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uniquorn

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Re: AWI AMSR2
« Reply #50 on: January 15, 2022, 01:56:12 PM »
Still some warmth in the WSC north of the FJL/Svalbard gap. Note the large floe drifting back over the WSC roughly centre in the awi sic-leads animation, jan1-14 (1.5MB)

A closer look at that floe using rammb, jan9-14 (14MB)
https://col.st/e9Tyf

some recent wsc buoy data
https://forum.arctic-sea-ice.net/index.php/topic,3665.msg329929.html#msg329929

edit: added an adaptive contrast image of https://go.nasa.gov/33kDH2N to emphasise floe structure/weakness which is just visible in parts of the rammb ani.
jan8-9 (1.1MB)

rough area measurement for scale, jan8
« Last Edit: January 15, 2022, 09:36:13 PM by uniquorn »

uniquorn

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Re: AWI AMSR2
« Reply #51 on: January 16, 2022, 10:53:12 AM »
A quick follow up on the WSC post above, here using awi SIC, v106, with LEADS colour inverted and overlaid at 50% transparent. This helps to show the difference between the two products while using the same colours for SIC and LEADS tends to overstate the open water imo.

jan8-15 (1MB)

uniquorn

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Re: AWI AMSR2
« Reply #52 on: January 17, 2022, 08:58:50 PM »
v106 regional extent/area update

uniquorn

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Re: AWI AMSR2
« Reply #53 on: January 26, 2022, 12:28:24 PM »
Recent low pressure event appears to have mixed some Barents water down to 60m and may have done similar in the WSC.

awi SIC, v106, with LEADS colour inverted and overlaid at 50% transparent
jan21-25
« Last Edit: January 27, 2022, 11:21:47 AM by uniquorn »

uniquorn

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Re: AWI AMSR2
« Reply #54 on: January 27, 2022, 10:22:58 AM »
regional extent/area update

SIC, Atlantic side jan21-26 am/pm

awi-esa smos, jan1-25. Looks more like melt than compaction in the western Barents. See what jan26 shows later.
« Last Edit: January 27, 2022, 11:27:08 AM by uniquorn »

uniquorn

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Re: AWI AMSR2
« Reply #55 on: January 27, 2022, 08:02:04 PM »
sic, Atlantic side, jan26 am/pm

uniquorn

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Re: AWI AMSR2
« Reply #56 on: January 28, 2022, 11:46:49 AM »
jan26 awi/esa SMOS came in.
Possibly some compaction south of FJL, still looks like melt in W Barents, too cloudy  to tell on worldview https://go.nasa.gov/3gbyKMl (light contrast)
Dispersion and melt along the shelf break to the Fram Strait.
Probably just dispersion north of Greenland


polarview jan27
crop at 40% scale
« Last Edit: January 28, 2022, 12:01:08 PM by uniquorn »

uniquorn

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Re: AWI AMSR2
« Reply #57 on: January 28, 2022, 06:41:24 PM »
Barents beginning to pick up again from the stats but looking quite fragile with the dispersion. Refreeze in the gaps and more ocean heat loss could be a positive outcome. See what tomorrow brings.

jan26-27 am/pm
« Last Edit: January 28, 2022, 06:46:39 PM by uniquorn »

uniquorn

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Re: AWI AMSR2
« Reply #58 on: January 29, 2022, 10:53:40 PM »
Refreeze south of the shelf break, v106 jan28 am/pm

uniquorn

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Re: AWI AMSR2
« Reply #59 on: January 30, 2022, 12:57:08 PM »
Drift speed slowing down over the WSC with the lighter winds.
1. https://go.nasa.gov/3AHT5mb, jan30 (light contrast). Cloud streets showing the heat escaping, though not directly to space. Refreeze over the eastern end.

A couple of longer animations for overview as the effects of the low pressure event die down
2. awi/esa smos, atlantic side, jan20-28

3. awi amsr2 SIC v106 with LEADS colour inverted and overlaid at 50% transparent.
jan11-29 (11.6MB)
Barents open water pushing into the northern Kara is interesting.
« Last Edit: January 30, 2022, 01:11:11 PM by uniquorn »

uniquorn

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Re: AWI AMSR2
« Reply #60 on: February 05, 2022, 12:15:59 PM »
regional extent/area update

uniquorn

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Re: AWI AMSR2
« Reply #61 on: February 07, 2022, 11:13:30 AM »
The jaxa drop yesterday perhaps mostly down to Greenland Sea, with a contribution from Barents and Kara.
The Bering blip in the awi v106 data is due to a missing swath on jan5AM
« Last Edit: February 07, 2022, 11:18:45 AM by uniquorn »

oren

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Re: AWI AMSR2
« Reply #62 on: February 08, 2022, 10:10:03 AM »
Looking at the 100k gain today, I suspect the JAXA drop yesterday also had to do with the missing swath.

uniquorn

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Re: AWI AMSR2
« Reply #63 on: February 08, 2022, 12:25:10 PM »
The missing swath was only on feb5AM. A full day probably wouldn't be affected the same way. It's not visible on the JAXA RGB, though I'm not sure what combination they use to generate their stats. It does have a nice presentation of the bomb cyclone though.

Both UHH and AWI AMSR2 struggled with that yesterday.
feb6-7

uniquorn

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Re: AWI AMSR2
« Reply #64 on: February 08, 2022, 12:51:12 PM »
regional extent/area update v106

AWI Greenland data reflecting the images above.

Hopefully not too confusing to add today's JAXA AMSR2 near Greenland here for comparison
« Last Edit: February 08, 2022, 01:04:52 PM by uniquorn »

oren

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Re: AWI AMSR2
« Reply #65 on: February 08, 2022, 01:35:59 PM »
Indeed the gain today appears like an artifact of the storm in the Greenland Sea. Thanks for shedding light on these mysteries.

Niall Dollard

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Re: AWI AMSR2
« Reply #66 on: February 08, 2022, 06:58:53 PM »
Indeed the gain today appears like an artifact of the storm in the Greenland Sea. Thanks for shedding light on these mysteries.

Yes thanks for shedding light on that.

Not to sound too pedantic but isnt it the storm in the Irminger Sea that caused the artefact ? (But I know we do include that sea as part of the Greenland sea ice area).

uniquorn

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Re: AWI AMSR2
« Reply #67 on: February 10, 2022, 11:38:57 AM »
regional extent/area update v106

Highlighting the Atlantic side: Greenland extent/area probably never went up significantly over the last 3 days. Maybe jaxa data was also affected during that time by the low pressure event in the Irminger Sea.

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Re: AWI AMSR2
« Reply #68 on: February 10, 2022, 12:29:55 PM »
sic v106, Labrador Sea, feb1-9

uniquorn

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Re: AWI AMSR2
« Reply #69 on: February 10, 2022, 11:03:18 PM »
Another venture south, this time to try an overlay of sic v106 at 50% transparent, 34.88%scale onto ascat, jan1-feb9. (11.5MB)

uniquorn

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Re: AWI AMSR2
« Reply #70 on: February 11, 2022, 01:07:46 PM »
Back to the Barents. It seems the effects of the low pressure event around jan13 jan24 may not have been temporary with a warmish southerly threatening to take extent and area back down to the levels during that event.
Probably due to ocean mixing. Where is FOoW?

1. v106 sic-leads atl side feb5-10
2. regional extent/area update v106
3. Focus on Atlantic side
4. Bremen smos feb1-10

Some ocean data here in the buoy thread
« Last Edit: February 11, 2022, 08:29:03 PM by uniquorn »

Niall Dollard

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Re: AWI AMSR2
« Reply #71 on: February 11, 2022, 07:50:37 PM »
Back to the Barents. It seems the effects of the low pressure event around jan13 may not have been temporary

Thanks Uniquorn. It has been a stormy year 2022 in the Barents. There was a depression there on Jan 13th but wasnt it the storm around Jan24th that did the most damage to the ice ?

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Re: AWI AMSR2
« Reply #72 on: February 11, 2022, 08:30:18 PM »
Thanks for checking Niall, agreed, it was jan24.

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Re: AWI AMSR2
« Reply #73 on: February 12, 2022, 03:32:10 PM »
From memory, when the extreme low hung over Barents there was a blocking high over the Faroes gap, preventing any huge interchange of Atl. Nord. sea waters. At that time it seemed any ocean movment would be biased from the direction of Bering but otherwise a general flow. The new moon followed so perhaps a little increase happened but the high persisted then as the effects of the new moon were waning a pronounced low established itself over that gateway, 960? so maybe double the amount that would 'normally' be exchanged at that moon phase and that low persisted so I'd expected some momentum in exchange to build. I believe once the Atl water crosses that ridge it's either recycled within the Nordic seas or if it has sufficient inertia a surge passes onto the Barents shelf, given the build in momentum the only unknown was how long before it's energy reached the Barents and it's shelf slope.

uniquorn

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Re: AWI AMSR2
« Reply #74 on: February 16, 2022, 01:23:17 PM »
A tale of two seas, Bering and Okhotsk

uniquorn

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Re: AWI AMSR2
« Reply #75 on: February 19, 2022, 12:48:28 PM »
regional extent/area update v106

uniquorn

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Re: AWI AMSR2
« Reply #76 on: February 27, 2022, 08:36:06 PM »
regional extent/area update v106

sudden drop in concentration north of FJL on feb25-26 possibly related to <976hPa moving between Svalbard/FJL

sic-leads, WSC, feb24-26 am/pm

nullschool, feb25

HapHazard

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Re: AWI AMSR2
« Reply #77 on: February 28, 2022, 01:39:20 AM »
I know it doesn't mean much more than a fart in the wind, but thanks for everything uniquorn.
If I call you out but go no further, the reason is Brandolini's law.

uniquorn

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Re: AWI AMSR2
« Reply #78 on: February 28, 2022, 11:25:46 AM »
Possible that this event will be similarly transient ;)

Just to verify v106 here is worldview, feb27-28   https://go.nasa.gov/35zonjJ

and rammb feb24-28  https://col.st/ptI95

uniquorn

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Re: AWI AMSR2
« Reply #79 on: March 03, 2022, 07:36:57 PM »
A lot of missing amsr2 data on awi, uhh and bremen today. At least it shows us some of the masked area on awi v106. This is the PM product which shows more of the mask.
« Last Edit: March 03, 2022, 08:03:52 PM by uniquorn »

uniquorn

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Re: AWI AMSR2
« Reply #80 on: March 05, 2022, 12:09:38 PM »
regional extent/area update v106
missing data = messy stats

uniquorn

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Re: AWI AMSR2
« Reply #81 on: March 12, 2022, 02:34:20 PM »
regional extent/area update v106

uniquorn

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Re: AWI AMSR2
« Reply #82 on: March 12, 2022, 09:47:38 PM »
Some discussion last melt season about N Kara failing to melt out completely. SIC-LEADS and SIC near surface features highlighting how protected the area south of SZ can be.
Note also that the Vilkitsky Strait cleared during feb8-17
jan1-mar11 (5MB)

uniquorn

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Re: AWI AMSR2
« Reply #83 on: March 15, 2022, 09:23:33 PM »
Here using SIC-LEADS to focus on the Nares 'funnel' flip from west to east in the Lincoln Sea, feb1-mar14.

rammb view, feb28-mar15
It flips around mar9 15:00, possibly wind driven, some tidal movement is discernible

nullschool not showing strong winds that day though the direction changes.
« Last Edit: March 15, 2022, 09:36:23 PM by uniquorn »

Glen Koehler

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Re: AWI AMSR2
« Reply #84 on: March 16, 2022, 12:22:20 AM »
     Naive but sincere question:  I know that the Nares ice arch has failed to form in some past winters, so I assume that the Nares Strait must have been a site of ice export in those years.  But here we are near the peak of ASI freeze up and those videos of flow through the Nares Strait look like a bucket with a hole in the bottom. 

     My question is -- how much precedent is there for Nares Strait ice export in March?  I guess the volume of ice involved is not that great compared to the total ASI, but it seems like one more step towards structural breakdown.  The Lincoln Sea is near the heart of the "Last Ice" area.  Having it actively exporting ice near the annual ASI maximum Extent/Area/Volume seems like another indication of a weakening ice pack.  All I know is that I don't know enough to have a firm opinion about this.  It just looks bad.
« Last Edit: March 16, 2022, 01:20:37 AM by Glen Koehler »
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Re: AWI AMSR2
« Reply #85 on: March 16, 2022, 01:11:11 AM »
 From one of my first posts here in 2015 ....
       Greenland and Arctic Circle / Re: The Nares Strait thread
« on: January 24, 2015, 10:06:07 PM »
.. I've never imagined I would see the Arctic pouring into the Atlantic so dramatically . Is what's happening in Lincoln Sea exceptional or should my awe be directed elsewhere :)

 Neven wrote in his blog that spring .
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oren

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Re: AWI AMSR2
« Reply #86 on: March 16, 2022, 02:02:56 AM »
Nares is either blocked by an arch - usually in Kane Basin, otherwise in the Lincoln Sea - or exporting ice throughout the winter. There is a near-constant current down the strait, and the pressure of the trans-polar drift helps push ice into the funnel.
Indeed, years where an arch fails to form are relatively rare, and the export effect is not negligible as this is the thickest ice in the Arctic. However, I seem to recall I once estimated the total volume and it came to some tens of km3 over the winter, so not a make-or-break factor. We can discuss this further in the Nares thread.

uniquorn

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Re: AWI AMSR2
« Reply #87 on: March 16, 2022, 08:29:41 PM »
Some details on data currently available for AWI AMSR2 development version 1.06

20210728 to present
202001-09
201908-12
201808-09
201708-09
201608-09
201508-09
201408-09
201308-09
201208-09

A new freezing thread and time to announce a new independent AMSR2 data source. Have a look at:

ftp://ftp.awi.de/sea_ice/product/amsr2/v106/analysis_nh/

It includes a table of the regional extent and area derived from AWI AMSR2 SIC product
nh_awi_amsr2_regional_extent_area.csv

Full reprocessing is not yet finished but data will be regularly updated.

See ftp://ftp.awi.de/sea_ice/product/amsr2/README.txt for a quick introduction.

Feedback and comments are very welcome!
my emphasis

I use winscp and/or filezilla to download them.

This works perfectly fine for me:
wget ftp://ftp.awi.de/sea_ice/product/amsr2/v106/analysis_nh/*

Latest daily images are available from http://seaice.de/

Yeah, too bad that the good old ftp vanishes. As a quick workaround I mirrored these files also on my site. i.e.
 
https://seaice.de/nh_awi_amsr2_regional_extent_area.csv
https://seaice.de/nh_extent_SSMI_ASI_Regional_1992_2020.csv

https://seaice.de/AMSR2_Central_Arctic_SIC-LEADS.gif
https://seaice.de/AMSR2_Central_Arctic.gif

https://seaice.de/Greenland_a.png
https://seaice.de/Beaufort_a.png
https://seaice.de/Total_e.png
https://seaice.de/Total_a.png
...

forgot about that...the two gif files are also updated (~10MB)
Someone might like to take the job of reposting a gif once in a while...

uniquorn

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Re: AWI AMSR2
« Reply #88 on: March 16, 2022, 08:44:23 PM »
and surely someone can do better than this

hmm, that's quite an area drop in central arctic, probably temporary though

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Re: AWI AMSR2
« Reply #89 on: March 17, 2022, 01:59:05 AM »
  '..that's quite an area drop in central arctic'  .. It sure is ! .. but to where we were at the beginning of August last year ? That shows both how well the central arctic was protected last year and how dramatic a start this year is enjoying . 
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Re: AWI AMSR2
« Reply #90 on: March 18, 2022, 05:02:17 PM »
First sign of the full moon tide surging out of Lincoln on the Canadian side.

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Re: AWI AMSR2
« Reply #91 on: March 18, 2022, 05:58:06 PM »
This has nothing to do with the moon. It's just changes in wind direction.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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uniquorn

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Re: AWI AMSR2
« Reply #92 on: March 18, 2022, 10:42:30 PM »
rammb at 1 frame roughly every 50mins is better for tidal motion. In this case it looks largely wind driven.
https://col.st/cp8Za

uniquorn

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Re: AWI AMSR2
« Reply #93 on: March 19, 2022, 10:38:26 AM »
v106 regional extent and area update and a look at Bering since it's not included in the link upthread.
feb1-mar18 (2.3MB)

oren

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Re: AWI AMSR2
« Reply #94 on: March 19, 2022, 11:04:55 AM »
https://seaice.de/AMSR2_Central_Arctic_SIC-LEADS.gif

Someone might like to take the job of reposting a gif once in a while...
I will try to post the Leads gif in the main thread in a timely manner.

uniquorn

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Re: AWI AMSR2
« Reply #95 on: March 23, 2022, 11:53:27 AM »
v106 regional extent and area update

Okhotsk repeatedly flash freezing but seemingly unable to consolidate. Too mobile perhaps or incomplete overturning.
sic v106, jan1-mar22  (5MB)

https://go.nasa.gov/3L5zu3c  mar23
« Last Edit: March 23, 2022, 12:47:28 PM by uniquorn »

uniquorn

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Re: AWI AMSR2
« Reply #96 on: March 26, 2022, 10:30:48 AM »
1. v106 regional extent and area update

2. Labrador sea, feb1-mar25  (4MB)

Glen Koehler

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Re: AWI AMSR2
« Reply #97 on: March 26, 2022, 09:27:36 PM »
Thanks Uniquorn for the regional extent and area updates.  My reluctance to ask for more is exceeded by my interest in seeing the long-term average to provide context (either extent or area, probably don't need to clutter the graphs with both).  Any chance of that happening? 8)
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uniquorn

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Re: AWI AMSR2
« Reply #98 on: March 26, 2022, 09:34:50 PM »
Some details on data currently available for AWI AMSR2 development version 1.06

20210728 to present
202001-09
201908-12
201808-09
201708-09
201608-09
201508-09
201408-09
201308-09
201208-09
https://seaice.de/nh_awi_amsr2_regional_extent_area.csv
« Last Edit: March 26, 2022, 09:49:09 PM by uniquorn »

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Re: AWI AMSR2
« Reply #99 on: March 27, 2022, 09:51:06 AM »
Yeah unfortunately the only comparison available at the moment is to 2020. I wish AWI would reprocess the past data for all the years, it would be very useful as I think the AWI algorithm is now the best AMSR data source, and by extension the best area/extent data source.