Support the Arctic Sea Ice Forum and Blog

Poll

By which route will itp128 leave the Arctic Ocean?

Fram Strait
14 (51.9%)
Nares Strait
11 (40.7%)
Further west via CAA
2 (7.4%)

Total Members Voted: 27

Voting closed: March 06, 2023, 07:38:20 PM

Author Topic: By which route will itp128 leave the Arctic Ocean?  (Read 11927 times)

A-Team

  • Young ice
  • Posts: 2977
    • View Profile
  • Liked: 944
  • Likes Given: 35
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #100 on: May 18, 2023, 04:13:31 PM »
Quote
After data collection ceased, the ITP apparently drifted through Nares Strait and resurfaced 995 days in Baffin Bay.
Indeed we have seen buoys go down the Nares but whether this particular one did requires an ascat time series of ice motion for the relevant non-GPS reporting period.

Alternately it made it over to the Fram, raced down the entire coast of Greenland in a couple of weeks, rounded the tip and rode the Irminger Current way up into Baffin Bay.

The attached text file provides direct urls to the 36 weekly ascats back to the beginning of the 2022-23 melt season. (They changed the file naming system mid-way!). Seven-day timing is less jerky than the ten-day below and still keeps the file size small. It might be advisable to go to daily for the most recent week rather than give the last frame more milliseconds.

Note Gimp has a better contrast adjustment (midpoint gamma) than ImageJ so that step should precede local contrast adjustment and bicubic resizing. The region of interest, say between Nares, Fram and NP, should be targeted for optimization rather than the whole image. A precise land masking ascat was previously posted. Any false color gifs made in ImageJ must be reset from 8-bit to 24 before saving to preserve the palette.

Since 15 frames at 500 pxl width already takes some 3 MB, the melt season to date at a weekly or five day rate would be pushing 10 MB so needs to go as mpg (which muddies individual frames) rather than gif.

To fast-forward a week or two in the future, not based on a wind forecast but simply on the seven day feature trajectory trend lines of features, this amounts to a specifying the displacement or deformation of current grayscale pixels. Thus if the pixel at coordinates n,m moved to p,q in the last seven days which might amount to 2 over and 3 down, that should be continued and any pile-ups averaged.
« Last Edit: May 18, 2023, 05:11:05 PM by A-Team »

A-Team

  • Young ice
  • Posts: 2977
    • View Profile
  • Liked: 944
  • Likes Given: 35
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #101 on: May 20, 2023, 01:12:32 AM »
In terms of timing persistent trends in sea ice motion, it's necessary to add a few dates over the buoy track. That's done over Ascat below by transferring the plot over AMSR2 provided by seaice.de and scrolling thru the raw data for lat/lon crossings and EWNS extremes.

Here the Framward linear drift is between 14 Feb - 19 May, so 98 days and counting. Much of the ice pack appears to be moving coherently along a Bering Strait to Svalbard path.

However the multiyear ice along the central CAA coast is being squeezed by ice moving down from the northwest, with ice there either partly forced into a westward arc off the Alaskan coast and partly pushed eastward.

It would be helpful to have select additional buoys for these same start/stop dates (or perhaps from 01 Jan 2023) for the whole Arctic Ocean as it's confusing when the trajectories cover very different date ranges. Only the final frame of the animation is needed.

Note buoy GPS locations and time stamps provide far more accurate descriptions of motion and area displaced and divergences than low resolution/low accuracy products like OsiSaf.

Significant ITP128 positions: year day number, longitude, latitude

2022  342.45855   -80.3012  87.1132  on 08 Dec 2022
2023    1.00049   -62.6646  86.4215  on 01 Jan 2023
2023    1.79242   -62.6604  86.4213  on 02 Jan 2023
2023   36.39639   -70.0007  85.9234  on 05 Feb 2023
2023   44.83424   -75.3334  85.4250  on 14 Feb 2023
2023   61.75054   -70.9690  85.2809  on 02 Mar 2023
2023  139.00036   -39.1800  85.1430  on 19 May 2023

https://www2.whoi.edu/site/itp/data/active-systems/itp128/
« Last Edit: May 20, 2023, 01:54:34 PM by A-Team »

uniquorn

  • First-year ice
  • Posts: 5117
    • View Profile
  • Liked: 2163
  • Likes Given: 388
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #102 on: May 20, 2023, 04:51:55 PM »
Will look at the whole arctic ocean another time. That needs the daily dat files and usually needs cleaning up more.

A-Team

  • Young ice
  • Posts: 2977
    • View Profile
  • Liked: 944
  • Likes Given: 35
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #103 on: May 21, 2023, 12:39:14 AM »
Quote
Will look at the whole arctic ocean another time
Thx, no rush! Here where this is going: The buoy tracks are colored by the matching time intervals as specified above (driven by critical features of itp128). Selection is needed but wasn't done against buoys with confusing or redundant tracks.

We are looking in part for trajectory parallelism that implies virtual buoys which then convert sparse point data into lines and area swept out, thus indicating regional rigidity of the ice pack.

Perfectly parallel trajectories (according to high precision high frequency distance GPS position differencing) means no leads or rafting because those change inter-buoy distances.

This could perhaps synergize with AMSR2 lead detection, give the widening history at 48x the temporal resolution of the daily satellite, and determine whether the lead froze over or just closed again. (This requires two buoys on opposite sides.)

The four frames are shown coloring the original, by themselves, 08 Dec-01 Jan parallel types, and overlaid on the 19 May 2023 Ascat.

The second animation shows the resolution limits of daily Ascat (which is one of the better satellites). It is no match for buoy GPS location and 30 minute sampling.

The third animation is at the better original scale (where colors are not pixelated). This will not animate without two clicks and few people will realize that. Ascat needs to be rotated 45º cw and enlarged 5.10x to overlay. It could have been done over an Ascat animation of the dates involved but wasn't.
« Last Edit: May 21, 2023, 03:28:24 AM by A-Team »

oren

  • Moderator
  • First-year ice
  • Posts: 9805
    • View Profile
  • Liked: 3584
  • Likes Given: 3922
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #104 on: May 24, 2023, 07:25:29 PM »
This little thread is a gem. The animations are great.
Did itp128 not depart yet? I would have expected it to happen already.

KenB

  • Frazil ice
  • Posts: 151
    • View Profile
  • Liked: 38
  • Likes Given: 35
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #105 on: May 25, 2023, 02:48:10 AM »
This little thread is a gem. The animations are great.
Did itp128 not depart yet? I would have expected it to happen already.

itp128 remains stubbornly N. of 85 degrees, but is now around 37 degrees W.  There's a very nice animation at https://seaice.de/nh_AMSR2_itp128_zoom_latest.gif which can be updated daily. 
"When the melt ponds drain apparent compaction goes up because the satellite sees ice, not water in ponds." - FOoW

oren

  • Moderator
  • First-year ice
  • Posts: 9805
    • View Profile
  • Liked: 3584
  • Likes Given: 3922
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #106 on: May 25, 2023, 10:13:34 AM »
Thanks!

gerontocrat

  • Multi-year ice
  • Posts: 20370
    • View Profile
  • Liked: 5289
  • Likes Given: 69
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #107 on: May 25, 2023, 10:16:36 AM »
Looking at GFS forecasts of the 10m asl wind over the next 10 days itp128 might end up heading for Svalbard?
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

uniquorn

  • First-year ice
  • Posts: 5117
    • View Profile
  • Liked: 2163
  • Likes Given: 388
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #108 on: August 13, 2023, 09:31:24 PM »
ITP128 is now almost at the Fram Strait. ITP125 also likely to exit the Arctic Ocean by a similar route. Any chance of either exiting via the Nares Strait was prevented by the southern arch formation on Mar30 as they were too far north. However, at least one buoy, ice ball 7423940 looks like it will drift into the Nares Strait soon. It began to change direction mid June.


Definitely well gone now. I can see a very small amount of movement all across the end (southwestern side) of the arch on June 9th.

So March 30th to June 9th would give it 71 days, not including the last date.

Since our records back to 2007, the shortest lived was 2008 (67 days).



Longevity and 5 year moving average shown on this chart. The 5 year average has plateaued around the 100 day mark. But of particular note is the increasing number of years when no arch formed.

Up to 2007 arches formed every year, or so I am told.

Based on the WHOI annual drift arrows in grey, ITP128 needed to drift closer to the 30°W line to catch any drift towards CAA but this year all buoys north of Ellesmere Island drifted east since March.


kassy

  • First-year ice
  • Posts: 8234
    • View Profile
  • Liked: 2041
  • Likes Given: 1986
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #109 on: August 13, 2023, 10:23:41 PM »
Well that took longer then i initially expected but at least it is leaving the correct way (vote wise).
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

Alexander555

  • Young ice
  • Posts: 2503
    • View Profile
  • Liked: 185
  • Likes Given: 49
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #110 on: August 13, 2023, 11:00:44 PM »
Do they place these buoys on the ice in winter ?

kassy

  • First-year ice
  • Posts: 8234
    • View Profile
  • Liked: 2041
  • Likes Given: 1986
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #111 on: August 13, 2023, 11:10:12 PM »
These at the start of refreeze season:

Quote
ITP125 was deployed on a 0.8 m thick ice floe in the Transpolar Drift on October 1, 2021 at 78° 45.0 N, 179° 39.4 W in collaboration with the Nansen and Amundsen Basins Observational System (NABOS) project from the Russian Research Vessel Treshnikov. On the same icefloe, a US Army Cold Regions Research and Engineering Laboratory (CRREL) Seasonal Ice Mass Balance Buoy 3 was also installed. The ITP includes a dissolved oxygen sensor and is operating on a fast sampling schedule of 4 one-way profiles between 5 and 760 m depth each day.

Quote
ITP128 was deployed on a 1.36 m thick ice floe in the Transpolar Drift on September 30, 2021 at 77° 26.5 N, 179° 54.3 E in collaboration with the Nansen and Amundsen Basins Observational System (NABOS) project from the Russian Research Vessel Treshnikov. On the same icefloe, a US Army Cold Regions Research and Engineering Laboratory (CRREL) Seasonal Ice Mass Balance Buoy 3 was also installed. The ITP is operating on a fast sampling schedule of 4 one-way profiles between 5 and 760 m depth each day.

itp125 looks more likely to exit via Nares imo. I'm going to vote for Fram for itp128.

PS for the buoy data threads the deployment will always be listed somewhere earlier in the thread.
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

Alexander555

  • Young ice
  • Posts: 2503
    • View Profile
  • Liked: 185
  • Likes Given: 49
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #112 on: August 13, 2023, 11:43:36 PM »
So when they say " the atlantic side stays behind " with melting. That's not really correct, if the pack has been moving east most of the time.

uniquorn

  • First-year ice
  • Posts: 5117
    • View Profile
  • Liked: 2163
  • Likes Given: 388
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #113 on: August 14, 2023, 12:07:38 AM »

HapHazard

  • Grease ice
  • Posts: 814
  • Chillin' on Cold Mountain.
    • View Profile
  • Liked: 284
  • Likes Given: 5241
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #114 on: August 14, 2023, 12:38:44 AM »
Thanks as always, Uni. Looks like you're correct, A555.
If I call you out but go no further, the reason is Brandolini's law.

binntho

  • Nilas ice
  • Posts: 2193
    • View Profile
  • Liked: 878
  • Likes Given: 235
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #115 on: August 14, 2023, 07:35:53 AM »
So when they say " the atlantic side stays behind " with melting. That's not really correct, if the pack has been moving east most of the time.

I wonder who's been saying that? It is fairly clear that with near constant northerly winds, Fram export and ice drift towards the Atlantic, while the ice edge doesnt really budge, that there is massive melt going on here all the time, and for several months now. The thickest ice is being pushed into the Atlantic shredder, as has been shown and discussed repeatedly in this forum. The volume being exported into the Atlantic, only to melt rapidly (and yes, also during winter), is much bigger this year than most other years.

Most of the time, the Arctic is cold enough to form new ice in stead of the ice being lost. But during melt season, no new ice is being produced. So even if the Atlantic side is not adding to extent losses, it is presumably adding signifcant volume loss. And the leads that wold freeze over in winter are now acting to lower the albedo of the central Arctic, and increasing melt there as well.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

be cause

  • Nilas ice
  • Posts: 2441
    • View Profile
  • Liked: 1012
  • Likes Given: 1034
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #116 on: August 14, 2023, 09:29:19 AM »
Apart from the obviously dispersed areas , the central Arctic leads have largely closed , with a covering of snow , so albedo is high : https://go.nasa.gov/3OVVBOu
Conflict is the root of all evil , for being blind it does not see whom it attacks . Yet it always attacks the Son Of God , and the Son of God is you .

binntho

  • Nilas ice
  • Posts: 2193
    • View Profile
  • Liked: 878
  • Likes Given: 235
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #117 on: August 14, 2023, 11:09:50 AM »
Apart from the obviously dispersed areas , the central Arctic leads have largely closed , with a covering of snow , so albedo is high : https://go.nasa.gov/3OVVBOu

My statement was more of a general description of things. Snowcover obviously increases albedo, and leads can disappear in one place and appear in another. But leads are not freezing over during the sommer months.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

KenB

  • Frazil ice
  • Posts: 151
    • View Profile
  • Liked: 38
  • Likes Given: 35
Re: By which route will itp128 leave the Arctic Ocean?
« Reply #118 on: December 04, 2023, 06:12:03 PM »
Just for posterity, as of today ITP128's position (as reported at https://www2.whoi.edu/site/itp/data/active-systems/itp128/
is 64.9641° N, 39.3133° W, having left the Arctic via the Fram Strait. 
"When the melt ponds drain apparent compaction goes up because the satellite sees ice, not water in ponds." - FOoW