2374 ppm as the 21st century weekly record, for comparisons during 2015 and the following years.

I would however wish for Christmas that Santa (or rather the US Govt) would 'declassify' the methane archives for current date minus 3 days and backwards, or perhaps a similar partial release of MetOp2 data from the now closed down MethaneTracker project.

MethaneTracker wrote OCR code that would automatically read CH4 data off of the daily MetOp2 plots, because the data was never released in readable text format. The site was shut down because of server and bandwidth costs, which reveals this to be a popular service that IMO, as a former student of Library & Information Science, should be publicly funded. Deleting all data older than 3 days is quite unheard of, and I would very much like to see a rationale for this practice.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on December 17, 2014, 10:40:57 PM
I keep watching HYCOM.
http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictn_nowcast_anim30d.gif (http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictn_nowcast_anim30d.gif)

Strong Fram export, also continuing dispersal of thicker ice into Chukchi and the ESS. Zooming in there's a ribbon throughout Nares into Baffin. But the mass movement from Kara polewards suggests the Atlantic sector may enter the 2015 summer season fairly thin.

I keep wondering if the current volume pulse will be wiped out in just a few years, would one year be too much to hope for?  :)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 17, 2014, 10:50:04 PM
I keep wondering if the current volume pulse will be wiped out in just a few years, would one year be too much to hope for?  :)

Interpreting this as a 'what I want for Christmas' thing, I also take it that by the 'current volume pulse' you mean the steadily gaining sea ice volume compared to last year? In that case, your wish is for volume to drop, which makes me doubt my interpretation.

Following the chaotic release of 2014 data from the Cryosat project, I understand that the 'current volume pulse' is a downward movement (not upward as per PIOMAS modeling) compared to last year. But as I've stated elsewhere, I fear we'll never get an adequate explanation for this rather extraordinary discrepancy.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on December 18, 2014, 07:38:36 PM
Viddaloo,

Of course I want the volume to drop.  ;D

The drop of volume is driven by the ice/ocean albedo effect, however, ultimately the cause of sea ice loss is increasing CO2 and anthropogenic global warming. There is no prospect of a massive reduction in human CO2 emissions, therefore there is no prospect of the sea ice climbing back out of the death spiral it is in. If it is going to transition to a seasonally sea ice free state then my preference is for a fast transition, this is my hobby and I want my hobby to be exciting!

As I've stated often, I don't expect a fast transition, as much as I would prefer one. However thinner ice increases the likelihood of large loss years like 2007 and 2012. As I have shown, the volume increase of last year was restricted to the Central Arctic, for as long as it tends to move out into the Pacific sector of the Arctic Ocean it tends to reduce the possibility of massive summer melt out in that region (note 'tends to reduce the possibility' not 'rules out'). In short the faster that volume dies the more anticipation I will have as each season starts. I don't want another boring year like 2013 or 2014, blogging on them has its own challenge, but I don't rush home every evening eager to see what that day has brought.


After you posted Crandles posted on another thread a reply citing a key reason Cryosat may be wrong. My problem with the alternative (that PIOMAS is wrong) is simply one of precedence, PIOMAS has a longer history of getting things right. I can't recall where it was on this board, but recently I posted a graph/numbers (can't remember which) and I think it was Crandles who pointed out that the PIOMAS data seemed to be in error in a past year. When I checked the regional numbers and map-plots it became clear that PIOMAS was not wrong, the apparently wrong feature was caused by a large wind driven export.

I have lost track and (as my vagueness above indicates) probably can't remember the details of numerous occasions I've found an interesting anomaly and have found that it has a reasonable explanation. That is the sort of 'behaviour' one sees in a robust data set, and while I cannot recall all details, I have a 'gist' formed from experience, the gist being 'PIOMAS works'. The one occasion I've been bugged by an anomaly that didn't go away, and defied explanation turned out to be the reason Dr Zhang released version 2.1 from the original version 2. Upon processing the version 2.1 gridded data the anomaly that had been bugging me had gone away.

As of the current moment I have no listed issues with PIOMAS data in the file where I keep such notes. It is feasible some factor is making PIOMAS report high, but the conservative position for me has to be that PIOMAS is probably right, Cryosat is probably wrong. But I'm not asserting this strongly because the difference between 2013 and 2014 for October is within one side of the uncertainty distribution, so technically even using PIOMAS October data alone one cannot claim a volume increase.

PS 'gist' = "the substance or general meaning of a speech or text.", pronounced 'jist'.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 19, 2014, 04:13:35 AM
I don't want another boring year like 2013 or 2014, blogging on them has its own challenge, but I don't rush home every evening eager to see what that day has brought.

Well, just as in white–water rafting, learning the basic skills in relatively quiet waters is advised, before the more hardcore action. I find the autumn of 2014 has been a good time for learning in that sense. I guess I just expect a major decline like 1300 cubic km less than 2013 would be contextualized vis-a-vis the only other ice volume dataset in the world, say, within the first week of BBC publishing said decline. But then again, I find that time and time again the world that I expect is not the world we live in.

Seems PIOMAS would be sad if proven wrong, or Cryosat wold be sad if proven wrong, so therefore everyone is just keeping their voice down. It's a sad state for scientific rigor.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on December 19, 2014, 05:24:12 AM
I think we need to keep in mind... independent of everything else... PIOMAS uncertainty is +/- 750KM3.  I haven't been able to chase down the same for Cryosat, but it is likely similar.

That means a 20% range of volume, relative to the stated totals (8-9000KM3).  It means that despite the stated figures, the actual volume could be virtually identical.  It also could be there was a significant drop from 2013 to 2014.

It highlights, looking at these numbers in timeframes shorter than decades is fraught with uncertainty.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 19, 2014, 05:53:25 AM
Guess 'Adam Ash' does have a point (http://neven1.typepad.com/blog/2014/12/in-the-meantime-cryosat.html?cid=6a0133f03a1e37970b01bb07c7cd76970d#comment-6a0133f03a1e37970b01bb07c7cd76970d):

Quote
'Arctic sea ice may be more resilient than many observers recognise.'

Yeah, rite...
From those two data points a straight line gives:
Year   October Vol
2013   8800
2014   7500
2015   6200
2016   4900
2017   3600
2018   2300
2019   1000
2020   -300

2020 she's all over rover!
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 19, 2014, 12:41:43 PM
I notice the US Department of Commerce only wants to talk about March in their December 2014 'Arctic Report Card (http://www.arctic.noaa.gov/reportcard/sea_ice.html)'. I wonder why.

Could it be because their cited source, Cryosat, that shows a decrease in sea ice volume for autumn, reveals a fact which doesn't jive with their 'rebound' and 'resilience' overall narrative?

The BBC tried hard to frame the sea ice volume decrease as sort of a setback for the general sea ice collapse, using sentences that obviously did not compute:

Quote from: bbc
While global warming seems to have set the polar north on a path to floe-free summers, the latest data from Europe's Cryosat mission suggests it may take a while yet to reach those conditions.

The spacecraft observed 7,500 cu km of ice cover in October when the Arctic traditionally starts its post-summer freeze-up.

This was only slightly down on 2013 when 8,800 cu km were recorded.

And from ESA itself:

Quote from: esa
Measurements made during October and November show that the volume of Arctic sea ice now stands at about 10 200 cubic km – a small drop compared to last year’s 10 900 cubic km.

The volume is the second-highest since measurements began in 2010, and the five-year average is relatively stable. This, however, does not necessarily indicate a turn in the long-term downward trend.

The autumn 2014 downward trend is not a turn in the long-term downward trend. OK, computer.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on December 19, 2014, 01:38:15 PM
Strong Fram export.

For any other buoy watchers out there, the raw ice mass balance buoy data has moved to a new location at: http://imb.erdc.dren.mil/newdata.htm (http://imb.erdc.dren.mil/newdata.htm)

Buoy 2014E, which started out in April near the North Pole, recently put in its greatest ever daily distance and is now well south of Svalbard: http://batchgeo.com/map/imb-2014e (http://batchgeo.com/map/imb-2014e) 
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: ChrisReynolds on December 19, 2014, 05:52:21 PM
Jim,

I must admit I rarely find the time to follow the buoys, but that is what I was expecting from following HYCOM.

Long may it continue.  :)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 19, 2014, 10:17:24 PM
I notice the US Department of Commerce only wants to talk about March in their December 2014 'Arctic Report Card (http://www.arctic.noaa.gov/reportcard/sea_ice.html)'. I wonder why.

Could it be because their cited source, Cryosat, that shows a decrease in sea ice volume for autumn, reveals a fact which doesn't jive with their 'rebound' and 'resilience' overall narrative?

FM14 Arctic Report Card 2014 PressConference (http://www.youtube.com/watch?v=jgT7ULr47C8#ws)

Amazingly, a full 47 minutes long AGU press conference on the Commerce Deparment's so–called 'Arctic Report Card', and yet no time to report on October and November sea ice losses, only March increases? Not a single word on the autumn? I think here we have to look at the Wikipedia detail on the US Department of Commerce, that says:

Quote from: Wikipedia
The United States Department of Commerce (DOC) is the Cabinet department of the United States government concerned with promoting economic growth.

So the reason may be as simple as applying a lucrative political 'spin' (known in Scandinavia and Europe especially from Tony Blair's first cabinet period in England). After all the main goal of the DOC is to promote economic growth. Follow the money.

Special ludicrous bonus climate denial quote from the Deparment of Commerce press conference:

Quote from: Department of Commerce
If not a *totally* ice–free summer/end of summer [by the end of the 21st century]
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 21, 2014, 12:38:50 AM
Bremen: An ice concentration of about 90% implies we now probably have some open water at the North Pole, 2 days from winter solstice.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Peter Ellis on December 21, 2014, 01:21:00 AM
No, it implies that passive microwave measurement has an error of about 10%. You can't overrule physics by fiat.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on December 21, 2014, 09:23:41 AM
Quote
Strong Fram export.

Race to the Fram North of Greenland (thanks to ESA and DMI for the daily Sentinel-1 images):

(click to start animation)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on December 21, 2014, 09:30:14 AM
Has everything to do with winds that for some time persist in the following pattern.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fpolarportal.dk%2Ffileadmin%2Fpolarportal%2Fweather%2FWthr_Raw_SM_EN_20141220.png&hash=46d21aea4aaceb60de813d495aacf9b3)

Fram export, Beaufort to Chukchi transport and the Laptev region the ice factory is operating hard (helped by the low Siberian temperature of the winds):
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on December 21, 2014, 12:13:41 PM
Quote
Strong Fram export.

Race to the Fram North of Greenland (thanks to ESA and DMI for the daily Sentinel-1 images):

(click to start animation)

Aside from the speed, I'm struck by how torn up the ice is.  Past years watching the same movement, I recall seeing far smoother, consistently similar surfaces.  This looks like gravel pouring down a sluice.

Regardless, lots of 2+ meter ice being replaced (elsewhere) by < 1 meter ice (initially).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 30, 2014, 04:31:40 AM
Interesting abrupt drop of 235 km³ at the end of the month/year.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Bryantfinlay on December 30, 2014, 05:57:15 AM
That is weird. Temporary or long-lasting?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on December 30, 2014, 08:44:47 AM
That is weird.

Not weird, totally incredible. Temperature over the Arctic Ocean is below -20 oC, most below -25  oC. No matter what happens at the fringes (look at Bering and Baffin), the freezing at the core will overwhelm that for some months to come.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 30, 2014, 08:52:05 AM
That is weird.

Not weird, totally incredible.

Nah. Sudden drops in gain anomalies happen almost every December.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on December 30, 2014, 05:37:37 PM
That is weird.

Not weird, totally incredible.

Nah. Sudden drops in gain anomalies happen almost every December.
Wipneus may have suffered an attack by autocorrect.  That said, yes, I see your point, Vid - by your numbers the rate of increase year over year dropped off. If consistent, that may have implications for April.

If I may offer a friendly suggestion - I find it a challenge to sort through the discontinuous values on your graph. I'm not sure what to suggest by way of changing it, but you might consider a different way of framing your numbers.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 30, 2014, 10:01:14 PM
Thanks, JD. I'm always open for constructive suggestions, though in this case the reason there are discontinuous values on my graph is that it is only supposed to show abrupt drops in gain anomalies. The graph is made to emphasize particularly astonishing exceptions to the rule of steady ice growth in winter.

The numbers — annotations — themselves I have explained earlier in this thread, show how much ice volume was caused by the abrupt drop to not be added to the total value, compared to a no–drop situation.

I could choose the easy way and just show a wave–shaped graph for December volume through the years, but then I wouldn't add anything that hasn't already been shown and presented adequately by others. I don't feel like being a copycat here :)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Unmex Chingon on December 31, 2014, 04:02:38 AM
Thanks, JD. I'm always open for constructive suggestions, though in this case the reason there are discontinuous values on my graph is that it is only supposed to show abrupt drops in gain anomalies. The graph is made to emphasize particularly astonishing exceptions to the rule of steady ice growth in winter.

The numbers — annotations — themselves I have explained earlier in this thread, show how much ice volume was caused by the abrupt drop to not be added to the total value, compared to a no–drop situation.

I could choose the easy way and just show a wave–shaped graph for December volume through the years, but then I wouldn't add anything that hasn't already been shown and presented adequately by others. I don't feel like being a copycat here :)
  What would these abrupt drop get us for average daily volume in 2030 and 2031?  Do you have a trendline for that?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on December 31, 2014, 07:43:50 AM
Wipneus may have suffered an attack by autocorrect.

No, I did not know that "a drop of 235 km³" was actually a drop in anomaly of something.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on December 31, 2014, 09:15:19 AM
<snip>

Neven: no more snark and childish word games in 2015, please.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 01, 2015, 07:45:08 AM
4th lowest November extent gain since 2002 (IJIS).

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D997.0%3Battach%3D12138%3Bimage&hash=bfa10a938776cbd9c63a40e5b5f058d2)

4th lowest December extent gain since 2002 (IJIS).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on January 01, 2015, 11:45:31 AM
Although in the Fram Strait ice keeps moving south,  the North Greenland source has stopped in the last few days.

(click for the animation of S1 images from DMI to start)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 01, 2015, 02:27:53 PM
The year ended with 238055 km² of lost extent refreeze during the last two CH₄ peaks.

Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Bryantfinlay on January 01, 2015, 04:26:23 PM
So what does that mean?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Gray-Wolf on January 04, 2015, 12:35:33 PM
Interesting post over on Neven's Arctic Sea ice site from Velo Kallio of the Sea research Society who notes;

"In addition, the continuing crushing and tumbling of large amounts of recently formed ice into pack ice (behind the North Pole) does not allow the saline brine within sea ice to drain out easily. This is because the brine is drained by gravity; if the block of ice turns upsided down the draining brine reverses to the opposite direction. As the ice is as restless as it is now, the direction of gravity field within ice blocks keeps changing. Thus ice remains more saline. This winters' "thick" pack ice behind North Pole will, therefore, melt very easily. (Ice rejects salt if it stays upright long enough, but this threshold has seen its own tipping point this winter.)"

I had noted overwash taking snow in early refreeze season but never considered the impact of rolling/tumbling on ice salinity levels but it does make perfect sense ( to me),

With ongoing export costing us our 2.5m+ ice from the Atlantic side ( replaced by late formed FT ice) any input from extra salty FY ice will not be a welcome addition to the mix of the pack?

We'd better be praying real hard for a 3rd year , back to back, of low export/low melt synoptics to dominate this coming melt season as any return to moderate export/moderate melt could wipe out any signs of rebound in one fell swoop.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on January 05, 2015, 05:51:33 PM
The refreeze has come to a near standstill. Even using the trailing 5 day mean since Dec 28th, the increase has been the lowest on record at just a 78.4k, well below the next lowest of 139.2.k in 1983. Even the increase from the 27th to now is lowest on record, albeit by a smaller margin. The pause with the 1 day extent is even more impressive, with no increase in extent since December 25th.


(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FsxZT6X5.jpg&hash=758e3da39542d1d6944b8fef718bad1e)


If we continue with this rate of increase, we'll be ranked as lowest on record on record in 5 days.


At this time of year, the central Arctic regions are mostly frozen over and the majority of coverage increases (both extent and area) come from the peripheral Arctic regions mainly the Bering Sea and Sea of Okhotsk, but also to a lesser extent the Baffin Sea.

Unfortunately, looking at the 850hPa temperature anomalies, there appears to persistently strong positive temperatures anomalies right across the Pacific sector regions (Okhotsk and Bering) for the foreseeable future, with some -ve anomalies over the Baffin Sea. This should keep extent and area growth well below average.


Below is the 850hPa temp anomalies across the northern hemisphere for the next 5 days, note the positive anomalies across the Pacific side.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FKEU4vwT.gif&hash=0eefa42c5ee2b422e52b703694cca323)

We'll most likely be 3rd lowest on tomorrows update, but where will we be by next weekend?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Hubert on January 05, 2015, 06:02:38 PM
No data Arctische Pinguin Wipneus

Bering Sea ice - catastrophe
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F2.bp.blogspot.com%2F-uR1Ol0ZbB9A%2FVKkfna59mCI%2FAAAAAAAAF8A%2Fnn0fiZSbvO8%2Fs1600%2Fanigif-berignarctic2015.gif&hash=3cd244ed4886e6dda9f46611b8f171fa)
What next??? 2015 or 2016 ice free Arctic Ocean?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on January 05, 2015, 06:30:42 PM
No data Arctische Pinguin Wipneus


Same thing happened previous new year: no data. BUT 20150101 just came in, I trust we will be back in business soon.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Gray-Wolf on January 05, 2015, 11:05:19 PM
We normally see some kind of balance with Fram losses being balanced out by ice factory synoptics over Bering but this period appears to differ with both losses from Fram an poor development over on the Pacific side?

The big lows over our side of the pond look to keep positioning the last of the 'retained ice' from the past two years over Fram awaiting the next northerly plunge to take it out of the basin?

I wonder how Piomas will reflect this in Dec/Jan figures? I think we may be rejoining the bottom set some time soon?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 06, 2015, 07:18:54 PM
New CH₄ peak: 2402 ppb.

Note the big drops in extent and volume anomalies, with already 98705 km² of lost extent refreeze and 157 km³ of lost volume refreeze by January 4th and 5th. Please also note that yesterday's peak of 2402 ppb is lower than all of the three peaks from last month. (chart faq (http://www.pheed.com/IceGraph/57428139/2500))

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13450028_ZoRwloB1robd.png&hash=2bc82d8c0d74c30558c4e566f51ab5db)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 06, 2015, 08:17:45 PM
That's actually 130,993 km² of lost sea ice extent refreeze by the 4th, corrected now in the script.

98705 km² is the total loss by January 5th.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on January 06, 2015, 08:44:45 PM
New CH₄ peak: 2402 ppb.

Note the big drops in extent and volume anomalies, with already 98705 km² of lost extent refreeze and 157 km³ of lost volume refreeze by January 4th and 5th. Please also note that yesterday's peak of 2402 ppb is lower than all of the three peaks from last month.
Questions suggested: is the CH4 driving the extent change, are both driven by another common cause, or are they independent and just synchronistic?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Gray-Wolf on January 06, 2015, 11:59:41 PM
 I'd imagine one's the dog and ones the tail JD?

The 'losses' appear to be low gains in the sea areas outside the basin ( Bering /Baffin/Okhotsk) and these appear due to synoptics? Out-gassing will occur if there is not 'cap' on the gasses? poor ice cover/ warm land surfaces ( relatively) must impact this?

JMA post 2014 as a record warm year. The current temp anoms across the basin must be a part of this ( and the constant influx of TM air into the Bering sea/Sea of Okhotsk ?)

Piomas will give us a better picture of what is occurring but I'd suggest we should expect a drop down into the other poor volume year is now likely?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on January 07, 2015, 03:20:44 AM
I'd imagine one's the dog and ones the tail JD?

The 'losses' appear to be low gains in the sea areas outside the basin ( Bering /Baffin/Okhotsk) and these appear due to synoptics? Out-gassing will occur if there is not 'cap' on the gasses? poor ice cover/ warm land surfaces ( relatively) must impact this?

JMA post 20124 as a record warm year. The current temp anoms across the basin must be a part of this ( and the constant influx of TM air into the Bering sea/Sea of Okhotsk ?)

Piomas will give us a better picture of what is occurring but I'd suggest we should expect a drop down into the other poor volume year is now likely?

All sounds reasonable.  I did a quick flyby of the Greenland nares strait threads... It showing no sign of slowing down export to Baffin (which is warmer than normal).  Previous recent winters with this were followed by significant retreats. We may have an interesting spring.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on January 07, 2015, 08:22:16 AM
No data Arctische Pinguin Wipneus


Same thing happened previous new year: no data. BUT 20150101 just came in, I trust we will be back in business soon.

All missing new year's data did come in (and has been processed). Jaxa/IJIS is back as well.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: tombond on January 08, 2015, 01:01:43 AM
The measurements made by NASA’s Clouds and the Earth’s Radiant Energy System (CERES) instruments show a 5 percent increase in  solar radiation absorbed in the Arctic since the year 2000.

http://climate.nasa.gov/news/2208/ (http://climate.nasa.gov/news/2208/)

When averaged over the entire Arctic Ocean, the increase in the rate of absorbed solar radiation is about 10 Watts per square meter.

Regional areas such as the Beaufort Sea have experienced the highest absorption with an incredible 50 watts per square meter increase.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 08, 2015, 05:48:44 AM
Yesterday's IJIS extent was 2nd lowest, and only 2014 remains to be beaten. 2015 was lower than 2014 on January 2nd, 3rd and 4th, but then 2011 and 2013 were lower than 2015, so therefore we weren't lowest ever.

The autozoom for Jan7 shows this downward turn in annual average extent on Jan 2–4:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13460236_dg7yfbGvFzl3.png&hash=a0d4c5520754e1aa53a2dbc90f8e1b6d)

If January 8th goes lower than 2014 again, we will see the graph turning down again, and the gap to 2011 narrowing. It's an exciting start of the year, but as we saw last year, 2014 was also lowest in January without going particularly low later in the year.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Gray-Wolf on January 08, 2015, 09:55:15 AM
And spring 2012 saw the highest extent for many a year? The good retention we saw in both 13 and 14 was all down to variability in weather over the melt season and had nothing to do with the extent/area/volume at the start of melt season?

I would not like to see us apeing the Deniers and trying to make press over positioning of extent ( in the series) as it would appear that everything depends on how the 'weather' over summer behaves and is not so dependent on the now familiar start of melt season extent/area/Volume?

I'd say again that another repeat of the ice friendly conditions of 2013/14 would have me wondering about a 'pattern shift' in summer conditions across the basin? The odds have to be even more stacked against another return of retention synoptics and must favour either an average summer ( like 2012) and a warm summer over a cool, cloudy low export summer???
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: OSweetMrMath on January 09, 2015, 07:14:36 PM
Here is my update on my predictions for the NSIDC extent and PIOMAS volume maxima.

My predicted value for the December monthly average volume from PIOMAS was 15.1 thousand cubic km. The actual value was 15.074 thousand cubic km, making this one of the best predictions I've had this year. My prediction for April is unchanged at 24.1 thousand cubic km. As we get closer, the confidence interval gets smaller, so my 95% CI is 22.7 - 25.6 thousand cubic km.

My predicted value for the December monthly average extent from NSIDC was 12.4 million sq km. The actual value was 12.52 million sq km. My prediction for March is unchanged at 14.8 million sq km, with 95% CI now 14.2 - 15.5 million sq km. Note that my prediction method does not take into account the fact that extent growth has been slow so far this month. It's reasonable to guess that my current predictions for both January's extent and March's extent are likely to be high.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 10, 2015, 02:27:16 PM
2015 already has the lowest January refreeze by Jan9 in IJIS history, and daily extent is also lowest ever for this date.

The previous record holder in this game was 2007, pretty much a gamechanger in the Arctic, so 2015 may be an interesting one.

(https://d22d7v2y1t140g.cloudfront.net/m_13473584_VSea4EMNkHFN.png)

(chart faq (http://www.pheed.com/IceGraph/57428139/2500))
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on January 11, 2015, 10:23:49 AM
Sequence of DMI's Sentinel 1A composites of Greenland Station Nord. The ice has stopped moving to the Fram, lots of compaction to be seen.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Gray-Wolf on January 11, 2015, 12:50:24 PM
If the current forecast pans out I'd expect this 'stop' to be a very temporary affair with the big low planning to swipe the UK introducing strong easterly then northerly flows to the ice behind Svalbard
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Apocalypse4Real on January 13, 2015, 04:49:50 AM
The METOP-1 AVHRR shows major collapse north of the Nares Strait, I do not recall seeing this previously in mid-January.

A4R
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Sonia on January 13, 2015, 07:04:29 AM
The METOP-1 AVHRR shows major collapse north of the Nares Strait, I do not recall seeing this previously in mid-January.

It's striking, hm?  Some of us have been following this eagerly on the Nares Strait thread.  The discussion there has been great.  I understand that in 2007 there was no arch so would expect it looked similar then.  I also understand that February isn't too late for an arch to form, but arch formation sure doesn't seem imminent.  Meanwhile, as you point out, the ice pack in the Lincoln Sea is going to be pretty loose.  I'm interested to see what effects this might cause if it persists.  Would it affect ice movement in the greater CAB?  Would ice be more mobile or would these conditions perhaps buffer ice pressure that normally drives the Beaufort Gyre, resulting in less movement?  The ice export through the Nares seems startling, but maybe the trans-polar drift exports the same amount of ice whether it can use both the Nares and the Fram or just the Fram.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on January 13, 2015, 08:32:25 AM
The METOP-1 AVHRR shows major collapse north of the Nares Strait, I do not recall seeing this previously in mid-January.

It's striking, hm?  Some of us have been following this eagerly on the Nares Strait thread.  The discussion there has been great.  I understand that in 2007 there was no arch so would expect it looked similar then.  I also understand that February isn't too late for an arch to form, but arch formation sure doesn't seem imminent.  Meanwhile, as you point out, the ice pack in the Lincoln Sea is going to be pretty loose.  I'm interested to see what effects this might cause if it persists.  Would it affect ice movement in the greater CAB?  Would ice be more mobile or would these conditions perhaps buffer ice pressure that normally drives the Beaufort Gyre, resulting in less movement?  The ice export through the Nares seems startling, but maybe the trans-polar drift exports the same amount of ice whether it can use both the Nares and the Fram or just the Fram.

I'm much less concerned about the export through Nares, which is nominal, and far more worried about the effect the erosion of ice in the Lincoln Sea will have on the rest of the pack.  It is already far too vulnerable to forces which would push ice through the Fram.  Even less coherence could mean one good solid "whack" could leave the ice exquisitely vulnerable to early melt, exposing substantial amounts of open ocean to sunlight at high latitude.

I'm hoping fervently for lots of positive feedbacks.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on January 13, 2015, 11:46:36 AM
The METOP-1 AVHRR shows major collapse north of the Nares Strait

DMI's AVHRR (http://ocean.dmi.dk/arctic/lincoln.uk.php) closeup also shows a sizeable crack currently creeping around from Nord:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Focean.dmi.dk%2Farctic%2Fimages%2FMODIS%2FLincoln%2F201501130443.NOAA.jpg&hash=a59faf763658cb2c2f86756cbceed0c7)

As Sonia points out, see also the Sentinel animations (http://forum.arctic-sea-ice.net/index.php/topic,176.msg43253.html#msg43253) over on the Nares Strait thread.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Gray-Wolf on January 13, 2015, 01:33:58 PM
http://www.woksat.info/wos.html (http://www.woksat.info/wos.html)

I find the above site useful for daily 'snaps' of Nares/Lincoln and Beaufort? It appears the sudden halt in the Gyre has lead to a , now familiar, fragmentation across Beaufort? Any 'relaxation' in Lincoln provides 'space' for the Beaufort event to relax into?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Apocalypse4Real on January 13, 2015, 02:15:36 PM
The Beaufort has been fractured since 112714, and has continued to refracture since.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 25, 2015, 04:07:49 PM
Today was another setback for the refreeze, in terms of extent:

2015/2 (12504555/12469040) 2015/7 (12617633/12582720) 2015/8 (12582720/12572767) 2015/20 (13235356/13223023) 2015/24 (13387581/13385153)

This puts Jan 2015 ahead of 2014, on par with 2010, 2011 and 2013 but behind 2012:

2012/4 (12787376/12752679) 2012/13 (13316476/13278795) 2012/14 (13278795/13255298) 2012/15 (13255298/13208256) 2012/16 (13208256/13123560) 2012/17 (13123560/13087285) 2012/25 (13419798/13419569) 2012/28 (13455059/13451393) 2012/29 (13451393/13446359)

No Jan days had volume setbacks in the 2010s, as the latest was 2007/29 (19639/19497). I've got two days of the first week in my Jan 2015 PIOMAS estimate, but we'll have to wait to have those confirmed.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 27, 2015, 06:20:50 AM
Average extent now looks set to return to 4th lowest during February (after crossing into 5th on New Year's Eve), and average volume may follow suit as early as July 19th. Prospects are also good for record low sea ice levels in 2015, thanks to record high ocean temperatures and CO2 and CH4 levels in the atmosphere.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13552762_K9CNQXfTEwoL.png&hash=1136e8934fdfa068b741a46d96762e0a)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13552785_OdFTMrbyFZeQ.png&hash=2d9c39f03cf8795dadcd343fe9e77bb7)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Steven on January 27, 2015, 08:20:05 PM
Average extent now looks set to return to 4th lowest during February (after crossing into 5th on New Year's Eve)

Seems very unlikely to me.

You are using a quadratic extrapolation of Annual Average Extent.  The graph below shows what that implies for the usual daily sea ice extent.  The red solid line shows the extent from 1 to 26 January 2015, and the red dotted line corresponds to your projection from 27 January to 28 February 2015.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FnHewpMd.png&hash=5bdeb02ce05c44dd58c886b4a2c6bfc5)


Do you seriously think that this is a realistic expectation?

Your extrapolation of Annual Average Volume is also very unlikely, for similar reasons.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 27, 2015, 09:49:26 PM
Average extent now looks set to return to 4th lowest during February (after crossing into 5th on New Year's Eve)

Seems very unlikely to me.

You are using a quadratic extrapolation of Annual Average Extent.  The graph below shows what that implies for the usual daily sea ice extent.  The red solid line shows the extent from 1 to 26 January 2015, and the red dotted line corresponds to your projection from 27 January to 28 February 2015.

No, it doesn't. You were right the last time, so I thought I'd give you the benefit of the doubt this time, but now you are wrong. Not sure how you came up with your dotted graph, but those are not my values. Guess it's just guesswork?  ;D
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on January 27, 2015, 10:14:09 PM
I think projections may get scrambled by the weather.  A huge storm is currently giving the eastern seaboard a pasting with hurricane force winds and upwards of 80CM (!) of snow.

All that energy is barreling north into the Norwegian and Barents.

There will be another following it in about three days.

That's been happening all season, and I think is contributing to the extreme fracturing of the ice which has taken place.  I can only postulate but not show, I expect this pattern is limiting thickening of the pack and reducing extent gains.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Steven on January 27, 2015, 10:55:09 PM
No, it doesn't. You were right the last time, so I thought I'd give you the benefit of the doubt this time, but now you are wrong. Not sure how you came up with your dotted graph, but those are not my values. Guess it's just guesswork?  ;D

I just double-checked my calculation, and couldn't find any error.

Could you provide the equation of the (quadratic?) polynomial that you are using for Annual Average Extent, please?  (In the topmost graph in your Reply #246 (http://forum.arctic-sea-ice.net/index.php/topic,997.msg44180.html#msg44180) upthread).  I've been assuming that you are using a quadratic polynomial, but perhaps you were using some higher-degree polynomial (e.g. cubic)?

Note that the graph that I posted upthread is for the usual IJIS extent  (i.e., no annual averages or stuff like that).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 27, 2015, 11:11:21 PM
It would be much more fun if you submitted your own original work with estimates for every day till the end of February. Then I could scoff at that if you were proven wrong by the Arctic itself  ;D

BTW, and this is a version of the question above, what do you think are realistic extent values for every day in February 2015?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on January 28, 2015, 04:44:46 PM
Yesterday's Hamburg AMSR2 reveals an interesting feature north of Greenland:
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on January 28, 2015, 08:38:19 PM
Yesterday's Hamburg AMSR2 reveals an interesting feature north of Greenland:

Fascinating!  I'd read elsewhere on the forums (Nares thread maybe?)  that wind has been pushing the pack north, even while flow through the Nares straight has continued unabated.  The feature your image shows may be visible evidence of it.

It similarly is evidence of a rather obvious lack of "fast" ice across northern Greenland....
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 28, 2015, 11:48:49 PM
Add some heat to the equation, and we may even see the scenes of a massive km's wide river transporting giant flows of ice from the north of Greenland down to the Nares, that we saw through the sat images on Wednesday. Scientists overwhelmingly agree heat is not good for the ice.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 29, 2015, 06:45:08 AM
Today's outlook: Feb15 AAE will be 4th lowest, Feb20 AAV will peak, Apr25 p1k (Piomas minus 1000) will be 2nd lowest, and Jun30 AAV will be 4th lowest.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13561471_9gZObhHYxGb7.png&hash=e1f493a89ab845575e2f16334bc64c96)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13561476_V91ErZq1nkSn.png&hash=0104e1ca19e9e5466c67a372e5d7d08a)

[graph faq (http://www.pheed.com/IceGraph/57751088/2502)]
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on January 30, 2015, 07:09:07 AM
Icelook jan30: Average extent 4th lowest in 18 days, average volume peaks in 21 days, p1k (Piomas minus 1000) will be 2nd in 12 weeks, and average volume will be 4th in 5 months.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13564927_ZBQPxO4AoweN.png&hash=1e9b17a235e9dddc9eea8d44ddb2ae4a)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13564937_AbIscUhTjjTj.png&hash=f4747234ecb13493acedf82b08afe158)
[chart faq (http://www.pheed.com/IceGraph/57751088/2502)]
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 05, 2015, 12:01:29 PM
Icelook feb5: Average extent 6th lowest in 8 weeks, average volume will be 6th in 9 weeks, and p1k (Piomas minus 1000) will be 4th in 24 days.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13587489_M4yQ7srROr02.png&hash=d35d0cd5445c542bc892ae2d0a7e0161)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13587558_TWyZGmCBRr6z.png&hash=c58f17eb7a75019c88afb45c3f59a105)
[chart faq (http://www.pheed.com/IceGraph/57751088/2502)]
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Peter Ellis on February 05, 2015, 06:49:31 PM
Why has your forecast changed so radically in 5 days, and what do you think this implies for its reliability as a method?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Peter Ellis on February 05, 2015, 06:58:37 PM
Sure, but you're also using the same method to forecast a complete absence of ice year round in a few years' time.  The Met Office don't use their weather models to forecast more than a couple of days ahead.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: OSweetMrMath on February 06, 2015, 09:49:46 PM
New monthly data for both PIOMAS and NSIDC extent is out, so I can update my predictions for the upcoming maximum.

My predicted value for the January monthly average volume from PIOMAS was 18.5 thousand cubic km. The actual value was 18.445 thousand cubic km. My prediction for April is slightly lower, at 24.0 thousand cubic km, with 95% confidence interval of 22.8 - 25.3 thousand cubic km.

My predicted value for the January monthly average extent from NSIDC was 13.8 million square km. The actual value was 13.62 million square km. My prediction for March is slightly lower, at 14.7 million square km, with 95% confidence interval of 14.1 - 15.4 million square km. I said last month that my prediction for January might be high, which turned out to be true, but not dramatically. I'm not aware of any current bias in the data which would be likely to make my current predictions off.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Nightvid Cole on February 06, 2015, 10:29:01 PM
Cryosat actually gets a LOWER volume for fall 2014 than it did for 2013:

http://www.esa.int/Our_Activities/Observing_the_Earth/CryoSat/CryoSat_extends_its_reach_on_the_Arctic (http://www.esa.int/Our_Activities/Observing_the_Earth/CryoSat/CryoSat_extends_its_reach_on_the_Arctic)

in stark contrast to PIOMAS.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: DavidR on February 07, 2015, 09:38:46 PM
My prediction for March is slightly lower, at 14.7 million square km, with 95% confidence interval of 14.1 - 15.4 million square km.
I'm going to take a punt on 14.7 MKm^2 being  the maximum extent for this year, not the March average. The only area available for significant expansion now is the Northern Pacific and that  has been exceptionally warm for the last 8 months. The January average was the warmest this century. The Barents already is high in extent and area so that's probably not going to contribute a lot more either.

Of course strong winds could blow that estimate away.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Michael Hauber on February 09, 2015, 10:37:17 PM
There have been the odd comment on reduced Fram export being a big factor in the increased ice, and that Fram export has increased of late.

However I don't think that Fram export is the big issue, but rather the angle of the Transpolar Drift.  This appears to have shifted from a more Pacific - Atlantic angle towards being on a more Laptev - Canada angle.  The result is that more of the thick ice is being pushed into the Beaufort, and less towards NE Greenland.  The change in angle does tend to mean less ice being pushed into the Fram, but currently the wind direction in the Arctic is very much in the same Laptev - Canada direction, so even with faster Fram export the export would only be pulling thinner ice that came from the Laptev sector.

At the same time this change in transpolar drift has been encouraging a strong Laptev bite, which appeared to be at record size last summer, and indications from the Navy model are that the ice in that sector is even thinner than same time last year.  Ice free north pole for 2015 anyone?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on February 10, 2015, 07:48:58 AM
...
However I don't think that Fram export is the big issue, but rather the angle of the Transpolar Drift.  This appears to have shifted from a more Pacific - Atlantic angle towards being on a more Laptev - Canada angle.  The result is that more of the thick ice is being pushed into the Beaufort, and less towards NE Greenland...

At the same time this change in transpolar drift has been encouraging a strong Laptev bite, which appeared to be at record size last summer, and indications from the Navy model are that the ice in that sector is even thinner than same time last year.  ...

How funny... I spent several hours last night staring at the HYCOM Navy thickness models, comparing February 2014 with this year.

I have to agree, their projection doesn't look particularly promising - their estimates of ice thickness across the ESS and Laptev are nearly half a meter thinner than they were last year at the same time.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 10, 2015, 08:06:40 AM
Icelook feb10: Average extent 6th lowest in 8 weeks, average volume will be 6th in 40 days, and p1k (Piomas minus 1000) will be 4th in 11 days.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13603483_jVVXKsrTXFVi.png&hash=2eb567d7af9ccfe16201b937ce3f99db)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13603486_RT0bdqeJqxsf.png&hash=9f0053b0d091a13078cbd93c18f3c00b)
[chart faq (http://www.pheed.com/IceGraph/57751088/2502)]
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 10, 2015, 10:01:34 PM
2011 of course is tough competition — the toughest, in fact, in terms of average extent drop during the year — so it's really no surprise 2015 cannot keep up the fight. Instead we've seen in the 2 latest 'Icelooks' that 2015 has been chickening out and taking on 2014 as a more equal opponent. Sometime in early April we may be higher, and 2015 extent will change to light blue to reflect this fact.

For volume, of course, the situation is even worse, and the projected crossing of the 2008 graph on March 22nd will in less than a month thereafter take us into the pink territory of 7th lowest pinkness.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: OSweetMrMath on February 11, 2015, 06:26:35 AM
I'm going to take a punt on 14.7 MKm^2 being  the maximum extent for this year, not the March average. The only area available for significant expansion now is the Northern Pacific and that  has been exceptionally warm for the last 8 months. The January average was the warmest this century. The Barents already is high in extent and area so that's probably not going to contribute a lot more either.

Of course strong winds could blow that estimate away.

Keep in mind that the daily extent is already nearly 14.3 Mkm^2. The monthly average runs well below the daily level during the freeze season.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 11, 2015, 02:55:28 PM
Keep in mind that the daily extent is already nearly 14.3 Mkm^2. The monthly average runs well below the daily level during the freeze season.

Not in my book, sir. In it, extent hasn't been at 14.3 million since March 22nd 2014.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on February 11, 2015, 08:04:07 PM
IJIS on feb 10 shows extent at 13.8 million KM2
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: crandles on February 11, 2015, 11:16:43 PM
IJIS on feb 10 shows extent at 13.8 million KM2

Following the links up you will see OSMM and David R were talking about NSIDC extent which shows:

2015,    02,  07,   14.22251
2015,    02,  08,   14.35378
2015,    02,  09,   14.38811
2015,    02,  10,   14.41547

Personally I prefer area and at 12.819 is just 325k below 2011 record low maximum achieved 27 days after the 12.819 data. We gained over 325k over last 18 days but as the rate of gain would be expected to be lower near the maximum, a record low maximum area is not implausible at this stage. Normal level of noise around the top of the arc makes such a record this year unlikely, I think.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: DavidR on February 11, 2015, 11:31:35 PM
IJIS on feb 10 shows extent at 13.8 million KM2

IJIS may be showing 13.8 but NSIDC (the measure we were referring to) is showing 14.4. Average extent increase from now to maximum ranges from 340 - 1000 K km^2 with an average under 500 for the past few years. My view is that we will be at the bottom of that range because of the relative warmth of the North Pacific.   
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 11, 2015, 11:46:09 PM
IJIS may be showing 13.8 but NSIDC (the measure we were referring to) is showing 14.4.

Interesting. What is their great dispute? What are the disputed territories?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 12, 2015, 07:12:32 AM
While this isn't yet the melt season thread: An interesting development at the Pole. Animation of 7–11 February. From Uni–Bremen.

What's happening up there? Any theories?

At any rate HYCOM got it right. Many polynyas opening up in the CAB.

ro4co4 from Lance Modis.

Vergent
The above quote is from early June 2013. February is early for this sort of break–up, right?

Edit: Another Open-water-in-June quote from June 2014:

Ok, previous discussion about open water aside, what disturbs me most right now is summarized well in this image:

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

In the quadrant between 80 N and 85N , between 150E and 165E, is an area of ice which is showing closer to 30% open water.

Considering that nothing lke that started showing up for closer to 30 days last year or the year before, I find that a bit disturbing.

I find that disturbing for two reasons.  First, I've found the DMI over all in two years of my following it, has tended to be more rather than less reliable. Second, it suggests profoundly unpleasant conclusions as to the state of the ice currently.

Add that to the various weather projections which have been getting discussed over the last week or so, it leads me to very pessimistic conclusions.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 12, 2015, 01:17:54 PM
What's happening up there? Any theories?

What precisely is your point Vid? I've been following this sort of thing for quite a while now:

http://GreatWhiteCon.info/2014/09/santas-secret-summer-swimming-pool-revisited/ (http://GreatWhiteCon.info/2014/09/santas-secret-summer-swimming-pool-revisited/)

Winds blow. Ice moves. Satellites see "noise". Ask Wipneus!

https://forum.arctic-sea-ice.net/index.php/topic,382.msg45152.html#msg45152 (https://forum.arctic-sea-ice.net/index.php/topic,382.msg45152.html#msg45152)

Quote
Area actually decreased with the same rate, about 13k/day. Again the winds explain most of the changes
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on February 12, 2015, 03:58:49 PM
Vid, it could be that strong winds are causing (temporary) leads in a certain part of the Central Arctic during winter. It's also possible - and usually more probable - that the satellite sensor is thrown off by clouds or some glitch occurs. You see this a lot during Summer when large swathes of yellow, green and pink show up on the Uni Bremen sea ice concentration maps, only to disappear within a day or two.

Only when the different colours persistently stay in the same place for several days can you be sure there is open water (or a lot of melt ponds). Or at least, that's my interpretation of watching these UB SIC maps for several years now.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 12, 2015, 04:02:50 PM
Yup. I know. That's why it's a 5–day vid.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on February 12, 2015, 04:47:39 PM
In that case it could be leads opening because of the strong winds Wipneus mentioned in the AMSR2 thread:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D382.0%3Battach%3D13743%3Bimage&hash=b76d2de8b2cedf7910278e07ba985ac7)

This will probably increase the thickness/volume of the ice in that particular area (ridging, leads freezing over again).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 12, 2015, 08:22:29 PM
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D997.0%3Battach%3D13739%3Bimage&hash=6197e10246024ca4f3972bbec0ced0a7)

What's happening up there? Any theories?
What precisely is your point Vid?
Allow me to expand a bit, as I've formulated my point rather short and clumsily:

By «What's happening up there?» I mean 'What is happening up there?'. Or with some added context: 'What do you people who frequent this forum believe may be happening up there?'.

Now, to the next sentence, I believe equally incomprehensible: «Any theories?». By that little enigma, I intend to request people who frequent this forum as to whether they have any ideas — not 'theories', strictly scientifically speaking — as to what may be 'happening up there' (see further explanation above).

In summary, I can see why you are confused. I should formulate more complete sentences where I also include some context to the questions. I should perhaps also explain that I would like people to answer said questions, they are not posed as 'statements' or any such thing, they are, in fact, questions, posed to the larger community, in hope of knowledgable answers.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 12, 2015, 08:35:02 PM
[
By «What's happening up there?» I mean 'What is happening up there?'. Or with some added context: 'What do you people who frequent this forum believe may be happening up there?'.

Short but sweet? An old thread:

"Drift, Deformation and Fracture of Sea Ice (http://forum.arctic-sea-ice.net/index.php/topic,624)"
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 12, 2015, 08:52:55 PM
"Drift, Deformation and Fracture of Sea Ice (http://forum.arctic-sea-ice.net/index.php/topic,624)"
February is early for this sort of break–up, right?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 12, 2015, 09:14:58 PM
A 2Mb vid for Vid:

[Edit - Now updated to February 17th]
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 12, 2015, 09:28:56 PM
I think... it on some level, is about fear.  I'll introduce my sumo wrestler metaphor here.

The "game" - net energy available in the environment - has been changing in more noticeable ways.  The weather is a symptom of that; the state of the ice is a symptom of that. 

We have already seen 6 months of absolutely extraordinary weather which has been very detrimental to the ice... to the degree that, in spite of a recovery last melt season, the ice at peak in April was no better off than at the start of 2012.  We have good reason to fear predictions of heat over the arctic.

Hyperbole aside, there are titanic forces at work energy-wise - my sumo wrestlers - and the mat has been progressively been tipping in favor of increasing melt.  One of these times, the "melt" wrestler will succeed in tossing his opponent off of the mat, this year, next, or whenever.  At some point the mat will tip so far in favor of melt, that any manner of supportive weather will fail, and we will see a catastrophic drop.

So, in view of that, I don't really find hyperbole that far out of place.  The way I look at it, it is just someone pointing out that this might be "it".

I find this analysis makes a lot of sense.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 12, 2015, 09:35:51 PM
Some 3 Mb of SAR for Vid:
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on February 12, 2015, 09:46:58 PM
My take-away is, over the last ten days or so, what we are seeing is the ice on the east side of the arctic reacting to the series of huge storms that raced north across the Atlantic to the Norwegian Sea after dumping upwards of 175CM (yes, that much) on parts of the eastern seaboard.

Coincidentally, they also pulled in train, huge amounts of moisture and heat from the ocean off of the U.S. coast.  SS Temperatures there are running as much as 8C above normal.  Some of that is what is keeping my parents snowed in in Scituate, MA.  They live about two blocks uphill from where CNN etc. were taking a bunch of the storm pictures they broadcast.

I wish we had a better sense of the snow over on the pack.  Increased precipitation is both a big positive heat transfer, and once down, inhibits ice formation.

(Further bit - that ice image looks rather "crunchy".  Lots of small interstitial leads rather than big ones? Or is it mostly/actually just differences in ice reflectivity?)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 12, 2015, 10:19:14 PM
The above quotes from June 2013 and 2014 are instructive, and perhaps less conservative?

Quote
Many polynyas opening up in the CAB.

Quote
...an area of ice which is showing closer to 30% open water.

Considering that nothing like that started showing up for closer to 30 days last year or the year before [about July 1st 2013 and July 1st 2012, respectively], I find that a bit disturbing.

Considering it now shows up in February on very rotten ice, I find that extremely promising for a smashing melt season (http://forum.arctic-sea-ice.net/index.php/topic,1149.0.html)!  ;D
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 13, 2015, 12:38:42 AM
Here's February 20th 2014, but what's a week or so between friends?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on February 13, 2015, 04:50:18 AM
Here's February 20th 2014, but what's a week or so between friends?
Very familiar; I'm more concerned about this year's weakness to the east and the ESS than the broken ice in 2014 NE of Svalbard.  I think that may be more crucial to the melt season, as it will have a more direct effect on MYI currently in the Beaufort and along the western extent of the CAA.

We may yet see an ice-free N pole in August.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on February 14, 2015, 02:38:20 AM
Cryosphere Today - 2/9/13 vs 2/9/15

In terms of extent, very similar at a gross level.

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=02&fd=09&fy=2013&sm=02&sd=09&sy=2015 (http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=02&fd=09&fy=2013&sm=02&sd=09&sy=2015)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on February 14, 2015, 02:56:46 AM
A bit of additional food for thought.

In four images, why I think significant additional thickening of the pack between now and mid April will be a serious up-hill climb for the arctic.

Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 15, 2015, 02:17:55 AM
Some 3 Mb of SAR for Vid:

Reading both Danish and English I should be able to one day figure out what those pretty images are supposed to tell me about the ice, even though neither DMI nor ESA seem to have made any effort at explaining or guiding first–time users. I'm thinking it would be a terrible shame if all that expensive equipment and all that heavy data processing went down for years on end without any one human being on this planet being able to understand their end product plots or being willing to admit as much. For now I'm guessing the open water leads we are talking about are either dark, light or fifty shades of grey:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.polarview.aq%2Fimages%2F107_S1pngthumbnaillarge%2FS1A_EW_GRDM_1SDH_20150215T041608_425D_N_1.tn_large.png&hash=5fd9517c5136a314356e2ed97f0528eb)

That's a pretty safe assumption, as that covers all of the info in the plot. I comfort myself with the knowledge that I now have some general idea about how heavy the satellites are, what programs they're taking part in, where in French Guiana they were launched from on what date and what scientific back history that kind of remote sensing has etc etc, the only thing I don't know the first thing about is how to interpret their main product, the ice maps. In other words the very first thing I myself would tell the end users if I was spending billions of their tax Euros in order to upload and distribute sea ice plots.

I find this amazing but intriguing. My long–term goal is to accidentally stumble upon a beginner's guide before I die. Then, of course, with a smile on my face!  :)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: nukefix on February 15, 2015, 06:11:53 PM
I find this amazing but intriguing. My long–term goal is to accidentally stumble upon a beginner's guide before I die. Then, of course, with a smile on my face!  :)
Google is your friend :)

http://www.tos.org/oceanography/archive/26-2_dierking.pdf (http://www.tos.org/oceanography/archive/26-2_dierking.pdf)
http://www.sarusersmanual.com/ManualPDF/NOAASARManual_CH20_pg417-442.pdf (http://www.sarusersmanual.com/ManualPDF/NOAASARManual_CH20_pg417-442.pdf)

Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 15, 2015, 10:52:14 PM
thx, nukefix!  ;D

Icelook feb15: Average extent 6th lowest in 30 days, average volume will be 6th in 26 days, and p1k (Piomas minus 1000) will be 4th in 5 days. The pendulum, in other words, is still swinging north. It may turn south during next week, but that's too early to tell yet. The implications of such a turn would be increasingly later dates for the estimated crossing from 5th to 6th lowest for both annual average volume and extent: They may be postponed back to April again. Volume may go light blue, but leave pink for the pre–2010 years. Refreeze is now slower than last year, has been for two days, that's why the pendulum is starting to slow down to zero.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13616925_OVQfO14YAAxP.png&hash=bb074fa412d307c76b27ee9180197ecd)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13616927_LkqUWja3HgS1.png&hash=6cc01fd4b2452ed7b733c1e1c8a98014)
[chart faq (http://www.pheed.com/IceGraph/57751088/2502)]
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 17, 2015, 07:21:13 AM
According to IJIS, this latest daily delta of –58225 km² was the biggest February melt since 2010. Also, my PIOMAS estimate algorithm reports the first ever February volume drop since 2007.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 18, 2015, 11:51:30 AM
I've just updated my February 2015 AMSR2 animation. Scroll back or click here (http://forum.arctic-sea-ice.net/index.php/topic,997.msg45202.html#msg45202).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 18, 2015, 03:14:47 PM
In associated news I arrive hotfoot from the ASIB where the latest "Shock News!" from the Arctic has just been reported:

IJIS Arctic Sea Ice Extent Lowest Ever! (http://greatwhitecon.info/2015/02/shock-news-ijis-arctic-sea-ice-extent-lowest-ever/)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D230.0%3Battach%3D13954%3Bimage&hash=d4fcedfd2c8ec9a51bc8e462c513a5b2)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on February 18, 2015, 03:19:48 PM
I've just updated my February 2015 AMSR2 animation....

It looks like the Atlantic side is pulsing to the frequency of storms rolling north along the US Eastern Seaboard and then onwards to the Barents.  No accident that, I expect.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 18, 2015, 04:38:19 PM
It looks like the Atlantic side is pulsing to the frequency of storms rolling north along the US Eastern Seaboard and then onwards to the Barents.

I just made a YouTube video to help bring the shock news to the masses:

http://youtu.be/xmZkpURTJZs (http://youtu.be/xmZkpURTJZs)

Please feel free to tell your friends.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 18, 2015, 05:22:27 PM
Stop Press!!!

The NSIDC daily extent (http://ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_nrt.csv) for February 17th has now been revealed to be 14,303,570  km², which is also their lowest ever reading for the day of the year (if my spreadsheet is to be believed at least).
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on February 19, 2015, 01:24:22 PM
With the daily extent for both NSIDC and IJIS now lowest on record for the time of year, we might expect a rebound to be on the horizon.
 
However, the outlook shows a strong ridges developing over western Russia and up into Alaska/western Canada, which could feed some milder air into the Arctic over the next 10 days. Somewhat similar to the very mild pattern we saw during much of last winter.

2 days out
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FsaO3LYs.png&hash=1b2ab8c1846936f9ab53ed2c756e8900)

4 days out
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FDeWWpim.png&hash=0fec71c71cb6dd44b8841c79ccf0462b)

6 days out
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FjYntt8n.png&hash=cfa9f52d27b49adcb3cb38b9089f928f)

8-10 days out
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FDjmgCfh.gif&hash=f8227280d55867400f40354fb46cf5fe)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: helorime on February 19, 2015, 09:51:59 PM
Meanwhile it stays cold in the great lakes area of the U.S.  Interetesting that this is the 2nd year of this odd weather pattern. It is substantially colder in Youngstown Ohio today than it is in Barrow Alaska.  ???
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 20, 2015, 06:37:42 AM
Icelook feb20: Average extent 6th lowest in 10 weeks, average volume will be 6th in 38 days, and p1k (Piomas minus 1000) will be 4th in 2 days. Refreeze has now been slower than last year 7 days in a row, in turn changing the outlook significantly. Today we even have the slowest February refreeze to date on IJIS record (see bottom table). 2015 extent has till now been roughly the same as last year, leading to the inconclusive annual average extent graph, going neither up nor down. This may change in the coming weeks, as 2014 climbs to its relatively late March 20 maximum extent of 14,448,416 km². 2015 volume has been at least 950 km³ higher than last year every single day, therefore the annual average volume graph is still just up, up, up. Next week we may get an estimate for a peak, but so far it's nowhere in sight. Such a peak would most likely require a significant abrupt plunge in daily volume figures some time during spring or summer, if not in the shape of actual volume losses, then at least in (much) slower refreeze than last year. In any case, it will be interesting to see official Piomas volume figures in two weeks' time.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13624321_Hk1wrkFs4af1.png&hash=7cd41f2a60347cdc95ecfa3a9b430e01)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13624324_umHl7eWsYGE6.png&hash=5ab42825d43e5dd0f421fb55d28686ba)
[chart faq (http://www.pheed.com/IceGraph/57751088/2502)]
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13624382_hPLIZY1S5DY5.png&hash=39bd6768ad5b222b93c32718c9ae2ef9)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Bob Wallace on February 20, 2015, 06:46:09 AM
Meanwhile it stays cold in the great lakes area of the U.S.  Interetesting that this is the 2nd year of this odd weather pattern. It is substantially colder in Youngstown Ohio today than it is in Barrow Alaska.  ???

And it's the second year in a row in which Northern California has had no winter.  Normally, where I live, we get a lot of snow.  Three times in the last ten years I've been snowed in for a month or longer.  (Snowshoe out or call the Cat.)

Last year there was one minor snowfall in October and one more in the spring (normal stuff). None at all from November to March.  This year there has been none at all. 

I think we can accurately say that weather patterns have been screwed up.  But on average things are warmer with more screwing up coming to where we live.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: LRC1962 on February 20, 2015, 07:37:59 AM
Meanwhile it stays cold in the great lakes area of the U.S.  Interetesting that this is the 2nd year of this odd weather pattern. It is substantially colder in Youngstown Ohio today than it is in Barrow Alaska.  ???

Around the Great Lakes it is cold now, but earlier in the winter it was mild. That is why the systems coming from the west have been hitting Boston with so much snow. The GL have not frozen that well and therefore any system going across them is picking up a lot of moisture.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 20, 2015, 02:44:28 PM
Espen's eagle eyes have spotted some "Shock News" from Greenland (http://forum.arctic-sea-ice.net/index.php/topic,154.msg45673.html#msg45673). IJIS extent is no longer "lowest for the date", but there is this:

"Massive Calving of Jakobshavn Isbræ (http://greatwhitecon.info/2015/02/shock-news-massive-calving-of-jakobshavn-isbrae/)"
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on February 23, 2015, 08:13:10 AM
The Race to Fram Strait , north of Greenland.

(click to animate)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on February 23, 2015, 09:04:57 AM
The Race to Fram Strait , north of Greenland.

(click to animate)

~15,000KM2/Day, of the thickest, oldest ice in the arctic, out the door, on the way to inevitable oblivion.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on February 23, 2015, 02:43:49 PM
Looking at the most recent ECMWF runs, I think there is potential to see some losses in extent later this week and into next weekend.

We're now seeing the start of a potentially abnormally mild pattern, with warm air flowing into the Arctic via both the Bering Strait and Barents seas. This pattern looks like strengthening over the coming week.

By Wednesday, we can see the strong blocking highs present both in western Russia and the Gulf of Alaska. This will steer increasingly mild southerlies into the Arctic pushing back and potentially melting some ice, especially in the Barents sea early on.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FEzrJngM.png&hash=cdcb95486c04d1b9d3c1d1dcfa4f5eda)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2F6xWj0Xe.png&hash=372e351f5bd121a225888fd56d67973a)

By the end of the week/early weekend, the pattern strengthens, dragging long draw southerlies into the Arctic, squeezing out much of the cold.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fll3HRpJ.png&hash=4a0490655f84a960445ff8d8ef130bae)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FpS7qmBk.png&hash=f19c236cd6438e0421c1e06c46c0cd2d)

The pattern continues to worsen by the start of next week, with the southerlies likely causing compactions and some melting in the Bering and Barents/Kara regions. Throughout all of this, slight gains in the Baffin sea region may offset things slightly, but probably not enough to balance things out

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FSWpm673.png&hash=3ee6eb7aba90eb79dd12c2fa87936fa7)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FkCmU63X.png&hash=28ad3d1c3dcdc243958a83762eef6d86)

If this patterns lasts well into March, I think we could see a very early maximum this year
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 23, 2015, 05:45:42 PM
Note that Sean@CCI-Reanalyzer has recently reinstated the Arctic closeups:

http://GreatWhiteCon.info/resources/arctic-sea-ice-graphs/#CCITemp (http://GreatWhiteCon.info/resources/arctic-sea-ice-graphs/#CCITemp)

Here's this morning's anomalies:
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on February 23, 2015, 09:47:42 PM
Thanks, BFTV and JH, very interesting.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Siffy on February 23, 2015, 10:14:23 PM
Is that anomaly map really showing zones in the arctic which are +20C hotter than normal?  :o

Is there a version of that map showing actual temperatures?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 23, 2015, 10:33:21 PM
Is that anomaly map really showing zones in the arctic which are +20C hotter than normal?  :o

Is there a version of that map showing actual temperatures?
Yes on both accounts. And in a way, twenty plus or minus anomalies are the 'norm' in the Arctic, there's always one area or other that has them, so in that sense, too, the Arctic is one of the most extreme — and interesting! — places to follow, weatherwise.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on February 24, 2015, 12:34:25 AM
Is there a version of that map showing actual temperatures?

Just click my link above! Alternatively here's the current one. The North Pole is currently warmer than large areas of North America.

Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jester Fish on February 24, 2015, 01:18:06 AM
You can see the warm air pumps running North along the West and East coasts of N. America.  They correspond well with the "warm" air illustrated by the circulation over the North Pole.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 25, 2015, 07:14:46 AM
Icelook feb25: Average extent 4th lowest in 37 days, average volume will be 6th in 11 weeks, and p1k (Piomas minus 1000) will be 5th in 44 weeks. With an annual average extent drop like the one for the previous 7 days, getting down to 10.32 mill should take only 4 or 5 days, and that will be the lowest we've been during 2015. The prognosis graph has this happening on Friday Feb 27th. This weekly pace persisting for a month would also lose over ten grand a month, taking us down to the 10.31 line by the end of March. This all presupposes declining daily extent and taking advantage of the late (March 20) yearly maximum of 2014 and the record early February 15 yearly maximum this year. Could it be that in really exceptionally badass years like 2007, there *is* a trend for early extent maxima, and could 2015 be an extra naughty player in this league? Nothing but time will tell, fellas, but 2015 could be the wrong year to go off the grid. Volume is a different dance entirely, and no–one knows exactly how much ice there is at this point. We could be back close to end–2007 levels like the graph shows, or we could be closer to the green p1k. Usually, after a rebound period, annual average volume climbs one or two positions on the (least) icy leaderboard before extent does. This implies we could be 4th lowest, or go 4th lowest, before annual average extent.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13635735_AFecjPnVcwuv.png&hash=69b2a80b556b36b3a91baa6db755dee0)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13635738_1hFMdV04Fcop.png&hash=3fd09e04cd291d248a636be16f350d93)
[chart faq (http://www.pheed.com/IceGraph/57751088/2502)]
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Lord M Vader on February 25, 2015, 07:17:04 AM
While we are about 1 month at most from the SIE maximum in the Arctic and discuss whether we'll see a very early maximum, things are interesting on the other pole. Due to Bremens sea ice graphs, the SIE minima seems to already have occurred at Antarctica and also at a very to extremely early date. Anyone who knows the extreme dates for Antarctica?

Best, LMV
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Laurent on February 25, 2015, 10:36:27 AM
I am not sure but I would say we are at the minimum or not far...?
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png (http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png)

You can have more here : http://greatwhitecon.info/resources/antarctic-sea-ice-graphs/ (http://greatwhitecon.info/resources/antarctic-sea-ice-graphs/)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on February 26, 2015, 12:04:26 AM
This all presupposes declining daily extent and taking advantage of the late (March 20) yearly maximum of 2014 and the record early February 15 yearly maximum this year. Could it be that in really exceptionally badass years like 2007, there *is* a trend for early extent maxima, and could 2015 be an extra naughty player in this league?

Studying *centuries* more generally, i find that once a year has gotten its first century drop (in IJIS extent), it is likely (83%) that it won't see a counteracting century *gain* for another 108–214 days (September at the earliest). Data also shows that if you survive the next 5 days after the year's first century drop without a century *gain* setback, then 100% of the years in the IJIS record give you *drop only* centuries until the end of the melt season. 2015 has gone 7 days since its first century drop, and so far any century gains before September seem unlikely.

Note also: 2007 had its first century drop on day 165. 2015 was 117 days ahead of that. 2007 had a (then) record amount of 27 century drops, beaten of course by 2012's 40 drops (but 17 of those 40 came ahead of day 165, which was 2007's first century drop).

Code: [Select]
2003/23 -117412 2003/27 114180 (x)
2004/72 -134385 2004/267 117886 195
2005/153 -119936 2005/273 102151 120
2006/115 -104556 2006/276 101255 161
2007/165 -101000 2007/273 107060 108
2008/107 -106549 2008/273 157121 166
2009/68 -116473 2009/282 110026 214
2010/123 -108481 2010/268 116753 145
2011/166 -106743 2011/274 103984 108
2012/67 -102529 2012/261 105906 194
2013/104 -120309 2013/277 140031 173
2014/67 -120789 2014/71 115282 (x)
2015/48 -113505
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: iceman on February 26, 2015, 12:56:49 AM
Looking at the most recent ECMWF runs, I think there is potential to see some losses in extent later this week and into next weekend.

We're now seeing the start of a potentially abnormally mild pattern, with warm air flowing into the Arctic via both the Bering Strait and Barents seas. This pattern looks like strengthening over the coming week.

............

If this patterns lasts well into March, I think we could see a very early maximum this year

Good call on Bering and Barents, BFTV.  I think the main reason we're not seeing losses in aggregate extent is that the anomaly was already extremely low, owing mainly to Oshkosh.  It's now back to re-freeze there - if erratically - and additional extent gains next few days in Baffin/Newfoundland (as you noted) and St. Lawrence will likely offset any further losses in Bering and Barents.  Net: no extent max any time soon.
      I am curious, however, to see whether the combination of northerly winds through Bering Strait, with concurrent acceleration of ice transport through Fram Strait, becomes a set-up for an early volume max.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on February 27, 2015, 09:09:24 PM
Good call on Bering and Barents, BFTV.  I think the main reason we're not seeing losses in aggregate extent is that the anomaly was already extremely low, owing mainly to Oshkosh.  It's now back to re-freeze there - if erratically - and additional extent gains next few days in Baffin/Newfoundland (as you noted) and St. Lawrence will likely offset any further losses in Bering and Barents.  Net: no extent max any time soon.
      I am curious, however, to see whether the combination of northerly winds through Bering Strait, with concurrent acceleration of ice transport through Fram Strait, becomes a set-up for an early volume max.

It was around now I was expecting the measures to start showing a drop, so I guess we'll see how the weekend goes.

Those southerlies are pulling some pretty impressive positive anomalies over the Bering strait already

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FI6Q6Qrw.png&hash=1ac3a9a6f96930a7e260cae55f6f758b)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on February 28, 2015, 12:32:06 PM
Lowest on record for JAXA, down almost 100k in the last 2 days.

No sign of a substantial improvement in conditions over the Bering strait until early next week, while things remain mild with persistent southerlies over the Barents/Kara region for the foreseeable future, extending up into 80N in a few days.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on February 28, 2015, 04:26:45 PM
Big drop on the daily NSIDC extent too, making it 100k in the last 2 days and 160k in the last 5.

Going by the new JAXA imagery,the vast majority of the loss is from the Bering sea, with Barents and Kara contributing a small loss. I'd expect to see the Bering sea stabilise and perhaps see some small increases early next week, but Barents and Kara to start seeing some bigger losses.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: DavidR on March 01, 2015, 06:10:30 AM
February 27th marked the maximum NSIDC extent in 2008.  Since 2007 five of the increases from Feb 27th to the maximum would leave the extent well below the 2011 record low of 14.671 Mkm^2, only two would take the ice past the current second lowest extent in 2007 and none would take it  near the third lowest in 2014.

With the weather predictions for the next  couple of weeks it  looks like the melting season will start from a very low base.  It  will be very interesting to see what PIOMAs does for February
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on March 01, 2015, 06:47:12 AM
With the weather predictions for the next  couple of weeks it  looks like the melting season will start from a very low base.  It  will be very interesting to see what PIOMAs does for February

Climate Reanalizer (University of Maine) models show an absolutely astonishing plume of warm air intruding all the way to the pole in about six days.  The model shows temperatures arriving at 90N of just below freezing.  It will affect most of the central arctic basin, as well as the Barents and Kara (which gets the same or even warmer). 

It looks like temperatures could be very close to that necessary to permit actual melt.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on March 01, 2015, 08:00:03 AM
Big drop on the daily NSIDC extent too, making it 100k in the last 2 days and 160k in the last 5.

Going by the new JAXA imagery,the vast majority of the loss is from the Bering sea, with Barents and Kara contributing a small loss.

The NSIDC loss is mostly caused by a drop in the south Greenland Sea: -69k. Bering much less in second place.

Regional Arctic Sea Ice Extent from NSIDC NASA Team concentration data
Date: 2015-02-27 12:00  Values in 1000 km^2  Anomalies are from the 1981-2010 mean values

Extent (value, one day change, anomaly):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
  4456.6   +0.0    +3.6    935.7   +0.0    +0.0    733.9   +0.0    +0.0
               Kara Sea             Barents Sea           Greenland Sea
   900.3   +0.0    +1.0    669.0   -1.3  -174.9    627.6  -68.5  -146.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
  1366.9  -11.2   -23.5    243.6   -2.4    +9.6   1232.3   +0.0    +0.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   747.0   +0.0    +0.0    527.6   +0.0    +0.0    602.9   +0.0    -0.0
             Bering Sea          Sea of Okhotsk                   Lakes
   489.6  -22.7  -256.8    695.4   +9.8  -378.5    312.8   +2.9   +77.8
          Other regions       Total (ex. lakes)
   142.8  +13.1  -115.6  14371.1  -83.2 -1081.5



 Jaxa AMSR2 data for 20150227 is similar, with Baffin dropping at the same rate as the Bering region.

Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                    7.1                    -2.2                     0.6
               Kara Sea             Barents Sea           Greenland Sea
                   -3.7                    -0.2                   -72.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -21.3                     3.4                    -4.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    4.7                    -0.4                    -0.8
             Bering Sea          Sea of Okhotsk            Total Extent
                  -22.3                    -0.7                  -112.4
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on March 01, 2015, 10:17:13 AM
If my scripts didn't just go crazy, this year has a 35% lower refreeze to date than record year 2012.

35%.
And we may not reach the 14 million mark for the first time in recent history!
Wow. As I said recently in my so–called 'Icelook': 2015 could be the wrong year to go off the grid.

PS: If we break it down, January only fell 16% short of 2012. February on itself had 69% lower refreeze than 2012. That is *collapse*! February has collapsed, folks.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on March 01, 2015, 11:02:14 AM
Another comparison, OSISAF sea ice concentration on February 26th:

(https://lh5.googleusercontent.com/-gdia5pNYfto/VPLjVKO6ebI/AAAAAAAACFc/F8YzO49p5Bk/s640/OSISAF%2520SIE%25202602.jpg)

The North Pole seems to be surrounded by first-year ice. 2012 is similar, but less pronounced. Let's see how far the ice edge goes this year...

And also, like Wipneus has been showing in the PIOMAS thread, quite a bit of volume is sitting right in front of the Fram abyss, more than in previous years. I wonder what volume does, when all of it is flushed out?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Shared Humanity on March 01, 2015, 05:16:39 PM
You can also clearly see the effects of Nares export this freeze season.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: iceman on March 01, 2015, 06:06:31 PM

The NSIDC loss is mostly caused by a drop in the south Greenland Sea: -69k. Bering much less in second place.
   ....
That's quite a remarkable effect (mainly of wind?) in the Greenland Sea, along with a big cumulative drop in Bering.

I'll put in a guess of an extent max on 15th March, with a surge from Baffin/Newfoundland followed by late extent growth elsewhere.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: LRC1962 on March 02, 2015, 01:26:14 AM
That's quite a remarkable effect (mainly of wind?) in the Greenland Sea, along with a big cumulative drop in Bering.
From Canada Ice service
Eastern Arctic

Quote
Summary for October 17 to November 4.
Average air temperatures were above normal values over most locations
except below normal over Gulf of Boothia. Ice formation was near normal
over most locations except 1 week later than normal over Baffin Bay.

Weather forecast for November 5 to 30.
Average air temperatures will be above normal over the whole area.
Do not know if they archive at all but did see the Feb forecast earlier and it was the basic same story. It was very windy as I recall from comments elsewhere, but compound that with above average temps that ice can be easily moved.  Your ice also will be mushier. This winter has been very poor for ice manufacturing and I do not think March wil be much better at least on the Canadian side based on average temps from Feb-Apr.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fweather.gc.ca%2Fdata%2Fsaisons%2Fimages%2Fs234pfe1t_cal.gif&hash=448ca490740c2fcaba8465c8215be96d)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on March 02, 2015, 01:28:33 AM
I'll put in a guess of an extent max on 15th March, with a surge from Baffin/Newfoundland followed by late extent growth elsewhere.
It's certainly possible, but I just don't see it coming, iceman. Before the 15th we'll have 1 or even 2 new century drops, taking us down to 13.7 or 13.6 million km² by IJIS, making it very hard to reach the Feb 15 max of 13.94 ever again.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on March 02, 2015, 07:30:03 AM
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fd22d7v2y1t140g.cloudfront.net%2Fm_13647008_WQVIivLFT8dJ.png&hash=a8307fb390c0df8555a70fb2a4c5cf9b)

2007 & 2012: These two had the most 'century' (>100,000 km² daily) drops and also went lowest in IJIS extent. They both lost over 3 million km² in century drops alone, a feat not seen by any other melt season, and ended up in September as the only two years below 4.2 million.

This display shows century gains in blue and century drops in red. The big number in the center is IJIS extent in millions for the stated date.

As you can see, 2015 currently is lowest on extent and has a lead on the two 'champions', both in century drop numbers and ice lost during those drops.

2012 had a century gain on March 1st, making the total so far this year 3. In comparison, 2015 has had only one century gain.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: iceman on March 02, 2015, 04:56:30 PM
I'll put in a guess of an extent max on 15th March, with a surge from Baffin/Newfoundland followed by late extent growth elsewhere.
It's certainly possible, but I just don't see it coming, iceman. Before the 15th we'll have 1 or even 2 new century drops, taking us down to 13.7 or 13.6 million km² by IJIS, making it very hard to reach the Feb 15 max of 13.94 ever again.
Let me try a little regional decomposition, A) for extent and B) for volume.
    A)  In regions with low extent anomaly (mainly Bering and Okhotsk), the greater-than-normal open water is losing lots of heat - notwithstanding relatively high SSTs.  So the anomaly there is likely to trend up in the next couple of weeks. 
         In Barents the anomaly is also low - relative to climatology if not to recent years - yet looks to drop farther in the near term.  Offset by extent gains in Baffin/Newfoundland.
   B)  Some of the heat radiated from water to air is moving northward over Chukchi, Beaufort and CAB.  It will retard volume growth especially for FIY, where thermodynamic growth accounts for much of the volume gain late in the freeze season.
   The unusual heat advection is why I'm looking for a relatively late extent max along with early volume max.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on March 02, 2015, 07:33:39 PM
Iceman - generally sound reasoning, but I'll quibble mildly with your point (A).

While additional exposure in the Bering, Okotsch and lesser degree, Barents an Kara, will facilitate greater heat loss, we are now late enough in the season where that will be offset by steadily increasing insolation.

So, unlike earlier in the season, that will balance the radiative loss. However, we will still have the heat being imported inti the Chukchi, Beaufort and basin generally.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on March 04, 2015, 10:22:06 AM
Things are getting really interesting now wrt the max:

(https://lh4.googleusercontent.com/-mk6saeS2svM/VPbOjsaLN7I/AAAAAAAACF4/0UgcRQsQMQs/s800/IJISSIE20150303.png)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: slow wing on March 04, 2015, 10:48:48 AM
Interesting question just popped into my head: has anyone ever modelled the total heat required to melt all the Arctic sea ice on any specific day?

Or, more work but more useful, a map over the Arctic of the total heat per square metre to melt the ice?

It would be similar to an average ice thickness map but there would be variations due to ice temperature and it could account for partial melting and different ice concentration fractions.

Then that could be compared with a predicted or average heat delivery to the ice over the melt season at any position to predict which parts would or wouldn't melt out.

Could that be practical and/or useful?
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Richard Rathbone on March 04, 2015, 02:58:43 PM
Interesting question just popped into my head: has anyone ever modelled the total heat required to melt all the Arctic sea ice on any specific day?

Or, more work but more useful, a map over the Arctic of the total heat per square metre to melt the ice?

It would be similar to an average ice thickness map but there would be variations due to ice temperature and it could account for partial melting and different ice concentration fractions.

Then that could be compared with a predicted or average heat delivery to the ice over the melt season at any position to predict which parts would or wouldn't melt out.

Could that be practical and/or useful?

Essentially this is what PIOMAS does. Normally its used with calculations of past energy transfer to estimate current ice conditions, but it could be run into the future by using weather forecasts rather than reanalysis.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on March 04, 2015, 09:30:43 PM
NSIDC daily extent and the 5 day mean are both lowest on record now.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: plinius on March 04, 2015, 11:51:18 PM
Interesting question just popped into my head: has anyone ever modelled the total heat required to melt all the Arctic sea ice on any specific day?

Or, more work but more useful, a map over the Arctic of the total heat per square metre to melt the ice?

It would be similar to an average ice thickness map but there would be variations due to ice temperature and it could account for partial melting and different ice concentration fractions.

Then that could be compared with a predicted or average heat delivery to the ice over the melt season at any position to predict which parts would or wouldn't melt out.

Could that be practical and/or useful?

Apart from the true comment about ice models -
This would not be very different from a normal ice thickness chart. Concerning heat of the ice - the specific heat capacity of ice near those temperatures is about 2.1 J/(gK), whereas the melting enthalpy is 333J/g, i.e. 150 times the amount. This means 10K below freezing (which is already quite a high value for an ice patch) changes your melting heat budget by less than 7%. similar for the concentration - in most cases it is above 90%. This plays a role for the albedo and heating, but not really for the warmth you need to melt it.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on March 05, 2015, 01:57:12 AM
The latest issue of Arctic Sea Ice News is out:

http://nsidc.org/arcticseaicenews/2015/03/possibly-low-in-the-north-definitely-high-in-the-south/ (http://nsidc.org/arcticseaicenews/2015/03/possibly-low-in-the-north-definitely-high-in-the-south/)

Quote
Arctic sea ice extent continues to track well below average, but it is still unclear whether March will see an increase in ice, or establish a record low maximum. Regionally, Arctic ice extent is especially low in the Sea of Okhotsk and the Bering Sea. In the Antarctic, sea ice shrank to the fourth highest minimum in the satellite record.

I felt compelled to quibble slightly with the NSIDC over that final assertion:

https://twitter.com/GreatWhiteCon/status/573259291580370945 (https://twitter.com/GreatWhiteCon/status/573259291580370945)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: LRC1962 on March 05, 2015, 02:48:22 AM
@ Jim H: I can see how NSIDC maybe skittish about Mar, because I believe it was last year where it looked like an early Mar max then a cool snap came in and it ended with one of the latest max on record.
Part 2 (not likely but possible) with all that very bad winter, snow and cold, in the American north east, declaring an early ASI max at this time maybe a little politically and media wise a very unwise thing to do. Why not soft peddle what you know is the truth and wait until middle to late Mar. to declare mid Feb. as your max.
Granted not what scientist or us would like to see coming out of them, and not that I am excussing them, but if that is their reasoning I can understand it.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on March 05, 2015, 07:29:11 AM
Hard to imagine a cold snap when most of the next week in the arctic look like this weather wise.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on March 05, 2015, 10:44:46 AM
Icelook mar5: Average extent 4th lowest in 8 weeks, average volume will be 6th in 10 weeks, and p1k (Piomas minus 1000) will be 3rd in 10 months. With daily melt (extent losses) going on for 6 of the past 7 days, many say the melt season already started and that Feb 15th was the sea ice extent maximum. However, the well–known Arctic deceitfulness demands that we wait at least 25 days from the possible max level, to see if it's nevertheless only a temporary max level. In any case, these huge losses in daily extent at this early stage lead to annual average extent drops, and during the weekend we crossed the 10.32 line for the first time this year, only 2 days later than predicted. Since then the melt has increased drastically, and with the current weekly AAE drop pace of 5040 km²/week, we should in fact be able to lose 20 grand per month. That will take us past the 10.3 million line before the end of March. On a shorter term, the weekly pace will have us below 10.31 million by Mar 13, or according to the prognosis graph on Wednesday March 11th. The forecast is of course most reliable in the short term, but has us crossing into 4th lowest territory on May 2nd. It takes months for the annual average to get down to the lowest position even if we're there already for daily extent, but as long as we're lowest — and thus also lower than last year — the AAE graph will keep going down, and with a steeper drop the further below daily extent gets. Volume — as usual — is harder to predict, especially right before the PIOMAS February release, and some people even claim we are 3000 km³ below last year on a daily volume basis. For March 4th this would mean 18086 km³, and for the p1k graph (Piomas minus 1000) it would mean it was drawn way too high on the chart and should be heading down rapidly towards the 2nd lowest and all–time lowest position. For the coming days, all eyes will be on PIOMAS, and the question on some people's minds is what PIOMAS will make of the record early extent maximum and the rapidly dropping and record low sea ice extent. In any case, both area, extent and volume will of course be zero on the same day, and PIOMAS being an up to 40 days delayed ice statistic and a theoretical model output on top of that, with obvious issues and an increasing number of questions being raised about it, suggests that PIOMAS will be less relevant and daily extent and area measurements more interesting as we step down the ladder towards the first Big Zero.

[chart faq (http://www.pheed.com/IceGraph/57751088/2502)]
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on March 08, 2015, 08:24:45 AM
Winds, 50km/h, push the ice around north Greenland to the Fram.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Jim Hunt on March 08, 2015, 10:39:22 AM
@ Jim H: I can see how NSIDC maybe skittish about Mar, because I believe it was last year where it looked like an early Mar max then a cool snap came in and it ended with one of the latest max on record.

I was quibbling slightly about their Antarctic number, in an endeavour to point out that Wipneus is now generating Antarctic regional metrics to complement his Arctic ones.

Getting back to the Arctic, there have been some late extent surges in recent years, as Walt Meier (of NASA Goddard fame) has now pointed out on the blog (http://neven1.typepad.com/blog/2015/03/mad-max.html?cid=6a0133f03a1e37970b01b7c75bf893970b#comment-6a0133f03a1e37970b01b7c75bf893970b).

Looking at area instead of extent, Wipneus' forecast reveals CT area finally reaching lowest for the date when they publish another update later today:

"Arctic Sea Ice Area Lowest Ever (For the Date!) (http://greatwhitecon.info/2015/03/arctic-sea-ice-area-lowest-ever/)"
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: DavidR on March 08, 2015, 03:23:13 PM
@ Jim H: I can see how NSIDC maybe skittish about Mar, because I believe it was last year where it looked like an early Mar max then a cool snap came in and it ended with one of the latest max on record.

I was quibbling slightly about their Antarctic number, in an endeavour to point out that Wipneus is now generating Antarctic regional metrics to complement his Arctic ones.

Getting back to the Arctic, there have been some late extent surges in recent years, as Walt Meier (of NASA Goddard fame) has now pointed out on the blog (http://neven1.typepad.com/blog/2015/03/mad-max.html?cid=6a0133f03a1e37970b01b7c75bf893970b#comment-6a0133f03a1e37970b01b7c75bf893970b).

Looking at area instead of extent, Wipneus' forecast reveals CT area finally reaching lowest for the date when they publish another update later today:

"Arctic Sea Ice Area Lowest Ever (For the Date!) (http://greatwhitecon.info/2015/03/arctic-sea-ice-area-lowest-ever/)"

Lowest extent : Lowest Area not a pair of records to  be celebrated.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: LRC1962 on March 08, 2015, 04:45:00 PM
@JH: Gotcha. Antarctica is always a problem when extent is included. As the seasons are opposite it would make much more sense if instead of adding the same date of global average, add the same season day. Or maybe even another better category would be an albedo number. Since one of the most important feed back loops is lose of albedo, come up with an albedo number for each day. You could then include the impact of dark snow .
Then I go back to my gripe and that is sea ice has virtually nothing to with what is happening in the Antarctic. There it is what is happening to the ice shelves and ice sheets.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Wipneus on March 10, 2015, 05:16:13 PM
North East Greenland, March 7-9. Sea ice seems to be flying.

(after you click the picture of course)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: jdallen on March 10, 2015, 06:42:17 PM
North East Greenland, March 7-9. Sea ice seems to be flying.

(after you click the picture of course)
Nice, and no surprise; those storms had wind ripping through the Fram at near 100KPH from the NW.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on March 10, 2015, 08:38:37 PM
I reckon that we're reaching the end of this period of ice loss, and that we'll see a slight increase overall during the next week.

Barents sea has lost about 250k in areas since early February (100k in the last week) and is back close to record low territory, so losses from there will be a bit slower during the coming week as winds vary from north westerly to southerly, causing expansion and compression on different days, but staying mild enough to prevent new ice formation. Kara may also see some minor losses too. Between them, I'd estimate another 50k could be lost this week.

Over the Bering sea, I'd expect to see some moderate increases, perhaps up to 100k. The air looks like remaining below average, with occasional light to moderate northerly winds through the Bering strait, helping to spread the ice out a little. Okhotsk looks like remaining mild however, so I wouldn't expect any significant gains there.

For other regions, the Greenland sea looks like seeing a combination of milder conditions and increased export, which should balance things out there. The Baffin sea will experience mainly colder conditions and northerly winds, but it's already slightly above average, so I'd only expect a slight increase here, perhaps 30k.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: OSweetMrMath on March 11, 2015, 11:48:10 PM
I've been holding off on an update on my predictions for the NSIDC extent and PIOMAS volume until the PIOMAS volume numbers for February were posted. Well, this update is now very late, and the PIOMAS monthly volume still hasn't been posted, but Wipneus calculated it as 21.5 thousand cubic km based on the gridded monthly data, so I'm running with that. UPDATE: When I checked the monthly file earlier, it had not been updated. I just poked it again and the February value is 21.456. I've recomputed my predictions, and there have been slight changes due to rounding.

Last month's prediction for the NSIDC monthly extent for February was 14.4 million sq km. The reported value was 14.43 million sq km, so my prediction was accurate to rounding. The interesting thing here is the daily behavior of the ice extent, which started falling in mid February and has continued to fall through March. Because my time series model only uses the monthly data, my prediction for March assumes the extent would increase through March, as it would in a more typical year. This means that my prediction for March is unchanged at 14.7 million sq km, with a 95% confidence interval of 14.2 - 15.3 million sq km. There is still some chance that the extent will increase enough in the next two weeks so the March extent will fall inside my confidence interval, but next month is still likely to result in one of my largest prediction errors of the last year.

I've been waiting for the PIOMAS data to see if the monthly value for the volume would reflect the recent extent loss even if the monthly value for the extent did not. I anticipated a possible reverse of last summer, where the PIOMAS volume was well above my prediction in July, but the NSIDC extent followed my prediction in July and then was above my prediction in August. This possibility was complicated by the fact that extent peaks in February or March, but volume continues to grow until April.

As it turns out, a break in the growth rate for the volume is visible in the daily data, although the volume is continuing to increase. On the other hand, the monthly volume is actually above my prediction. My predicted value was 21.1 thousand cubic km, and the reported value is 21.456 thousand cubic km. The prediction error is larger than I would like, but not so large as to be exceptional.

I have updated my prediction for the maximum volume in April to 24.7 thousand cubic km, with a 95% Confidence Interval of 23.7 - 25.6 thousand cubic km. The change in growth in the daily PIOMAS data in late February implies that this prediction maybe somewhat high, so I would not be surprised if the volume ends up at the low end of this range.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on March 11, 2015, 11:51:31 PM
PIOMAS has been updated, OSMM, all the way up to March 8th.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: viddaloo on March 11, 2015, 11:57:57 PM
PIOMAS has been updated, OSMM, all the way up to March 8th.

That's probably the day before they started their script. Meaning it has been running for two three days straight before it spat out (among other things) 36 daily volume numbers. My advice would be to look into their code to rewrite possible unnecessary loops and other inefficient code, ideally so it can run every day and present volume numbers (total and regional) before lunchtime.

(I would volunteer for the job, but I wouldn't want to live in America if they paid me for it!)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: seaicesailor on March 12, 2015, 12:28:53 AM
PIOMAS has been updated, OSMM, all the way up to March 8th.

(...)

(I would volunteer for the job, but I wouldn't want to live in America if they paid me for it!)

"I refuse to join any club that would have me as a member" ;-)


Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: OSweetMrMath on March 12, 2015, 01:09:59 AM
PIOMAS has been updated, OSMM, all the way up to March 8th.

Thanks. When I checked earlier, the monthly file still had not been updated. I've made small corrections to my previous post based on the correct number.

I realized that I had intended to mention that my post last month provoked some discussion of the maximum extent for the year, with DavidR supporting 14.7 million square km as the daily maximum for the year, rather than the March monthly average as I was predicting. Based on subsequent events, it seems we were both wrong, but I was more wrong than him.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on March 13, 2015, 11:20:35 AM
I won't be calling a maximum yet. The latest ECM suggests a gradual increase in area and extent for the next week.

During the next day or 2, conditions remain ideal for further ice growth in the Baffin sea, perhaps setting the highest area coverage since 2008. The Bering sea has below average temps in the west and close to average in the east, which may allow for a small increase.
Meanwhile, mainly westerly winds an average/slight above average remain over the Barents/Kara region, so little change there or perhaps a slight drop.
Overall, a continued slight increase in area and extent could be expected.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fph03gcF.png&hash=743e1920a91fa47051206a3aa2ef2b10)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FRYqy0T7.png&hash=2912efa44730191800acacd56518b575)

Out to 3-4 days, Baffin sea continues to see cold north westerlies, which could result in further increases. The Bering sea sees a return to weak northerlies and generally average to slightly below average temps. While this generally wouldn't do much, given how low the sea ice currently is there, the forecast conditions will probably cause a continued increase in coverage.
The Barents/Kara region sees further strong westerly winds with well above average temps, so some slight decreases could be seen in this regions.
Overall, I think slight increases Arctic-wide ice coverage during this time.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FV0A9WNd.png&hash=c8ad53b6acc97f220bc1d2151c716afd)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fe3DIenk.png&hash=c6758000706bf4d8479c43e25241b4e6)

Days 4-5 sees a considerable change.
Mixed conditions over the Baffin Sea should see things level off there and perhaps drop back a little. In the Bering sea, while temps remain close to or slightly below average, moderate northerly winds take hold which could help to spread ice south and increase area and extent coverage. Similarly, over the Barents and Kara sea's northerly winds take hold and become strong. With the ice being so mobile this winter, we will likely see a ice spreading out and down from the central Arctic, increasing area and extent here.
Overall, there could be moderate increases during this time.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FMiUnSMC.png&hash=d474b8d58a464a2d142c828dae813a05)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fcf6qkmJ.png&hash=ba07044c427cf3f48f62f8fa147d5c58)

Out to 7 days, the conditions remain favourable for extent and area increases. Northerlies (albeit light) continue in the Bering sea which could result in a slow increase, while Barents/Kara see cooler air and northerlies continuing giving a moderate increase.
Nowhere else should see much change, perhaps a small drop in Baffin. There is warmer air about, such as up near north west Greenland, but that's not enough to cause melt this early in the year.
Overall, continued increases are likely during this time.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2F9ibQuC0.png&hash=e76b930ff0211845f8b5451463599eaa)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FUoQmy1k.png&hash=5669c50fb346a3ceb32d7b5e2bfe7b27)

While I doubt we'll see increases as dramatic as last year, I wouldn't go calling a maximum just yet. Last year saw about 500k increase in area around this time. I wouldn't be surprised if we put on 250k during the next week this year, which would challenge the previous max set in February.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on March 13, 2015, 02:55:08 PM
Days 4-5 sees a considerable change.
Mixed conditions over the Baffin Sea should see things level off there and perhaps drop back a little. In the Bering sea, while temps remain close to or slightly below average, moderate northerly winds take hold which could help to spread ice south and increase area and extent coverage. Similarly, over the Barents and Kara sea's northerly winds take hold and become strong. With the ice being so mobile this winter, we will likely see a ice spreading out and down from the central Arctic, increasing area and extent here.
Overall, there could be moderate increases during this time.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FMiUnSMC.png&hash=d474b8d58a464a2d142c828dae813a05)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fcf6qkmJ.png&hash=ba07044c427cf3f48f62f8fa147d5c58)

Yes, that's the one. If this forecast comes about, things will get exciting!
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Michael Hauber on March 13, 2015, 08:50:42 PM
Also keep in mind the sea of Okhotsk.  While the charts show a little warmer than average conditions for the week keep in mind that the ice there is currently about 150k below previous record lowest max, so even average temps could sea some growth there.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: DavidR on March 19, 2015, 07:46:03 AM
Also keep in mind the sea of Okhotsk.  While the charts show a little warmer than average conditions for the week keep in mind that the ice there is currently about 150k below previous record lowest max, so even average temps could sea some growth there.
Although there appears to be quite a bit of ice increase in the Bering Sea, looking at the satellite  images from EOSDIS I  am wondering if all we are seeing is a lot of ice being spread out over warmer waters where it will melt faster than if it stayed huddled together in the north.

There seems to  be a lot of rapid melt at the edges as well as large areas of open water appearing near the coastline.  This suggests that when the winds switch to southerly  there may not be a lot of ice to blow back to the coast.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Tor Bejnar on March 19, 2015, 02:03:45 PM
The  Arctic HYCOM site (http://www7320.nrlssc.navy.mil/hycomARC/arctic.html)  projects a great deal of under 10% concentration ice spreading out east of Labrador, Canada in the next week.   Of course, this 'under 10% concentration ice' would, if realized, count as naught, but if it became '15% concentration ice', another story.  I wonder if this projection is ice spreading out or new growth or a mixture of the two; the HYCOM wind forecasts are not clear to me.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Shared Humanity on March 20, 2015, 04:17:57 PM
I think  we  can put this Arctic refreeze thread to bed.  :-\
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on March 20, 2015, 05:00:08 PM
I'd say wait until Monday, if we're not within 100k of the Feb max, then it's safe to call it.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Michael Hauber on March 22, 2015, 03:23:38 AM
Just let the thread die from lack of posting.  And if by some fluke, or collective error of reasoning we get a renewed max beyond expectation someone can post about it no problem.

Or we can keep the thread going a little while longer arguing about whether to kill it or not :P
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on March 22, 2015, 10:13:56 AM
I've already un-stickied it.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Tensor on March 22, 2015, 07:56:30 PM
I've already un-stickied it.

Hmmmmmm, does this qualify as you calling the max?  :P
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on March 22, 2015, 08:11:20 PM
I think it's perfectly safe to call the max now. The northerlies through into the Barents and Bering sea's didn't have the expected impact, especially as Hudson Bay lost some coverage at the same time. I wouldn't be surprised to see further increases over the next few days, just not enough to challenge the max.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on March 22, 2015, 08:56:59 PM
Hmmmmmm, does this qualify as you calling the max?  :P

Don't tell anyone.  ;)

The northerlies through into the Barents and Bering sea's didn't have the expected impact, especially as Hudson Bay lost some coverage at the same time.

I had expected more of that combination of cold and winds, especially given the low extent, otherwise I wouldn't have written that blog post. Maybe an effect will become more noticeable in the next 2-3 days, but like you say, most probably not enough to challenge the prelim max.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on March 23, 2015, 09:27:16 AM
I had expected more of that combination of cold and winds, especially given the low extent, otherwise I wouldn't have written that blog post. Maybe an effect will become more noticeable in the next 2-3 days, but like you say, most probably not enough to challenge the prelim max.

There it is, 100K in two days on JAXA SIE. Difference with the prelim max is now 137K.
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: BornFromTheVoid on March 23, 2015, 10:36:27 AM
I had expected more of that combination of cold and winds, especially given the low extent, otherwise I wouldn't have written that blog post. Maybe an effect will become more noticeable in the next 2-3 days, but like you say, most probably not enough to challenge the prelim max.

There it is, 100K in two days on JAXA SIE. Difference with the prelim max is now 137K.

Looking at the JAXA imagery, it seems like the Kara sea has seen a big increase, as well as fresh ice on the north west coast of Russia. Bering has seen an extra push south, and Barents a small increase too.

Looks like these conditions, for the Kara/Barents region, will be reversed during Thursday, so just 3 days left for coverage increases. 194k (265k) off the max with the 5 day (1 day) NSIDC data. A sliver of a chance remaining to beat the max.


(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FpPT0XmZ.png&hash=cc6a8849714b6810eae45b8cc6886237)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FkLaLV9a.png&hash=d22e0e44249fc6d7d16d60c108e48a7a)
Title: Re: Arctic Refreeze Discussion: 2014/2015
Post by: Neven on March 23, 2015, 11:53:06 PM
What the heck, I wrote another blog post about the max: The Ns are calling the maximum (http://neven1.typepad.com/blog/2015/03/the-ns-are-calling-the-maximum.html).

Quote
As expected, the Bering and Barents show an uptick in recent days (black and purple trend lines):

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fneven1.typepad.com%2F.a%2F6a0133f03a1e37970b01bb080d934e970d-pi&hash=dd6ffb2ae8962e80f79e2c4076dc53ad)

And as expected, this uptick was dampened by the start of the melting season on the outer fringes of the ice pack in Baffin Bay and the Gulf of St. Lawrence, where sea ice levels have been high all winter:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fneven1.typepad.com%2F.a%2F6a0133f03a1e37970b01b7c769a03a970b-800wi&hash=fc5a87d1bcd350a16103191c6b9b1a2c)

I won't be posting the forecast in detail, but suffice to say that JAXA needs to report very big upticks in the next two days to make up for the 137K difference with the preliminary max. And all of this ice has to appear in the Barents Sea, because warm waters in the North Pacific seem to be hampering serious ice growth in the Bering Sea.

The forecast has temps increasing and winds decreasing/turning in the Barents Sea after these two days, and so this really is the last opportunity for a slightly higher record. If it wasn't for my promise, I would now be joining the other Ns and call the maximum.