Support the Arctic Sea Ice Forum and Blog

Author Topic: Home brew AMSR2 extent & area calculation  (Read 1344253 times)

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3300 on: September 25, 2017, 06:48:40 PM »
Smallish increases, botyh extent and area.

Update 20170924.

Extent: +30.2 (+114k vs 2016, +74k vs 2015, -320k vs 2014, -378k vs 2013, +1225k vs 2012)
Area: +36.3 (+139k vs 2016, +26k vs 2015, -338k vs 2014, -486k vs 2013, +1080k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                    5.7                    -4.1                     6.2
               Kara Sea             Barents Sea           Greenland Sea
                    1.2                     0.0                     8.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -2.0                     0.0                     0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   14.2                     0.7                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                    30.2

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   20.6                    -4.9                     6.9
               Kara Sea             Barents Sea           Greenland Sea
                    0.7                     0.0                     5.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -3.2                     0.0                     0.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    7.7                     2.7                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                    36.3


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

iceman

  • ASIF Citizen
  • Posts: 273
    • View Profile
  • Liked: 2
  • Likes Given: 7
Re: Home brew AMSR2 extent & area calculation
« Reply #3301 on: September 26, 2017, 12:18:17 PM »
Wipneus, thank you again for your wonderful animations (and relentless updates).

My thanks as well, this is a great thread

echoughton

  • ASIF Lurker
  • Posts: 77
    • View Profile
  • Liked: 8
  • Likes Given: 32
Re: Home brew AMSR2 extent & area calculation
« Reply #3302 on: September 26, 2017, 12:45:21 PM »
Yes thanks, Wipneus. I really appreciate this group and all your hard work.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3303 on: September 26, 2017, 06:30:17 PM »
More serious increases in extent and area. Area even scores a century. Most of this happens in the CAB, Laptev and ESS.

Update 20170925.

Extent: +61.1 (+55k vs 2016, +115k vs 2015, -330k vs 2014, -396k vs 2013, +1240k vs 2012)
Area: +110.5 (+116k vs 2016, +96k vs 2015, -314k vs 2014, -446k vs 2013, +1164k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   33.8                     4.6                    13.1
               Kara Sea             Barents Sea           Greenland Sea
                    3.4                     0.5                     3.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -2.4                     0.0                     0.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    2.4                     2.0                    -0.2
             Bering Sea          Sea of Okhotsk            Total Extent
                   -0.1                     0.0                    61.1

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   68.9                     9.1                    16.7
               Kara Sea             Barents Sea           Greenland Sea
                    2.5                     0.3                    14.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.7                     0.0                     0.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -1.9                     0.7                    -0.1
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   110.5


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3304 on: September 27, 2017, 07:09:54 PM »
Refreezing in the pack and advancing ice edge on the Pacific and Asian sides.

Update 20170926.

Extent: +58.9 (+4k vs 2016, +149k vs 2015, -316k vs 2014, -370k vs 2013, +1253k vs 2012)
Area: +100.1 (+100k vs 2016, +162k vs 2015, -268k vs 2014, -394k vs 2013, +1192k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   27.8                     9.3                    17.0
               Kara Sea             Barents Sea           Greenland Sea
                    5.2                    -0.3                    -8.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    3.9                     0.0                     0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    5.9                    -1.1                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                    58.9

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   67.5                     6.0                    15.0
               Kara Sea             Barents Sea           Greenland Sea
                    5.1                    -0.1                   -13.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    5.2                     0.0                     0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   15.4                    -0.9                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   100.1


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3305 on: September 28, 2017, 06:07:43 PM »
The +48k increase in extent is small enough to go below 2016. The increases are again on the Pacific side.

Update 20170927.

Extent: +48.0 (-12k vs 2016, +148k vs 2015, -257k vs 2014, -372k vs 2013, +1261k vs 2012)
Area: +32.6 (+44k vs 2016, +142k vs 2015, -230k vs 2014, -433k vs 2013, +1188k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   52.6                    10.8                    -0.8
               Kara Sea             Barents Sea           Greenland Sea
                   -8.1                    -0.2                     0.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    2.0                     0.0                    -0.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -5.5                    -3.0                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                    48.0

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   40.0                    13.2                     0.7
               Kara Sea             Barents Sea           Greenland Sea
                   -6.1                    -0.2                    -2.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    0.5                     0.0                    -0.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -11.8                    -0.9                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                    32.6


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3306 on: September 29, 2017, 06:56:05 PM »
Visible on the delta map: AMSR2 had a glitch so take the numbers with some skepticism. On face value they look believable (missing data are filled in from previous day or days), continuing refreezing especially in area.

Update 20170928.

Extent: +29.5 (+12k vs 2016, +99k vs 2015, -232k vs 2014, -422k vs 2013, +1334k vs 2012)
Area: +119.8 (+120k vs 2016, +199k vs 2015, -123k vs 2014, -401k vs 2013, +1526k vs 2012)
 
You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   26.6                    17.3                     8.2
               Kara Sea             Barents Sea           Greenland Sea
                   -2.6                     0.0                     5.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.2                     0.0                    -0.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -30.1                     4.6                     0.2
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                    29.5

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   83.8                    28.3                    22.7
               Kara Sea             Barents Sea           Greenland Sea
                   -0.4                     0.0                     3.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.1                     0.0                    -0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -25.6                     8.0                     0.1
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   119.8


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Tor Bejnar

  • ASIF Governor
  • Posts: 2636
    • View Profile
  • Liked: 229
  • Likes Given: 85
Re: Home brew AMSR2 extent & area calculation
« Reply #3307 on: September 29, 2017, 07:31:55 PM »
... waiting for the PACMAN comment ...
 :D
Arctic ice is healthy for children and other living things.

Neven

  • Administrator
  • ASIF Royalty
  • *****
  • Posts: 6779
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 441
  • Likes Given: 296
Re: Home brew AMSR2 extent & area calculation
« Reply #3308 on: September 29, 2017, 10:40:17 PM »
Hey, that looks like...

*computer explodes*

 ;)
Il faut comparer, comparer, comparer, et cultiver notre jardin

echoughton

  • ASIF Lurker
  • Posts: 77
    • View Profile
  • Liked: 8
  • Likes Given: 32
Re: Home brew AMSR2 extent & area calculation
« Reply #3309 on: September 30, 2017, 02:53:12 AM »
even I can see that missing triangle....quite a calving
 :P

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3310 on: September 30, 2017, 11:51:41 AM »
From the GCOM-W1 (the satellite that carries the AMSR2 instrument) site:

Quote
≪Sep 29, 2017≫[New!]
The AMSR2 global observation data distribution was resumed.
We are sorry for any inconvenience caused.

≪Sep 28, 2017≫[New!]
The AMSR2 global observation data distribution has been suspended from September 27, 2017 (UTC), but the Japan and vicinity observation data (near-real time) distribution is continuing.
Please wait for a while until the data distribution resumes.
We are sorry for any inconvenience caused.


Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3311 on: September 30, 2017, 06:50:19 PM »
AMSR2 data stream restored, but the missing data from the 28th is still missing. So today's delta map will still have the Pac-man appearance. Calculations work on filled-in data, so the affected slice (mostly Greenland Sea) will actually reflect a two-day change.
Ignoring that, the refreeze is now going well with centuries for extent and area.

Update 20170929.

Extent: +116.8 (+132k vs 2016, +127k vs 2015, -142k vs 2014, -339k vs 2013, +1331k vs 2012)
Area: +105.4 (+252k vs 2016, +211k vs 2015, -7k vs 2014, -328k vs 2013, +1294k vs 2012)
 
You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   18.6                    25.9                    31.4
               Kara Sea             Barents Sea           Greenland Sea
                    4.8                     0.1                    -1.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    4.1                     0.0                     0.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   29.1                     4.1                    -0.2
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   116.8

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   23.3                    19.2                    20.2
               Kara Sea             Barents Sea           Greenland Sea
                    3.4                     0.0                     6.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    5.5                     0.0                     0.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   29.4                    -1.5                    -0.1
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   105.4


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3312 on: October 01, 2017, 07:03:39 PM »
Extent and area continue to increase with good speed. 2017 area "overtook" 2014 and is now only lower than 2013 in my limited data set.

As usual the first of October is the last of my daily reports on my home brew extent and area numbers. During the coming months I intend report less frequent, but the data and standard graphs will be updated as usual. For the location of this data and graphs see the top post of this thread.

Update 20170930.

Extent: +79.7 (+192k vs 2016, +146k vs 2015, -112k vs 2014, -339k vs 2013, +1268k vs 2012)
Area: +76.7 (+308k vs 2016, +211k vs 2015, +43k vs 2014, -291k vs 2013, +1235k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   10.3                    17.7                     9.2
               Kara Sea             Barents Sea           Greenland Sea
                    2.4                     0.1                    -4.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    4.9                     0.0                     0.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   42.6                    -3.4                     0.1
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                    79.7

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   14.9                    22.0                     8.7
               Kara Sea             Barents Sea           Greenland Sea
                    1.1                     0.1                    -2.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    1.0                     0.0                     0.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   35.1                    -3.4                     0.1
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                    76.7


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3313 on: October 01, 2017, 07:11:14 PM »
ESS-Laptev animation. The first (real) coastal ice gets visible.

voyageur9

  • ASIF Lurker
  • Posts: 1
    • View Profile
  • Liked: 0
  • Likes Given: 2
Re: Home brew AMSR2 extent & area calculation
« Reply #3314 on: October 02, 2017, 09:03:22 PM »
Wipneus,
.... and, from a long-time lurker, many, many, thanks for your valuable work this season.
very best regards

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3315 on: October 08, 2017, 07:08:02 PM »
One week further, the ice is spreading  over the Laptev and along the ESS coast. Unlike 2016.
Click to start the animation.

Shared Humanity

  • ASIF Governor
  • Posts: 3514
    • View Profile
  • Liked: 197
  • Likes Given: 22
Re: Home brew AMSR2 extent & area calculation
« Reply #3316 on: October 08, 2017, 07:38:08 PM »
That animation is mildly encouraging.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3317 on: October 09, 2017, 09:24:51 AM »
Week 1-8 October. Accelerating freezing, last few days saw solid (up to 150k) centuries.

The attached  delta map (red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%) shows where to find the one week differences.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3318 on: October 09, 2017, 09:38:00 AM »
The SMOS data stream has resumed, here is an animation of the first 7 days in October.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3319 on: October 09, 2017, 09:43:16 AM »
SMOS data used to start the season around the 15th, so I can only compare to 2016.

(click the picture)

jdallen

  • ASIF Governor
  • Posts: 2903
    • View Profile
  • Liked: 120
  • Likes Given: 148
Re: Home brew AMSR2 extent & area calculation
« Reply #3320 on: October 10, 2017, 08:52:00 AM »
That animation is mildly encouraging.
Gonna throw some cold water at you.  The sooner the ice shows up, the sooner it locks accumulated heat in the water.
This space for Rent.

Adam Ash

  • ASIF Citizen
  • Posts: 301
    • View Profile
    • The 100 metre line
  • Liked: 7
  • Likes Given: 17
Re: Home brew AMSR2 extent & area calculation
« Reply #3321 on: October 10, 2017, 01:41:01 PM »
'The sooner the ice shows up, the sooner it locks accumulated heat in the water'
So does that mean: More heat in the water beneath new ice which (although not enough to cause bottom melt) will slow thickening of the ice as heat is lost from the ice's upper surface to the Arctic night's atmosphere and space? 
Or do inversion layers form in the ocean beneath the ice which 'insulates' the water from the heat loss?  As the underside freezes the remaining water will become denser (saltier) and colder.  How is the circulation arising from that density gradient affected by the accumulated heat locked in beneath the ice?  Just trying to understand the implications of your comment, please, thank you!

A-Team

  • ASIF Upper Class
  • Posts: 2309
    • View Profile
  • Liked: 248
  • Likes Given: 14
Re: Home brew AMSR2 extent & area calculation
« Reply #3322 on: October 10, 2017, 02:03:53 PM »
Quote
So does that mean: More heat in the water beneath new ice which (although not enough to cause bottom melt) will slow thickening of the ice as heat is lost from the ice's upper surface to the Arctic night's atmosphere and space?
Good question. That's why we're using ESRL; their daily graphics page provides quantitative information on energy fluxes. Even if these aren't spot-on accurate, they depict the situation better than 'it's clear/it's cloudy' or 'there's a really thick snow blanket'.

Quote
The SMOS data stream has resumed, here is an animation of the first 7 days in October.
The data is at this link, in the form of netCDF files that open easily in Panoply for those wishing to make their own maps. In addition to sea ice thinness, the snow surface temperature and bulk ice salinity maps might be of interest, as well as the error studies.

The version of the thickness map below, like all Panoply maps, makes faithful use of the color key in coloring the map. This enables palette scoring: the number of pixels of each thickness class  provides the ice thickness distribution.

SMOS sea ice thickness, probably best of breed this time of year, looks significantly different from either Piomas or ESRL. It is straightforward to subtract SMOS and ESRL for the same date at the level of grids and then display the difference map (as this is the Panoply default).

We haven't previously looked at 'bulk ice salinity' (4th image below). That would be brine channels, sea spray, spent melt ponds and so forth. This refers to ice only; no measurement is made of sea water surface salinity (which would be about 34 psu on their scale). Brine exclusion proceeds as sea ice ages so it might be feasible to track age classes with this method.

https://icdc.cen.uni-hamburg.de/thredds/catalog/ftpthredds/smos_sea_ice_thickness/v3/catalog.html

https://icdc.cen.uni-hamburg.de/thredds/catalog/ftpthredds/smos_sea_ice_thickness/v3/catalog.html?dataset=ftpthreddsscan/smos_sea_ice_thickness/v3/SMOS_Icethickness_v3.1_north_20171008.nc
« Last Edit: October 10, 2017, 07:11:48 PM by A-Team »

A-Team

  • ASIF Upper Class
  • Posts: 2309
    • View Profile
  • Liked: 248
  • Likes Given: 14
Re: Home brew AMSR2 extent & area calculation
« Reply #3323 on: October 10, 2017, 03:15:07 PM »
The UH SMOS product by design (and by the soil satellite's limitations) specializes in measurement of thinner ice. That's an important contribution because thin ice is an area of weakness for other ice thickness products.

The flip side is that UH SMOS cannot measure thick ice, maxing out at about 1.2 m. One of the UH files (below) shows the ratio of measured thickness to maximal possible measurable thickness, ie where SMOS starts to lump all the thicker ice into one bin. The map below shows in pink where this ratio is 97% or greater. That is of interest but the best part of a SMOS thickness map is elsewhere, on the periphery.

UH also provides a most welcome uncertainty estimate map in the daily netCDF bundle. This may diminish later in the season as Oct 1st is at the limits of usefulness. Their recent paper needs to be consulted as to exactly what uncertainty means here and how it is calculated.

The uncertainty data, like the thickness data, is shown in meters whereas it might have been in percentages. That is, when the ice is 1.00 m thick and the uncertainty is 0.25 m, that is a different situation from the ice being 0.5 m thick and the uncertainty still 0.25 m.

These are formal uncertainties; they do not mean that the thickness posted is necessarily wrong by that much. In fact, combining successive days in their time series might very much reduce uncertainty, which originates in part from variable radio frequency interference from ground stations and other sources.

'Combine Arrays' in Panoply can draw the percent error map from the two data sets (3rd image, looks too much like 2nd?). It would be trickier to work out a rolling average and the diminishing uncertainty.

The SMOS-derived snow surface temperature, 4th image, is quite relevant to the ability of cold air to induce ice thickness growth. The UH product may be better than modeled products in this regard.

The palette names are shown to allow replication by others or to revisit later for a time series. Panoply provides over a hundred of these so trial and error duplication is slow. The original color tables can be found in palette galleries by searching on the name provided. Some of these like .cpt are dynamic scripts rather than an explicit layout.
« Last Edit: October 10, 2017, 04:45:50 PM by A-Team »

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3324 on: May 02, 2018, 10:09:34 AM »
The ESS-Laptev crack opening, as shown by my delta map.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3325 on: May 02, 2018, 10:28:37 AM »
Illustrating the first of the month effect:
Coastal (false) Ice along the North Sea coast is masked (away) starting with the new monthly mask for May.

This does not have a big effect on my UH AMSR2 extent data: there is an "coastal filter" in effect that removes the coastal ice (effectivity >95%). The NSIDC numbers expected later today are affected much more, a 100k drop is almost certain, double century possible.

oren

  • ASIF Governor
  • Posts: 3746
    • View Profile
  • Liked: 519
  • Likes Given: 1041
Re: Home brew AMSR2 extent & area calculation
« Reply #3326 on: May 02, 2018, 11:39:46 AM »
Thank you Wipneus for all your updates and calculations.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3327 on: May 03, 2018, 05:49:08 PM »
Okhotsk is dropping fast now, today's drop is -47k.

Animation needs a click to start.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3328 on: May 09, 2018, 01:34:46 PM »
Hudson starts the melt(-out) season from the top.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3329 on: May 12, 2018, 11:52:27 AM »
The CAB shows signs of "torching" even blowing over the CAA, early as far as I can tell. Note that the contrast was enhanced, darkest parts correspond to about 65% concentration. A concentration drop that is probably not real but due to temperature effects.

jdallen

  • ASIF Governor
  • Posts: 2903
    • View Profile
  • Liked: 120
  • Likes Given: 148
Re: Home brew AMSR2 extent & area calculation
« Reply #3330 on: May 12, 2018, 06:58:46 PM »
The CAB shows signs of "torching" even blowing over the CAA, early as far as I can tell. Note that the contrast was enhanced, darkest parts correspond to about 65% concentration. A concentration drop that is probably not real but due to temperature effects.
I see... disturbing amounts of open water in the Chukchi... the Barents in the process of flashing out (as I've been kind of expecting), the Beaufort well on the way to turning into a bowl of ice cubes.

The next 72 hours on ECMWF and GFS both have high pressure dominating the Arctic along with continuing strong positive temperature anomalies.  This really isn't the weather we need to reverse the current trend.
This space for Rent.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3331 on: May 15, 2018, 12:01:29 PM »
The (apparent) sea ice concentration just dropped to 50% levels in the "torch lane"  between Ellesmere and the Pole.

Shared Humanity

  • ASIF Governor
  • Posts: 3514
    • View Profile
  • Liked: 197
  • Likes Given: 22
Re: Home brew AMSR2 extent & area calculation
« Reply #3332 on: May 15, 2018, 03:27:41 PM »
Melt Ponds?

marcel_g

  • ASIF Lurker
  • Posts: 60
    • View Profile
    • Art by Marcel Guldemond
  • Liked: 2
  • Likes Given: 54
Re: Home brew AMSR2 extent & area calculation
« Reply #3333 on: May 15, 2018, 04:48:43 PM »
Melt Ponds?
Maybe it’s wind pushing the ice?  we probably need a worldview image of that area to get past guessing about it.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3334 on: May 15, 2018, 07:19:06 PM »
I do not doubt here is some melting, not necessarily -ponding. A Modis Terra image (20180514 bands 3-6-7) shows the same  as some slightly darker red stripes.

johnm33

  • ASIF Upper Class
  • Posts: 1206
    • View Profile
  • Liked: 72
  • Likes Given: 22
Re: Home brew AMSR2 extent & area calculation
« Reply #3335 on: May 16, 2018, 01:13:21 AM »
I'm thinking some deep Atlantic water was drawn through, quite how I don't know, energetically it should move ccwise. However if it is drawn through north of Greenland it would be full of rotational forces and would affect the ice from below, close to the coast but more pronounced along the edge of the shelf. It started around the 7th and seems to be building up again. I don't recall seeing anything like this before, so it may be something new or perhaps just more apparent due to thinning ice, either way since the tides are peaking we should see some action over near 120e 82n if what I'm thinking is valid.














Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3336 on: June 11, 2018, 08:57:25 AM »
The Uni Hamburg AMSR2 sea ice concentration source has stopped since the 7th. While waiting for the data to resume, here is a view using Jaxa's product.

seaice.de

  • ASIF Lurker
  • Posts: 80
    • View Profile
  • Liked: 20
  • Likes Given: 3
Re: Home brew AMSR2 extent & area calculation
« Reply #3337 on: June 11, 2018, 01:22:39 PM »
Hard disk full. UH AMSR2 should be up and running again. Thanks, Wipneus, for your great service!

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3338 on: June 11, 2018, 04:36:04 PM »
Hard disk full. UH AMSR2 should be up and running again. Thanks, Wipneus, for your great service!

Thanks Lars, things like that always happens in or just before the weekend.

Data update seems to be complete, so we can have a look what the UH ASI algorithm does with the heat intrusion.

Readers that are familiar with my animations know that I mostly enhance contrast somewhat to make the variability better visible. That is not needed here: the apparent sea ice concentration of the land-fast ice in the Laptev is gone to 0% in many places. The added color-coded concentration map will show you that.


JimboOmega

  • ASIF Citizen
  • Posts: 139
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3339 on: June 11, 2018, 09:32:57 PM »
Readers that are familiar with my animations know that I mostly enhance contrast somewhat to make the variability better visible. That is not needed here: the apparent sea ice concentration of the land-fast ice in the Laptev is gone to 0% in many places. The added color-coded concentration map will show you that.

Looking in worldview that ice is still there, though it is very blue; its surface has dramatically changed over the last week.

Pagophilus

  • ASIF Citizen
  • Posts: 221
    • View Profile
  • Liked: 89
  • Likes Given: 125
Re: Home brew AMSR2 extent & area calculation
« Reply #3340 on: June 12, 2018, 04:36:46 PM »
Far be it from me to contradict you, most revered Wipneus (I mean that, I've been reading your posts like scripture for a couple of years) but Jimbo's point makes sense to me.  Images attached.  I know there must be something I am missing, so if you have time, could you please explain?  The cognitive dissonance of seeing the ice so clearly on Worldview is a bit too much for me.   

BTW, I see AMSR2 for June 11 (closeup below) shows something similar to your images and implicitly your interpretation.


Readers that are familiar with my animations know that I mostly enhance contrast somewhat to make the variability better visible. That is not needed here: the apparent sea ice concentration of the land-fast ice in the Laptev is gone to 0% in many places. The added color-coded concentration map will show you that.

Looking in worldview that ice is still there, though it is very blue; its surface has dramatically changed over the last week.
« Last Edit: June 12, 2018, 04:46:28 PM by Pagophilus »

oren

  • ASIF Governor
  • Posts: 3746
    • View Profile
  • Liked: 519
  • Likes Given: 1041
Re: Home brew AMSR2 extent & area calculation
« Reply #3341 on: June 12, 2018, 04:46:47 PM »
From the little that I know, water on the ice makes the AMSR2 algorithm report lower concentration of ice. Wipneus knows the ice is still there, which is why he wrote "the apparent sea ice concentration of the land-fast ice in the Laptev is gone to 0% in many places".

Pagophilus

  • ASIF Citizen
  • Posts: 221
    • View Profile
  • Liked: 89
  • Likes Given: 125
Re: Home brew AMSR2 extent & area calculation
« Reply #3342 on: June 12, 2018, 04:49:08 PM »
Aaaaaah.   Thank you, oren.

(Note to self: learn to read)

From the little that I know, water on the ice makes the AMSR2 algorithm report lower concentration of ice. Wipneus knows the ice is still there, which is why he wrote "the apparent sea ice concentration of the land-fast ice in the Laptev is gone to 0% in many places".
« Last Edit: June 12, 2018, 10:06:47 PM by Pagophilus »

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3343 on: June 14, 2018, 07:53:20 PM »
ADS/NIPR Sea Ice Monitor does not show images beyond 29th May, bummer because the meting images are of interest.

Luckily forum member Tealight found a source for the binary data, so the images can be created independently (and that data source is up to date).

So here is an animation for the last couple of days, light blues are the regions with over 30% melt (what ever that means). Thickness colors don't mean much during the melt season.

Neven

  • Administrator
  • ASIF Royalty
  • *****
  • Posts: 6779
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 441
  • Likes Given: 296
Re: Home brew AMSR2 extent & area calculation
« Reply #3344 on: June 14, 2018, 08:32:36 PM »
Nice, Wipneus!
Il faut comparer, comparer, comparer, et cultiver notre jardin

Pagophilus

  • ASIF Citizen
  • Posts: 221
    • View Profile
  • Liked: 89
  • Likes Given: 125
Re: Home brew AMSR2 extent & area calculation
« Reply #3345 on: June 14, 2018, 10:55:35 PM »
Thank you Wipneus, for bringing more data out of the darkness and into the light of animation.  For what it is worth, I had some fun and took the Worldview June 13 image, pushed saturation +58 on Photoshop and rotated and sized it to compare with the June 13 frame on your animation.  Correspondence of what I perceive to be the bluest-tinged ice on the Worldview image is indeed close with the Caribbean blue color areas on the animation frame: in the Laptev, the north/east Kara sea and, very subtly, the southwestern area of the CAA.  A small offering in the spirit of contributing to a point.

   
ADS/NIPR Sea Ice Monitor does not show images beyond 29th May, bummer because the meting images are of interest.

Luckily forum member Tealight found a source for the binary data, so the images can be created independently (and that data source is up to date).

So here is an animation for the last couple of days, light blues are the regions with over 30% melt (what ever that means). Thickness colors don't mean much during the melt season.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3346 on: June 15, 2018, 03:44:30 PM »
  For what it is worth, I had some fun and took the Worldview June 13 image, pushed saturation +58 on Photoshop and rotated and sized it to compare with the June 13 frame on your animation.  Correspondence of what I perceive to be the bluest-tinged ice on the Worldview image is indeed close with the Caribbean blue color areas on the animation frame: in the Laptev, the north/east Kara sea and, very subtly, the southwestern area of the CAA.  A small offering in the spirit of contributing to a point.


Using the false color infra-red bands can distinguish between dry and melt even better. In Worldview MODIS the 7-2-1 and 3-6-7 can be tried, or NPP/VIIRS M11-I2-I1.

In these Jaxa images it matters whether the Ascending or the Descending orbital images are chosen (I used ascending). Local time for ascending satellite passage is later in the day than the descending passage, which seems to matter even during the Arctic summer when the sun never sets.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3347 on: June 15, 2018, 03:51:58 PM »
Serious torching in the CAA  on the other side of the Arctic. Some ice in the southern Coronation Gulf seems to disappear as the apparent ice concentration drops to zero. It is not real but a sign of serious top melting.

oren

  • ASIF Governor
  • Posts: 3746
    • View Profile
  • Liked: 519
  • Likes Given: 1041
Re: Home brew AMSR2 extent & area calculation
« Reply #3348 on: June 15, 2018, 05:12:19 PM »
Thanks Wipneus. Such extreme and widespread top melt causes JAXA to report drops in extent, not just in area, which will reverse later.

Wipneus

  • ASIF Governor
  • Posts: 3922
    • View Profile
    • Arctische Pinguin
  • Liked: 366
  • Likes Given: 0
Re: Home brew AMSR2 extent & area calculation
« Reply #3349 on: June 15, 2018, 06:08:13 PM »
Here are the latest Jaxa thickness/melting maps (Ascending has the wider pole hole, Descending the smaller one.). Notice the melting at the NP.