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ra3000

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Re: The 2015/2016 freezing season
« Reply #100 on: October 27, 2015, 11:08:41 AM »
Hey there!
I follow daily since early September the refreezing trend, but I'm new on this.
I'd like to ask why there's a 0,5 million km sq. difference in Arctic extent between MASIE and IJIS.
Which is more "accurate"? Or is it based on difference ice concentration parameters?
Thanks.

Neven

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Re: The 2015/2016 freezing season
« Reply #101 on: October 27, 2015, 08:01:43 PM »
I don't know what the exact reason is, but differences are mostly due to different satellite sensors, resolutions, algorithms, land masks, total Arctic area that is included. Probably more reasons, but these are just a few I can think of!

My experience is that it's not much use comparing different data sets, it's all about comparing different years in one data set (or other).
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DavidR

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Re: The 2015/2016 freezing season
« Reply #102 on: October 28, 2015, 05:53:46 AM »
Hey there!
I follow daily since early September the refreezing trend, but I'm new on this.
I'd like to ask why there's a 0,5 million km sq. difference in Arctic extent between MASIE and IJIS.
Which is more "accurate"? Or is it based on difference ice concentration parameters?
Thanks.
MASIE : https://nsidc.org/data/masie/index.html

MASIE is designed to identify where the edge of the ice is, whereas the Sea ice extent  products identify the areas which have at  least 15% ice coverage.  There can be a lot of water beyond the SIE figures that  still contains lower concentrations of ice. 

MASIE is designed to  provide advice on where it is safe to take a ship rather than provide an estimate of total coverage so  MASIE will always return a higher figure than IJIS or NSIDC sea ice extent.

seaicesailor

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Re: The 2015/2016 freezing season
« Reply #103 on: November 08, 2015, 02:33:56 PM »
Buoy 2015F at CAB (Pacific side) continues to show no thickness growth. This is nothing out of the ordinary since other buoys in the past years did not show growth until December, even January.
Single cherry to be picked out there, it will be interesting to compare its data (especially growth trend) to thickness models.


Neven

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Re: The 2015/2016 freezing season
« Reply #104 on: November 11, 2015, 12:54:46 AM »
AO index is showing some mighty peaks:



Anyone following the freezing season so far? I want to, but can't seem to find the time.  :)
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seaicesailor

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Re: The 2015/2016 freezing season
« Reply #105 on: November 11, 2015, 12:34:48 PM »
AO index is showing some mighty peaks:



Anyone following the freezing season so far? I want to, but can't seem to find the time.  :)

Ice extending fast but lagging in ESS and Kara wrt historical extent. PIOMAS Volume slower increase might reflectn that bottom freezing n thickest areas of CAB is none. Not much Beaufort high nor polar drift nor Fram transport but it was picking up. Temps in NP above average as usual in past years. SSTs all around above average in line with record twmperature year globally. Snow precipitation some, but no idea how it compares to recent years. 2015F is for me the best source of data for this season. Cryosat and SMOS show some strange values as stressed by NSIDC News.
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BornFromTheVoid

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Re: The 2015/2016 freezing season
« Reply #106 on: November 11, 2015, 02:17:44 PM »
Judah Cohen has offered some thoughts on the upcoming winter on his blog.

https://www.aer.com/science-research/climate-weather/arctic-oscillation

The polar vortex is very strong atm. The AO is likely to trend back towards neutral the near to medium term, while there is a signal for a negative AO in the long term during winter.

DavidR

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Re: The 2015/2016 freezing season
« Reply #107 on: November 12, 2015, 08:03:19 AM »
AO index is showing some mighty peaks:



Anyone following the freezing season so far? I want to, but can't seem to find the time.  :)


Ice extending fast but lagging in ESS and Kara wrt historical extent. PIOMAS Volume slower increase might reflectn that bottom freezing n thickest areas of CAB is none. Not much Beaufort high nor polar drift nor Fram transport but it was picking up. Temps in NP above average as usual in past years. SSTs all around above average in line with record twmperature year globally. Snow precipitation some, but no idea how it compares to recent years. 2015F is for me the best source of data for this season. Cryosat and SMOS show some strange values as stressed by NSIDC News.
Cheers

These figures aren't that  high when you consider we are usually given monthly  average.
The figures predict  a very smooth circular jet  stream and right  now that  is just how it  looks.

http://earth.nullschool.net/#current/wind/isobaric/10hPa/orthographic=-94.05,77.28,279

Laurent

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Re: The 2015/2016 freezing season
« Reply #108 on: November 12, 2015, 10:21:55 AM »
I was astounded at first with the regularity of this jet stream and then I wondered ...
Generally I am looking at 250hP
http://earth.nullschool.net/#current/wind/isobaric/250hPa/orthographic=-94.05,77.28,279
The Pole isn't quite so stable !

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Re: The 2015/2016 freezing season
« Reply #109 on: November 14, 2015, 04:23:04 PM »
Judah Cohen has offered some thoughts on the upcoming winter on his blog.

https://www.aer.com/science-research/climate-weather/arctic-oscillation

The polar vortex is very strong atm. The AO is likely to trend back towards neutral the near to medium term, while there is a signal for a negative AO in the long term during winter.

Thanks for that, people at work have been asking me but I haven't had anything to say as I've been otherwise busy.

DavidR

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Re: The 2015/2016 freezing season
« Reply #110 on: November 17, 2015, 09:19:08 PM »
Global Temperatures in October were rated as hottest on record by both NOAA and GISS by  approximately 0.2 deg C. The Northern Hemisphere was particularly hot.

The PDO also remains well above 1 and has now been above 1 for longer than any  period in the record.

This doesn't bode well  for long term predictions of Arctic melt.

jdallen

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Re: The 2015/2016 freezing season
« Reply #111 on: December 02, 2015, 04:13:30 AM »
I've been watching Navy HYCOM for the last week or so.

It appears Fram export is *very* active.   There appears to be a lot more ice being exported than last year - and it is pretty definitively MYI.

I suspect the export may be contributing significantly to the slack SIA numbers we've been seeing.

Link to the animation (yes, it will not be static...)
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim30d.gif
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jdallen

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Re: The 2015/2016 freezing season
« Reply #112 on: December 02, 2015, 04:20:31 AM »
Image from the Canadian weather service.

For all of the temperature being fairly cold, the pack near the CAA and extending into the Beaufort is still not integrated at all.
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jdallen

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Re: The 2015/2016 freezing season
« Reply #113 on: December 02, 2015, 04:24:12 AM »
Some more detail.

Note how seriously the Beaufort pack is dissected.  This is where most observers think the lions share of the thicker ice is located.

My concern is... we are less than 3 weeks from the solstice.  I would expect the ice to be far better consolidated at this point in the refreeze.  It absolutely is not.
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Peter Ellis

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Re: The 2015/2016 freezing season
« Reply #114 on: December 02, 2015, 09:35:13 AM »
I don't know how much we can really read into fracturing during the freezing season.  Remember how "Crackocalypse" in Feb/March 2013 was going to make the entire ice pack melt away that year? Yeah, me too.

Remember that one of the key mechanisms driving fracturing is shrinkage cracking - as ice gets colder, it contracts, which leads to cracking and new ice formation in the resulting leads. The colder it gets, the more shrinkage there is and the wider the cracks are.  Just eyeballing it from space and saying "cracks BAD" is misleading.

jdallen

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Re: The 2015/2016 freezing season
« Reply #115 on: December 02, 2015, 05:35:15 PM »
Peter - I agree it needs to be taken in context, and eventual outcomes depend more on conditions much further along in the season.  I wish I'd archived more of these in order to compare them.
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Neven

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Re: The 2015/2016 freezing season
« Reply #116 on: December 02, 2015, 09:27:22 PM »
I was surprised at this, because my impression was that low pressure areas were dominating the Arctic and for cracking you need high pressure over the Beaufort/CAB, but I just saw that a big high-pressure is positioned there (see below), so the cracking must be a result of the past few days.

As for the effect: At this time of year I think it helps to strengthen the ice, as cracks help the heat to dissipate, with extra, new ice forming in the leads that grows faster than thicker ice.

I wish I'd archived more of these in order to compare them.

Well, those organisations should put their archives online.
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DavidR

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Re: The 2015/2016 freezing season
« Reply #117 on: December 03, 2015, 09:39:27 AM »
NOAA has just  released its temperature estimates for November.

http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl

According to their figures, the Arctic and the area above 80N were hottest on record.

Globally temperatures were more than 0.2 degrees hotter than any  previous November. 

According to their figures we would now need to have the coldest December in their 67 year record to not have the hottest year on record.

Worse than that, if the monthly temperature differential between 2016 and 2015 is the same as that  between 1998 and 1997, the global temperature would jump almost 0.4 degrees.  According to their figures 1997 was the hottest year  on record prior to 1998 and  in the current  El Nino cycle 2015  is comparable to 1997.

Neven

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Re: The 2015/2016 freezing season
« Reply #118 on: December 10, 2015, 06:00:04 PM »
It's winter, so I figured this fits in here (from Science Codex):

NCAR develops method to predict sea ice changes years in advance

BOULDER - Climate scientists at the National Center for Atmospheric Research (NCAR) present evidence in a new study that they can predict whether the Arctic sea ice that forms in the winter will grow, shrink, or hold its own over the next several years.

The team of scientists has found that changes in the North Atlantic ocean circulation could allow overall winter sea ice extent to remain steady in the near future, with continued loss in some regions balanced by possible growth in others, including in the Barents Sea.

"We know that over the long term, winter sea ice will continue to retreat," said NCAR scientist Stephen Yeager, lead author of the study published online today in the journal Geophysical Research Letters. "But we are predicting that the rate will taper off for several years in the future before resuming. We are not implying some kind of recovery from the effects of human-caused global warming; it's really just a slow down in winter sea ice loss."



The researchers tested how well they were able to predict winter sea ice changes by "hindcasting" past decades and then comparing their retrospective predictions to observations of what really happened. This image shows how the model stacked up to real life for the period of 1997-2007. Credit: ©UCAR

The research was funded largely by the National Science Foundation, NCAR's sponsor, with additional support from the National Oceanic and Atmospheric Administration and the U.S. Department of Energy.

Yeager is among a growing number of scientists trying to predict how the climate may change over a few years to a few decades, instead of the more typical span of many decades or even centuries. This type of "decadal prediction" provides information over a timeframe that is useful for policy makers, regional stakeholders, and others.

Decadal prediction relies on the idea that some natural variations in the climate system, such as changes in the strength of ocean currents, unfold predictably over several years. At times, their impacts can overwhelm the general warming trend caused by greenhouse gases released into the atmosphere by humans.

Yeager's past work in this area has focused on decadal prediction of sea surface temperatures. A number of recent studies linking changes in the North Atlantic ocean circulation to sea ice extent led Yeager to think that it would also be possible to make decadal predictions for Arctic winter sea ice cover using the NCAR-based Community Earth System Model.

Linking ocean circulation and sea ice

The key is accurately representing the Atlantic Meridional Overturning Circulation (AMOC) in the model. AMOC sweeps warm surface waters from the tropics toward the North Atlantic, where they cool and then sink before making a return south in deep ocean currents.

AMOC can vary in intensity. When it's strong, more warm water is carried farther toward the North Atlantic and Arctic oceans, accelerating sea ice loss. When weak, the warm water largely stays farther south, and its effects on sea ice are reversed. The variations in AMOC's vigor--from weak to strong or vice versa--occur over multiple years to decades, giving scientists some ability to predict in advance how it will affect winter sea ice, in particular.

AMOC now appears to be weakening. Yeager and his co-authors, NCAR scientists Alicia Karspeck and Gokhan Danabasoglu, found in their new study that this change in the ocean is likely to be enough to temporarily mask the impacts of human-caused climate change and stall the associated downward trend in winter sea ice extent in the Arctic, especially on the Atlantic side, where AMOC has the most influence.

The limits of a short satellite record

The amount of sea ice covering the Arctic typically grows to its maximum in late February after the long, dark winter. The sea ice minimum typically occurs at the end of the summer season, in late September. The new study addresses only winter sea ice, which is less vulnerable than summer ice to variations in weather activity that cannot be predicted years in advance, such as storms capable of breaking up the ice crust.

Despite their success incorporating AMOC conditions into winter sea ice "hindcasts," the scientists are cautious about their predictions of future conditions. Because satellite images of sea ice extend only back to 1979, the scientists had a relatively short data record for verifying decadal-scale predictions against actual conditions. Additionally, AMOC itself has been measured directly only since 2004, though observations of other variables that are thought to change in tandem with AMOC--such as sea surface height and ocean density in the Labrador Sea, as well as sea surface temperature in the far North Atlantic--go back much farther.

"The sea ice record is so short that it's difficult to use statistics alone to build confidence in our predictions," Yeager said. "Much of our confidence stems from the fact that our model does well at predicting slow changes in ocean heat transport and sea surface temperature in the subpolar North Atlantic, and these appear to impact the rate of sea ice loss. So, we think that we understand the mechanisms underpinning our sea ice prediction skill."
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Pmt111500

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Re: The 2015/2016 freezing season
« Reply #119 on: December 11, 2015, 04:15:40 AM »
Thank you Neven for highlighting the study. It looks like the model they've used has underestimated the accumulation of oceanic heat during the pretty long absence of strong El Ninos. The whys and hows of the Atlantic side of the world ocean are a bit harder to get though. could blame the whole discrepancy there on more pronounced GW and the intensification of AO compared to the model, but that would be a cheapo, as they are pretty much derived qualities of the ocean-atmospheric system in the case of excess energy. We've seen warmish currents reach Arctic pretty regularly, though. Has there, for example, been an increase in the exchange between the Indian Ocean and the south Atlantic to give the Atlantic side melt the boost we see? Also it looks to me that Greenland melt hasn't been much of a contributor here. But that fits into my view of the world, the oceanic and atmospheric effects of Greenland melting should be more of a seasonal thing, in my view anyway. Well, until the melt there is such it cannot be ignored by the denialists ;-).
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Re: The 2015/2016 freezing season
« Reply #120 on: December 11, 2015, 10:25:52 AM »
I must say that for a model based on hindcasting, after the parameters were tweaked and fitted to known data, the forecast they are showing compared to the actual result for 1997-2007 is pretty poor. I distrust any predictions made by this model for the next few years.

Neven

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Re: The 2015/2016 freezing season
« Reply #121 on: December 16, 2015, 04:25:01 PM »
Over on another thread a new member asked the following question:

Hi,

I'm new to the site so forgive me if this has been covered before but could somebody explain this massive fracture showing on the AARI website?
 
http://www.aari.ru/odata/_d0015.php?lang=1&mod=0&yy=2015   

I've tried researching online but have been unable to find an explanation. Cheers

My answer:

I'm not sure the fracture is real, although there has been some cracking recently because of a high-pressure area over the Beaufort. On the other hand, I think I'm seeing something on this radar image (but very faintly).

It looks like AARI may have exaggerated the crack, but it's still an interesting observation. Anyone else have another idea/opinion?

Edit: not seeing anything on the more detailed Environment Canada radar image:
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crandles

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Re: The 2015/2016 freezing season
« Reply #122 on: December 16, 2015, 04:53:17 PM »
Not too uncommon on AARI eg

http://www.aari.ru/resources/d0015/arctic/gif.en/2015/20150407.GIF
http://www.aari.ru/resources/d0015/arctic/gif.en/2015/20150127.GIF

Couldn't see similar in Dec but not sure that means much  - other than perhaps there is currently plenty of time over remainder of winter for ice to thicken and heal.

Jim Hunt

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Re: The 2015/2016 freezing season
« Reply #123 on: December 16, 2015, 07:31:16 PM »

It looks like AARI may have exaggerated the crack, but it's still an interesting observation. Anyone else have another idea/opinion?


Sentinel 1A via PolarView catches part of the "crack":

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johnm33

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Re: The 2015/2016 freezing season
« Reply #124 on: December 16, 2015, 08:20:52 PM »
Looking at Null School persistent winds for a few days probably got the ice moving, then circumstances were just right  for a massive compensating internal wave to wash up against the shelf/shore of the islands, crack opens and rapidly freezes over. Well thats my guess. http://www7320.nrlssc.navy.mil/hycomARC/beaufort.html  Worth looking at  thickness movement and opening.

jdallen

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Re: The 2015/2016 freezing season
« Reply #125 on: December 17, 2015, 12:36:52 AM »
Looking at Null School persistent winds for a few days probably got the ice moving, then circumstances were just right  for a massive compensating internal wave to wash up against the shelf/shore of the islands, crack opens and rapidly freezes over. Well thats my guess. http://www7320.nrlssc.navy.mil/hycomARC/beaufort.html  Worth looking at  thickness movement and opening.


It doesn't seem like anything that much out of the ordinary considering our experience of the last 3-4 years, especially considering the general lack of integration of the ice.

I'm more concerned about the rather thin ice over large stretches of the Chukchi, Kara and Barents and to a lesser degree the ESS.  I'm anxious to see that thicken up.

Wild card - the Fram has been ramping up.  That wasn't much of a factor the last couple of years and is now pulling a moderate amount of remaining MYI out of the basin.
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Re: The 2015/2016 freezing season
« Reply #126 on: December 17, 2015, 11:30:46 AM »
Thanks for the welcome's and informative replies. Having looked at the 30 day gif http://www7320.nrlssc.navy.mil/hycomARC/navo/beaufortictn_nowcast_anim30d.gif supplied by Johnm33, could this fracture have originated from a (possible)methane hole which showed up in October? http://arctic-news.blogspot.co.uk/2015/10/methane-vent-hole-in-arctic-sea-ice.html . Rather like a windscreen chip turning into a crack.

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Re: The 2015/2016 freezing season
« Reply #127 on: December 17, 2015, 01:10:19 PM »
The crack is sort of interesting but it's more indicative of the changing weather patterns over the ice at the moment.

Far more interesting is the way that the consistent low pressure systems south east of Greenland over the last month have contributed to sucking ice through the Fram straight.

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim30d.gif

Looking at nullschool shows how the winds at the moment are helping to build the gyre again whilst there is still a flow through the Fram. As the ice pack consolidates and gets colder its viscosity changes leading to less slushie type movements and more brittle fractures.

http://earth.nullschool.net/#current/wind/isobaric/1000hPa/overlay=temp/orthographic=-89.56,83.97,1045



jdallen

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Re: The 2015/2016 freezing season
« Reply #128 on: December 17, 2015, 05:53:20 PM »
Thanks for the welcome's and informative replies. Having looked at the 30 day gif http://www7320.nrlssc.navy.mil/hycomARC/navo/beaufortictn_nowcast_anim30d.gif supplied by Johnm33, could this fracture have originated from a (possible)methane hole which showed up in October? http://arctic-news.blogspot.co.uk/2015/10/methane-vent-hole-in-arctic-sea-ice.html . Rather like a windscreen chip turning into a crack.

An appealing but flawed conclusion I'm afraid.

To prove this you would have three problems which your proof would have to overcome.

1) Thermal lag - the prompt forcing caused by CH4 would be negligible. It's impact would show up only after a fairly significant passage of time.

2) Diffusion - even if emitted in volume, concentrations of CH4 would be rapidly dispersed over a large volume and area (think - millions of cubic kilometers of atmosphere).  By extension, the change in forcing would be similarly dispersed.

3) Amplitude - The net change in local forcing per square meter would be quite low, even with fairly large emissions of CH4.  The transitory effects would be far less than that caused by fluctuations in humidity and cloud cover.

CH4 is a potential amplifier of greenhouse forcing, but its effect will be expressed over longer time frames - years to decades - rather than days to weeks.

As others have said, the crack is more indicative of weather than anything else.
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Neven

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Re: The 2015/2016 freezing season
« Reply #129 on: December 17, 2015, 08:44:26 PM »
could this fracture have originated from a (possible)methane hole which showed up in October?

No, and I advise you to be wary of anything that originates at that blog. What they very often do, is make a mountain out of a glitch or artifact on some graph or map (usually those from the Naval Research Laboratory, which has had problems in the past few months).

And how could it be heat from some volcano on the Gakkel ridge? It would have to well up through hundreds of metres (kilometres?) of water, and the halocline and everything, and then end up right there in that 'small' spot? Impossible.

The crack is sort of interesting but it's more indicative of the changing weather patterns over the ice at the moment.

Far more interesting is the way that the consistent low pressure systems south east of Greenland over the last month have contributed to sucking ice through the Fram straight.

I agree. The crack on AARI is interesting because it's so long, because it's not accompanied by several other cracks, and because of the time of year (I've seen those pink cracks before during cracking events). But it will probably be gone on the next AARI Ice Analysis map, and have very little effect on the ice (if it has, it's probably thickening it).

Transport through Fram on the other hand, is usually bad for MYI.
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Jim Hunt

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Re: The 2015/2016 freezing season
« Reply #130 on: December 17, 2015, 10:48:55 PM »
Nothing to do with methane holes, but Sentinel has now covered some more of the area between the CAA and the Pole:

Reality is merely an illusion, albeit a very persistent one - Albert Einstein

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Re: The 2015/2016 freezing season
« Reply #131 on: December 17, 2015, 10:52:29 PM »
And so has RadarSat:

Reality is merely an illusion, albeit a very persistent one - Albert Einstein

GT

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Re: The 2015/2016 freezing season
« Reply #132 on: December 18, 2015, 12:25:37 AM »
Thanks for the detailed response jdallen and for expertly picking apart my amateur theory ;) I must admit that I don't fully understand the detail of what you have written as I am basically a novice weather watcher trying to better understand the Polar Vortex and it's influence on the weather at the lower latitudes of Europe and the UK. I will however research the points in your response...so cheers for the extra homework!

Neven, thanks also for setting me straight and for your advice to take the information from that other blog with a large pinch of salt. As stated above I am far less knowledgeable on this subject than the likes of yourself but I am enjoying learning as I go using your excellent blogs.

   

jdallen

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Re: The 2015/2016 freezing season
« Reply #133 on: December 18, 2015, 09:40:11 AM »
And so has RadarSat:


Nothing really standing out as exceptional.  At a macro level it looks broadly similar to both 2013 and 2014, perhaps a bit more dissected.  The major difference that seems to stand out to me is the increased export through the Fram and lack of ice development on the Atlantic side.

On the Pacific side, the Chukchi, Bering and Okhosk don't seem to be doing anything particularly unusual.  Hudson's bay's coverage is lower, but probably as a side effect of the exceptional warmth being sent NE across the Great Plains of North America.  Those flows of heat I've occasionally been able to track back to the El Nino heated expanses off of SW Mexico.  Fascinating to be able to follow it all the way up to Greenland.

All in all, in spite of some of my earlier excitement, pretty blaise.
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Re: The 2015/2016 freezing season
« Reply #134 on: December 23, 2015, 11:20:43 PM »
And again, a highly positive AO, accompanied by a slowdown in sea ice extent/area growth. Due to the position of the large lows in the northern Atlantic there's a lot of transport through Fram right now.
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Neven

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Re: The 2015/2016 freezing season
« Reply #135 on: December 23, 2015, 11:33:32 PM »
I quickly made this animation of ASCAT radar images for the past week:



You can clearly see Fram transport picking up, and on the other side MYI getting transported further into the Beaufort Sea and towards the Chukchi Sea. The cracks we talked about earlier, also show up more clearly now, but they're fading away on the latest AARI ice analysis map.
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jdallen

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Re: The 2015/2016 freezing season
« Reply #136 on: December 25, 2015, 04:01:42 AM »
I quickly made this animation of ASCAT radar images for the past week:

<snippage>

You can clearly see Fram transport picking up, and on the other side MYI getting transported further into the Beaufort Sea and towards the Chukchi Sea. The cracks we talked about earlier, also show up more clearly now, but they're fading away on the latest AARI ice analysis map.


That export is worrisome, as it's taking old ice out of the arctic at the rate of 10-20,000KM2/day.

Also worrisome is the extraordinarily high temps in the Barents (in spite of the North Atlantic chilling some).

We have a fairly strong polar vortex, but there are still bursts of energy intruding into the arctic.  there's cold air being shoved out ... but it's not *as* cold as it should be.  Lots of places are 10-15C warmer than normal, and over all, the entire region is quite a bit warmer, which is in line with predictions for Arctic Amplification.

I'm expecting the minimum to be somewhere in line with last years, +/- 5% or so.  If the export continues, I'm thinking next year's melt season will take a serious run at 2012.
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jdallen

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Re: The 2015/2016 freezing season
« Reply #137 on: December 26, 2015, 09:42:20 AM »
There apparently is some astonishingly weather coming up for the CAB over the next 96 hours or so.  Climate Reanalyzer has portions of the central basin warming over 40C, to the extent that significant areas of the pack north of 80 will be exposed to above freezing temperatures; almost warm enough to permit surface melt of the snow pack.

There may be rain as far north as Svalbard.

Anyone have context for how singular this is?  It seems pretty extreme from what I can tell.  It certainly doesn't look favorable to building volume.
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Tensor

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Re: The 2015/2016 freezing season
« Reply #138 on: December 27, 2015, 04:52:52 AM »
I don't have an answer for you jdallen, but after reading your post, I looked at the predicted temperature anomaly on the GFS World Map (not the Arctic map) at Climate Reanalyzer.   At 108 hours out, the entire top of the map (say from 85 to 90 North was a bright red.  Wow.
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jdallen

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Re: The 2015/2016 freezing season
« Reply #139 on: December 27, 2015, 05:12:24 AM »
I don't have an answer for you jdallen, but after reading your post, I looked at the predicted temperature anomaly on the GFS World Map (not the Arctic map) at Climate Reanalyzer.   At 108 hours out, the entire top of the map (say from 85 to 90 North was a bright red.  Wow.

Yah, it's alarming.  However, past about 72-96 hours out, the reliability of the forecast decays dramatically.

Out past that, mostly I look at it to understand expected trends.  In that regard, yes, it looks pretty disturbing.
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jdallen

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Re: The 2015/2016 freezing season
« Reply #140 on: December 27, 2015, 05:24:44 AM »
But, what the heck, let's go out full bore, 177 hours and have a look at what the model thinks the trend will be.  Be advised, this is what the model is suggesting; it's far from solid, but even so...

Yikes!

The model just doesn't think the arctic is going to get "cold"....
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werther

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Re: The 2015/2016 freezing season
« Reply #141 on: December 27, 2015, 09:05:52 AM »
Thanks for pointing at the forecasts. It fits with some pretty amazing ridging projected by ECMWF:



The locked position of the planetary waves hasn’t changed much since I analysed it a couple of days ago on the ‘Weird weather’-thread. Still ridges over Eastern N America and Europe. And a firm trough over Greenland. But it did move some, including a tremendous amplitude.

Reaching out into the Laptev Sea, it almost joins another strong ridge along America’s Western coast and into the Beaufort Sea.
It also suggests a splitting SSW, but I haven’t noticed it on the CPC timeseries yet.

Shared Humanity

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Re: The 2015/2016 freezing season
« Reply #142 on: December 27, 2015, 02:34:40 PM »
I speculated about the role that an ice covered Greenland in an era of disappearing sea ice might play in northern hemisphere weather several years ago. While the rest of the Arctic is changing dramatically with regards to its interaction with the atmosphere, ice covered Greenland, despite the melt of the sheet, is still ice covered. Could this cold pole be impacting the behavior of the jet stream? Said differently, is the cold pole shifting towards Greenland as the Arctic Ocean north of 80 becomes more ice free with significant heat released into the atmosphere, particularly in the early winter? As is typical, I have little actual knowledge to suggest such a thing....pure speculation on my part.

I can't be sure but it seems that lows frequently settle over Greenland, just as it has now. Is this pattern one of the reasons for the persistent rain over Britain for the past few seasons?

One of the reasons for the question is I am really fixated on the issue of stuck weather patterns and am constantly perusing threads on this site, trying to glean some insight into this issue.
« Last Edit: December 27, 2015, 02:42:12 PM by Shared Humanity »

jdallen

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Re: The 2015/2016 freezing season
« Reply #143 on: December 27, 2015, 09:43:57 PM »
I'm going to redirect my postings from the SIA/SIE discussion to here.

http://forum.arctic-sea-ice.net/index.php/topic,1112.msg67472.html#msg67472

I think Greenland absolutely is a key factor here - both for the ice, and for the obstacle.  a 2-3KM block of ice ~500+ KM wide by ~2000 KM long will absolutely alter low level circulation.  The high level circulation we are seeing tends to support your speculation as well.
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bbr2314

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Re: The 2015/2016 freezing season
« Reply #144 on: December 27, 2015, 10:18:59 PM »
bbr2314 I've been having similar thoughts, except in my scenario the 3 cells collapse to 1, and then the prevailing winds blow to the south and west. After a chaotic period the remaining NAD gets pushed against the east coast of Greenland through Fram and then into the CAB. So lots of rain on Greenland, and an ice free north CAA. The warm current bathes eastern Siberia giving it a permanent spring climate. The fresh waters flowing into the Arctic, from Siberia, are pushed west, by prevailing winds, and emerge into the north Atlantic around Britain plunging it into permanent winter, with the North sea frozen over for much of the year. Pacific waters continue to flow in and carry most of the fresher waters, from Alaskan and Canadian rivers, with them through the CAA. Lots more snow to the west of Greenland/Baffin/Hudson and in Europe to the west of the Urals and on the northern slopes of the Pyrenees/Alps/Carpathians. So two cold 'poles' to make the weather interesting.


^this is particularly relevant to what is being discussed above, IMO. and it seems to be happening before our eyes...

(other relevant comments in thread: http://forum.arctic-sea-ice.net/index.php/topic,1423.0.html)

Shared Humanity

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Re: The 2015/2016 freezing season
« Reply #145 on: December 27, 2015, 10:49:42 PM »
I'm going to redirect my postings from the SIA/SIE discussion to here.

http://forum.arctic-sea-ice.net/index.php/topic,1112.msg67472.html#msg67472

I think Greenland absolutely is a key factor here - both for the ice, and for the obstacle.  a 2-3KM block of ice ~500+ KM wide by ~2000 KM long will absolutely alter low level circulation.  The high level circulation we are seeing tends to support your speculation as well.


Thanks jdallen. I went over there and looked at the comments.

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Theta

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Re: The 2015/2016 freezing season
« Reply #147 on: December 28, 2015, 02:48:50 PM »
The refreeze was off to a good start, but now it seems that 2016 is going to.beat the ice to a pulp
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jdallen

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Re: The 2015/2016 freezing season
« Reply #148 on: December 28, 2015, 06:17:17 PM »
In view of current weather conditions and strong surface air flows encouraging export out the Fram, I did some browsing for relevant research.

Found this, looked interesting.

http://www.the-cryosphere-discuss.net/9/4205/2015/tcd-9-4205-2015-print.pdf

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Shared Humanity

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Re: The 2015/2016 freezing season
« Reply #149 on: December 28, 2015, 07:53:10 PM »
I understand why traffic to this site drops after the melt season but am not sure why it drops so severely. I find the freeze season just as interesting and it provides a valuable context with which to watch the next melt season. Needless to say, this freeze season is very fun to watch.