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greatdying2

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Re: Home brew AMSR2 extent & area calculation
« Reply #3100 on: July 26, 2017, 07:50:48 PM »
A big divergence from Jaxa  extent data
At least some of this is because the data Wip uses has higher resolution, ~3 km vs 10km for Jaxa. For example, have a look at the map he attached to his latest post. Most of those holes that are beginning to appear in Wip's data set will not show up as Jaxa extent drops until they get bigger.
« Last Edit: July 26, 2017, 07:58:46 PM by greatdying2 »
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3101 on: July 27, 2017, 08:30:20 AM »
Most of the change today in the ESS / Chukchi.

Update 20170726.

Extent: -49.3 (+41k vs 2016, -98k vs 2015, -428k vs 2014, -223k vs 2013, +102k vs 2012)
Area: -79.1 (+55k vs 2016, -41k vs 2015, -551k vs 2014, -324k vs 2013, -14k vs 2012)
 

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -5.0                   -29.3                     4.7
               Kara Sea             Barents Sea           Greenland Sea
                    2.8                    -6.0                    -5.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    3.6                     0.0                     1.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -10.3                     5.5                   -11.3
             Bering Sea          Sea of Okhotsk            Total Extent
                   -0.4                    -0.2                   -49.3

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -32.7                   -34.5                     7.1
               Kara Sea             Barents Sea           Greenland Sea
                    4.2                    -4.7                    -8.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    4.1                     0.0                     1.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -6.6                     3.5                   -11.7
             Bering Sea          Sea of Okhotsk              Total Area
                   -0.3                    -0.3                   -79.1


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%.

FishOutofWater

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Re: Home brew AMSR2 extent & area calculation
« Reply #3102 on: July 27, 2017, 03:16:42 PM »
Low pressure gathers air and smoke but the ocean underneath it does the opposite. Water and ice are flung out from the center of intense storms such as hurricanes. After an intense hurricane passes it's path can be seen as a cool track in sea surface temperature anomalies. Low pressure drives Ekman pumping, high pressure brings convergence. That's why a relatively fresh river and melt water enhanced dome builds up under the Beaufort high.

We're seeing some volume loss of the Beaufort dome this summer. That cold fresh water is reducing ice melt in the areas where it has flowed.


Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3103 on: July 28, 2017, 06:37:36 PM »
ESS is where most of the action is.

Update 20170727.

Extent: -110.6 (+12k vs 2016, -129k vs 2015, -418k vs 2014, -272k vs 2013, +198k vs 2012)
Area: -72.2 (+116k vs 2016, -6k vs 2015, -558k vs 2014, -300k vs 2013, +41k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -8.3                   -44.5                    -6.0
               Kara Sea             Barents Sea           Greenland Sea
                  -10.1                     3.4                    -6.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -6.1                     0.0                    -8.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -2.4                    -5.9                   -15.6
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.4                    -0.2                  -110.6

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                    0.2                   -20.7                   -14.4
               Kara Sea             Barents Sea           Greenland Sea
                   -8.7                     3.6                    -2.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -3.8                     0.0                   -12.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    8.4                   -12.0                   -11.1
             Bering Sea          Sea of Okhotsk              Total Area
                    0.5                     0.0                   -72.2



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

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Re: Home brew AMSR2 extent & area calculation
« Reply #3104 on: July 29, 2017, 01:30:30 PM »
Extent drop moves to the Chukchi and Beaufort ice edge. Both on the Pacific and the Atlantic side open water is resolved within the main pack.

Update 20170728.

Extent: -86.1 (+45k vs 2016, -151k vs 2015, -467k vs 2014, -260k vs 2013, +236k vs 2012)
Area: -71.7 (+182k vs 2016, -19k vs 2015, -599k vs 2014, -382k vs 2013, +113k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                    3.1                    -6.8                    -7.2
               Kara Sea             Barents Sea           Greenland Sea
                  -15.4                    -1.4                     4.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -7.3                     0.2                   -11.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -6.0                   -15.5                   -23.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.4                     0.5                   -86.1

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -30.5                    -9.1                    -5.8
               Kara Sea             Barents Sea           Greenland Sea
                  -10.3                     0.5                     3.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    3.7                     0.1                    -9.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    2.6                   -10.4                    -7.2
             Bering Sea          Sea of Okhotsk              Total Area
                    0.3                     0.4                   -71.7


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

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Re: Home brew AMSR2 extent & area calculation
« Reply #3105 on: July 29, 2017, 01:39:01 PM »
Comparative animation of the 2016/2017 sea ice concentration in the Barents Section.

Must click to start.

iceman

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Re: Home brew AMSR2 extent & area calculation
« Reply #3106 on: July 29, 2017, 01:48:36 PM »
So the Northern Sea Route is open, for any ships willing to dodge those remaining few floes.

Though I don't comment here often, it's a daily go-to page for me.  I greatly appreciate the updates and graphics.

be cause

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Re: Home brew AMSR2 extent & area calculation
« Reply #3107 on: July 29, 2017, 02:00:35 PM »
Yes Wipneus .. by mid july 2016 the ice near the pole began to compact and continued for some time . this year .. as you show ; the opposite is happening . Last year no pole hole .. this year ... ?
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greatdying2

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Re: Home brew AMSR2 extent & area calculation
« Reply #3108 on: July 29, 2017, 05:27:20 PM »
This will certainly be an interesting area to watch (att.).

Also, amazing how quickly now any ice pushed south between Franz Josef Land and Severnaya Zemlya seems to melt away.

Also, I totally agree with the others: Thank-you Wipneus, without your thread I would be in the dark.
« Last Edit: July 29, 2017, 05:33:42 PM by greatdying2 »
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

greatdying2

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Re: Home brew AMSR2 extent & area calculation
« Reply #3109 on: July 29, 2017, 05:44:48 PM »
Also, the Jaxa and NSIDC extent curves, which went off in a different direction than AMSR2 in the last little while, seem to coming back into agreement.

https://sites.google.com/site/arctischepinguin/home/amsr2/grf/amsr2-extent-all-cmpare.png
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Ice Shieldz

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Re: Home brew AMSR2 extent & area calculation
« Reply #3110 on: July 29, 2017, 06:18:42 PM »
.. by mid july 2016 the ice near the pole began to compact and continued for some time . this year .. as you show ; the opposite is happening.
Technically, the opposite of compaction is dispersion, and rather than dispersing, it seems more accurate to me to say this ice has been melting in situ. Indicative of wimpy ice formed by record low FDD and many previous dispersion events - mostly toward the Atlantic.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3111 on: July 29, 2017, 07:06:45 PM »
This will certainly be an interesting area to watch (att.).

Also, amazing how quickly now any ice pushed south between Franz Josef Land and Severnaya Zemlya seems to melt away.

Also, I totally agree with the others: Thank-you Wipneus, without your thread I would be in the dark.

Any ice making it to the Barents between Franz Josef and Svalbard is melting quickly. It is interesting to see how quickly the ice that is pushing up against Franz Josef is being compacted. All of the exposed water towards the pole is certainly heating up but we are already over a month past peak insolation so this is less damaging than if it had occurred in early June.

greatdying2

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Re: Home brew AMSR2 extent & area calculation
« Reply #3112 on: July 29, 2017, 07:18:38 PM »
Technically, the opposite of compaction is dispersion, and rather than dispersing, it seems more accurate to me to say this ice has been melting in situ. Indicative of wimpy ice formed by record low FDD and many previous dispersion events - mostly toward the Atlantic.
Yes -- maybe it came from this green band at the end of last melt season?
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3113 on: July 30, 2017, 09:48:00 AM »
Baffin keeps contributing significantly to the daily decline in extent. Within the basin, the area around the Beaufort/Chukchi/CAB takes a hit. Actually it looks like the major start of extent decline in the CAB. Rather late compared with recent years I must add.

Update 20170729.

Extent: -95.6 (+12k vs 2016, -179k vs 2015, -462k vs 2014, -312k vs 2013, +193k vs 2012)
Area: -55.1 (+250k vs 2016, +25k vs 2015, -566k vs 2014, -336k vs 2013, +45k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -19.9                     3.6                   -11.9
               Kara Sea             Barents Sea           Greenland Sea
                   -7.0                     1.4                     7.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -28.6                     0.0                     6.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -20.9                   -17.5                    -8.3
             Bering Sea          Sea of Okhotsk            Total Extent
                   -0.1                    -0.2                   -95.6

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   32.5                     2.8                   -10.4
               Kara Sea             Barents Sea           Greenland Sea
                   -2.3                     4.2                     3.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -28.7                     0.0                    10.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -44.2                   -18.2                    -4.1
             Bering Sea          Sea of Okhotsk              Total Area
                   -0.2                    -0.2                   -55.1



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

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Re: Home brew AMSR2 extent & area calculation
« Reply #3114 on: July 30, 2017, 09:59:32 AM »
An illustration of what I mean by "rather late". Beaufort an neighbors.

Click to start.

JayW

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Re: Home brew AMSR2 extent & area calculation
« Reply #3115 on: July 30, 2017, 10:47:52 AM »
An illustration of what I mean by "rather late". Beaufort an neighbors.

Click to start.

The clouds are making the concentration appear to be near 100% north of Wrangel for 2017 in my opinion. This year also lacks that multi year ice that lingered near Wrangel.  Lots of "storminess" is progged in this area as well.    Not sure 2017 catches up to last year, but I think it's a possibility.


Let me add to the many thanks for your contributions Wip!

I attached AVHRR Imagery to show the clouds.
http://weather.gc.ca/satellite/satellite_anim_e.html?sat=hrpt&area=dfo&type=nir
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greatdying2

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Re: Home brew AMSR2 extent & area calculation
« Reply #3116 on: July 30, 2017, 11:02:18 AM »
The Beaufort piggy bank?
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3117 on: July 31, 2017, 11:56:17 AM »
Extent drops in Laptev, ESS and the Cab. A larger than usual polynia is establishing in the "Laptev Bite".

Update 20170730.

Extent: -62.9 (+17k vs 2016, -135k vs 2015, -479k vs 2014, -362k vs 2013, +220k vs 2012)
Area: -67.8 (+271k vs 2016, +70k vs 2015, -682k vs 2014, -289k vs 2013, +53k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -12.9                   -11.9                   -20.7
               Kara Sea             Barents Sea           Greenland Sea
                    2.3                     1.8                    -4.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    3.6                     0.1                    -4.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -7.3                   -11.7                     1.7
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.4                    -0.1                   -62.9

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -38.5                    -0.3                   -15.1
               Kara Sea             Barents Sea           Greenland Sea
                    4.7                    -4.4                    -6.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    4.6                     0.1                    -3.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -12.3                     6.2                    -2.8
             Bering Sea          Sea of Okhotsk              Total Area
                    0.6                    -0.1                   -67.8



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%.

The section from the Laptev Sea to the pole is shown. An enlarging polynia is seen in the middle of the image. A "bite" is developing to the left.

greatdying2

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Re: Home brew AMSR2 extent & area calculation
« Reply #3118 on: July 31, 2017, 08:33:57 PM »
A larger than usual polynia is establishing in the "Laptev Bite".
Does anyone know what causes this polynya? Currents? What is the significance of it being larger than usual?
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3119 on: July 31, 2017, 09:00:11 PM »
"Does anyone know" I suspect the recent high tides accelerated more Atlantic waters into the Arctic, increasing currents, it takes a while for effects to show so there's always other explanations possible. Look at the position of the polynyas and the focal points of the shelves in the area. As long as there's warm water at depth any movement at the surface will do.
 
added; possibly something like this happening to deeper layer. Skip to 2:30
« Last Edit: August 01, 2017, 09:43:58 AM by johnm33 »

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Re: Home brew AMSR2 extent & area calculation
« Reply #3120 on: August 01, 2017, 02:50:37 AM »
It appears to be positioned above the Gakkel Ridge (almost at its eastern end). Volcanism?? 
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Tor Bejnar

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Re: Home brew AMSR2 extent & area calculation
« Reply #3121 on: August 01, 2017, 03:41:53 AM »
It is generally understood that volcanic heat cannot reach the surface, however I did find this 2008 article: Volcanoes Erupt Beneath Arctic Ice that includes:
Quote
But the Gakkel Ridge, which is relatively unexplored and considered unique for its slow spreading rate, is just the place for surprises.

Robert Reeves-Sohn of the Woods Hole Oceanographic Institution (WHOI) in Massachusetts and his colleagues discovered jagged, glassy fragments of rock scattered around the volcanoes, suggesting explosive eruptions occurred between 1999 and 2001.

They hypothesize that the slow spreading could allow excess gas to build up in pockets of magma beneath the oceanic crust. When the gas pressure gets high enough, it pops like a champagne bottle being uncorked.

With news this week that polar ice is melting dramatically, underwater Arctic pyrotechnics might seem like a logical smoking gun. Scientists don't see any significant connection, however.

 "We don't believe the volcanoes had much effect on the overlying ice," Reeves-Sohn told LiveScience, "but they seem to have had a major impact on the overlying water column."

The eruptions discharge large amounts of carbon dioxide, helium, trace metals and heat into the water over long distances, he said.
Arctic ice is healthy for children and other living things because "we cannot negotiate with the melting point of ice"

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Re: Home brew AMSR2 extent & area calculation
« Reply #3122 on: August 01, 2017, 05:43:36 AM »
It is generally understood that volcanic heat cannot reach the surface, however I did find this 2008 article: Volcanoes Erupt Beneath Arctic Ice that includes:
Quote
But the Gakkel Ridge, which is relatively unexplored and considered unique for its slow spreading rate, is just the place for surprises.

It's an interesting area indeed but only one Earthquake greater than 2.5 in the last 30 days suggest no recent major vulcanism in this area of the Laptev.

That said interesting to see the Laptev back in our thoughts for another year - it's been a bit neglected this melt season.
« Last Edit: August 02, 2017, 12:01:38 PM by Mark Tough »

greatdying2

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Re: Home brew AMSR2 extent & area calculation
« Reply #3123 on: August 01, 2017, 05:47:11 AM »
I wonder if, even if the heat does not reach the surface, a volcanic eruption might lead to mixing near the surface. Fun to think about anyways.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3124 on: August 01, 2017, 08:43:13 AM »
A larger than usual polynia is establishing in the "Laptev Bite".
Does anyone know what causes this polynya? Currents? What is the significance of it being larger than usual?

I Concur with Johnm33 that its probably more Atlantic Water making it into the Laptev. The tides may be involved but I think Wip's excellent earlier animation illustrates whats going on very well

The ice front pushed up against Svalbard, Franz Josef Land and the end of Sev'Zem' seems to be depriving the Atlantic water of the opportunity to slip off the shelf, and it looks from that animation that rather than sliding down the channel that you can see on the Bathometry on the Laptev side of the channel between SZ and the mainland:

Where last year a slice in the Ice opened above it in Wips Gif, this year it looks to be more strongly flowing, and in obedience to mr Coriolis, hugging the Laptev coast instead.

 Perhaps its less saline hence easier able to stay in the shallows, due to mixing with, from what looks like to me in the below image, an almost entirely over shallow bottom, Florida to Laptev melt-water front. This sort of scenario has been concerning me greatly for sometime. There's over 1500km of shallow shelf between the coast and the edge of the deeper basin where it can be more safely stowed past that point :'(
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Re: Home brew AMSR2 extent & area calculation
« Reply #3125 on: August 01, 2017, 09:24:25 AM »
Moderate declines in the Basin, with some clearings in the Baffin region. The +174k extent distance from 2012 is still based on SSMIS measurements in 2012. From tomorrow those will be based on AMSR2, apples to apples.

Update 20170731.

Extent: -69.5 (+29k vs 2016, -65k vs 2015, -493k vs 2014, -376k vs 2013, +174k vs 2012)
Area: -61.3 (+184k vs 2016, +149k vs 2015, -746k vs 2014, -340k vs 2013, +79k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -8.9                   -13.4                   -10.9
               Kara Sea             Barents Sea           Greenland Sea
                    6.3                    -1.0                    -8.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -16.9                    -0.3                    -8.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    0.8                    -7.5                    -1.4
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.1                   -69.5

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                    9.0                   -33.3                    -7.1
               Kara Sea             Barents Sea           Greenland Sea
                    3.1                     0.0                    -6.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -5.1                    -0.3                    -9.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    6.9                   -11.5                    -6.4
             Bering Sea          Sea of Okhotsk              Total Area
                   -0.2                     0.1                   -61.3



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%.

The detail is the Beaufort/Chukchi/CAB corner where most of the melt is.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3126 on: August 02, 2017, 09:11:34 AM »
Big drops takes 2017 down to 2012 level, both extent and area. Most of the extent drop in the Beaufort/Chukchi/CAB border with contribution from removal of former fast ice in ESS and Laptev.
The first-of-the-month effect is small with this product: drops in Bering and Okhotsk together about 2k.

Update 20170801.

Extent: -163.7 (-140k vs 2016, -611k vs 2015, -493k vs 2014, +112k vs 2013, -1k vs 2012)
Area: -188.1 (+27k vs 2016, -826k vs 2015, -478k vs 2014, +321k vs 2013, -17k vs 2012)

Extent: -163.7 (-43k vs 2016, -140k vs 2015, -611k vs 2014, -493k vs 2013, +112k vs 2012)
Area: -188.1 (+124k vs 2016, +27k vs 2015, -826k vs 2014, -478k vs 2013, +321k vs 2012)
[EDIT: Steven pointed out the error, the comparison with 2012 was with still with SSMIS data and other years pointed to the wrong year]

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -46.4                   -26.1                   -14.2
               Kara Sea             Barents Sea           Greenland Sea
                   -2.7                    -1.4                   -20.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -10.1                     0.0                     4.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -11.8                   -29.2                    -3.9
             Bering Sea          Sea of Okhotsk            Total Extent
                   -1.4                    -0.8                  -163.7

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                 -122.1                   -13.9                    -3.5
               Kara Sea             Barents Sea           Greenland Sea
                   -6.8                     0.1                   -12.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -12.0                     0.0                     3.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -11.7                    -5.9                    -1.8
             Bering Sea          Sea of Okhotsk              Total Area
                   -1.0                    -0.6                  -188.1



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%.
« Last Edit: August 02, 2017, 02:16:03 PM by Wipneus »

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Re: Home brew AMSR2 extent & area calculation
« Reply #3127 on: August 02, 2017, 09:41:43 AM »
By mid-September much of ice could be so thin and disperced that satelites won't notice it

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Re: Home brew AMSR2 extent & area calculation
« Reply #3128 on: August 02, 2017, 10:42:10 AM »
Big drops takes 2017 down to 2012 level, both extent and area.
Whoa.

Seems the recent storm in the Beaufort/Chukchi, even though it was not particularly strong, did have a major impact. Maybe this will be an exception, since it hit where the ice was already barely surviving, but if on the other hand this sets the trend for August...  :o
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Re: Home brew AMSR2 extent & area calculation
« Reply #3129 on: August 02, 2017, 12:58:32 PM »
Big drops takes 2017 down to 2012 level, both extent and area.
...
Update 20170801.

Extent: -163.7 (-140k vs 2016, -611k vs 2015, -493k vs 2014, +112k vs 2013, -1k vs 2012)
Area: -188.1 (+27k vs 2016, -826k vs 2015, -478k vs 2014, +321k vs 2013, -17k vs 2012)

That comparison isn't correct.  You are obviously still using SSMIS data for 2012, rather than AMSR2.  I guess you inserted the AMSR2 2012 numbers at the wrong place: 2013 rather than 2012.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3130 on: August 02, 2017, 02:21:22 PM »
Big drops takes 2017 down to 2012 level, both extent and area.
...
Update 20170801.

Extent: -163.7 (-140k vs 2016, -611k vs 2015, -493k vs 2014, +112k vs 2013, -1k vs 2012)
Area: -188.1 (+27k vs 2016, -826k vs 2015, -478k vs 2014, +321k vs 2013, -17k vs 2012)

That comparison isn't correct.  You are obviously still using SSMIS data for 2012, rather than AMSR2.  I guess you inserted the AMSR2 2012 numbers at the wrong place: 2013 rather than 2012.

Thanks a lot for noticing that. Moreover, the other years were wrong as well!
(I build a little table with differences for all years with the same day. Indexing in this table went wrong).
Fixed for now.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3131 on: August 02, 2017, 03:07:09 PM »
By mid-September much of ice could be so thin and disperced that satelites won't notice it
SAR will still see it, unless it's possibly some kind of slush, but I don't think that is a stable configuration for the ice (?).

http://www.polarview.aq/arctic

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Re: Home brew AMSR2 extent & area calculation
« Reply #3132 on: August 03, 2017, 10:36:52 AM »
Extent drops in the CAB continue to be "cliffy". Cliffs in August are not uncommon among the strongest melt seasons (but usually followed by partial rebounds). I have attached a detailed graph of the CAB region: same colors as the usual regional graphs: 2017 is black for UH AMSR2 and purple is Jaxa AMSR2. 

Update 20170802.

Extent: -63.6 (+25k vs 2016, -100k vs 2015, -602k vs 2014, -476k vs 2013, +235k vs 2012)
Area: -98.8 (+161k vs 2016, +58k vs 2015, -803k vs 2014, -549k vs 2013, +375k 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
                  -26.9                   -19.5                   -14.7
               Kara Sea             Barents Sea           Greenland Sea
                  -12.2                    -0.6                     7.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   11.0                     0.0                    -6.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    2.0                    -0.7                    -3.7
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.1                     0.0                   -63.6

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -82.4                   -16.3                     2.8
               Kara Sea             Barents Sea           Greenland Sea
                   -8.7                     1.5                     7.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    0.7                     0.0                    -1.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   16.6                   -17.7                    -1.6
             Bering Sea          Sea of Okhotsk              Total Area
                    0.1                     0.0                   -98.8


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%.

The detail shows where the CAB sea ice is damaged most.

greatdying2

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Re: Home brew AMSR2 extent & area calculation
« Reply #3133 on: August 03, 2017, 10:47:54 AM »
Extent drops in the CAB continue to be "cliffy". Cliffs in August are not uncommon among the strongest melt seasons (but usually followed by partial rebounds).
Seems as though extent (ice edge) did rebound somewhat in the regions most affected by recent southerly winds, only to be overwhelmed by extent drops inside the "pack" (there is no pack, it's mush -- I mean not at the edge). What would happen if we get a real storm, I wonder...
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3134 on: August 03, 2017, 01:40:59 PM »
Seems as though extent (ice edge) did rebound somewhat in the regions most affected by recent southerly winds, only to be overwhelmed by extent drops inside the "pack" (there is no pack, it's mush -- I mean not at the edge). What would happen if we get a real storm, I wonder...

Looks like the short-lived dipoles next several days will undo the localized rebound, after first putting another dent in the higher-concentration ice near Wrangel. 
As for a "real storm," yesterday's ECMWF forecast a brief one: down to 979 hPa on D4, as Neven pointed out.  Today's GFS forecasts another low a few days later moving in on a different track.  The latter has been somewhat unreliable: someone else noted that it is prone to err by merging lows together later in the forecast interval, if I understood correctly.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3135 on: August 03, 2017, 04:17:55 PM »
Extent drops in the CAB continue to be "cliffy". Cliffs in August are not uncommon among the strongest melt seasons (but usually followed by partial rebounds).
Seems as though extent (ice edge) did rebound somewhat in the regions most affected by recent southerly winds, only to be overwhelmed by extent drops inside the "pack" (there is no pack, it's mush -- I mean not at the edge). What would happen if we get a real storm, I wonder...

It...would...be...a...disaster.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3136 on: August 04, 2017, 08:50:08 AM »
An uptick in CAB extent (and area) undoes much of yesterdays drop. Ice is being cleared in Baffin, ESS and Laptev.

Update 20170803.

Extent: -27.2 (+147k vs 2016, +9k vs 2015, -539k vs 2014, -434k vs 2013, +363k vs 2012)
Area: +41.9 (+321k vs 2016, +136k vs 2015, -678k vs 2014, -468k vs 2013, +448k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   32.3                   -15.3                    -9.5
               Kara Sea             Barents Sea           Greenland Sea
                   -2.5                     1.3                     0.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -17.6                     0.0                    -8.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -8.1                    -2.4                     2.7
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -27.2

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   68.6                     7.7                   -10.7
               Kara Sea             Barents Sea           Greenland Sea
                   -4.3                    -0.1                    -4.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -4.3                     0.0                    -7.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -11.9                     6.9                     1.3
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                    41.9



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%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3137 on: August 04, 2017, 08:55:37 AM »
More and more open sea in the ESS and Laptev regions.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3138 on: August 04, 2017, 09:29:16 AM »
There's the bounce back... for today at least -- I'll be surprised if the respite lasts more than a day or two.
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Re: Home brew AMSR2 extent & area calculation
« Reply #3139 on: August 04, 2017, 11:58:56 AM »
That bounce back looks to me in part like inaccurate measurement due to clouds.
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Re: Home brew AMSR2 extent & area calculation
« Reply #3140 on: August 05, 2017, 01:00:41 PM »
A century extent drop, about half of it outside the basin. The CAB sees a big

Update 20170804.

Extent: -113.6 (+85k vs 2016, -87k vs 2015, -585k vs 2014, -506k vs 2013, +298k vs 2012)
Area: +5.9 (+316k vs 2016, +218k vs 2015, -552k vs 2014, -403k vs 2013, +592k vs 2012)
 
You will find the updated graphs in the top post


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -2.5                   -18.9                   -12.3
               Kara Sea             Barents Sea           Greenland Sea
                   -9.4                    -1.2                   -20.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -25.7                     0.0                    -1.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -3.1                    -5.3                   -13.5
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                  -113.6

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   77.2                    -8.3                   -12.0
               Kara Sea             Barents Sea           Greenland Sea
                   -5.1                    -1.9                    -8.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -13.9                     0.0                    -2.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    0.4                   -16.2                    -3.4
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                     5.9


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%.

The detail shows  the ice facing Chukchi is getting packed by winds from the south, leaving open water and increasing area within the pack.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3141 on: August 05, 2017, 01:02:09 PM »
Little left of the non-fast ice in the Greenland Sea.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3142 on: August 05, 2017, 02:13:53 PM »
Given the fractured nature of the ice, we are lucky to have little Fram export.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3143 on: August 05, 2017, 05:48:01 PM »
A century extent drop, about half of it outside the basin. The CAB sees a big

... "rebound in area", did you mean to say?
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3144 on: August 06, 2017, 08:44:21 AM »
A century extent drop, about half of it outside the basin. The CAB sees a big

... "rebound in area", did you mean to say?

Yes, something ate that!

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Re: Home brew AMSR2 extent & area calculation
« Reply #3145 on: August 06, 2017, 08:49:44 AM »
Slow extent drops everywhere except the CAB.

Update 20170805.

Extent: -39.2 (+175k vs 2016, -149k vs 2015, -598k vs 2014, -503k vs 2013, +388k vs 2012)
Area: -63.6 (+324k vs 2016, +244k vs 2015, -580k vs 2014, -392k vs 2013, +649k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -23.4                    -2.7                    -7.6
               Kara Sea             Barents Sea           Greenland Sea
                    4.3                    -0.3                    12.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.6                     0.0                    -2.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -8.9                    -3.1                    -7.1
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -39.2

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -22.4                   -11.0                    -5.9
               Kara Sea             Barents Sea           Greenland Sea
                    3.8                     2.6                    12.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -2.4                     0.0                    -1.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -24.7                   -10.5                    -3.5
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   -63.6


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%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3146 on: August 06, 2017, 08:54:28 AM »
Comparative animation 2016/2017 of the Canadian Archipelago. Much more and less mobile ice in 2017.

Pavel

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Re: Home brew AMSR2 extent & area calculation
« Reply #3147 on: August 06, 2017, 09:02:02 AM »
Thanks for the animation. So the CAA still import ice from Beaufort/CAB. Thereby Beaufort may get ice free till mid-September. CAA will have much  MYI but melting could continue till the very end of season

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Re: Home brew AMSR2 extent & area calculation
« Reply #3148 on: August 07, 2017, 08:48:38 AM »
It looks more and more that 2017 will not have a 2013/2014-like minimum, neither like 2012 but is in a race with 2015 and 2016.
Most of the extent and area drops are in the CAB facing the Beaufort/Chukchi. That delivers another spectacular delta image (attached).

Update 20170806.

Extent: -62.0 (+206k vs 2016, -71k vs 2015, -622k vs 2014, -482k vs 2013, +453k vs 2012)
Area: -172.0 (+324k vs 2016, +138k vs 2015, -669k vs 2014, -523k vs 2013, +493k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -42.6                    -8.9                   -12.7
               Kara Sea             Barents Sea           Greenland Sea
                    3.3                    -0.7                    -2.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    5.9                     0.0                    -0.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -0.6                    -0.4                    -2.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -62.0

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                 -151.5                   -10.4                    -9.4
               Kara Sea             Barents Sea           Greenland Sea
                    1.2                    -1.8                    -6.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    2.2                     0.0                     0.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    8.9                    -3.0                    -1.7
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                  -172.0


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%.

greatdying2

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Re: Home brew AMSR2 extent & area calculation
« Reply #3149 on: August 07, 2017, 09:04:03 AM »
It looks more and more that 2017 will not have a 2013/2014-like minimum, neither like 2012 but is in a race with 2015 and 2016.

Sounds about right. By the way, it looks like the Chukchi (proper) bottomed out (today?), and rather early.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.