Arctic Sea Ice : Forum

Cryosphere => Greenland and Arctic Circle => Topic started by: Tor Bejnar on March 01, 2019, 05:04:30 PM

Title: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 01, 2019, 05:04:30 PM
Floes entering Nares Strait take between a week and two month (plus?) to go the 500 km to Baffin Bay (when the Strait is open).  The arch around the Lincoln Sea Polynya has been stable for a couple of weeks, basically, so (basically) all the mobile thick ice ("old") in the Lincoln Sea has now flushed into Nares Strait.  The last bits are circled in the image below (DMI image dated 2019-02-27). 

So, will the 'old' ice that recently entered Nares Strait get to Baffin Bay before new 'old' ice enters the Strait?

"Yes" will be correct if the current Lincoln Polynya arch holds on long enough (How long will be enough?) or a bridge forms in the Kennedy Channel above these circled bits of 'old' ice before more recently mobilized thick ice gets to the Strait during March or April 2019 [edit: and no southern bridge forms …].

"No" is split. 
"Maybe so" will be correct if a southern bridge holds the circled bits for 50 days or more, but a northern bridge holds back all Lincoln Sea ice until after the southern bridge breaks and all the circled bits flow into Baffin Bay.
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 01, 2019, 05:30:33 PM
I can't imagine the arch holding much longer. This is not a consistent ice mass but foes pressed together from above so my feeling is they will crack soonish.
Title: Re: Old ice moving through Nares Strait
Post by: gerontocrat on March 01, 2019, 05:55:45 PM
I can't imagine the arch holding much longer. This is not a consistent ice mass but foes pressed together from above so my feeling is they will crack soonish.
foes pressed together from above - for a moment there I was back reading about Brexit.
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 01, 2019, 06:05:46 PM
LOL  ;D
Title: Re: Old ice moving through Nares Strait
Post by: Niall Dollard on March 01, 2019, 08:21:03 PM
I voted for No : Kane Arch, before I looked at the forecast on null school.

Current forecast said northerlies in the Kane Basin until 4th March, when a decent southerly arrives. Will all the old ice be gone by that stage ! ? 

Movement is slow in the Kane Basin at the moment but those northerlies wont help.  :(
Title: Re: Old ice moving through Nares Strait
Post by: oren on March 01, 2019, 08:44:32 PM
I am guessing it will hold. It's been two weeks already, and the date is normal for an arch to form.
Title: Re: Old ice moving through Nares Strait
Post by: uniquorn on March 01, 2019, 09:26:34 PM
Thanks for the poll Tor.
Recent wound refractures just after the floes enter the Kane basin.
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 02, 2019, 05:13:52 AM
Uniquorn,
Then the race would be on!
(It was fun setting the poll up!)
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 02, 2019, 04:19:26 PM
A (left hand): 2019-03-01, B (right hand): 2019-03-02
Nighttime Imagery (Day/Night Band, Enhanced Near Constant Contrast), Suomi NPP / VIIRS

Looks like little pieces broke up but could be clouds as well.

Title: Re: Old ice moving through Nares Strait
Post by: uniquorn on March 02, 2019, 10:58:37 PM
Shame about the clouds but it is possible to follow the floes down the strait and it is quite a race. I hope I have identified the stragglers correctly.
Worldview viirsbt15day feb27-mar2
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 03, 2019, 03:28:33 PM
Further breakups today.

Nighttime Imagery (Day/Night Band, Enhanced Near Constant Contrast), Suomi NPP / VIIRS

Date Range: 2019-02-01 - 2019-03-03
Title: Re: Old ice moving through Nares Strait
Post by: Iain on March 04, 2019, 11:14:51 PM
I think it would depend largely on Sea Surface Temperature, as Nares is the first left turn exit for the Atlantic drift,  but my goto source for day to day graphics has a snapshot archive for 2017 but not '18:

https://www7320.nrlssc.navy.mil/hycomARC/navo/arc_list_arcticsst.html

Ignore the warning, advanced > allow exception

So I can't decide.
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 05, 2019, 02:02:43 AM
About 15 hours to cast (or change) your vote. 

Some qualifying 'old' ice has broken off the Lincoln Polynya arch, but I don't know how fast it will head to Nares Strait: it has a long ways to go.  Meanwhile, the rearguard of the 'old' ice is in the Kennedy Channel, and the ice in Kane Basin is moving right along. We almost have Uniquorn's prophesied situation!
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 05, 2019, 02:33:31 PM
Two and a half hours to vote...
The 'old' ice that broke off the Lincoln Polynya arch 'on' March 2nd moved away from the arch, then moved back to almost where it started from! Have a look for yourself:  http://ocean.dmi.dk/arctic/lincoln.uk.php
I've combined a couple screen shots below (March 3 & 4), with the loose ice circled.  All the other ice in Lincoln Sea is either tied up in the arch or is young (less than about 3 weeks old).

Meanwhile, the stragglers past Hans (tiny, in the middle of the channel) and Franklin (largest) Islands on March 4th, but the larger 'old' ice floes (with pale brown dots added) just ahead of the stragglers have slowed down in Kane Basin.  Combined images below (March 2 & 4).
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 05, 2019, 09:52:57 PM
Well, the polls closed and no new voters came.  I find it curious that this thread has been visited 862 times (per top header), and there are only 14 votes.  I realize that about 10 of the visits ("views") are from me.  Did I have the 'right' lure, but wrong 'bait'?

Regardless, the identifiable stragglers are just approaching Kane Basin and the recently mobilized 'old' ice in the Lincoln Sea is re-mobilized (yesterday having appeared to re-attach itself to the old-ice arch).

Today's images from http://ocean.dmi.dk/arctic/lincoln.uk.php (and "kane" equivalent - click on the green squares on the Greenland map)
Title: Re: Old ice moving through Nares Strait
Post by: uniquorn on March 05, 2019, 10:12:18 PM
Sometimes you have to believe in the music and not worry about the audience participation Tor.
Despite voting option2 I don't think that tiny break from the polynya is a win. I was thinking more of this...
Title: Re: Old ice moving through Nares Strait
Post by: Sebastian Jones on March 06, 2019, 02:01:44 AM
Well, the polls closed and no new voters came.  I find it curious that this thread has been visited 862 times (per top header), and there are only 14 votes.  I realize that about 10 of the visits ("views") are from me.  Did I have the 'right' lure, but wrong 'bait'?
.....
Speaking purely for myself, I did not vote because I know too little about the dynamics to do more than guess. Which sounds rather lame, but it is also the excuse I use for not voting on dates or sizes of maxima or minima for sea ice.
Oh, and I don't buy lottery tickets either....
Title: Re: Old ice moving through Nares Strait
Post by: Rod on March 06, 2019, 03:56:04 AM
Thank you for the thread Tor. 

Like Sebastian, I did not vote because I don't feel I have a good understanding of the subject matter.  I would have just been guessing.  But, every time someone posts something new I click on it so that I can learn more. 

Thanks again for starting this thread and I look forward to seeing the results of the race!
Title: Re: Old ice moving through Nares Strait
Post by: oren on March 06, 2019, 06:08:21 PM
What matters is not the quantity of the readership, but the quality...
And I don't buy lottery tickets either, but I'll take them whenever they're freely given. So thanks Tor.
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 06, 2019, 08:29:46 PM
Thanks for the replies.  This poll deals with 'weather' much more than 'climate', so the 'race' is more of a gymkhana* than an Olympics event.  It does offer the nudge for multiple people looking at the data (maps, weather forecasts), and there is a tiny bit of payback (the good kind) for doing so.

But, like my understanding of a gymkhana, the intent is to have a good outing, enjoy the company, and raise a bob for a good cause.  [Here's where I remind myself and others of the "Support & Donate" button on the ASIB (https://neven1.typepad.com/).]

Oh, I'd 'a loved it if 10,000 people cast votes.  I don't care what they voted for, but they'd have had to be on this-here forum and would get a spot of education along the way.   :)
____
* - at least, the gymkhana fundraiser I once attended included a horse race where the Arabian contestant had maybe three times the distance to run as the Percheron, and tickets were sold 'randomly' (one bought a ticket and then discovered which horse was bet on). (The Arabian won, by the way, but only by 5 lengths [as I recall] - it was exciting to watch.)
Title: Re: Old ice moving through Nares Strait
Post by: interstitial on March 06, 2019, 09:45:58 PM
I didn't vote either for lack of a hypothesis of what would happen.



I like to say buying a lottery ticket does not significantly increase your chances of winning the lottery.
Title: Re: Old ice moving through Nares Strait
Post by: magnamentis on March 07, 2019, 02:17:59 AM
I didn't vote either for lack of a hypothesis of what would happen.



I like to say buying a lottery ticket does not significantly increase your chances of winning the lottery.

sorry but even as a non-lottery-player i must say that you are totally wrong and i mean totally which is a term i try to avoid.

why?

because if you don't buy a ticket your chance is zero and any chance to win, no matter how small, is significantly higher than zero.

even mathematically every number above zero is significantly higher than zero because zero is just that, nill, nothing and that's one of the rare absolute numbers.

of course i know what you wanted to say while even then, if you admit that you have no theory, why relativate it? it's a good thing to admit that we have no clue but we should not ridicule those who try to develop a theory, independent of it's outcome because this is the way we can develop and reach unknown territories/spheres ;)
Title: Re: Old ice moving through Nares Strait
Post by: Adam Ash on March 07, 2019, 04:52:46 AM
At best, any choice here would just be a WAG.  Nares' behaviour, like that of most of the pack, sees anomalous happenings which are - like the CA Garlic Press - depleting the Old Ice resource very fast.  One year old mush and thin ice offers little resistance to export via any channel it finds in front of it.  If wind and currents point it to an Exit, it departs to oblivion.
Title: Re: Old ice moving through Nares Strait
Post by: interstitial on March 07, 2019, 06:06:22 AM
sorry but even as a non-lottery-player i must say that you are totally wrong and i mean totally which is a term i try to avoid.
Quote
I say this because it gets people to think about what they are doing. I have repeated it often and get a wide variety of responses. I think the most accurate is "Its worth a few bucks to me to rent the dream of winning".
Quote
it's a good thing to admit that we have no clue but we should not ridicule those who try to develop a theory, independent of it's outcome because this is the way we can develop and reach unknown territories/spheres ;)
I wasn't trying to ridicule anyone. Sorry for the misunderstanding. One thing I don't like about online interactions is I have to give contextual clues like emoticons manually. IRL I don't have to think about it.

I also like to read peoples theories even those that disagree with my own, unless they are unwilling to drop a point when they are given solid evidence to the contrary. They don't even have to admit they are wrong if they just drop it. Sometimes I find taking a contrary view to what I believe and defend it to get a better understanding of the issue.

Oops I have gotten OT.
Title: Re: Old ice moving through Nares Strait
Post by: gerontocrat on March 07, 2019, 02:44:24 PM
I didn't vote either for lack of a hypothesis of what would happen.



I like to say buying a lottery ticket does not significantly increase your chances of winning the lottery.

sorry but even as a non-lottery-player i must say that you are totally wrong and i mean totally which is a term i try to avoid.

why?

because if you don't buy a ticket your chance is zero and any chance to win, no matter how small, is significantly higher than zero.

If you don't buy a ticket there is a possibility that a friend has bought one for you, i.e. a non-zero possibility exists.
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 07, 2019, 03:32:05 PM
Haha, great thought Gerontocrat!!

Now, who can tell the odds of this? And how much less likely is it than winning the lottery with one's own ticket. I love this! :D
Title: Re: Old ice moving through Nares Strait
Post by: magnamentis on March 07, 2019, 04:43:15 PM
I didn't vote either for lack of a hypothesis of what would happen.



I like to say buying a lottery ticket does not significantly increase your chances of winning the lottery.

sorry but even as a non-lottery-player i must say that you are totally wrong and i mean totally which is a term i try to avoid.

why?

because if you don't buy a ticket your chance is zero and any chance to win, no matter how small, is significantly higher than zero.

If you don't buy a ticket there is a possibility that a friend has bought one for you, i.e. a non-zero possibility exists.

that's the way one can end every reasonable discussion and if a friend bought one it's he who wins but he can give me the win and then it's not a lottery win but a gift from a friend.

this is similar like those who run out of arguments/reason and end the discussion with:

Everything Is Relative

which is when i tell them to jump from a bridge and test the relativity of gravitation as well as
kinetic energy but perhaps a friend installed a net underneath ;)
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 07, 2019, 04:44:52 PM
If you don't buy a ticket there is a possibility that a friend has bought one for you, i.e. a non-zero possibility exists.

So i went ahead and asked Reddit:

Quote
[–]Negified96 [score hidden] 23 minutes ago
This sounds like a Bayesian statistics problem:
P(win given gift) = (P(gift given win) * P(win))/(P(gift))
However, since there is no reason for any particular ticket to be special or correlated with any other data, P(gift given win) should equal P(gift) in purely random scenario (which this is).
As a result, the probability of winning from a particular ticket is the same regardless of whether or not it was gifted.

Link >> https://www.reddit.com/r/theydidthemath/comments/aydcd5/request_it_is_very_unlikely_to_win_the_lottery/ehzy4ye/
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 07, 2019, 04:54:49 PM
The gift before it wins is 'worth' a buck or two.  The gift after it wins is worth a pretty penny or $880,000,000 (recent South Carolina, USA take home amount [before taxes, I presume]). 

I have been given a ticket by a friend, and I haven't won 'big'; this suggests (caution: small sample size) the former is more likely than the latter.

In other news, we have DMI sponsored Sentinel images (http://ocean.dmi.dk/arctic/kane.uk.php) from yesterday. ("goal" lines shown)
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 07, 2019, 05:20:01 PM
These images show "Remnants" or "Rear Guard" (what should we call them?) have moved about 40 km in one day in Kane Basin (240 km to go) while "new old ice" (name?) has moved about 4 km in one day in Lincoln Sea (85 km to go).  ("One day" is difference between DMI images identified by date.) 

What a race!
Title: Re: Old ice moving through Nares Strait
Post by: Niall Dollard on March 07, 2019, 05:37:40 PM
These images show "Remnants" or "Rear Guard" (what should we call them?) have moved about 40 km in one day in Kane Basin (240 km to go) while "new old ice" (name?) has moved about 4 km in one day in Lincoln Sea (85 km to go).  ("One day" is difference between DMI images identified by date.) 

What a race!

It's a good race Tor. Thanks for organising. Day to day changes are big.

Looking for names ? Remnants sounds fine. Re the new bit broken off in the Lincoln Sea - how about the D Day ice ? It is the final piece for this competition and Uniquorn first mentioned it fracturing on St David's Day (March 1st). D for David !    :)
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 07, 2019, 06:58:13 PM
With one vote (and my addition below), we have some winners!  "Remnants" and "D Day Ice" are what I circled just above.

I think I found another part of the rear guard.  Below are excerpts from images from Feb. 27 and Mar. 6., with a new circle around the found "Matched Pair".  (Some matched pairs are better matched than others.  Heaven help us if Matched Pair separate!)  Obviously, both Remnants and Matched Pair need to cross the relevant finish line, and any part of D Day Ice.
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 08, 2019, 04:20:37 PM
DMI's Sentinel images (http://ocean.dmi.dk/arctic/lincoln.uk.php) show the following movements between March 6 and 7:
At these rates, D Day will reach its goal first.  :'(
[Yes, I know, this is an anthropomorphization, but it sounds exciting!]
Title: Re: Old ice moving through Nares Strait
Post by: Niall Dollard on March 08, 2019, 06:12:15 PM
A quick look at nullschool suggest the following windspeeds and directions in the Kane Basin:

March 9 : NE  5-10 km/hr
March 10: S  5-10 km/hr
March 11: S  10-20 km/hr
March 12: S  20-25 km/hr

So only light NE breeze until tomorrow and then increasing S and SW winds in the Basin looks like slowing things down.
Title: Re: Old ice moving through Nares Strait
Post by: uniquorn on March 08, 2019, 07:14:38 PM
Travelling so can't contribute. Thanks for the updates and the pleasant OT.
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 08, 2019, 07:35:07 PM
DMI's Sentinel images show the following movements between March 7 and 8:
•Remnants moved 43 km
•Marched Pair moved a sluggish 11 km (it is closer to Greenland, so out of the swiftest current - why did I have to find this ice?  It might cause me not to win my own poll.)
•D Day Ice moved 10 km (towards goal - it actually moved a little farther, but not directly toward goal)

I'm going to guess Marched Pair and D Day Ice will be more affected by the wind shift than Remnants.  (Location, location, location)
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 08, 2019, 08:14:26 PM
This is one exciting race!  8)

Thanks, Tor, having fun.
Title: Re: Old ice moving through Nares Strait
Post by: Iain on March 10, 2019, 09:43:25 AM
Look like new ice is entering from the North.
Title: Re: Old ice moving through Nares Strait
Post by: Iain on March 10, 2019, 09:47:11 AM
Better view on Polar View
Title: Re: Old ice moving through Nares Strait
Post by: Iain on March 10, 2019, 09:58:14 AM
And there is still movement along the full length.

Potentially significant because:

The date has passed when it blocked last year
The sun is coming up
Though narrow, there is a fast current carrying the ice southwards. Only a strong South wind would halt or reverse the floes
There is an accumulation of thick ice nearby, against the N coast of Greenland and the CAA.
Much of that is fragmented

One to watch
Title: Re: Old ice moving through Nares Strait
Post by: Jim Hunt on March 10, 2019, 03:48:28 PM
There is an accumulation of thick ice nearby, against the N coast of Greenland and the CAA.

Blended CryoSat-2/SMOS thickness in the vicinity:
Title: Re: Old ice moving through Nares Strait
Post by: gerontocrat on March 10, 2019, 04:43:18 PM
"Things fall apart,
The Arch cannot hold,
Mere anarchy is loosed upon the Nares Strait."
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 10, 2019, 04:49:13 PM
"Hold the door!"
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 10, 2019, 08:32:02 PM
But, B_, which door do you want held shut, or is it which do you want held open???? Or are you just  being a gentleman and want to 'hold the door' for the ladies?

Windy.com (https://www.windy.com/?2019-03-11-15,81.551,-35.200,4,m:fWbaeuw) shows today's winds are fairly calm, but tomorrow's are from the south (and stronger over the Lincoln Sea).
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 10, 2019, 08:41:49 PM
Tor, you got to watch Game Of Thrones one day. :P
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 12, 2019, 12:36:44 AM
D Day Ice has been blown north a bit, per DMI Lincoln Sea (http://ocean.dmi.dk/arctic/lincoln.uk.php) images.  In Kane Basin, the Matched Pair have gone their separate ways, but both are just ahead of a, yet un-named, larger floe that looks like it stalled at 79o 30' N, but that is getting 'back into the flow of things'.  (That un-named floe, "Slowpoke"(?) was opposite Franklin Island when Remnants were (was?) just fully into Nares Strait on March 2nd (https://forum.arctic-sea-ice.net/index.php/topic,2592.msg191108.html#msg191108) and was in Kane Basin on the 4th.)

Image is a screenprint from today's DMI Kane (http://ocean.dmi.dk/arctic/kane.uk.php) Sentinel image.  If I have time, I'll annotate the image tomorrow. [Edit: image annotated]
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 12, 2019, 05:57:16 PM
Slowpoke is stuck (for a day, anyway)
Title: Re: Old ice moving through Nares Strait
Post by: uniquorn on March 12, 2019, 09:45:03 PM
Slowpoke could well be a resident for quite some time. I had trouble finding the disparate matched pair but I think I identified the remnants. Worldview, mar7-12.
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 13, 2019, 02:19:13 PM
Forecast 17.03. showing southwards winds throughout the whole channel. There have been northwards/no winds since ~08.03.

Let's see if this changes something.
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 14, 2019, 09:29:35 AM
Big crack evolving!
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 14, 2019, 02:39:25 PM
Good catch, B_.  That screen print, by the way, is from DMI Sentinel March 13 image.  Unless that crack mends, there will be lots of mobile ice in the Lincoln Sea that will eventually reach Nares Strait.  D Day Ice, however, move slightly northward between the 12th and 13th.

Meanwhile in the Kane Basin, here is an mp4 from DMI (http://ocean.dmi.dk/arctic/kane.uk.php)'s 2019-03-06 to 2019-03-13 (sans the 7th) Sentinel images showing Slowpoke moving a little between the 6th and 9th, but not at all since then.  Matched Pair, which shows up in this part of Kane Basin on the 9th (and separated from each other on the 10th just west of the NW corner of Slowpoke) didn't move much between 12th and 13th.

Is an ice bridge forming in Kane Basin now that there are no 'bull dozers' plowing their way through the thin, weeks-old ice?  If so, will this save the race for another month (or three) (presuming an ice bridge in Kane Basin will stop import of ice at the north end of Nares Strait)?
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 14, 2019, 03:30:21 PM
Houston, we have a problem:  I was about to enter an "[Edit: xxx]" to the first post about some of the terminology used in that first post, but reading what I'd written, the details were pretty clear, and that I specified "the circled bits" (now called Remnants and Matched Pair), and not "all old thick ice now (on 1st) mobile in Nares Strait" (and the actual question referred to ice "recently entered Nares Strait" which reasonably could exclude Slowpoke, especially after using the term "circled bits").  Our situation is that Slowpoke took over the drag position (from "cowboy who rides at the tail end of a cattle drive").  In running commentary, I've assumed if Slowpoke was the only 'old thick ice' left in Kane Basin when the first part of D Day Ice (or other Lincoln Sea thick ice) entered the Strait, then the "Yes" vote would not be a winner.  But the first post that defines terms clearly only cares about 'the circled bits', so I think Slowpoke is just a distraction.

Of course, if the still identifiable parts of Matched Pair get stuck too, it won't matter, and Houston can go back to watching SpaceX.
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 14, 2019, 05:30:14 PM
Good catch, B_.

Thanks, Tor! :)

Only, in today's shot over at PolarView i can't see the crack anymore...

http://bslmagb.nerc-bas.ac.uk/iwsviewer/?image=DataPolarview/111_S1jpeg2000_201903/S1B_EW_GRDM_1SDH_20190314T114236_4E7B_N_1.8bit.jp2
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 14, 2019, 05:50:20 PM
Interesting, B_, the crack does appear mended (but we'll see if it stays stuck).   D Day Ice, on the other hand, inched southwards about 2 km between the 13th and 14th. DMI Sentinel images (http://ocean.dmi.dk/arctic/lincoln.uk.php).
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 15, 2019, 12:27:54 PM
Minor breakups from the arch today.
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 15, 2019, 02:18:38 PM
The Canadian side of Kane Basin is still flowing at the surface, but the two parts of Matched Pair are suck in fast ice, as is Slowpoke (comparing 13th and 14th DMI images (http://ocean.dmi.dk/arctic/kane.uk.php)).
Title: Re: Old ice moving through Nares Strait
Post by: uniquorn on March 16, 2019, 01:37:14 PM
Some cloud today but (mostly) new ice is flowing along the western edge down to the remnants. There might be a bit of a logjam near there but it's tricky to see on worldview.
I'm happy for slowpoke to be an interested bystander in all this. D-Day slipped its shackles, newbie changed its mind and edged back.
Worldview-viirsbt15n, mar15-16   https://go.nasa.gov/2Hp99Aw
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 18, 2019, 08:17:40 PM
D Day Ice (in Lincoln Sea) has moved about 20 km closer to Nares Strait between March 17 and 18, and has about 20 km to go.  Tomorrow?

Down south, Remnants has passed its goal line (congratulations for doing your part in this "Poohsticks (https://en.wikipedia.org/wiki/Poohsticks)" competition), but Matched Pair remains stuck in 'the middle' of Kane Basin.  Images from DMI (http://ocean.dmi.dk/arctic/kane.uk.php).
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 19, 2019, 07:16:00 AM
Today we see further minor breakups from the arch.
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 19, 2019, 03:49:10 PM
Well, I'll be …
Slowpoke and the Matched Pair are on the move again, comparing two March 18 DMI (http://ocean.dmi.dk/arctic/kane.uk.php) Sentinel images.  Also, you can see Remnants go from 'having crossed the finish line' to 'out of the picture'.  (The older of the two images in this mp4 has the same source as the image posted yesterday, so you can identify named floes from that image.)
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 20, 2019, 04:19:18 PM
The results are in.

The question was, "Will the 'old' ice that recently entered Nares Strait get to Baffin Bay before new 'old' ice enters the Strait?"  In the first post, the details of the question were fleshed out, identifying certain "circled bits of 'old' ice" as being 'one' of the contestants; once broken up, these were later labeled "Remnants" and "Matched Pair".  Some qualifying 'old' ice broke off the Lincoln Polynya arch about March 3rd and was labeled "D Day Ice".

Remnants crossed into Baffin Bay before D Day Ice crossed into Nares Strait, but Marched Pair didn't.

Therefore, I declare those who voted "No: the arch around the Lincoln Sea Polynya will break (soon)" the winners.  (I'm not one of them.)

In the DMI (http://ocean.dmi.dk/arctic/lincoln.uk.php) Sentinel images dated 2019-03-19 (screen prints thereof included below), D Day Ice is circled as are the two parts of Matched Pair.

The race was close, until the Matched Pair got stuck in temporarily fast ice (then released yesterday).  It was exciting when D Day Ice was blown northwards within the Lincoln Sea for a couple days.  And we had a nice distraction with "Slowpoke", until I realized it wasn't in the competition (also temporarily stuck in fast ice and subsequently released).

To anybody who wants to track D Day Ice, and its relation to the very recently mobilized "North Rim Floes", I suggest you (we) do so in the Nares Strait thread (https://forum.arctic-sea-ice.net/index.php/topic,176.msg192290.html#msg192290) (as at least one person missed our presence there).
Title: Re: Old ice moving through Nares Strait
Post by: b_lumenkraft on March 20, 2019, 04:49:38 PM
I voted "No: the arch around the Lincoln Sea Polynya will break (soon)". I have to admit, i didn't think that one little piece of ice would make this true. My assumption at the time was there would be a major breakup.

Thanks so much, Tor, for this thread, that was fun!  ;D
(and no, this is not 'rooting' for a fast decline of sea ice as it was intended in another thread recently  ::) )
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 20, 2019, 05:43:23 PM
Quote
My assumption at the time was there would be a major breakup.
Of course, As you noted (https://forum.arctic-sea-ice.net/index.php/topic,2592.msg191919.html#msg191919), there almost was.

Quote
I ... didn't think that one little piece of ice would make [my no vote] true.
The "No" clarification you voted for in the first post (https://forum.arctic-sea-ice.net/index.php/topic,2592.msg190641.html#msg190641) included (emphasis added) So, congratulations!
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on March 25, 2019, 07:25:24 PM
Epilogue:  Matched Pair (circled) have crossed their finishing line, and Slowpoke-the-Distraction (or at least most of it - with a yellow dot) is not far behind in Smith Sound (as of yesterday's DMI (http://ocean.dmi.dk/arctic/kane.uk.php) Sentinel image, of which a screen print can be seen below).  At the other end of Nares Strait, the Lincoln Sea Polynya's arch 'totally' collapsed, Lincoln Sea is 'full' of old ice floes, and the North Rim Floes crossed into the Strait (and are near Petermann Fjord as of yesterday).
Title: Re: Old ice moving through Nares Strait
Post by: uniquorn on March 25, 2019, 07:47:19 PM
Thank you Tor for a pleasant distraction from what looks like being a gloomy melting season.
(despondent rather than overcast)
Title: Re: Old ice moving through Nares Strait
Post by: Tor Bejnar on June 13, 2019, 04:54:29 AM
A summary posted elsewhere:
Who's to say if "Nares was closed (or not)" this year?  Certainly the Lincoln Sea Polynya arch prevented Arctic Ocean floes from entering the Strait for about a month.  We watched a 'race' in late February and March:
  • The Lincoln Sea arch stopped crumbling about February 17, 2019 (https://forum.arctic-sea-ice.net/index.php/topic,176.msg190004.html#msg190004)
  • The last 'old' ice in the Lincoln Sea entered Nares Straight about February 27 (https://forum.arctic-sea-ice.net/index.php/topic,2592.msg190641.html#msg190641)
  • The last of the 'old' ice floes exited into Baffin Bay about March 26 (https://forum.arctic-sea-ice.net/index.php/topic,2592.msg192889.html#msg192889)
  • The Lincoln Sea arch had several 'minor' edge collapses starting March 5 (https://forum.arctic-sea-ice.net/index.php/topic,2592.msg191108.html#msg191108)
  • The March 5 edge ice entered Nares Strait about March 19 (https://forum.arctic-sea-ice.net/index.php/topic,2592.msg192381.html#msg192381)
  • The Lincoln Sea arch totally collapsed about March 20 (https://forum.arctic-sea-ice.net/index.php/topic,176.msg192495.html#msg192495)