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Messages - Ktb

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1
Arctic sea ice / Re: The 2020 melting season
« on: August 10, 2020, 10:24:45 PM »
If I were to short-list the best tools for a quick daily state-of-the-ice in August, it would consist of AMSR2 concentration, OsiSaf 2day drift, WorldView vis and viirs, Nullschool-gfs and Hycom thickness. All but OsiSaf have seen major upgrades this year. The latter two make modest forecasts.

Rammb, the buoys and 10 km Polarstern bow radar are the big three informational innovations this year, though situational. Sentinel-1AB radar has been a disappointment: it has ok resolution, a good portal and a cloud-free view but that coverage is episodic and incomplete with uneven contrast, showing few features of the ice for the resolution.

Hycom goes out six days and so incorporates anticipated effects of its internal weather forecast on the ice, along with bottom, top, lateral melt and ice pack displacement. However the Hycom animation is offered at exceedingly poor resolution (230 x 200 pixels for the Arctic Ocean proper) oriented along the prime meridian (the rest of the world having settled on Greenland-down to facilitate visual comparison).

Hycom continues to see a retreat and contraction of the core CAB to the west though no overall drama. The unusual palette has a blackish break between the green for thick ice and blue for intermediate. This is a navy 'operational' product so that transition may be a cut-off for icebreakers.

It seems that recent near-zero ice thickness is represented as whitish rather than open water gray. It's not clear slush is something we want to be tracking; perhaps from the navy's perspective it is at special risk for re-freezing or still has isolated floes. It can be removed to whatever level with a single click on the intermediate tile-up. 

This product lacks sufficient resolution to provide updates on the unprecedented Ellesmere to north pole opening. For that, AMSR2, WorldView, RAMMB or Sentinel-1AB are better.

The slide show has the corrected Hycom thickness of Aug 10th (and its posterized palette) over the 5-day cloud-removal AMSR2, showing the expected.

The Hycom thickness forecast updates every day and so needs a regular reprocessing, as it's not easy to automate. To empower more people per a suggestion of Oren, our moderator extraordinaire, the steps for doing this in Gimp are provided below. Degree of difficulty 2 in 5, ten minutes with practice.

Steps to extract the 7day forecast, enlarge(433.2%) and rotate (45º cw) it to match scale and Greenland-down orientation of AMSR2 uhh, clean up distracting datestamp and excessive palette:

download, open, change to RGB, unoptimize gif (to remove transparencies)
delete early days leaving top 7 frames (mark earliest frame, hold command-x down below it)
duplicate stack, make reusable palette in new window, deleting >3.0 m (not used) to 45x352
duplicate stack file, crop out month and day, adjust width to match palette (45)
crop stack to 631x631 data circle
rotate 45º cw about center
change from indexed to RGB
crop to region of current interest
enlarge 433.2% to match AMSR2uhh (or new AWI as that size finalizes)
enlarge canvas on palette and date to match new width.
tile thickness, palette and date, adjust view, make new layer from visible
move to imageJ and de-tile to make avi/mp4 or gif

https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictn_nowcast_anim30d.gif
ftp://ftp-projects.cen.uni-hamburg.de/seaice/AMSR2/3.125km/
http://osisaf.met.no/p/osisaf_hlprod_qlook.php?year=2020&month=08&day=05&action=Today&prod=LR-Drift&area=NH&size=100%25
https://earth.nullschool.net/#current/wind/isobaric/1000hPa/overlay=temp/orthographic=-57.56,85.91,1296
https://go.nasa.gov/30HqqNF

2
Arctic sea ice / Re: The 2020 melting season
« on: July 24, 2020, 04:45:55 AM »
Quote from: Freegrass on July 24, 2020, 03:25:11 AM
Quote from: Frivolousz21 on July 24, 2020, 03:20:40 AM
Quote from: be cause on July 24, 2020, 01:14:48 AM
There ain't no stoppin' it now .. https://go.nasa.gov/39oSyYL
  for the 1'st time in 10 days we get to see the unfolding horror of the Atlantic side . Pagophilus showed the damage north of FJL . I see it extends as far as can be seen .. 86.5'N . The state of the ice here is as bad or worse than the ice between Laptev and pole . Coupled with the video of Polarstern and the ice flow , I see no reason for any of the ice on the Eurasian side of the meridian 0/180' to survive .
  this update has just been patched into worldview .. between G'land and the pole .. the hue of the blue has darkened and it is easy to see water between the rubble = trouble . It looks as if even here in the bastion of ice there is no defence . Looks like only 5% of the ice here would make it through a serious assault .. the whiter blocks and specks . 
     https://go.nasa.gov/39pnnwi

  of course , weather and seasons changing may delay the inevitable for another year .

  b.c.
.

This is exactly what I mean it's only freaking July 23rd.

2020 is going to finish lowest in area, extent, and volume
But the beaufort is gonna save us this year, right?
Oh wait... Storm coming...  :-\

The Beaufort/Western CAB is ironically in freaking shambles.

The Southern CAB/central arctic,north pole,Atlantic side is in deep shit.  An absolutely wicked Southerly/SW flow over the CAA and incredible warmth plowing through the CAB/Eastern CAB/Atlantic side. 

Expect UNPRECEDENTED melt.  Expect huge areas of open water is going to develop over the next 1-2 weeks.

Going to be never before seen melt IN MODERN HUMAN HISTORY.

BY MID AUGUST AREA WILL DROP AT RECORD PACE.


Concentration keeps dropping.   Imagine If the entire central arctic basin was clear.   

Concentration would be way lower.

3
Arctic sea ice / Re: The 2020 melting season
« on: July 05, 2020, 12:53:23 PM »
Сan see how quickly the large ice floe of fast ice 30 km in size disappears into the Laptev Sea.

4
Arctic sea ice / Re: The 2020 melting season
« on: June 11, 2020, 04:34:44 PM »
I received this in a mail from David Schröder, the scientist whose melt pond fraction model I would write a lot about on the ASIB:

Quote
Just submitted this year's prediction:

We predict the September ice extent 2020 to be 3.8 (3.3-4.3) million km2. This is the lowest prediction we have made based on spring melt pond fraction. The likehood is around 30% that this September extent will be a new minimum record. In our model simulation since 1979, May 2020 has the highest mean melt pond fraction for May including some unprecedented melt pond formation in the Central Arctic during 15-18 May when air temperature exceeded 0deg C.

5
The politics / Re: Who should be the Democratic nominee for President in 2020?
« on: March 13, 2020, 04:03:35 AM »
As I said, I don't think lady luck will play along, and the societal and economic parameters of the USA do not lend themselves to controlling this virus - lack of sick leave, absurd medical costs, tens of millions who lack any kind of healthcare plan, low societal cohesiveness, a science-denying administration, an egomaniac idiot at its helm, and many other factors.

6
The politics / Re: Elections 2020 USA
« on: February 09, 2020, 06:14:44 PM »

7
Greenland and Arctic Circle / Re: Greenland 2019-20 SMB (Snowfall & Melting) Year
« on: January 18, 2020, 03:32:36 AM »
After over 2 months, new data from GRACE-FO - at last.

Updated GRACE-FO ice mass fromftp://isdcftp.gfz-potsdam.de/grace/GravIS/GFZ/Level-3/ICE/GIS

Last measurement date mid-November 2019.
12 month ice mass loss 479 GT, i.e. 1.32 mm sea level rise.

Note the precipitous loss in ice sheet mass in the south/central coast of West Greenland (basin 306) since around 2017.

The lower than average snowfall over the last month or so might show an uptick in the 12 month change in ice sheet mass in the next month or two.

8
Arctic sea ice / Re: Are you hoping to witness a BOE?
« on: August 23, 2019, 09:27:08 PM »
For me it's simple: Humans have proven incapable of sufficient self control to forestall ecological disaster. So, Mother Nature will have to do it instead, and the sooner she does (incl. BOE), the less the long-term damage.

9
Greenland and Arctic Circle / Re: Greenland 2019 Melt Season
« on: July 27, 2019, 10:46:24 PM »
 GRACE-FO is producing new mass loss data that I can read. Also posted on what's new.

We will get a much better handle on what's going on from now on.

10
Consequences / Re: Worst consequence of AGW
« on: June 03, 2019, 12:52:31 PM »
increased threads ? :) .. b.c.

11
Arctic sea ice / Re: The 2018 melting season
« on: September 01, 2018, 09:56:28 PM »
From the very first post in this thread, way back in March:

Quote from: Lord M Vader on March 19, 2018, 08:12:14 PM
Personally, I think we will end up somewhere around 4,5 Mn km2 by the middle of September.

FWIW, it's now September and the current projected JAXA minimum (rounded to one decimal place) is in fact 4.5 million km2.  Not bad!

12
The rest / Re: We made it to Reddit!
« on: July 21, 2018, 08:59:30 AM »
Well, one thing's for sure, the answer won't be given there.  ::)

13
The forum / Re: Arctic Sea Ice Forum Humor
« on: June 30, 2018, 05:35:36 PM »
I think this applies to many here

14
Arctic sea ice / Re: The 2018 melting season
« on: June 05, 2018, 11:21:03 PM »
Maybe I am missing something, but that Slater projection for July 25 looks a lot more like the current ice extent from AMSR2 for June 5 (today) than it looks like, for example, the actual ice extent for July 25 last year (see below -- I've put all three maps together).  In addition to that, we are at the second lowest measured extent since 1979 for any June 5 right now, implying, at least, that ice extent should look something like last year's extent on July 25.  To me, the Slater forecast looks strange, and I would be glad to be enlightened.

AMSR2 image for July 25 2017 is a little smaller scale than the other maps... apologies.  Pattern of lower extent is still obvious, though.  No ice in Baffin Bay, Hudson Bay, Kara Sea, most of ESS free of ice etc.

Quote from: Ktb on June 05, 2018, 10:46:18 PM
Slater projection shows ice beginning to open in the CAB for July 25th, extremely close to the pole. Extent of 7.42 mil km^2 at that time.

15
The rest / Re: Climate, Agriculture and Other Pertinent Documentaries
« on: May 23, 2018, 12:21:01 AM »
I'm sure it will be too lefty and optimistic for some on here but I enjoyed the French doc called Demain (Tomorrow in English).




16
Consequences / Re: Forests: An Endangered Resource
« on: March 27, 2016, 05:50:38 PM »
Are you thinking of Wendell Berry's:

“We thought we were getting something for nothing,

But we were getting nothing

for everything.”

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