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Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #850 on: June 19, 2014, 09:14:59 AM »
I'm with jdallen on the credibility of the day-to-day numbers. It strikes me that the picture we have of the ice on any given day is not a contemporaneous snapshot - it's a collage built up over multiple satellite passes in the course of a 24 hour period. If the ice is both occupying more than half of the CAB and unusually fragmented/mobile, would this not make it more likely to be counted twice on any given day? In other words - could an uptick in "area" at this time of year be an indication of fragility?



epiphyte, each point in the arctic is measured in multiple passes. Each pass contributes to the final concentration according to the number of passes over each grid cell.
So if one piece of gridcell-sized ice moves from one cell to another between two passes, each cell gets 50% and the totals are unaffected.   

You can actually see the effect in an image editor, a histogram of all cell values has little peaks at 50%, 33%, 25%... (and a big one at 100% of course).  I have been able to follow it until 17% (6 passes). The peaks are small, the calculation looks correct so I believe any residual effect on totals is negligible.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #851 on: June 20, 2014, 07:17:40 AM »
Update 20140619.

Extent: -119k8 (-462k vs 2013)
Area: -164k5 (-286k vs 2013)

The days of slow seem to be over. The huge drop in area in Kara is noticed first, yet it goes with a relative moderate drop in extent. With the exception of the ESS and Greenland Sea there is melt all over the place, with Baffin and Hudson still taking the biggest hits.

The details (in 1000 km2):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -4.0                     4.7                   -14.8
               Kara Sea             Barents Sea           Greenland Sea
                  -11.5                    -9.9                     9.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -35.6                     0.1                   -21.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -18.3                   -13.2                    -4.1
             Bering Sea          Sea of Okhotsk            Total Extent
                   -0.8                    -0.2                  -119.8

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -8.2                     2.9                   -20.7
               Kara Sea             Barents Sea           Greenland Sea
                  -63.2                    -8.2                    16.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -45.6                     0.1                     0.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -14.5                   -17.7                    -6.2
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                    -0.1                  -164.5


Frivolousz21

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Re: Home brew AMSR2 extent & area calculation
« Reply #852 on: June 20, 2014, 07:29:06 AM »
So that is back to back big drops on Home brew in area.

You use amsr2 channel 89ghz.

Of course your products are very high res and much more precise then the SSMIS 91ghz products.

Never the less both bands are relatively similar outside of actual spatial res.

I would expect to see big drops come from CT in conjunction. 

IIRC you said the drop in a few days is -194K on CT.  That would coincide with the home brew drop yesterday.

While tomorrow morning(from an US perspective) you will have the newest NSIDC chart to see if CT is going to follow the home brew path.

I think CT will have bigger drops since it has way more fake ice to lose then home brew.
I got a nickname for all my guns
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a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #853 on: June 20, 2014, 07:33:41 AM »
The delta map of Barents and Kara shows a bit more. Concentration and extent is dropping in an area near the north of Nova Zemlya. More to the south there is shrinking and closing of the polynya, keeping the extent drop moderate.


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Re: Home brew AMSR2 extent & area calculation
« Reply #854 on: June 20, 2014, 07:53:34 AM »
Torch over Beaufort.

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Re: Home brew AMSR2 extent & area calculation
« Reply #855 on: June 20, 2014, 08:43:12 AM »
So that is back to back big drops on Home brew in area.

You use amsr2 channel 89ghz.


Of course I use the Uni Hamburg sea ice concentration product, that is using that channel.

Quote
Of course your products are very high res and much more precise then the SSMIS 91ghz products.

I am not sure what products you mean. Neither NSIDC, CT or Jaxa is using that channel.

Further there may some misunderstandings or not, but let me clarify:

Resolution has little influence on Area, more on Extent. Think of it, with infinitesimal grid cell sizes, extent and (true) area must be equal.

So if area is not really influenced by resolution, is heavily depending on algorithms (and therefore channels, there is a one-to-one  relationship). Around this time of year CT (using NT, NASA Team algorithm) is measuring area below the true values, more than other algorithms.
(melt ponds affect all algorithms, but the effect with NT is exaggerated by its sensitivity for surface conditions) .

So yes, if "home brew" has a big drop, you can expect at least the same drop on CT two days later.

Last, "false ice" is mostly low concentration (~15% concentration). The effect on extent is far bigger than on area.

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Re: Home brew AMSR2 extent & area calculation
« Reply #856 on: June 20, 2014, 08:57:00 AM »
Thanks for the info.

I thought the daily NSIDC number came from ssmis channel 91ghz.

Or at the least SSMI 85 ghz.  but not those terribly bad sampling resolution channels ssmis has.

If they are using the lower channels like Jaxa uses that is crazy.  SSMIS has terrible resolution and always thinks there is way more ice along the coasts then the Jaxa/hamburg/bremen products.

I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #857 on: June 20, 2014, 09:30:22 AM »
The SSM/I was the first satellite with a near 90GHz receiver, that was mid 1988. So any time series starting in 1978 is not using that channel. Being conservative gives longer and better climatological homogeneous data series.
Further it is not straightforward to just use another channel. There is a successor to Nasa Team, aptly named Nasa Team 2, that solves many of the problems with the original version but it is incredibly complicated and not available (AFAIK) near real time.

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Re: Home brew AMSR2 extent & area calculation
« Reply #858 on: June 20, 2014, 10:03:35 AM »
So todays NSIDC and CT uses channels 91 GHZ

Or combines channels 19 and 37ghz?

Or does it combine all three?

Similar to how Jaxa uses channels 18 and 36 ghz instead of channel 89ghz?

While Bremen and Hamburg use channel 89ghz for temperature brightness.



The scanning resolution on those lower SSMIS channels is pitiful.  If they are used I don't see why considering AMSRE now AMSR2 has been around for over a decade.


I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #859 on: June 20, 2014, 12:40:02 PM »
Laptev fast ice cracking is extending.

(click to animate)

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Re: Home brew AMSR2 extent & area calculation
« Reply #860 on: June 20, 2014, 03:12:24 PM »
Torch over Beaufort.

This is rather frightening for MYI and the CAB long term. A large quantity of the remaining thick MYI was transported into the Beaufort and this side of the CAB. With the heat hitting this area and an active Beaufort Gyre, that MYI is circling the drain. While this may not spell disaster this year (depends on how much of this MYI survives the melt season, particularly that in the CAB adjacent to the Beaufort 75N) but it sure could make 2015 exciting.
« Last Edit: June 20, 2014, 03:22:23 PM by Shared Humanity »

Tor Bejnar

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Re: Home brew AMSR2 extent & area calculation
« Reply #861 on: June 20, 2014, 04:48:59 PM »
Wipneus' post «Today at 01:17:40 AM» showing increases in Greenland Sea (GS) sea ice area(+16.5) and extent (+9.4) suggests to me that more CAB export is happening than has happened in recent days.  (Certainly, the GS import rate [yesterday] from the north was greater than its melt rate in the south.)

How much does the GS melt rate vary during any period of time?  I regularly read Friv's 'The CAB is about to get tourched,'  but I don't recall ever reading 'The GS is melting faster than normal,' or 'The GS current is faster than normal,' only descriptions of CAB export happening or not.
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Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #862 on: June 20, 2014, 05:05:50 PM »
Tor, unless the values are extreme I seldom mention the Greenland Sea. That is partly for the reasons you mention: a decrease there is often good for the preservation of Arctic ice.

And yes you are right, some Fram transport is taking place. I was going to wait for an animation to see if it holds up, but in the mean time here is the movement north of Greenland. It is definitely moving more than last year.

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Re: Home brew AMSR2 extent & area calculation
« Reply #863 on: June 21, 2014, 07:55:13 AM »
Update 20140620.

Extent: -125k6 (-521k vs 2013)
Area: -147k9 (-394k vs 2013)

Start noticing the drop in area in the CAB, which is nearly matched by an equal increase in area in the Kara sea. The drop in the CAB takes place in the zone previously named "Barents bite", the ice there is very fragmented but nothing compared with last year yet.
Baffin and Hudson continue with decline in extent and area as they have done the last 10 days or so. With few exceptions the other regions have solid bu unexceptional declines. Kara is the main exception, and in much smaller way the CAA. The Greenland Sea continues its up-and-down: today it is down.


The details (in 1000 km2):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -8.7                    -2.6                    -9.0
               Kara Sea             Barents Sea           Greenland Sea
                   12.8                    -1.9                   -30.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -33.3                     0.3                   -33.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    5.8                   -14.1                   -11.7
             Bering Sea          Sea of Okhotsk            Total Extent
                    1.3                    -0.6                  -125.6

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                  -57.5                   -10.1                    -2.5
               Kara Sea             Barents Sea           Greenland Sea
                   54.6                    -4.5                   -25.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -10.7                     0.1                   -67.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    0.5                   -17.1                   -10.2
             Bering Sea          Sea of Okhotsk              Total Area
                    2.1                    -0.4                  -147.9


Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #864 on: June 21, 2014, 08:00:03 AM »
Greenland Sea, more ice in the north while melting in the south. A a decrease in ice does not necessary mean lower Fram transport.

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Re: Home brew AMSR2 extent & area calculation
« Reply #865 on: June 21, 2014, 08:06:54 AM »
Disappearing ice in Hudson and Baffin Bay.

(click to animate)

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Re: Home brew AMSR2 extent & area calculation
« Reply #866 on: June 21, 2014, 08:29:00 AM »
The "Barents bite" does not seem to develop much this year, so I looked elsewhere. The pack is still very solid compared with 2013, except this patch here  in the CAB near the Laptev and Kara regions.
Will it join the ESS/Laptev open water, or develop into a bite on its own? Or will it disappear again quietly as the winds blow?
« Last Edit: June 21, 2014, 08:34:44 AM by Wipneus »

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Re: Home brew AMSR2 extent & area calculation
« Reply #867 on: June 21, 2014, 09:19:03 AM »
So this is the 3rd major loss day in a row.  Damn!
I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

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Re: Home brew AMSR2 extent & area calculation
« Reply #868 on: June 21, 2014, 09:24:24 AM »
So this is the 3rd major loss day in a row.  Damn!

Completely intuitively, I'm expecting at least a couple more "century breaks" in area, mostly Hudson and Baffin evaporating.  It *might* slow down a touch after that.  *Might*.
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Re: Home brew AMSR2 extent & area calculation
« Reply #869 on: June 21, 2014, 09:31:13 AM »
So this is the 3rd major loss day in a row.  Damn!

Completely intuitively, I'm expecting at least a couple more "century breaks" in area, mostly Hudson and Baffin evaporating.  It *might* slow down a touch after that.  *Might*.

The CAB, Chukchi, ESS, Arctic basin, Kara, all over for the most part will make up for that. 

Look at that horse work.



On day 3 the CAB gets roasted bad news bears style.  Full SE flow.  Nasty as hell.

I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

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Re: Home brew AMSR2 extent & area calculation
« Reply #870 on: June 21, 2014, 10:08:04 AM »
Previous appearances to the contrary, it does look like both the NW passage and the Beaufort are going to be hammered rapidly inti slush.  Looking at the CAA, there are large areas of open water (500+ KM2) shoeing up in the middle of nowhere.  Most of the CAA ice now has extensive melt pond coverage as well, it appears.  Any local correspondents care to chime in on that?
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Re: Home brew AMSR2 extent & area calculation
« Reply #871 on: June 21, 2014, 02:51:41 PM »
Here are my home brew, Wipneus inspired, sea ice consentration comparison maps for June 19th, a snapshot of how 2014 compare to some other years just before "the great melt of 2014".

2007 vs 2014 (AMSR-E vs AMSR-2)


2012 vs 2014 (SSMIS/F18 vs AMSR-2)


2013 vs 2014 (AMSR-2 vs AMSR-2)


Once again, the most obvious difference between 2012 and 2014 is Kara, and in my oppinion this causes the 2012 to be a little easier to catch up with later in the season than the overall SIA numbers currently suggest. Thus, I still insist there is a significant chance of beating 2012 with the current weather/weather forecast.
« Last Edit: June 21, 2014, 08:31:34 PM by Rubikscube »

Shared Humanity

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Re: Home brew AMSR2 extent & area calculation
« Reply #872 on: June 21, 2014, 04:27:43 PM »
The Kara is way ahead of 2012 but I still feel the Beaufort (and the CAB just north and, to a lesser degree, the CAA)) is the key for this melt season. How well will this large amount of MYI hold up? It is getting hit hard but it has far more ice than 2012 and the CAB north of it looks stronger too. The CAA adjacent to this area also looks to be holding up well.

If the always approaching torch does finally materialize this area will be fun to watch.

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Re: Home brew AMSR2 extent & area calculation
« Reply #873 on: June 22, 2014, 08:29:47 AM »
Update 20140621.

Extent: -90k6 (-566k vs 2013)
Area: -120k0 (-439k vs 2013)

The situation is easy to explain for your reporter/amateur analyst . Of the 90k extent loss today, about 60k can be attributed to Hudson/Baffin Bay and Greenland Sea. Of the remaining 30k, Beaufort takes half with the remainder split up between Chukchi and Barents Sea. There are no significant upticks, area tells a similar tale.



The details (in 1000 km2):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -0.1                     2.3                    -4.2
               Kara Sea             Barents Sea           Greenland Sea
                    1.2                    -6.3                   -16.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -19.0                    -0.2                   -25.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    1.7                   -14.0                   -11.7
             Bering Sea          Sea of Okhotsk            Total Extent
                    1.1                     0.6                   -90.6

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -0.5                    -6.5                     8.4
               Kara Sea             Barents Sea           Greenland Sea
                    4.9                    -3.0                    -9.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -41.2                     0.0                   -22.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -24.6                   -15.9                   -10.0
             Bering Sea          Sea of Okhotsk              Total Area
                   -0.2                     0.4                  -120.0


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Re: Home brew AMSR2 extent & area calculation
« Reply #874 on: June 22, 2014, 08:58:15 AM »
Today's image is Beaufort. Most of the melt is in the corner with the CAA. From the regional AMSR2 extent page, it looks quite possible that the Beaufort will melt out this year.

A permanent link to this page, updated daily, is https://sites.google.com/site/arctischepinguin/home/amsr2/grf/amsr2-extent-regional.png

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Re: Home brew AMSR2 extent & area calculation
« Reply #875 on: June 22, 2014, 11:14:07 AM »
So 4 massive Area losses in a row on Home Brew.

And nothing but wall to wall melt is coming.

I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

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Re: Home brew AMSR2 extent & area calculation
« Reply #876 on: June 23, 2014, 07:19:25 AM »
Update 20140622.

Extent: -87k4 (-567k vs 2013)
Area: -11k0 (-396k vs 2013)

Area dropped little while extent continues the decline. Most of that decline is still Hudson Bay, in the Arctic there is a big drop in Beaufort and Chukchi. In other regions extent did not change much.

The details (in 1000 km2):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -1.1                    -3.9                    -4.5
               Kara Sea             Barents Sea           Greenland Sea
                    0.5                    -4.5                    -5.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    0.5                     0.0                   -34.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    1.2                   -22.6                   -11.0
             Bering Sea          Sea of Okhotsk            Total Extent
                   -2.0                    -0.3                   -87.4

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                    4.9                    -5.4                    -2.5
               Kara Sea             Barents Sea           Greenland Sea
                    6.8                    -1.5                     7.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   11.8                     0.0                   -22.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    2.5                     0.9                   -12.0
             Bering Sea          Sea of Okhotsk              Total Area
                   -1.5                    -0.2                   -11.0


Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #877 on: June 23, 2014, 08:06:44 AM »
Today's region is the ESS, the ice is continuously but slowly going down in concentration. As can be seen in the regional graph (see yesterdays post) the "regional cliff" in 2012 and 2013 did not start until the first week in July. So there is still room for an early melt here.

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Re: Home brew AMSR2 extent & area calculation
« Reply #878 on: June 23, 2014, 08:51:32 AM »
It is midsummer, the highest insolation on the globe is now in the far North. As absorbed sunlight depends on ice concentration it may be interesting to compare 2013 and 2014.
There really is no comparison, other factors will be needed to stir things up. 

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Re: Home brew AMSR2 extent & area calculation
« Reply #879 on: June 23, 2014, 09:17:33 AM »
It is midsummer, the highest insolation on the globe is now in the far North. As absorbed sunlight depends on ice concentration it may be interesting to compare 2013 and 2014.
There really is no comparison, other factors will be needed to stir things up.
I've been pondering the state of the CAA also. Catching snippets of view through overcast, it is just as fragmented, but much better concentrated than last year. I'm still deciding what implications that has for the ongoing torchy-ness.

As I recall that low concentration was cause for great excitment right up to when the weather shut down the slide.  I recall our theory at the time in part for the shift was that self-same low concentration facilitating ice-favorable circulation and cloudiness by way of increased energy in the form of moisture.  This year is acting much differently, but, the dice are still rolling.
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Neven

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Re: Home brew AMSR2 extent & area calculation
« Reply #880 on: June 23, 2014, 12:37:19 PM »

As I recall that low concentration was cause for great excitment right up to when the weather shut down the slide.

Indeed, for a long time I expected that all that dispersal would lead to rapid drops, once the weather turned. But it never did turn. We had quite a large hole very near to the Pole as a final spectacle, until freezing temps closed it again.
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Re: Home brew AMSR2 extent & area calculation
« Reply #881 on: June 23, 2014, 12:58:20 PM »
The ice seems to be more concentrated than last year but it is not necessarily a good omen to keep the ice from melting, the main reason is it is easier for the winds to push the whole pack toward Fram-Barentz. It seems the ice is already more advanced toward Fram than it was last year.

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Re: Home brew AMSR2 extent & area calculation
« Reply #882 on: June 23, 2014, 01:02:41 PM »
We had quite a large hole very near to the Pole as a final spectacle, until freezing temps closed it again.

Indeed we did. From September 4th 2013:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/summer-2013-images/#Pole

"The evil that is in the world always comes from ignorance, and good intentions may do as much harm as malevolence, if they lack understanding." Albert Camus, The Plague

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Re: Home brew AMSR2 extent & area calculation
« Reply #883 on: June 23, 2014, 01:29:35 PM »
If I remember well that wasn't only a hole but a big wide open from the Pacific to the Atlantic."

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Re: Home brew AMSR2 extent & area calculation
« Reply #884 on: June 23, 2014, 02:03:12 PM »
If I remember well that wasn't only a hole but a big wide open from the Pacific to the Atlantic."

A bit like this, from August 26th?
"The evil that is in the world always comes from ignorance, and good intentions may do as much harm as malevolence, if they lack understanding." Albert Camus, The Plague

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Re: Home brew AMSR2 extent & area calculation
« Reply #885 on: June 23, 2014, 04:26:16 PM »
yes...it did close earlier than we thought it should have done and that the main reason of the failure of Babouchka.

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Re: Home brew AMSR2 extent & area calculation
« Reply #886 on: June 24, 2014, 07:46:44 AM »
Update 20140623.

Extent: -135k3 (-633k vs 2013)
Area: -155k6 (-526k vs 2013)

Strong declines in ice area and extent. Most of it is in the non-Arctic Basin regions: Hudson, Baffin and Greenland Sea together drop -120k in extent from the -135k net. In area this ratio is less severe: Beaufort has a huge drop, but it is nearly matched by yet another uptick in CAB area.

(due to circumstances images will be posted later today)

The details (in 1000 km2):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                    0.1                     4.1                    -8.8
               Kara Sea             Barents Sea           Greenland Sea
                   -0.5                     4.4                   -13.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -39.8                    -0.1                   -67.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -2.2                    -9.9                    -2.9
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.2                     0.4                  -135.3

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   42.8                    -6.6                   -14.0
               Kara Sea             Barents Sea           Greenland Sea
                   -8.0                     6.4                     2.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -32.9                    -0.1                   -85.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -9.9                   -48.0                    -2.5
             Bering Sea          Sea of Okhotsk              Total Area
                   -0.4                     0.2                  -155.6

« Last Edit: June 24, 2014, 08:44:33 AM by Wipneus »

Michael Hauber

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Re: Home brew AMSR2 extent & area calculation
« Reply #887 on: June 24, 2014, 08:03:28 AM »
On area 2014 has quite quickly caught up to 2012 in Beaufort - but may rise up a bit when the current torch ends.  Still behind there on extent.  The other areas 2014 are behind on 2012 is Kara - big time, and the central Arctic Basin - which is critically important but I'm not sure how reliable the measure is until we see real drops in this area (eg consider 2013 vs 2012).

All other areas 2014 is equal or ahead of 2012.
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Re: Home brew AMSR2 extent & area calculation
« Reply #888 on: June 24, 2014, 08:24:53 AM »
Update 20140623.

Extent: -135k3 (-633k vs 2013)
Area: -155k6 (-526k vs 2013)

Strong declines in ice area and extent. Most of it is in the non-arctic regions: Hudson, Baffin and Greenland Sea together drop -120k in extent from the -135k net. In area this ratio is less severe: Beaufort has a huge drop, but it is nearly matched by yet another uptick in CAB area.

We're running out of ice in Baffin, Hudson and Greenland Sea.   The uptic in CAB has the look of being import from other regions.  Considering the current trend in wind, I'd bet on it coming from the pacific side of the basin, out of the Beaufort, Chukchi and ESS.

I'm wondering if we will see a push in export.

@Michael Hauber

The lions share of the difference between 2012 and 2014 now lies in the Kara, I expect.  I wouldn't put much faith in weather saving it; short term there is a "torch" coming up there as well, and perhaps worse, precipitation.  Extensive melt ponds have been established as well.  It will be later, but I'm expecting it to melt out.

DMI is showing weaknesses appearing across some areas of the CAB.  We know that much of the FYI there is quite thin - well under 200CM across wide areas.  With the stage now set by the late June torch, it will now need to resist the best part of 8 weeks of solid threat from weather and sun.  That may be a tall order.

Reaching 2012 is still a bit of a stretch, but much less so than it was even a couple of days ago.
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Re: Home brew AMSR2 extent & area calculation
« Reply #889 on: June 24, 2014, 08:34:21 AM »
Thanks, Wipneus.
For the sake of definition; Hudson, Baffin and East Greenland Sea are part of the Arctic Ocean; if said 'not-Arctic-Basin' it would be fine.

Michael, JDAllen,
I agree with your attention for Kara Sea; that's the outlier now. Not unforeseen; it got the best of what 'winter-power' was at hand last winter. It will be interesting to see if there will be a stubborn survivor-pack out there like last year.
The CAB doesn't feature the North-Svalbard-Frantsa Yosefa 'Bay', which was usually 100-150K during June each past '07 year. The rest is compaction.
« Last Edit: June 24, 2014, 10:40:58 AM by werther »

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Re: Home brew AMSR2 extent & area calculation
« Reply #890 on: June 24, 2014, 09:02:05 AM »
Thanks, Wipneus.
For the sake of definition; Hudson, Baffin and East Greenland Sea are part of the Arctic Ocean; if said 'not-Arctic-Basin' it would be fine.

Michael, JDAllen,
I agree with your attention for Kara Sea; that's the outlier now. Not unforeseen; it got the best of what 'winter-power' was at hand last winter. It will be interesting to see if there will be a stubborn survivor-pack out there like last year.
The CAB doesn't feature the North-Svalbard-Frantsa Yosefa 'Bay', which was usually 100-150K during June each past '07 year. The rest is compaction.

Judging from CT concentration maps, the Svalbard-Fransta bay is in the process of forming.

I'd put long odds on a Kara "survivor pack"; as best as I can tell, all the fast ice has shattered under the clouds and there are extensive melt ponds.  Far from optimal starting point.
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Re: Home brew AMSR2 extent & area calculation
« Reply #891 on: June 24, 2014, 09:20:29 AM »
The arch in the Nares Strait is crumbling (disscussed in the Nares Strait thread https://forum.arctic-sea-ice.net/index.php/topic,176.msg29284.html#msg29284), and it shows in the hi-res sea concentration map.


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Re: Home brew AMSR2 extent & area calculation
« Reply #892 on: June 24, 2014, 09:58:54 AM »
The ice in southern branches of the Canadian Archipelago is rather low in concentration. In the North the ice better packed, although some degradation is visible. We did see last year in the beginning of the freezing season that these straits got filled with MYI from the CAB so it may not give in so easily as in the south where I expect more FYI to be present.

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Re: Home brew AMSR2 extent & area calculation
« Reply #893 on: June 24, 2014, 10:07:05 AM »
The transport through the Fram Strait has come to a complete stand still. Here we catch some ice making it through the Franz Victoria Strait (formerly wrongly called Olga St.).

(click to animate)

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Re: Home brew AMSR2 extent & area calculation
« Reply #894 on: June 24, 2014, 11:12:49 AM »
The ice in southern branches of the Canadian Archipelago is rather low in concentration.

That low concentration must be due to melt ponds since the ice still looks mostly intact.
It may not stay intact long though, since the temperatures there are pretty high this week:

https://weather.gc.ca/city/pages/nu-15_metric_e.html
https://weather.gc.ca/city/pages/nu-16_metric_e.html

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Re: Home brew AMSR2 extent & area calculation
« Reply #895 on: June 25, 2014, 07:46:21 AM »
Update 20140624.

Extent: -80.7 (-663k vs 2013, +249k vs 2012)
Area: -77.1 (-631k vs 2013, +48k vs 2012)

Another day of continuing declines. The distance with 2013 is now getting impressive, the numbers are very close to 2012. That may change: 2012 speeded up on this date and 2013 did the same but even harder coming close to 2012 in  July. 
You can judge this by the graphics in the top post top post

On the regional break down: lion's share is still Baffin/Hudson/Greenland Sea. The continuing declines in the Greenland Sea are getting remarkable, I have been getting used to highly volatile numbers there. In the Arctic Basin Laptev and Kara loose most ice extent. Area drops there even faster, but Beaufort has stopped its decline and shows a small uptick.

The details (in 1000 km2):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -1.6                     0.2                   -11.6
               Kara Sea             Barents Sea           Greenland Sea
                   -7.0                     6.1                   -12.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -12.1                    -0.1                   -44.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    4.9                    -1.4                    -0.9
             Bering Sea          Sea of Okhotsk            Total Extent
                   -0.8                     0.1                   -80.7

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -9.1                    -7.6                   -25.5
               Kara Sea             Barents Sea           Greenland Sea
                  -20.5                     9.0                   -15.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    8.7                     0.0                   -26.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    6.0                     7.7                    -3.3
             Bering Sea          Sea of Okhotsk              Total Area
                   -0.5                     0.1                   -77.1

« Last Edit: June 25, 2014, 10:02:28 AM by Wipneus »

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #896 on: June 25, 2014, 07:53:02 AM »
Modis images are of course much better when there are no clouds. But the AMSR2 gives a good idea what is happening too.

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Re: Home brew AMSR2 extent & area calculation
« Reply #897 on: June 25, 2014, 08:01:02 AM »
The partly broken fast ice in the ESS and Laptev is not moving much. The sequence suggests strong in situ melting though, these are regions where some big drops may occur soon.

(click to animate)

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Re: Home brew AMSR2 extent & area calculation
« Reply #898 on: June 25, 2014, 09:27:01 AM »
Update 20140624.
<snippage>
Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -9.1                     -7.6                  -25.5
               Kara Sea             Barents Sea           Greenland Sea
                  -20.5                     9.0                   -15.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    8.7                     0.0                   -26.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                     6.0                     7.7                    -3.3
             Bering Sea          Sea of Okhotsk              Total Area
                   -0.5                     0.1                   -77.1


Has the sense of a great breath being drawn in before a blasting roar.

Based on some of the images you posted, and temperature numbers posted elsewhere (buoys reporting central Beaufort temps at around 11C...), the ESS and Chukchi may not be too far behind.  Climate Reanalyzer shows the entire Pacific coast side of the basin being blistered over the next 24 hours from the ESS right straight around to the center of the CAA.  After that, it doesn't particularly improve.

The Kara of course is now showing the effects of near continuous heat flowing out of NE Europe...

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werther

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Re: Home brew AMSR2 extent & area calculation
« Reply #899 on: June 25, 2014, 09:35:09 AM »
....and temperature numbers posted elsewhere (buoys reporting central Beaufort temps at around 11C...), ...

JD, as Friv has pointed out, that ITP sensor must have difficulties. It is near the Northern boundary of the Beaufort, Climate R. puts temp on max +2-+3 dC (still high...) and 2013C shows +1.4dC.

Never mind, Beaufort going down impressively....