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oren

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Re: The Nares Strait thread
« Reply #1050 on: May 12, 2017, 01:55:08 PM »
Did some quick research about approx. breakup times, southern "arch" in Kane Basin unless noted otherwise:
2007 - No arches formed.
2008 - June 10th(?)
2009 - No southern arch. Northern arch broke around June 30th.
2010 - July 10th
2011 - July 5th.
2012 - June 30th.
2013 - July 10th.
2014 - June 20th.
2015 - July 5th.
2016 - June 30th
2017 - No southern arch. Northern arch broke around May 10th.

Yes, it's early.

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1051 on: May 12, 2017, 07:05:06 PM »
Thanks, oren!  I wonder if Baffin Bay had more ice than in other years in 2009 due to more Nares-Strait-born ice getting created and exported. (Similar question for 2007.)

There is no Lincoln Sea shoe (I didn't expect it to last long), just jagged (recently broken) floes just starting to enter Nares Strait.  DMI image (screen shot) is dated today.  Windytv wind forecast for tonight shown.
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Neven

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Re: The Nares Strait thread
« Reply #1052 on: May 12, 2017, 10:25:41 PM »
Did some quick research about approx. breakup times, southern "arch" in Kane Basin unless noted otherwise:
2007 - No arches formed.
2008 - June 10th(?)
2009 - No southern arch. Northern arch broke around June 30th.
2010 - July 10th
2011 - July 5th.
2012 - June 30th.
2013 - July 10th.
2014 - June 20th.
2015 - July 5th.
2016 - June 30th
2017 - No southern arch. Northern arch broke around May 10th.

Yes, it's early.

Thanks, oren. I always wanted to do this (as well as for the NWP and NSR), but never got around to it. I know some of these break-up times can be found on the ASIB, and some on Patrick Lockerby's Science 2.0 Blog. Did you use other sources as well?
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romett1

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Re: The Nares Strait thread
« Reply #1053 on: May 12, 2017, 10:31:01 PM »
Nares Strait May 10 - May 12, Worldview.

oren

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Re: The Nares Strait thread
« Reply #1054 on: May 13, 2017, 12:29:31 AM »
Thanks, oren. I always wanted to do this (as well as for the NWP and NSR), but never got around to it. I know some of these break-up times can be found on the ASIB, and some on Patrick Lockerby's Science 2.0 Blog. Did you use other sources as well?
Being ignorant on most sources, I actually used imagery on Worldview from 2012 onward (accurate), NSIDC concentration on Worldview for the earlier years (crude - is there visual Worldview before 2012?), and this paper which gives some information:
The effects of ice arch formation on currents in Nares Strait during the springs of 2008 and 2009

Regarding effects of arches, according to the above-mentioned paper in 2009 (year with only northern arch) the southbound current in Nares was much stronger than in 2008 . And Kwok et al (2010) report that in 2007 (year with no arch) the total annual ice export was more than twice that of other years.
As for Baffin extent (NSIDC), I generated this quick and dirty chart of years and day of year which I think implies extent wasn't visibly impacted by the increased export in 2007 and 2009. Note there is no down trend in extent either. All to say that Baffin melts in its own time every year regardless of what is exported into it and regardless of the overall melting season. So any ice exported through Nares weakens the CAB without having any positive impact elsewhere.

johnm33

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Tor Bejnar

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Re: The Nares Strait thread
« Reply #1056 on: May 13, 2017, 12:55:43 AM »
I doubt it. Nope.  I believe it is all first year ice, and not over 2 meters or so thick.  I think it is just big and sluggish.  I expect winds and current (what little there is in Kane Basin) will move it southward these next few days.  (Winds were not helpful a couple days ago.)  Here is a screen shot from a bathimetry map of Kane Basin:  Oceanographic Cruse Summary Kane Basin September 1969 (I cannot copy the link for some reason, but an internet search should be able to duplicate the find!) 
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #1057 on: May 13, 2017, 04:20:21 PM »
Kane Basin's "Big Chunk" seems to be caught in the Kane Basin gyre.  Without steady winds from the north, there is often a noticeable counterclockwise spin (e.g., reference).  Given how it is moving (see Wipneus's movie on Home brew thread), my guess when it would head south may have been premature.

Here is a Lincoln Sea 'close up' of what johnm33 posted (yesterday's WorldView) (Image from yesterday)
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romett1

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Re: The Nares Strait thread
« Reply #1058 on: May 13, 2017, 07:33:05 PM »
Latest images of Nares Strait, May 11 - May 13 (Worldview).

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1059 on: May 13, 2017, 09:51:36 PM »
When the Lincoln Sea ice bridge first began to break (1st day or so), I saw new cracks (specifically, two on the right) radiating quite a distance into the Arctic (see my May 11 post above, reproduced just below).  I don't see those cracks anymore, as if they were healed (certainly squeezed back together).  I suspect the ice in the Lincoln Sea has returned to a state of short-term temporarily-stable arches that will repeatedly shed ice.  I'm picturing an hour glass with coarse angular sand (not well rounded grains) that repeatedly get stuck in the neck, but a little shake of the hour glass will get them flowing again.  The convergent forces on the ice, I'm sure, are just asking for bridges to form!

This 2nd image is from today's DMI Sentinel
« Last Edit: May 13, 2017, 09:57:25 PM by Tor Bejnar »
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Neven

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Re: The Nares Strait thread
« Reply #1060 on: May 13, 2017, 10:34:13 PM »
Thanks, oren. I always wanted to do this (as well as for the NWP and NSR), but never got around to it. I know some of these break-up times can be found on the ASIB, and some on Patrick Lockerby's Science 2.0 Blog. Did you use other sources as well?
Being ignorant on most sources, I actually used imagery on Worldview from 2012 onward (accurate), NSIDC concentration on Worldview for the earlier years (crude - is there visual Worldview before 2012?), and this paper which gives some information:
The effects of ice arch formation on currents in Nares Strait during the springs of 2008 and 2009

Regarding effects of arches, according to the above-mentioned paper in 2009 (year with only northern arch) the southbound current in Nares was much stronger than in 2008 . And Kwok et al (2010) report that in 2007 (year with no arch) the total annual ice export was more than twice that of other years.

When I have time, I'll try and check those dates on my blog and on Patrick's. I know I have animations for a couple of those years. Not that I think the dates aren't correct. They most probably are.
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #1061 on: May 15, 2017, 06:33:38 PM »
cross post from "The 2017 melting season" thread:
(The following posts there discuss Nares Straight as well.)
Speaking of the relative soda straw that is the Nares. The first image below is a current still of the entire straight - click if you want to zoom in. The second is an animation from 4/28 to 5/14 of Kane Basin (at bottom of the straight). Check out the movement of the big slab - notice i didn't say big block  ::).  Wondering how that slab will fare given the favorable-for-export winds that are forecasted. Also at the end of the animation, notice the comparison between 4/28 and 5/14 - lots of slush ice seems to have melted and/or made its way out.

Edit: I had to compress the gif more so that it would play i guess 6mbs is too big for this site? The gif compressor app removed the loop so it won't start over from the beginning.  If you want to see it again you'll have to right click on it and open it in a new browser tab to restart the animation.

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Tor Bejnar

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Re: The Nares Strait thread
« Reply #1062 on: May 15, 2017, 06:54:40 PM »
Winds in Kane Basin, according to windytv, are often more gentle than they are further south in Smith Sound or further north in the Kennedy Channel.  Today's 'now' forecast is an example of this.
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #1063 on: May 15, 2017, 09:39:35 PM »
When the Lincoln Sea ice bridge first began to break (1st day or so), I saw new cracks (specifically, two on the right) radiating quite a distance into the Arctic ...  I suspect the ice in the Lincoln Sea has returned to a state of short-term temporarily-stable arches that will repeatedly shed ice.  ...  The convergent forces on the ice, I'm sure, are just asking for bridges to form!
...
Today's World View of the Lincoln Sea sure suggests these "short-term temporarily stable arches" are very short-term and temporary!
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #1064 on: May 16, 2017, 06:26:08 PM »
Another interesting post to cross post:
Any idea how Nares compares with Fram on volume basis?
Looks like Nares export (on any measure) will be unusually large this year, owing to lack of arch formation.

Looking at the export over the last couple of days at start of the Robeson Channel (see gif) I estimate about 500 km^2 exported per day (each of the big rectangular blocks are around 20k x 10k). If the ice is 2m thick that is about 1 km^3 per day.

Assuming that we have an additional 2 month's flow through Nares compared to previous years, that is an additional 60 km^3 lost which is, very roughly, about 2-3% of the total ice volume in September.

So it's not very significant; but could make an impact in the thickest area.

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dosibl

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Re: The Nares Strait thread
« Reply #1065 on: May 16, 2017, 07:34:26 PM »
Worldview images from today show another large jump in cracking area, almost the entire region looks compromised.

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1066 on: May 16, 2017, 07:39:45 PM »
Another cross-post:
....
bairgon, thanks for the analysis. I think these floes are suposedly closer to 4m thick than to 2m thick, so maybe it's double the volume exported.

measurements taken by scientists on the ice in that area show a mean thickness of 3m
http://blogs.esa.int/campaignearth/2017/05/01/cryovex-first-results-show-sea-ice-continues-to-thin/
Screen shot from this paper showing the four (western) Lincoln Sea ice bridge ice thickness measurements [and snow depths] on (apparently) April 12, 2017:
Quote
At 12 Twin Otter landing sites between 83N and 87.1N, we gathered 36.7 km of electromagnetic (EM) ice- and snow-thickness data and acquired some 13 000 snow-thickness measurements. EM soundings were calibrated with drill-hole measurements. Data were edited to remove any bias due to thinner snow and ice conditions in the immediate vicinity of our landing sites, which were mostly on refrozen leads. Our results represent conditions on thick, old first- and multiyear ice floes typical for the wider regions around the landing sites.
« Last Edit: May 16, 2017, 07:45:07 PM by Tor Bejnar »
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romett1

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Re: The Nares Strait thread
« Reply #1067 on: May 16, 2017, 08:23:08 PM »
Worldview images from today show another large jump in cracking area, almost the entire region looks compromised.

Yes, Nares has decided to attract ice from 84°N - 85°N. Images: Worldview, May 14 - May 16.

oren

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Re: The Nares Strait thread
« Reply #1068 on: May 16, 2017, 08:43:13 PM »
The big slab in Kane basin has completed a 180 degree turn, and is now poised for head-first birth into Baffin bay.

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1069 on: May 16, 2017, 08:59:22 PM »
I was thinking it was a ship, docked for the winter facing up stream, getting launched and turned around, and now heading slowly (~5 km/day?) toward Smith Sound and beyond.

If it's a baby that started growing this past winter, I wonder if it knows that there's a cruel world out there!
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romett1

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Re: The Nares Strait thread
« Reply #1070 on: May 17, 2017, 08:17:38 PM »
So far seems like it's going smoothly down towards Nares Strait and some new cracks further north. May 15 - May 17, Worldview.

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1071 on: May 18, 2017, 04:27:43 PM »
"Big Chunk" (the largest piece of fast ice that broke off within Kane Basin on April 22 [other pieces broke off earlier]) is definitely heading into Smith Sound, finally (and slowly - 10 km/day).  Pieces of the "foot bridge" (or was it "arch of the boot"?) in Lincoln Sea (that broke on May 10) are catching up quickly - 100 km/day (purple arrows)! Worldview screen shot below from May 17.  Floe speed determined by comparing May 16 & 17 images.
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #1072 on: May 19, 2017, 04:42:29 PM »
"Big Chunk" moved about 4 km between May 17 and 18, while the "foot bridge" pieces moved about 85 km.  What will today bring? Winds, per windytv, are mildly contrary today (contrary for southward travel).  Currents favor export, winds favor stillness.
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Phil.

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Re: The Nares Strait thread
« Reply #1073 on: May 19, 2017, 05:12:14 PM »
"Big Chunk" moved about 4 km between May 17 and 18, while the "foot bridge" pieces moved about 85 km.  What will today bring? Winds, per windytv, are mildly contrary today (contrary for southward travel).  Currents favor export, winds favor stillness.

As of 11:15 UCT today it looks like three pieces have blocked the entrance (temporarily?), it'll be interesting to see what happens there.

Phil.

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Re: The Nares Strait thread
« Reply #1074 on: May 20, 2017, 10:53:28 PM »
As of today that temporary dam has broken and many more chunks of ice are entering the strait.

https://lance3.modaps.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl1_143.A2017140180500-2017140181000.2km.jpg

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1075 on: May 20, 2017, 11:53:51 PM »
In Kane Basin (and Smith Sound) Big Chunk (BC) looks like it intends to shut off the export of the pesky Foot Bridge floes like the ones that just zoomed right past BC yesterday and today, but I don't think it will succeed.  It is curious to watch the little floes zip along and the big oaf lumbers erratically along.
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Andreas T

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Re: The Nares Strait thread
« Reply #1076 on: May 21, 2017, 12:35:16 AM »
without offering any evidence I seem to remember that the western side of the straight is usually flowing faster than the eastern side, this made big chunk rotate so swiftly I  think. The odd thing is that it isn't drawn towards the west or does another rotation. Maybe the wind has an effect?

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1077 on: May 21, 2017, 03:09:24 AM »
According to windytv, the current winds are mild and from the north, helping floes go south. 

A paper discussed a couple or several years ago on this thread detailed that most of the Nares Strait has a current that flows south on the western side and a small current flows to the north on the eastern side. (I tried, but failed, to find the reference. Anybody have it?  It was alluded to a few days ago.)
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TerryM

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Re: The Nares Strait thread
« Reply #1078 on: May 21, 2017, 03:47:49 AM »
Tor
The most up to date & detailed information on Nares currents is likely to be found at Dr Muenchow's site


https://icyseas.org/


Andreas posts here and at Neven's Blog from time to time. He's very open to questions about his work & very free with his vast knowledge.


https://icyseas.org/2014/09/21/a-short-summary-of-nares-strait-physics/


Will take you to a summary of Nares Strait from 2014 - but much more is available roaming his pages,


Have Fun!
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bairgon

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Re: The Nares Strait thread
« Reply #1079 on: May 21, 2017, 09:49:03 AM »
I found this in https://icyseas.org/2015/07/13/oceanography-of-nares-strait-ice-flushing/:

"Now there is more to the “hill” story that is modified near the surface by the earth’s rotation in a fluid that has different densities at different depths. In a nutshell, the surface flow is 2-3 times as strong as the depth averaged flow. Furthermore, the surface flow on the Canadian side of Nares Strait is often twice as strong as that closer to Greenland, but all these spatial variations in flow actually help to smash large pieces of ice by moving and rotating them different sides of the same large piece of ice differently."

Phil.

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Re: The Nares Strait thread
« Reply #1080 on: May 21, 2017, 05:45:58 PM »
without offering any evidence I seem to remember that the western side of the straight is usually flowing faster than the eastern side, this made big chunk rotate so swiftly I  think. The odd thing is that it isn't drawn towards the west or does another rotation. Maybe the wind has an effect?

The block appears to have just developed a crack about two thirds of the way down, I expect we'll see more developments now.  The crack appears to have originated at the point of contact with the coast?

FishOutofWater

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Re: The Nares Strait thread
« Reply #1081 on: May 21, 2017, 06:01:02 PM »
The crack in the large ice flow is widest where it collided with the small fast moving diamond shaped block. That may be where the crack initiated.

Shared Humanity

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Re: The Nares Strait thread
« Reply #1082 on: May 21, 2017, 07:00:18 PM »
The crack in the large ice flow is widest where it collided with the small fast moving diamond shaped block. That may be where the crack initiated.

I think the crack was caused by it slamming into land on the Greenland side. (Wouldn't that be cool to watch?) The front flow is now pivoting on that point.

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1083 on: May 21, 2017, 09:17:41 PM »
Looks like a hammer [stone] (small floe) and anvil (Greenland) approach to floe size reduction (of Big Chunk), or a wedge and Big Chunk in a tightening vice.
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Reallybigbunny

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Re: The Nares Strait thread
« Reply #1084 on: May 21, 2017, 09:38:56 PM »
 8) The crack is developing swiftly!


oren

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Re: The Nares Strait thread
« Reply #1085 on: May 22, 2017, 12:49:25 AM »
Regardless of the (interesting) details, this thing is not going to plug Kane Basin. The way is open and will stay open until the end of the year.

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1086 on: May 22, 2017, 03:00:11 AM »
I fully agree with you, oren, but it is fun watching ice appear to 'attempt' to close things down (with inadequate 'tools'), at both ends, even when they last only half a day.
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oren

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Re: The Nares Strait thread
« Reply #1087 on: May 22, 2017, 07:27:28 AM »
Agreed. It is fun watching, and even educational when such a large piece of (first-year) fast ice crumbles at first contact without offering any resistance.

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1088 on: May 22, 2017, 04:31:04 PM »
Yesterday's DMI Sentinel imagery shows a large "diamond" floe entering Robeson Channel (the northern section of Nares Strait).  It's narrowest width is about 17 km.  I look forward to its interacting with Hans Island, as there is only about 15 km of passageway available to passing floes.  (Or will "Diamond" be 'faceted' before then due to its many flaws?) [The fast ice area is greater than that represented by the yellow line.  Both screen prints are from the same DMI image.] [Huge edit/woops, written on May 23: Fast ice on Hans Is. broke about May 9.  This image shows fast ice on Franklin Is. and passing floes (mostly) between Hans and Greenland.  See my May 23 post for some details.  This doesn't much affect the concerns raised in this original post, however.]
« Last Edit: May 23, 2017, 10:01:45 PM by Tor Bejnar »
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romett1

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Re: The Nares Strait thread
« Reply #1090 on: May 22, 2017, 09:08:03 PM »
From today's worldview images the diamond is already gone.


That was quick. I thought maybe this diamond will survive some weeks.

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1091 on: May 22, 2017, 09:34:28 PM »
Diamonds, although very hard (10 of 10 on Mohs scale), are quite brittle: bouncing off the Greenland coast did "the Diamond" floe in. (Boy was it faceted!)  'Gotta name these floes fast or you'll miss your chance.
« Last Edit: May 22, 2017, 09:52:28 PM by Tor Bejnar »
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Tor Bejnar

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Re: The Nares Strait thread
« Reply #1092 on: May 22, 2017, 09:51:06 PM »
Cross post (thanks, Tigertown):
Where did it go?
Charts show this that's now ice entering Nares to be old thick ice, but the way it crumbles makes for doubt. 5-21 vs. 5-22

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be cause

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Re: The Nares Strait thread
« Reply #1093 on: May 22, 2017, 11:26:59 PM »
it may be old thick ice but as Sentinel images show the diamond was a molsaic of shattered fragments randomly conglomerated and held together by ... not very much .
there is little old ice with any more integrity anywhere in the Arctic .
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Shared Humanity

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Re: The Nares Strait thread
« Reply #1094 on: May 22, 2017, 11:34:25 PM »

there is little old ice with any more integrity anywhere in the Arctic .

I agree.

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Re: The Nares Strait thread
« Reply #1095 on: May 23, 2017, 12:40:03 AM »
There is not much multi-year ice up there, and what there is is broken up with thinner lead ice in between, often less than a meter thick. Julienne Stroeve ran an ice thickness campaign to ground substantiate the Cryosat measurements along with Ice Bridge.

Here are three links:

http://blogs.esa.int/campaignearth/2017/05/01/cryovex-first-results-show-sea-ice-continues-to-thin/

https://weather.com/news/climate/news/arctic-sea-ice-april-2017-record-low

https://nsidc.org/arcticseaicenews/2017/05/

Must interesting comments in the NSIDC field report:

NSIDC scientist Julienne Stroeve continued her Arctic field work into early April, moving from Cambridge Bay, Canada to Alert in Ellesmere Island. In Alert, Stroeve focused on sampling ice thickness and snow pack characteristics along a CryoSat-2 flight track within the Lincoln Sea. This is an area between northernmost Greenland and Ellesmere Island where thick, old ice remains. The scientists flew by Twin Otter each day, out onto the sea ice between latitudes 83°N and 87.1°N. The field campaign was also supported by an aircraft from the British Antarctic Survey carrying a Ka band radar, LiDAR, and a broadband radiometer. A NASA Operation IceBridge flight also flew over the same track.

The group noted that the ice was unusually broken up and reduced to rubble, with few large multi-year floes, forcing the pilots to land on refrozen leads that at times were only 70 centimeters (28 inches) thick. Pilots remarked that they had never seen the ice look like this.

Preliminary estimates suggest mean thicknesses ranging from 2 to 3.4 meters (6.6 to 11 feet), with the thickest ice found between an ice bridge in the Lincoln Sea and mobile pack ice to the north.

Modal thickness, a representation of thermodynamically-grown level ice, ranged between 1.8 and 2.9 meters (6 and 10 feet), including 0.25 to 0.4 meters (10 to 16 inches) of snow. Second- and first-year modal ice thicknesses ranged between 1.8 and 1.9 meters (6 and 6.2 feet), about 0.2 meters (8 inches) thinner than previous airborne measurements indicated.

TenneyNaumer

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Tor Bejnar

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Re: The Nares Strait thread
« Reply #1097 on: May 23, 2017, 02:52:11 AM »
From Wipneus's May 9 post, see that Big Chunk came from west of Hulmbolt Glacier's front.  Looking at the October 1, 2016 DMI Sentinel, there are bits of ice that got glued into the fast ice, but nothing looks very significant.
Arctic ice is healthy for children and other living things.

georged

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Re: The Nares Strait thread
« Reply #1098 on: May 23, 2017, 07:27:29 AM »
There is not much multi-year ice up there, and what there is is broken up with thinner lead ice in between, often less than a meter thick. Julienne Stroeve ran an ice thickness campaign to ground substantiate the Cryosat measurements along with Ice Bridge.

Here are three links:

http://blogs.esa.int/campaignearth/2017/05/01/cryovex-first-results-show-sea-ice-continues-to-thin/

https://weather.com/news/climate/news/arctic-sea-ice-april-2017-record-low

https://nsidc.org/arcticseaicenews/2017/05/

Must interesting comments in the NSIDC field report:

NSIDC scientist Julienne Stroeve continued her Arctic field work into early April, moving from Cambridge Bay, Canada to Alert in Ellesmere Island. In Alert, Stroeve focused on sampling ice thickness and snow pack characteristics along a CryoSat-2 flight track within the Lincoln Sea. This is an area between northernmost Greenland and Ellesmere Island where thick, old ice remains. The scientists flew by Twin Otter each day, out onto the sea ice between latitudes 83°N and 87.1°N. The field campaign was also supported by an aircraft from the British Antarctic Survey carrying a Ka band radar, LiDAR, and a broadband radiometer. A NASA Operation IceBridge flight also flew over the same track.

The group noted that the ice was unusually broken up and reduced to rubble, with few large multi-year floes, forcing the pilots to land on refrozen leads that at times were only 70 centimeters (28 inches) thick. Pilots remarked that they had never seen the ice look like this.

Preliminary estimates suggest mean thicknesses ranging from 2 to 3.4 meters (6.6 to 11 feet), with the thickest ice found between an ice bridge in the Lincoln Sea and mobile pack ice to the north.

Modal thickness, a representation of thermodynamically-grown level ice, ranged between 1.8 and 2.9 meters (6 and 10 feet), including 0.25 to 0.4 meters (10 to 16 inches) of snow. Second- and first-year modal ice thicknesses ranged between 1.8 and 1.9 meters (6 and 6.2 feet), about 0.2 meters (8 inches) thinner than previous airborne measurements indicated.

Thank you for this, it gives a lot of context to what's happening right now.

It's what's above Ellesmere that worries me most. The advanced transport has the potential to pull in quite a bit of surrounding ice over the next month. This year the Nares seems less like a garlic-press and more like a juicer.

Tor Bejnar

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Re: The Nares Strait thread
« Reply #1099 on: May 23, 2017, 05:12:16 PM »
Yesterday's DMI NOAA AVHRR image shows Smith Sound very nicely. I've annotated a screenshot.
Arctic ice is healthy for children and other living things.