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MikeAinOz

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Re: The Nares Strait thread
« Reply #450 on: January 24, 2015, 10:57:11 PM »
I also have been watching, bc, and I think this is exceptional. I was trying to figure out if the Nares Strait arches were going to form and block the strait, and when they normally do form when I came across this: http://www.nasa.gov/topics/earth/features/earth20100218.html regarding the arches and what happened in 2007. There are other awesome things happening in the Arctic, particularly in Greenland, but this gets my upvote for awesomeness   :).
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #451 on: January 25, 2015, 06:41:21 AM »
I have compared Sentinel images of the Lincoln Sea dated 01-22 and 01-24.  All distance moved are over this two day period.

A large floe in the middle of Lincoln Sea went about 7 km.  A large floe almost to Nares Strait (on 01-24) went about 20 km.  Floes closer to or in Nares went further (45 km or more). 

Looking at ice floes in the upper left part of the images that, although with identifiable boundaries, are in close contact with their pre-separated neighbors, and ice that looks to be part of the Arctic ice sheet (no clear floe boundaries, at the top left of the image) I see ice moving 9 to 12 km toward Nares Strait.  (Some cracks open wider, and others close up.)

From this data, I conclude that not only is ice breaking off the Arctic ice sheet in the Lincoln Sea and heading for the Nares Strait, but that a section of the Arctic ice sheet is also moving toward the Lincoln Sea. 

Looking at ice in the upper center and upper right of these Sentinel images, the ice is moving very little; in some places it is moving a tiny bit toward Fram Strait. 

Comparing NOAA  AVHRR images (2015-01-19  13:30 and 2015-01-23  12:46 - among the best recent images available) that show a much larger part of the Arctic (over 400 km north of Nares Strait), note the major crack that goes from the Ellesmere coast near Nares Straight almost straight up the images.  I can identify marks on the ice to the left of this major crack (e.g., one about 270 km from Nares) that don’t move between these two images, whereas marks to the right of this crack (e.g., one also about 270 km from Nares) show about 7 km movement toward Nares. (A mark about 400 km north of Nares moved about 10 km, but as it is to the right of a Fram-related crack, its motion is toward a point on Greenland some 200 km east of Nares.)  This data supports my conclusion (above) that a section of the Arctic ice sheet is moving toward Lincoln Sea, although this movement may be more related to what I have called Fram Strait related cracking and that the movement toward Nares may be coincidental.

With my geological education, I call a crack that has transverse movement (like the San Andres fault) a fault.  Natural ice is a mineral, so the ice sheet and floes, etc. are monomineralic rocks.  I consider the major cracks identified in the previous paragraph which have transverse movement to be faults.

All of these images are available from http://ocean.dmi.dk/arctic/kane.uk.php.  [All of these distances are very approximate, given, among other things, the poor quality of the wooden ruler I’m using.]

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Tor Bejnar

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Re: The Nares Strait thread
« Reply #452 on: January 25, 2015, 06:59:37 AM »
Besides the no-ice-bridge in 2006-7, only a short-lived bridge formed in 2007-8 (lasted 65 days, starting, I think, in March).  All it will take is for one sturdy floe to get stuck.  The 'shark' got stuck for a day or so, but then shattered.
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Wipneus

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Re: The Nares Strait thread
« Reply #453 on: January 25, 2015, 09:41:53 AM »
Sonia's ice floe/berg seems to have raced to Franklin island. I could be wrong, but there is no data in the public Sentinel archive of this area after Jan 22.

Tor Bejnar

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Re: The Nares Strait thread
« Reply #454 on: January 25, 2015, 03:38:42 PM »
Yes, Sonia's floe/berg moved 90 km in two days.  A recognizable floe behind it went 75 km and one ahead of it went only 65 km.  As Sonia's iceberg(?) is going faster than nearby floes, I think it might be an iceberg that is more strongly affected by Nares current. (The wind at two points on/near Nares Strait is a crosswind, per http://stratus.ssec.wisc.edu/products/rtpolarwinds/, so the iceberg's speed is unlikely associated with wind.)
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Sonia

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Re: The Nares Strait thread
« Reply #455 on: January 25, 2015, 06:34:18 PM »
Interesting wind links, Tor, I didn't know those.  But if the wind is determined from cloud tracking, I would expect it may or may not correspond well to surface wind.  I kind of like http://dalriada.sams.ac.uk/aws_hans/ as a surface data point on the Nares.

Incidentally, the weather station is currently reporting that the wind has recently dropped.  So I'll be watching the Kane for arch formation.  From the latest Sentinal images, the channel of briskly moving ice has been narrowing and other ice in the Kane, while not completely stationary, has looked sluggish.  I can imagine that these conditions -- sluggish ice and light winds -- might be conducive to freeze up.

A-Team

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Re: The Nares Strait thread
« Reply #456 on: January 25, 2015, 10:54:42 PM »
This has some potential for visual comparison of different multiple dates ... but I wouldn't say that potential was realized yet ...

viddaloo

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Re: The Nares Strait thread
« Reply #457 on: January 26, 2015, 09:50:35 AM »
Check out this 20C anomaly 'heatwave' over Fram:

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Jim Hunt

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Re: The Nares Strait thread
« Reply #458 on: January 26, 2015, 10:13:31 AM »
Check out this 20C anomaly 'heatwave' over Fram:

Looks cold in Kane though, which is the topic of this thread?
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

A-Team

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Re: The Nares Strait thread
« Reply #459 on: January 26, 2015, 11:28:26 AM »
Just to follow up on MikeAinOz's link above on the time series of ice export through Nares: that story references two papers, both online, by R Kwok that provide a 13 year record. A 2014 poster suggests that a follow-up study is well underway. It is hard to discern a trend given natural variability and a fairly short record.

A O'Brien 2014. Variability of Arctic Sea Ice Export and Deformation through Nares Strait
http://www.candac.ca/create/ss2014/posters/obrien_ashley_CSI_poster_2014.pdf

R Kwok 2010. Large sea ice outflow into Nares in 2007
http://onlinelibrary.wiley.com/doi/10.1029/2009GL041872/full

R Kwok 2005. Variability of Nares Strait ice flux
http://onlinelibrary.wiley.com/doi/10.1029/2005GL024768/full

viddaloo

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Re: The Nares Strait thread
« Reply #460 on: January 26, 2015, 02:54:17 PM »
Check out this 20C anomaly 'heatwave' over Fram:
Looks cold in Kane though, which is the topic of this thread?
I bet we'll see repercussions of this in the Lincoln Sea above the Nares Strait, as the collapse zones of the two straits are practically already merged. And this heatwave can easily spread to the Nares itself, plus there is a 10C anomaly already in the Lincoln. But other than that, I agree with you, we should stay on topic and stick to the Nares.
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #461 on: January 26, 2015, 03:00:41 PM »
Sentinel images of 01-24 and 01-25 of "Kennedy" (Robeson Channel and a spot of Hall Basin and Lincoln Sea) show ice moving into Robeson Channel going about 30 km (in one day) and floes already in the channel going up to 65 km. 

There are no Sentinel images showing the active flow in Kane Basin or the north end of Baffin Bay on 01-25, so cannot tell how fast ice is moving there.
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solartim27

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Re: The Nares Strait thread
« Reply #462 on: January 26, 2015, 07:48:09 PM »
Nice coverage today.  The latest large floe is off of Peterman at one of the usual sticking points, moved really far from yesterday. There's one more large chunk in Lincoln getting ready to try to plug it up, could that be the last chance of an ice bridge this year?  I think so, nothing else looks big enough.
 
http://ocean.dmi.dk/arctic/images/MODIS/Kennedy/20150126s01a.ASAR.jpg

http://ocean.dmi.dk/arctic/images/MODIS/Lincoln/20150126s01a.ASAR.jpg
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #463 on: January 26, 2015, 09:50:19 PM »
Sonia's iceberg(?) went about 130 km in two days.  On 01-26 Sentinel it is in the middle of the actively flowing channel in the (top) middle of Kane Basin.  (It is 7 and 30 km behind two floes that it was 20 and 65 km behind on the 01-24 Sentinel image.)

Floes leaving Nares Strait and entering Baffin Bay traveled about 45 km in two days.  Floes just in Robeson Channel went 20 km this past one day.  Floes in Lincoln Sea moved 4 or 5 km in one day. 

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MikeAinOz

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Re: The Nares Strait thread
« Reply #464 on: January 26, 2015, 10:51:50 PM »
Hey A-Team thanks for a great post and some great links. The short period and changing conditions make it difficult to say anything but the obvious, that it's a little late in the season for ice arches, but we should see some soon  :). A little more googling took me to Icy Seas at http://icyseas.org/tag/nares-strait/  and Andreas Muenchow's fine post on the physics of the Nares Strait, which left me a more informed on the subject.
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Sonia

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Re: The Nares Strait thread
« Reply #465 on: January 27, 2015, 02:38:17 AM »
A-Team, thanks.  The papers were interesting.  The attached graph from the 2010 paper shows how February is a typical time for ice outflow to drop, so I think arch formation this year isn't overdue at all here in January still.

Tor, thanks for running the numbers.  Yep, ice is still ripping right through the Kane.  A day of light winds wasn't enough to let the passage freeze up and now the northerlies have returned.  I guess I'll go back to watching for a show stopper in the Robeson.

viddaloo

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Re: The Nares Strait thread
« Reply #466 on: January 27, 2015, 12:03:49 PM »
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?

This site is great, Gråbein!

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viddaloo

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Re: The Nares Strait thread
« Reply #467 on: January 27, 2015, 12:28:33 PM »
12 UTC today over Nares: 15–20C above normal.
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #468 on: January 27, 2015, 05:07:24 PM »
Thanks, viddaloo for putting the http://www.woksat.info/wos.html link (daily images of entire Nares Strait, etc.) on this thread.  It is quite amazing.
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viddaloo

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Re: The Nares Strait thread
« Reply #469 on: January 27, 2015, 05:31:49 PM »
You're welcome, Tor.

Lincoln Sea–centric winter heatwave: Wonder how it all will look in a couple days when the clouds clear over Fram & Nares.

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Tor Bejnar

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Re: The Nares Strait thread
« Reply #470 on: January 27, 2015, 09:17:31 PM »
Interesting event happening in the Lincoln Sea, per the very partial Sentinel image dated 2015-01-27.  While floes within the Lincoln Sea continue to move toward Nares Strait at 5 or so Km per day, the ice against Greenland has lifted off a few km in the past day.

Rather exciting for a 'watching ice disappear in the winter' sort of guy. :D
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viddaloo

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Re: The Nares Strait thread
« Reply #471 on: January 27, 2015, 10:44:45 PM »
While floes within the Lincoln Sea continue to move toward Nares Strait at 5 or so Km per day, the ice against Greenland has lifted off a few km in the past day.

Probably related to the so–called heatwave? Do you reckon the pull on it is from the Nares?
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solartim27

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Re: The Nares Strait thread
« Reply #472 on: January 28, 2015, 01:16:37 AM »
Wind.
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viddaloo

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Re: The Nares Strait thread
« Reply #473 on: January 28, 2015, 08:45:01 AM »
Interesting event happening in the Lincoln Sea, per the very partial Sentinel image dated 2015-01-27.  While floes within the Lincoln Sea continue to move toward Nares Strait at 5 or so Km per day, the ice against Greenland has lifted off a few km in the past day.

Rather exciting for a 'watching ice disappear in the winter' sort of guy. :D

Almost looks like the Nares Strait was extended beyond the north tip of Greenland?

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viddaloo

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Re: The Nares Strait thread
« Reply #474 on: January 28, 2015, 12:56:35 PM »
Looks like that's just what happened.

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Laurent

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Re: The Nares Strait thread
« Reply #475 on: January 28, 2015, 02:23:14 PM »
Ouahou...could it be that the Atlantic is surfacing in arctic ?...let's see...
Thanks for the updates.

viddaloo

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Re: The Nares Strait thread
« Reply #476 on: January 28, 2015, 04:58:09 PM »
Yup. Meet the new, extended Nares Strait. Twice the length.
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Jim Hunt

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Re: The Nares Strait thread
« Reply #477 on: January 28, 2015, 05:07:33 PM »
A cross post of the AMSR2 version also:

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

viddaloo

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Re: The Nares Strait thread
« Reply #478 on: January 28, 2015, 05:38:20 PM »
The Arctic is now officially toast, guys. Waiting for them melt records to fall.

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viddaloo

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Re: The Nares Strait thread
« Reply #479 on: January 28, 2015, 05:47:41 PM »
Hat–tip to Arctic News:

Quote
´When the Arctic ice cap finally melts towards the end of next year, the Arctic sea will be aggressively heated by the sun and the Gulf Stream. The cold Arctic air will then be confined to the Greenland Ice cap and the hot Arctic air with its methane will flow south to the United States to further heat up the Gulf Stream, setting up an anticlockwise circulation around Greenland. Under these circumstances Great Britain and Europe must expect even more catastrophic storm systems, hurricane force winds and massive flooding after the end of next year, due to a further acceleration in the energy transport of the Gulf Stream.´
« Last Edit: January 28, 2015, 06:19:04 PM by viddaloo »
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #480 on: January 28, 2015, 06:22:41 PM »
I'm also interested in the cracks that both follow and are perpendicular to the Ellesmere Island coast in and near the Lincoln Sea that show up in two recent posts from viddaloo's (from this morning) .

Here is a train or jumble of thoughts (unrelated to the ice pulling away from the Greenland and Ellesmere coasts):
1) Arctic ice piles up against Canadian islands and Greenland due to prevailing winds and currents.
2) An open Nares Strait is allowing export of ice from the Lincoln Sea.
3) Arctic ice that is shoved toward the Lincoln Sea is able to move faster and easier than ice that has to buckle, fold and raft (or ice that is behind this buckling and rafting ice) if it is to move much at all. In fact, ice heading toward the Lincoln Sea will do very little buckling and rafting.
4) With a little time, cracks facilitate more ice being channeled towards the Lincoln Sea.
5) Until Nares Strait is closed down, the Arctic ice in this funnel area will be more fractured and thinner (less rafted, etc.) than it would be otherwise.  If Nares never closes down (as in 2006-07), the following early summer melt may have a significant head start.

6) Fram Strait provides the same (but much larger) outlet, but as it never closes, its processes are part of the status quo.
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viddaloo

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Re: The Nares Strait thread
« Reply #481 on: January 28, 2015, 06:47:41 PM »
Wind.

Nah.

Sentinels show the ice near the coast melting from below due to the hot ocean currents.

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solartim27

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Re: The Nares Strait thread
« Reply #482 on: January 28, 2015, 07:23:23 PM »
I don't know about bottom melt, but the motion is from wind, look at sentinel from the past three days up the coast at Morris Jessup. 

In the strait, NOAA radar shows the larger chunk moving slowly towards the narrow choke point, mild winds flowing to the north against the water flow, dying down later today.
http://www.weatheronline.co.uk/weather/maps/city?LANG=en&CEL=C&SI=mph&CONT=euro&LAND=GL&REGION=0004&WMO=x9500&LEVEL=52&R=310&NOREGION=1

http://www.windfinder.com/weather-maps/forecast/greenland#2/71.7/-42.2
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #483 on: January 28, 2015, 08:45:55 PM »
The following distances use Sentinel 01-26 and 01-28 images (2 days apart).

There appears to be a bit of a bottleneck in Smith Sound (south end of Nares Strait):
  • Floe exiting Smith Sound (into Baffin Bay) went 48 km.
  • Floe entering Smith Sound from Kane Basin went 23 km.
  • Floes within the southern part of Kane Basin (including Sonia’s iceberg(?)) went 36 km.
  • Floe within the central part of Kane Basin (almost running into Sonia’s iceberg) went 57 km!
At the north end of Nares Strait (there being a gap in Sentinel coverage):
  • Floes going from Robeson Channel into Hall Basin (by Petermann Fjord) went 71 km!!
  • Floes in the Lincoln Sea near Nares Strait went 21 and 26 km.
  • Floe in the middle of the Lincoln Sea went 9 km.
  • Floes further away from Nares Strait went 4 or 5 km.
  • Floes close to Greenland and Ellesmere went 1 or 2 km toward Nares Strait.
My big question:  What became of the large floe (13 x 20 km) that was in Hall Basin on 01-26?  Did it slip by Hans Island? Get stuck there? Shatter?  (I’m going to guess “shatter”.)

As always, Sentinel images are available at http://ocean.dmi.dk/arctic/kennedy.uk.php.
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jdallen

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Re: The Nares Strait thread
« Reply #484 on: January 28, 2015, 08:55:13 PM »
I don't know about bottom melt, but the motion is from wind, look at sentinel from the past three days up the coast at Morris Jessup. 

In the strait, NOAA radar shows the larger chunk moving slowly towards the narrow choke point, mild winds flowing to the north against the water flow, dying down later today.
http://www.weatheronline.co.uk/weather/maps/city?LANG=en&CEL=C&SI=mph&CONT=euro&LAND=GL&REGION=0004&WMO=x9500&LEVEL=52&R=310&NOREGION=1

http://www.windfinder.com/weather-maps/forecast/greenland#2/71.7/-42.2

I concur that wind is what we see driving the movement.  Rather than bottom melt, I'd say any exchange from depth at this time of year would be more likely expressed in less thickening of the ice. 

At any given time, far and away enough heat resides in the Arctic ocean to melt the rather pitiable skin of ice which covers it, and to keep it melted.  What prevents that is lack of circulation from depth, and attendant thermo and haloclines.

I don't sense the flow from the Atlantic will loop anti-clockwise around Greenland.  They physics of motion aren't right, and the constraints of ocean bottom topography are wrong.  The tendency of momentum is to carry the flow NE - and we can see that expressed in the melting/lack of ice formation which takes place north and west of Svalbard.

However, wind on the current fractured, weakened pack (driven by cyclone after cyclone after cyclone! roaring up the US Eastern Seaboard, dragging huge amounts of heat with them, and slamming into NE Europe and the Barents...) will cause movement.  That movement at the surface can cause ekman transport.  That can cause local movement of heat from depth.   Not enough I think to cause serious bottom melt, but enough to restrict growth and strengthening of the pack.

I agree that the general havoc we see with Nares and the movement of ice may have dangerous implications for the coming melt season.

Thank for ferreting out the images, Jim and Vidd.
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viddaloo

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Re: The Nares Strait thread
« Reply #485 on: January 28, 2015, 09:21:49 PM »
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Sonia

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Re: The Nares Strait thread
« Reply #486 on: January 28, 2015, 10:56:58 PM »
Wind.

viddaloo

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Re: The Nares Strait thread
« Reply #487 on: January 28, 2015, 11:18:20 PM »
If you want to turn a part of the Arctic Ocean into a raging river 10 times the size of the Amazon you need more than just wind. Heat has been suggested, as heat has been scientifically proven to have devastating effects on ice, for instance in the Arctic where huge amounts of sea ice has disappeared because of global warming.
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Jim Hunt

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Re: The Nares Strait thread
« Reply #488 on: January 29, 2015, 12:45:50 AM »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

A-Team

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Re: The Nares Strait thread
« Reply #489 on: January 29, 2015, 01:00:52 AM »
Whatever. Lincoln Sea is falling apart. Seems like Andreas M showed with tide gauges (see above) that the Arctic Ocean is 6-8" higher than Baffin Bay so the current is always to the south regardless of the wind. I've spent some weeks on the Amazon -- it is hardly moving. And yes, you can see the tree line on both sides as far down as Manaus.

And here's something to ponder (on the appropriate forum):

Arctic freshwater export: Status, mechanisms, and prospects
TWN Haine 2013
https://www.sciencedirect.com/science/article/pii/S0921818114003129?np=y

Quote
Large freshwater anomalies clearly exist in the Arctic Ocean. For example, liquid freshwater has accumulated in the Beaufort Gyre in the decade of the 2000s compared to 1980–2000, with an extra ≈ 5000 km3 — about 25% — being stored. The sources of freshwater to the Arctic from precipitation and runoff have increased between these periods (most of the evidence comes from models).

Despite flux increases from 2001 to 2011, it is uncertain if the marine freshwater source through Bering Strait for the 2000s has changed, as observations in the 1980s and 1990s are incomplete. The marine freshwater fluxes draining the Arctic through Fram and Davis straits are also insignificantly different. In this way, the balance of sources and sinks of freshwater to the Arctic, Canadian Arctic Archipelago (CAA), and Baffin Bay shifted to about 1200 ± 730 km3 yr− 1 freshening the region, on average, during the 2000s.

The observed accumulation of liquid freshwater is consistent with this increased supply and the loss of freshwater from sea ice. Coupled climate models project continued freshening of the Arctic during the 21st century, with a total gain of about 50,000 km3 for the Arctic, CAA, and Baffin Bay (an increase of about 50%) by 2100. Understanding of the mechanisms controlling freshwater emphasizes the importance of Arctic surface winds, in addition to the sources of freshwater.

The wind can modify the storage, release, and pathways of freshwater on timescales of O(1–10) months. Discharges of excess freshwater through Fram or Davis straits appear possible, triggered by changes in the wind, but are hard to predict. Continued measurement of the fluxes and storage of freshwater is needed to observe changes such as these.

viddaloo

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Re: The Nares Strait thread
« Reply #490 on: January 29, 2015, 02:02:51 AM »
I think the ferryman who said that was far east of Manaus, where the river is far wider. However, with the tall mountains around the Nares, I suspect you should be able to see some land even mid–fjord.
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solartim27

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Re: The Nares Strait thread
« Reply #491 on: January 29, 2015, 04:40:30 AM »

My big question:  What became of the large floe (13 x 20 km) that was in Hall Basin on 01-26?  Did it slip by Hans Island? Get stuck there? Shatter?  (I’m going to guess “shatter”.)

As always, Sentinel images are available at http://ocean.dmi.dk/arctic/kennedy.uk.php.

Sentinel finally came through.  It is on Hans island, about to be hit from behind by a good sized chunk.  Hope tomorrows pics come through, should be interesting.
http://ocean.dmi.dk/arctic/images/MODIS/Kennedy/20150128s01a.ASAR.jpg
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viddaloo

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Re: The Nares Strait thread
« Reply #492 on: January 29, 2015, 07:10:35 AM »
Uni–Bremen January 26—28th.
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #493 on: January 29, 2015, 05:23:45 PM »
Comparing the 01-28 and 01-26 Sentinel images for Kennedy (http://ocean.dmi.dk/arctic/kennedy.uk.php) – two days:
  • Floe going from Franklin Island to (northern) Kane Basin went 83 km.
  • Floe going from near Hans Island to Kane Basin went 90 km.
  • Other floes that were just behind Franklin & Hans Islands have mostly disintegrated, it appears to me.
  • The large floe near Petermann Fjord went 65 km.  I think it bounced off Hans Island a km (at time of 01-28 image) and is at least temporarily stuck.  Floes would be able to get around it, but this might mark 'the beginning of the end'.
  • Two floes that were behind this large floe went 65 and 70 km.  I think mélange (ice soup) slowed them down.
  • A 7 x 5 km square floe with a big black mark went 92 km from north of to south of Hall Basin (& Petermann Fjord).  I think this floe might actually strike the big floe ‘stuck’ on Hans Island.
 

What will the next episode bring?

(Other 01-28 and 01-26 Sentinel images were compared yesterday.)
Arctic ice is healthy for children and other living things.

viddaloo

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Re: The Nares Strait thread
« Reply #494 on: January 29, 2015, 05:55:14 PM »
  • The large floe near Petermann Fjord went 65 km.  I think it bounced off Hans Island a km (at time of 01-28 image) and is at least temporarily stuck.  Floes would be able to get around it, but this might mark 'the beginning of the end'.

Thx, Bejnar. PS: What happens if "the end" begins at Hans? How far below Lincoln Sea are we talking in terms of sea–level, and how would this affect transport into the strait?
« Last Edit: January 29, 2015, 06:05:08 PM by viddaloo »
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #495 on: January 29, 2015, 06:29:18 PM »
... PS: What happens if "the end" begins at Hans? How far below Lincoln Sea are we talking in terms of sea–level, and how would this affect transport into the strait?
A bridge that forms anywhere in Nares Strait will ultimately stop the export of ice from the Lincoln Sea.  Without export, the Lincoln Sea will either be filled by thickish ice 'from the north' or new ice which will thicken (due to cold, and due to buckling and rafting from the pressure caused by winds/currents), and then winter ice movement and stresses would be 'back' to the non-2006-7 winter norm.

I don't think sea level issues are relevant, once a sturdy ice bridge forms.  Arctic water will continue to pour through Nares Strait under the ice functionally unimpeded.
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Sonia

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Re: The Nares Strait thread
« Reply #496 on: January 29, 2015, 06:40:08 PM »
Smith Sound looks like the end to me.  Winds were from south and brisk for two days.  They have started to turn now but it looks like they slowed the ice enough to promote arch formation.

I didn't measure accurately but it looks like my maybe-iceberg went just 40 km or so between the 1-26 and 1-28 Sentinal images and is still well upstream of the nascent arch.

But in another day the wind will have filled in stronger from the north and my iceberg, if it is, should be pushing hard to get through.  We'll see how well the arch holds up.

viddaloo

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Re: The Nares Strait thread
« Reply #497 on: January 29, 2015, 06:57:11 PM »
A bridge that forms anywhere in Nares Strait will ultimately stop the export of ice from the Lincoln Sea.

You'd have to fill up the entire strait with ice first, then, all the way up to Lincoln Sea. For what it's worth, I don't think that's likely to happen this year.
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Andreas Muenchow

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Re: The Nares Strait thread
« Reply #498 on: January 30, 2015, 12:14:37 AM »
I think the ferryman who said that was far east of Manaus, where the river is far wider. However, with the tall mountains around the Nares, I suspect you should be able to see some land even mid–fjord.
On a clear summer day the visibility in Nares Strait exceeds 100 km, so unless it is foggy (rare in summer), one always sees both Greenland and Ellesmere Island that are only 30-40 km apart north of 80 N. This is a very typical, little hazy picture from August-5, 2012. View is to the north by north-west. The land just above the horizon is Cape Baird about 100 km to the north from our main mooring location in Kennedy Channel. Helicopter is trying to find the best route to very loose ice. Funny thing to compare this to the MODIS image for that day at http://muenchow.cms.udel.edu/Nares2012/Band01/T2012218.pdf or any other source if such imagery.
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solartim27

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Re: The Nares Strait thread
« Reply #499 on: January 30, 2015, 06:29:09 AM »
Coverage was not good today, Looks like the chunk remains on Hans island and the bottleneck at the south end is getting bigger, but still letting ice pass through.  Hard to say for certain, are the winds pushing everything up against the Greenland side of the strait?  Very mild winds through tomorrow.  No motion at all up n the Lincoln.

http://ocean.dmi.dk/arctic/images/MODIS/Kennedy/201501291320.NOAA.jpg

http://ocean.dmi.dk/arctic/images/MODIS/Kane/201501291825.NOAA.jpg
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