Author Topic: Home brew AMSR2 extent & area calculation (Read 1981324 times)

Wipneus · « **Reply #500 on:** September 13, 2013, 06:24:33 AM »

Update 20130912.

Extent: -3k5 (+1416k vs 2012)
Area: +39k2 (+1453k vs 2012)

The big increase in CAB area shows the freezing season is near. A small decline of the CAB extent is still possible. All other changes are small.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea -5.3 -1.1 0.1 Kara Sea Barents Sea Greenland Sea -1.0 -0.1 4.7 Baffin/Newfoundland Bay St. Lawrence Hudson Bay -5.9 0.0 1.5 Canadian Archipelago Beaufort Sea Chukchi Sea 10.1 -5.7 -1.0 Bering Sea Sea of Okhotsk Total Extent 0.2 0.0 -3.5 Area: Arctic Basin East Siberian Sea Laptev Sea 35.8 2.1 -0.1 Kara Sea Barents Sea Greenland Sea -0.5 -0.1 2.6 Baffin/Newfoundland Bay St. Lawrence Hudson Bay -3.6 0.0 1.2 Canadian Archipelago Beaufort Sea Chukchi Sea 7.4 -4.7 -1.0 Bering Sea Sea of Okhotsk Total Area 0.1 0.0 39.2

Wipneus · « **Reply #501 on:** September 13, 2013, 06:42:57 AM »

The Polar Polynya has closed, probably frozen over. The ice edge north of Svalbard-Frans Josef lLand is still retreating.

(images attached)

Wipneus · « **Reply #502 on:** September 14, 2013, 08:04:37 AM »

Update 20130913.

Extent: +27k5 (+1395k vs 2012)
Area: +24k8 (+1435k vs 2012)

Large uptick for the CAA today, which may be reversed tomorrow. The rise in the Greenland Sea could be a trend, it has been increasing for a week now. The CAB still shows declines.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea -5.9 2.8 -0.7 Kara Sea Barents Sea Greenland Sea 4.6 0.1 7.6 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 1.6 0.0 -1.1 Canadian Archipelago Beaufort Sea Chukchi Sea 21.0 -1.6 -0.7 Bering Sea Sea of Okhotsk Total Extent -0.1 0.0 27.5 Area: Arctic Basin East Siberian Sea Laptev Sea -5.8 4.7 -0.5 Kara Sea Barents Sea Greenland Sea 3.8 0.1 11.4 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 1.4 0.0 -0.9 Canadian Archipelago Beaufort Sea Chukchi Sea 14.7 -3.3 -0.8 Bering Sea Sea of Okhotsk Total Area 0.0 0.0 24.8

Wipneus · « **Reply #503 on:** September 14, 2013, 08:21:36 AM »

A small cyclone causes the ice edge to retreat on the Laptev side and to advance to the Kara seas. The NE passage is wide open, around Severnaya Zemlya islands.

(image is attached, log in to see)

Wipneus · « **Reply #504 on:** September 14, 2013, 09:01:48 AM »

Here is a Greenland Sea animation of the last week, actually I don't see much evidence of an increase of the Fram transport. Some larger digital artifacts (squares bigger than the 3.125km pixel size) shows that the Arstist Sea Ice (ASI) algorithm has some trouble on the ice edge here.

Wipneus · « **Reply #505 on:** September 14, 2013, 09:07:34 AM »

For comparison, a week in June.

jdallen · « **Reply #506 on:** September 14, 2013, 10:30:47 AM »

Quote from: Wipneus on September 14, 2013, 09:01:48 AM

Here is a Greenland Sea animation of the last week, actually I don't see much evidence of an increase of the Fram transport. Some larger digital artifacts (squares bigger than the 3.125km pixel size) shows that the Arstist Sea Ice (ASI) algorithm has some trouble on the ice edge here.

I agree - certainly doesn't look like much movement at all out of the Fram.

Intuition/what I'm seeing suggests a refreeze; however, from what I've seen elsewhere regarding weather, neither the air or sea surface temps are low enough to support that. I wonder what's going on?

Wipneus · « **Reply #507 on:** September 14, 2013, 11:25:33 AM »

Quote from: jdallen on September 14, 2013, 10:30:47 AM

Quote from: Wipneus on September 14, 2013, 09:01:48 AM
Here is a Greenland Sea animation of the last week, actually I don't see much evidence of an increase of the Fram transport. Some larger digital artifacts (squares bigger than the 3.125km pixel size) shows that the Arstist Sea Ice (ASI) algorithm has some trouble on the ice edge here.

I agree - certainly doesn't look like much movement at all out of the Fram.

Intuition/what I'm seeing suggests a refreeze; however, from what I've seen elsewhere regarding weather, neither the air or sea surface temps are low enough to support that. I wonder what's going on?

There is a 980mbar cyclone before the east coast, I think this causes the following to be applicable:

Quote

3.1. Weather Filters
One disadvantage of the 89 GHz channels is the pro-
nounced inﬂuence of atmospheric cloud liquid water and
water vapor on the brightness temperatures. Especially cy-
clones over open water can reduce the polarization diﬀer-
ence to values similarly small as those of sea ice. Therefore
eﬀective ﬁlters are necessary to remove spurious ice concen-
tration in open water areas. The weather ﬁltering process
consists of three steps. All of them use the lower frequency
channels with lower spatial resolution. This does not lead to
a lower resolution of the marginal ice zone [Kaleschke et al.,
2001] but it may cause pixels along the ice edge to show too
high ice concentrations due to missing weather ﬁlters. If this
is the case the resolution of the ice edge is determined by
the resolution of the weather ﬁlter.

Spreen, G., L. Kaleschke, G. Heygster (2008), "Sea Ice Remote Sensing Using AMSR-E 89
GHz Channels", J. Geophys. Res., 113, C02S03, doi:10.1029/2005JC003384.

So, water vapor and liquid water in clouds (associated with weather fronts) cannot be compensated in the hi resolution over the very fragmented ice cover (it is all edge actually) of the Greenland Sea.
Wait for the clouds to clear, and the ice concentration should drop.

Richard Rathbone · « **Reply #508 on:** September 14, 2013, 01:45:01 PM »

I'd have thought that clear skies now would mean lower temperatures and more ice forming.

I assume you are talking about a measurement artefact going away, but it might be difficult to spot that against the actual refreeze I'd expect from clearer skies.

Wipneus · « **Reply #509 on:** September 14, 2013, 02:07:46 PM »

Richard, if you look ate the regional graphs refreeze is not to be expected before October in all regions except the CAB and perhaps the CAA.
The Greenland Sea is a region where melt will dominate most of the year. The Fram Strait transport is most important there.

Richard Rathbone · « **Reply #510 on:** September 14, 2013, 08:55:10 PM »

I don't think 2012 is a good guide to the timing of regional refreezes this year. Refreeze will start earlier than 2012 in regions that melted out in 2012 and haven't melted out this year. Fram Transport gives the Greenland Sea its own pattern, but seas like the Beaufort are going to start refreezing much earlier, because the ice edge is still in them and hasn't got to freeze its way back out of the CAB first. Or to put it another way, the ocean at the CAB/Beaufort boundary has had ice sitting on top of it stopping whatever sun there has been from heating the water up, and the heat that didn't get in, doesn't have to get out before it starts refreezing.

There's still scope for the wind to push the edge around for a while, but the minimum is about now, and that means new ice is starting to appear around the pack edge in whatever seas the edge is in now.

Wipneus · « **Reply #511 on:** September 15, 2013, 08:21:41 AM »

Update 20130914.

Extent: +1k2 (+1482k vs 2012)
Area: -5k2 (+1455k vs 2012)

Minimal net changes, but the regional numbers of the CAB, CAA and Greenland Sea say otherwise. The CAA extent and area increase, while that of the CAB and the Greenland Sea declines.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea -19.1 2.0 0.0 Kara Sea Barents Sea Greenland Sea 3.5 -0.1 -8.7 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 1.6 0.0 -0.6 Canadian Archipelago Beaufort Sea Chukchi Sea 22.9 -0.9 0.8 Bering Sea Sea of Okhotsk Total Extent -0.1 0.0 1.2 Area: Arctic Basin East Siberian Sea Laptev Sea -8.1 -0.7 -0.1 Kara Sea Barents Sea Greenland Sea 2.8 -0.1 -19.1 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 0.6 0.0 -0.5 Canadian Archipelago Beaufort Sea Chukchi Sea 16.1 3.3 0.6 Bering Sea Sea of Okhotsk Total Area -0.1 0.0 -5.2

Wipneus · « **Reply #512 on:** September 15, 2013, 09:14:04 AM »

The far side (seen from where I live, the Netherlands) has not been the subject of the region of the day. There has been a slow net decline, a mixture of "reds" and "blues". Looking at today's delta map, a movement for Canada -> Siberia can be seen. The crack above Prince Patrick Island underlines that.

(log in to see the image)

Wipneus · « **Reply #513 on:** September 15, 2013, 09:26:14 AM »

And an animation of the cracks above the Canadian Archiplago. As I see it, a great mass of the CAB ice is moving suddenly in NW direction. For weeks the ice movement was south, into the channels between the islands.

(click on the image if there is no animation)

Wipneus · « **Reply #514 on:** September 15, 2013, 09:35:36 AM »

Quote from: Richard Rathbone on September 14, 2013, 08:55:10 PM

I don't think 2012 is a good guide to the timing of regional refreezes this year. Refreeze will start earlier than 2012 in regions that melted out in 2012 and haven't melted out this year.

Richard, if I expected a duplication of 2012, I would have said "mid October". Anyway, the Greenland Sea dropped today from 101k to 81k with the cyclone loosing intensity but the area still under thick clouds.

Wipneus · « **Reply #515 on:** September 16, 2013, 08:14:02 AM »

Update 20130915.

Extent: -14k1 (+1421k vs 2012)
Area: +5k4 (+1428k vs 2012)

Melt continues as the CAB figures show. The Greenland Sea extent and area decline as expected due to better weather conditions. Opposite are CAA and Baffin, some channels are filling up with ice drift from the CAB, including the Nares Strait (which is part of the Baffin region).

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea -16.7 -2.2 -0.3 Kara Sea Barents Sea Greenland Sea -6.7 0.2 -14.1 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 8.5 0.0 -0.1 Canadian Archipelago Beaufort Sea Chukchi Sea 12.8 2.9 1.7 Bering Sea Sea of Okhotsk Total Extent 0.1 0.0 -14.1 Area: Arctic Basin East Siberian Sea Laptev Sea 0.5 -2.5 -0.3 Kara Sea Barents Sea Greenland Sea -7.3 0.2 -5.5 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 6.1 0.0 -0.1 Canadian Archipelago Beaufort Sea Chukchi Sea 10.0 2.4 1.8 Bering Sea Sea of Okhotsk Total Area 0.1 0.0 5.4

Wipneus · « **Reply #516 on:** September 16, 2013, 08:37:58 AM »

Yesterday I showed the "far" side of the pack, now the opportunity for the "near" or Atlantic side.

Melt along the edge all over.

(image attached log in to see)

Richard Rathbone · « **Reply #517 on:** September 16, 2013, 02:52:45 PM »

Quote from: Wipneus on September 15, 2013, 09:35:36 AM

Quote from: Richard Rathbone on September 14, 2013, 08:55:10 PM
I don't think 2012 is a good guide to the timing of regional refreezes this year. Refreeze will start earlier than 2012 in regions that melted out in 2012 and haven't melted out this year.

Richard, if I expected a duplication of 2012, I would have said "mid October". Anyway, the Greenland Sea dropped today from 101k to 81k with the cyclone loosing intensity but the area still under thick clouds.

Clearly I am not understanding what you think your graphs show.

All I am trying to say is that there are competing effects going on and that its dangerous to draw any inference from a daily change correlating with one effect without also checking that it doesn't correlate against other effects that are in play. In particular I am claiming that refreeze is in play now and disputing that 2012 is a good analogue for when refreeze comes into play.

As for whether refreeze is in play in the Greenland Sea now, Greenland itself is refreezing exceptionally fast this September (its above the 2 standard deviation region on the surface mass balance plot http://beta.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/). W and S coasts are still showing mass balance reduction but NE is accumulating. Ice going south to melt is the dominant process, but I don't think you can rule out freezing in the part closest to NE Greenland.

jdallen · « **Reply #518 on:** September 16, 2013, 07:21:24 PM »

@Richard R - refreeze north of the Fram - maybe. South of the Fram neither SSTs nor 2 meter temps are low enough yet. They are barely low enough across the top of the island.

Wipneus · « **Reply #519 on:** September 17, 2013, 07:09:06 AM »

Update 20130916.

Extent: -9k8 (+1428k vs 2012)
Area: -23k4 (+1432k vs 2012)

A net decline day again. In the Beaufort the ice increased and more ice is entering the Baffin region, but the CAB continued its decline and the CAA and Greenland Sea recovered from the previous increases.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea -15.7 -5.8 0.2 Kara Sea Barents Sea Greenland Sea 0.7 0.1 -5.4 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 6.4 0.0 0.3 Canadian Archipelago Beaufort Sea Chukchi Sea -7.5 14.5 2.6 Bering Sea Sea of Okhotsk Total Extent -0.1 0.0 -9.8 Area: Arctic Basin East Siberian Sea Laptev Sea -12.3 -7.8 0.1 Kara Sea Barents Sea Greenland Sea 1.2 0.1 -11.2 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 3.0 0.0 0.2 Canadian Archipelago Beaufort Sea Chukchi Sea -8.5 9.7 2.2 Bering Sea Sea of Okhotsk Total Area -0.1 0.0 -23.4

Wipneus · « **Reply #520 on:** September 17, 2013, 07:31:49 AM »

So how about the minimum? Since in the daily report I normally note the changes that is not easy to follow. Here are the absolute numbers last ten days:

YYYYMMDD Total.Extent Total.Area 20130907 4.693800 4.344824 20130908 4.680139 4.333682 20130909 4.621491 4.250043 20130910 4.628799 4.274677 20130911 4.635514 4.311544 20130912 4.631994 4.350772 20130913 4.659530 4.375571 20130914 4.660765 4.370364 20130915 4.646696 4.375721 20130916 4.636934 4.352362

So the minimum was on Sep 9. Yet the extent is only about 15k above that, so extent could stiil be lower.

So has the refreeze started? I think you can argue it has not. Most of the increases have come from the disappearance of melt pools (affecting mostly CAB area) and the peripheral regions. These can be shown are affected by increasing bad weather and ice transport.

Further, refreeze should be shown first in the CAB (as it contains the NP). For these reasons I prefer (and I argued this in this thread before) to look at the CAB extent.
These are the numbers for the CAB:

YYYYMMDD Arctic.Basin.extent Arctic.Basin.area 20130907 3.795692 3.593694 20130908 3.780346 3.573741 20130909 3.769694 3.533063 20130910 3.756253 3.530225 20130911 3.765868 3.570044 20130912 3.760546 3.605888 20130913 3.754614 3.600090 20130914 3.735482 3.591955 20130915 3.718788 3.592422 20130916 3.703126 3.580083

Area was minimum at Sep 10 (50k below current) but extent is now at its lowest.

Remember that near real time regional extent was not available before (since nobody bothered to do the calcs).

In my definition, refreeze cannot be said to have started yet.

TerryM · « **Reply #521 on:** September 17, 2013, 08:22:25 AM »

Wipneus

"[size=78%]Most of the increases have come from the disappearance of melt pools"[/size][/i]
Wouldn't melt pond freezing be showing as area increase as opposed to extent? I'm in agreement that refreeze hasn't started yet, at least in any meaningful way, but I am confused about melt ponds at this time of year as well as their freezing leading to higher extent figures.
Terry

Wipneus · « **Reply #522 on:** September 17, 2013, 09:09:56 AM »

Terry, sorry I was so short. I had to catch a train. Which has terrible wifi btw.

It is an assumption that area decline in the CAB is mostly caused by freezing melt pools. If there are arguments otherwise, I'd like to hear them.

The compactness is nearly back to winter levels, all methods except the Crysosphere Today derived CAPIE index. Since meltpools must (by physics) lower compactness, these should be minimal by now. See the compactness graphic if in doubt.

Peter Ellis · « **Reply #523 on:** September 17, 2013, 06:33:29 PM »

I think this is falling into a semantic trap - some people are taking "refreeze" as starting when the melt ponds freeze over, while others are taking it to be when the sea between adjacent ice floes starts to freeze over. Both definitions are defensible, and the refreeze has started by the former metric but likely not yet by the latter.

Wipneus · « **Reply #524 on:** September 18, 2013, 06:05:23 AM »

Update 20130917.

Extent: +10k2 (+1418k vs 2012)
Area: +12k2 (+1432k vs 2012)

Add another melt day for the CAB, most other regions are quiet or have slight increases.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea -12.2 2.6 0.3 Kara Sea Barents Sea Greenland Sea 1.6 -0.2 8.8 Baffin/Newfoundland Bay St. Lawrence Hudson Bay -4.1 0.0 -0.6 Canadian Archipelago Beaufort Sea Chukchi Sea 5.5 7.2 1.3 Bering Sea Sea of Okhotsk Total Extent 0.0 0.0 10.2 Area: Arctic Basin East Siberian Sea Laptev Sea -19.0 0.6 0.2 Kara Sea Barents Sea Greenland Sea 2.2 -0.2 13.4 Baffin/Newfoundland Bay St. Lawrence Hudson Bay -1.4 0.0 -0.3 Canadian Archipelago Beaufort Sea Chukchi Sea 11.1 4.9 0.7 Bering Sea Sea of Okhotsk Total Area 0.0 0.0 12.2

Bob Wallace · « **Reply #525 on:** September 18, 2013, 06:08:32 AM »

CAB - melting or outsourcing?

CA and GS are up just a bit more than the CAB is down.

Wipneus · « **Reply #526 on:** September 18, 2013, 07:14:29 AM »

I cannot see a region interesting enough to single out. Therefore a changed extent ice map for the 8 days after the total minimum extent (20130909).
Things to notice:
CAB Polynya mostly gone

ice seriously increases in CAA and the Nares Strait (region Baffin);
ice gets a little more south in the Greenland Sea (I don't think that is significant);
There is a huge widening of the gap between Banks Island and the ice pack;
Ice edge advancing in the Beaufort;
The resisting ice field in the ESS is moving west;
Ice retreating from the edges of the Laptev, Kara and Barentsz section;

The image is attached, log in to see.

Wipneus · « **Reply #527 on:** September 18, 2013, 07:32:49 AM »

Quote from: Bob Wallace on September 18, 2013, 06:08:32 AM

CAB - melting or outsourcing?

Yes Bob, that is the question, to which the easy answer is of course "both". I have been trying to collect some fact in the previous weeks. There is probably some freezing as well: just north of the Canadian Islands, some cracks developed last week. The wide crack above Prince Patrick did not close, but is now filled with low concentration ice. Such cracks can close again and lower extent without any melting or "outsourcing".

Quote

CA and GS are up just a bit more than the CAB is down.

Yes but the changes are so small that there is not so much meaning there.
At the same time last year, CAB extent increased 63k according to my Jaxa calculations. According to the official Jaxa/IJIS V2 numbers, Sep 17 2012 scored its first positive century (+106k).

Just underlining 2013 is a remarkable year, at least it is not 2012.

Frivolousz21 · « **Reply #528 on:** September 18, 2013, 09:44:16 AM »

I doubt we could even walk on the "new" CAA ice.

Passive Microwave during the Summer when it's much warmer misses ice much thicker and more widespread than what is going on in the CAA.

Give me a break. The models show much warmer air moving in soon. Above freezing air with a strong Southerly flow. We will probably see all of that new ice vanish.

jdallen · « **Reply #529 on:** September 18, 2013, 09:42:31 PM »

Quote from: frivolousz21 on September 18, 2013, 09:44:16 AM

I doubt we could even walk on the "new" CAA ice.

Passive Microwave during the Summer when it's much warmer misses ice much thicker and more widespread than what is going on in the CAA.

Give me a break. The models show much warmer air moving in soon. Above freezing air with a strong Southerly flow. We will probably see all of that new ice vanish.

I'm at least partly with Friv on this. There looks to be a lot of energy still being dumped into low clouds which implies to me sea surfaces which are more rather than less open. Add to that, that the temps still look marginal for ice formation, there may be other explanations for the uptic.

Wipneus · « **Reply #530 on:** September 19, 2013, 06:19:52 AM »

Update 20130918.

Extent: +39k3 (+1494k vs 2012)
Area: +43k1 (+1516k vs 2012)

CAA and Greenland Sea have rather big increases, smaller for the Beaufort. Among this the CAB still manages a small decline, reaching another new CAB extent minimum.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea -4.8 -1.1 -0.6 Kara Sea Barents Sea Greenland Sea 2.2 0.3 12.6 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 2.5 0.0 0.0 Canadian Archipelago Beaufort Sea Chukchi Sea 19.6 6.4 2.2 Bering Sea Sea of Okhotsk Total Extent 0.0 0.0 39.3 Area: Arctic Basin East Siberian Sea Laptev Sea -3.9 -0.4 -0.4 Kara Sea Barents Sea Greenland Sea 0.0 0.2 24.1 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 2.4 0.0 0.0 Canadian Archipelago Beaufort Sea Chukchi Sea 13.8 5.1 2.3 Bering Sea Sea of Okhotsk Total Area 0.0 0.0 43.1

Wipneus · « **Reply #531 on:** September 19, 2013, 06:35:34 AM »

The Polar Polynya opened again, with some in what is known as the Barents Bite.

(log in to see attached images)

Wipneus · « **Reply #532 on:** September 20, 2013, 07:52:24 AM »

Update 20130919.

Extent: +39k6 (+1474k vs 2012)
Area: +11k4 (+1483k vs 2012)

Ice is increasing in most regions, including the CAB which may be past its minimum now.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea 8.8 -2.9 0.8 Kara Sea Barents Sea Greenland Sea -2.6 -0.2 7.2 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 0.1 0.0 -0.1 Canadian Archipelago Beaufort Sea Chukchi Sea 22.6 1.3 4.3 Bering Sea Sea of Okhotsk Total Extent 0.0 0.0 39.6 Area: Arctic Basin East Siberian Sea Laptev Sea 4.4 -7.9 0.4 Kara Sea Barents Sea Greenland Sea -3.7 -0.1 -1.3 Baffin/Newfoundland Bay St. Lawrence Hudson Bay -1.4 0.0 -0.1 Canadian Archipelago Beaufort Sea Chukchi Sea 18.4 0.0 2.6 Bering Sea Sea of Okhotsk Total Area 0.0 0.0 11.4

Wipneus · « **Reply #533 on:** September 20, 2013, 08:04:29 AM »

With ice now increasing everywhere, the East Siberian Sea has the largest slice of ice that is disappearing. Looking at the changes image shows that the ice is actually moving (by winds) west.

(log in to see attached image)

Wipneus · « **Reply #534 on:** September 21, 2013, 07:57:34 AM »

Update 20130920.

Extent: +34k9 (+1498k vs 2012)
Area: +64k3 (+1524k vs 2012)

Extent increased especially in the CAA. The CAA seems to be filling up weeks ahead of last year. That is not visible in the other regions yet. Today the ESS and CAB had smaller extent growth, in other regions it is quiet.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea 5.2 9.6 -0.5 Kara Sea Barents Sea Greenland Sea -1.8 0.1 -2.9 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 2.0 0.0 -0.1 Canadian Archipelago Beaufort Sea Chukchi Sea 14.9 4.5 4.0 Bering Sea Sea of Okhotsk Total Extent 0.0 0.0 34.9 Area: Arctic Basin East Siberian Sea Laptev Sea 22.1 8.6 -0.2 Kara Sea Barents Sea Greenland Sea 0.4 0.1 3.0 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 2.0 0.0 0.0 Canadian Archipelago Beaufort Sea Chukchi Sea 19.2 4.8 4.3 Bering Sea Sea of Okhotsk Total Area 0.0 0.0 64.3

Wipneus · « **Reply #535 on:** September 21, 2013, 08:08:37 AM »

The Beaufort did not melt out this year as it did in 2012. In the last week the ice has not changed much in total. But the changes map of the last week shows that the ice edge advanced in the west but in the eastern corner the gap between Banks island and the ice increased big way.

jdallen · « **Reply #536 on:** September 21, 2013, 08:42:32 AM »

Quote from: Wipneus on September 21, 2013, 08:08:37 AM

The Beaufort did not melt out this year as it did in 2012. In the last week the ice has not changed much in total. But the changes map of the last week shows that the ice edge advanced in the west but in the eastern corner the gap between Banks island and the ice increased big way.

At this point, a bowl of ice cubes sloshing around. It will be interesting to see how long it takes for the ice to recover some coherence. Might be good to try to identify some identifiable patterns to track movement later on in the season.

Wipneus · « **Reply #537 on:** September 22, 2013, 08:37:03 AM »

Update 20130921.

Extent: +61.5 (+1512k vs 2012)
Area: +89.8 (+1565k vs 2012)

Big refreeze in the ESS today. The CAA continues to increase.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea 5.2 36.5 0.2 Kara Sea Barents Sea Greenland Sea 0.2 0.1 -9.2 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 2.8 0.0 0.5 Canadian Archipelago Beaufort Sea Chukchi Sea 18.9 1.3 4.6 Bering Sea Sea of Okhotsk Total Extent 0.1 0.0 61.5 Area: Arctic Basin East Siberian Sea Laptev Sea 41.7 43.0 0.2 Kara Sea Barents Sea Greenland Sea 0.4 0.1 -14.2 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 3.5 0.0 0.3 Canadian Archipelago Beaufort Sea Chukchi Sea 10.5 0.8 3.5 Bering Sea Sea of Okhotsk Total Area 0.1 0.0 89.8

Wipneus · « **Reply #538 on:** September 22, 2013, 08:47:33 AM »

The ice edge in the East Siberian Sea is expanding everywhere.

Image attached: log in to see.

Wipneus · « **Reply #539 on:** September 23, 2013, 06:55:10 AM »

Update 20130922.

Extent: +13k4 (+1442k vs 2012)
Area: -5k8 (+1467k vs 2012)

The growth in the ESS continues. Also the CAB extent did have a big increase. Declines in the CAA and Beaufort moderate the total increase.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea 19.5 27.4 -0.6 Kara Sea Barents Sea Greenland Sea -5.2 -0.5 -2.5 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 2.9 0.0 0.6 Canadian Archipelago Beaufort Sea Chukchi Sea -20.3 -9.5 1.9 Bering Sea Sea of Okhotsk Total Extent -0.1 0.0 13.4 Area: Arctic Basin East Siberian Sea Laptev Sea 4.7 20.3 -0.4 Kara Sea Barents Sea Greenland Sea -2.5 -0.3 -0.7 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 2.8 0.0 0.5 Canadian Archipelago Beaufort Sea Chukchi Sea -22.1 -10.0 2.0 Bering Sea Sea of Okhotsk Total Area -0.1 0.0 -5.8

Wipneus · « **Reply #540 on:** September 23, 2013, 07:12:26 AM »

Autumn equinox 2013: ice increase on the Siberian side and declines in Beaufort, CAA and towards the Atlantic. The area of the Barents Bite is still clearly visible.

(attached, must log in to see)

Wipneus · « **Reply #541 on:** September 24, 2013, 11:05:27 AM »

Update 20130923.

Extent: +28k4 (+1431k vs 2012)
Area: +25k7 (+1434k vs 2012)

Continuing the pattern of the day before: sea ice increased in the ESS and the CAB. A decline is noted in the CAA.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea 13.8 16.0 -0.1 Kara Sea Barents Sea Greenland Sea 0.4 0.0 -2.1 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 3.8 0.0 2.3 Canadian Archipelago Beaufort Sea Chukchi Sea -12.3 4.6 2.0 Bering Sea Sea of Okhotsk Total Extent 0.0 0.0 28.4 Area: Arctic Basin East Siberian Sea Laptev Sea 5.9 5.5 0.0 Kara Sea Barents Sea Greenland Sea 0.5 0.0 -17.8 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 7.4 0.0 1.8 Canadian Archipelago Beaufort Sea Chukchi Sea 7.6 11.4 3.4 Bering Sea Sea of Okhotsk Total Area 0.0 0.0 25.7

Wipneus · « **Reply #542 on:** September 24, 2013, 11:18:22 AM »

The edge of the ice pack is expanding along the Laptev and Kara sections of the CAB. But the concentration along that edge is quite low. Sign of divergence? May the movement reverse when the wind do the same?

(log in to see the attached images)

jdallen · « **Reply #543 on:** September 24, 2013, 05:39:47 PM »

Quote from: Wipneus on September 24, 2013, 11:18:22 AM

The edge of the ice pack is expanding along the Laptev and Kara sections of the CAB. But the concentration along that edge is quite low. Sign of divergence? May the movement reverse when the wind do the same?

(log in to see the attached images)

I have a hard time believing that is refreeze. Koeln shows temps across the region between 0 to minus 3C. Even at the low end, that's not enough for more than nilas. If there is any wind driven roughness, it's not even cold enough for that.

Jim Hunt · « **Reply #544 on:** September 24, 2013, 06:20:20 PM »

Quote from: jdallen on September 24, 2013, 05:39:47 PM

I have a hard time believing that is refreeze.

It doesn't look like "refreeze" to me either. See some recent Arctic art from my blue period for a visual impression of what's going on:

http://GreatWhiteCon.info/2013/09/central-arctic-art/

jdallen · « **Reply #545 on:** September 24, 2013, 06:46:58 PM »

Quote from: Jim Hunt on September 24, 2013, 06:20:20 PM

Quote from: jdallen on September 24, 2013, 05:39:47 PM
I have a hard time believing that is refreeze.

It doesn't look like "refreeze" to me either. See some recent Arctic art from my blue period for a visual impression of what's going on:

I remember that image... Very nice. It looks like the "slush" we've talked about most of the season spreading out even more thinly. The ice equivalent of sea foam rafts one sees frequently just beyond the surf.

Edit: considering the apparent thickness and density of that stuff, and how we watched it melt out of areas like the Chukchi and Barents, another half a degree warmer water, or slightly higher salinity, and that stuff would all melt out, possibly even now. It affirms for me just how close by the "bullet" - serious melt out - passed by us this season. How long will we stay lucky?

Wipneus · « **Reply #546 on:** September 25, 2013, 06:58:23 AM »

Update 20130924.

Extent: +58k0 (+1474k vs 2012)
Area: +63k7 (+1491k vs 2012)

The big increases are the ESS and the CAB, other regions are quiet or decline slightly (CAA).

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea 29.6 32.4 0.8 Kara Sea Barents Sea Greenland Sea 1.9 0.0 -4.4 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 2.8 0.0 1.0 Canadian Archipelago Beaufort Sea Chukchi Sea -5.4 -0.4 -0.3 Bering Sea Sea of Okhotsk Total Extent 0.0 0.0 58.0 Area: Arctic Basin East Siberian Sea Laptev Sea 35.3 35.0 0.5 Kara Sea Barents Sea Greenland Sea 1.1 0.0 4.2 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 1.9 0.0 0.7 Canadian Archipelago Beaufort Sea Chukchi Sea -8.2 -6.1 -0.9 Bering Sea Sea of Okhotsk Total Area 0.0 0.0 63.7

Bob Wallace · « **Reply #547 on:** September 25, 2013, 06:59:53 AM »

Quote

How long will we stay lucky?

2016 +/- 3

Wipneus · « **Reply #548 on:** September 25, 2013, 07:30:11 AM »

Wind and wind-direction play a major role in the ice development at the moment. There is a broad wind field from the Canadian islands to Siberia. This causes the ice pack to move off the islands leaving crakcs with low concentration ice and open water above Prince Patrick Island. The existing gap above Banks keeps widening.

(log in to see attached image)

Wipneus · « **Reply #549 on:** September 26, 2013, 07:00:36 AM »

Update 20130925.

Extent: +79k4 (+1524k vs 2012)
Area: +70k5 (+1493k vs 2012)

Continuing steep increase in the ESS and CAB, quiet elsewhere.

You will find the updated graphs in the top post

The details (in 1000 km²):

Extent: Arctic Basin East Siberian Sea Laptev Sea 29.5 46.9 0.2 Kara Sea Barents Sea Greenland Sea 3.4 0.0 1.6 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 0.5 0.0 -1.7 Canadian Archipelago Beaufort Sea Chukchi Sea 7.9 -4.0 -4.7 Bering Sea Sea of Okhotsk Total Extent 0.0 0.0 79.4 Area: Arctic Basin East Siberian Sea Laptev Sea 36.7 34.4 0.1 Kara Sea Barents Sea Greenland Sea 0.9 0.0 0.9 Baffin/Newfoundland Bay St. Lawrence Hudson Bay -0.1 0.0 -1.1 Canadian Archipelago Beaufort Sea Chukchi Sea 9.2 -7.0 -3.6 Bering Sea Sea of Okhotsk Total Area 0.0 0.0 70.5

News:

Author Topic: Home brew AMSR2 extent & area calculation (Read 1981324 times)