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Jim Pettit

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Re: 2014 sea ice area and extent data
« Reply #900 on: August 19, 2014, 01:01:52 PM »
IJIS Extent:
5,674,861 km2 (18 August)
Down 8,773,555 km2 (60.72%) from 2014 maximum of 14,448,416 km2 on 20 March.
2,497,406 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).
Down 38,297 km2 from previous day.
Down 432,539 km2 over past seven days (daily average: -61,791 km2).
Down 1,088,268 km2 for the month of August (daily average: -60,459 km2).
502,002 km2 below 2000s average for this date.
408,306 km2 above 2010s average for this date.
75,255 km2 above 2013 value for this date.
1,368,653 km2 above 2012 value for this date.
Sixth lowest August to-date average.
Seventh lowest value for the date.
11 days this year (4.78% year-to-date) have recorded the lowest daily extent.
14 days (6.09%) have recorded the second lowest.
56 days (24.35%) have recorded the third lowest.
81 days (35.22%) in total have been among the three lowest on record.


CT Area:
4,531,841 km2 (18 August [Day 0.6274])
Down 8,955,496 km2 (66.4%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].
2,297,832 km2 above record minimum area of 2,234,010 km2 (14 September 2012).
Down 18,808 km2 from previous day.
Down 25,337 km2 over past seven days (daily average: -3,620 km2).
Down 612,055 km2 for the month of August (daily average: -34,003 km2).
172,510 km2 above 2000s average for this date.
772,766 km2 above 2010s average for this date.
429,705 km2 above 2013 value for this date.
1,611,907 km2 above 2012 value for this date.
Eighth lowest August to-date average.
11th lowest value for the date.
12 days this year (5.22% year-to-date) have recorded the lowest daily area.
21 days (9.13%) have recorded the second lowest.
17 days (7.39%) have recorded the third lowest.
50 days in total (21.74%) have been among the lowest three on record.
« Last Edit: August 19, 2014, 02:42:07 PM by Jim Pettit »

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #901 on: August 19, 2014, 04:35:47 PM »
From area calculated from NSIDC sea ice concentration I expect a CT-area decline next Thursday of about -80k.

Its not just the CAB (-38k) but also ESS (-20k) and Beaufort (-15k). Even the lakes are joining in (-15k)!

Same regions drop in extent, and Chukchi chimes in.

All the details:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data
Date: 2014-08-18 12:00  Values in 1000 km^2  Anomalies are from the 1981-2010 mean values

Extent (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  4089.6  -31.4  -258.5    411.1  -20.5  -138.8     10.2   -0.6  -325.4
               Kara Sea             Barents Sea           Greenland Sea
   181.8   +0.7  -128.5    128.6   +2.0   +68.2    182.4  +13.0   -83.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    30.1  -13.6   -61.2      0.0   +0.0    +0.0     76.9  +20.7   -21.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   561.8   -1.5   +70.6    188.6  -20.2  -118.5     30.6  -20.4  -148.3
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0    151.5  -51.5   +17.1
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   5891.7  -71.8 -1144.8

Area (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  3528.2  -38.1   -60.5    203.5  -19.8  -131.9      4.9   -0.4  -196.6
               Kara Sea             Barents Sea           Greenland Sea
    73.9   -0.1  -101.4     63.5   +2.8   +39.3     82.1   +3.6   -39.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    12.7   -3.0   -26.6      0.0   +0.0    +0.0     23.3   +5.9   -10.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   349.6   +4.8   +68.7    105.0  -14.9   -61.5     11.1   -4.8   -78.5
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0     83.8  -14.8   +24.3
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   4457.8  -63.9  -599.1

crandles

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Re: 2014 sea ice area and extent data
« Reply #902 on: August 19, 2014, 05:02:35 PM »
CT area with Wipneus' updates:
4.532 - 0.039 -0.080 = 4.413

If this year has insufficient decline to get below 4.41 then this year would be 17th lowest year for minimum area.

compared with same day of year:
2012.6329  -2.2564530   2.8442657
2007.6329  -2.0392168   3.0732198
2011.6329  -1.8430079   3.2694285
2008.6329  -1.4953854   3.6053333
2010.6329  -1.3918799   3.7205565
2009.6329  -1.2628456   3.8495908
2013.6329  -1.1874338   3.9250026
2005.6329  -0.9120404   4.2003961
2002.6329  -0.8052908   4.3071456
2014
2006.6329  -0.6443139   4.4681225

To 10th lowest for day from 11th lowest.
Down to 1569k above 2012.

Losses from day .6329 to minimum and where we end if losses from now on are the same
2005   0.109   4.304
2006   0.438   3.975
2007   0.154   4.259
2008   0.602   3.811
2009   0.425   3.988
2010   0.648   3.765
2011   0.365   4.048
2012   0.610   3.803
2013   0.371   4.042
      
07+Average___   0.454   3.959 (8th lowest)
07+Average+3sd   0.987   3.426 (7th lowest)
07+Average+2sd   0.809   3.604 (8th lowest)
07+Average+sd_   0.631   3.782 (8th lowest)
07+Average-sd_   0.276   4.137 (11th lowest)
07+Average-2sd   0.098   4.315 (16th lowest)
07+Average-3sd   -0.080   4.493(19th lowest, but already had 4.413 for 17th lowest)
      
Further CT losses for 2007 onwards range is down to 0.15 to 0.65. Typical reductions like years 2007 onwards using 1sd range results in 8th to 11th lowest area, using 2sd range leads to 8th to 16th lowest area, and using 3sd deviation range leads to 7th to 17th lowest area.

greatdying2

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Re: 2014 sea ice area and extent data
« Reply #903 on: August 19, 2014, 05:37:12 PM »
What’s up with Hudson Bay?

Today:

Extent (value, one day change, anomaly):
Hudson Bay
76.9  +20.7   -21.1

And previously, for example:

I refuse to say anything sensible about the Hudson Bay region (-35k).

CAA is having similar issues in Home brew AMRS2:

Update 20140818.

Extent:
   Canadian Archipelago           
                   11.9                 
Area:
   Canadian Archipelago
                   21.0

Neither of these seem to reflect changes in the ice. I’ve been watching the CAA, which appears to continue a steady and even accelerating decline. Am I missing something?
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.

Lord M Vader

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Re: 2014 sea ice area and extent data
« Reply #904 on: August 19, 2014, 05:51:02 PM »
The CAA should take a huge damage right now as a small but powerful cyclone have entered the area.. The cyclone should remain in this area for about 24 hours before dissipating. We have seen on the Bremen and Wipneus maps that the ice there have shown signs to decent melting. This cyclone may smash the ice and eventually help the Northwest Passage to become ice free before refreezing starts..

Greatdying: I suspect this cyclone to be the reason for the change in Hudson Bay by dispersing the remaining ice there.. Should be zero ice in Hudson Bay before the end of the week...


greatdying2

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Re: 2014 sea ice area and extent data
« Reply #905 on: August 19, 2014, 06:17:23 PM »
The CAA should take a huge damage right now as a small but powerful cyclone have entered the area.. The cyclone should remain in this area for about 24 hours before dissipating. We have seen on the Bremen and Wipneus maps that the ice there have shown signs to decent melting. This cyclone may smash the ice and eventually help the Northwest Passage to become ice free before refreezing starts..

Greatdying: I suspect this cyclone to be the reason for the change in Hudson Bay by dispersing the remaining ice there.. Should be zero ice in Hudson Bay before the end of the week...
Yeah, good point, the cyclone might explain it.

I have been watching (Worldview) the CAA daily for several weeks, and fragmentation, southward transport, and melting are all increasing. If forecasts are correct, there should be relatively cloud-free views later in the week to visually assess the damage currently taking place.
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: 2014 sea ice area and extent data
« Reply #906 on: August 19, 2014, 06:57:37 PM »

CAA is having similar issues in Home brew AMRS2:

Update 20140818.

Extent:
   Canadian Archipelago           
                   11.9                 
Area:
   Canadian Archipelago
                   21.0

Neither of these seem to reflect changes in the ice. I’ve been watching the CAA, which appears to continue a steady and even accelerating decline. Am I missing something?

Maybe it helps (understanding) when I show the images. The influence of the cyclone is clearly visible with lots of (presumably) false ice. I do manage to filter a lot away in the "home brew calculation", but not with the NSIDC numbers that I reproduce as good as possible. That saves me an uptick in Baffin at least.


greatdying2

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Re: 2014 sea ice area and extent data
« Reply #907 on: August 20, 2014, 12:59:48 AM »
Maybe it helps (understanding) when I show the images. The influence of the cyclone is clearly visible with lots of (presumably) false ice. I do manage to filter a lot away in the "home brew calculation", but not with the NSIDC numbers that I reproduce as good as possible. That saves me an uptick in Baffin at least.
Absolutely, your images are terrific! Thanks also for explaining that nuance between your home brew and NSIDC calculations; makes sense.

It will be interesting to see how far the CAA (extent) falls this year, and how late it hits minimum. Very late, I would guess.
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: 2014 sea ice area and extent data
« Reply #908 on: August 20, 2014, 05:28:03 AM »
There's been so much talk of the weather in the melt season thread I thought I put this here. Last year Werther and I estimated independently the amount of 'mesh ice' on at least couple of occasions. Here's a contrast enhanced image of yesterdays' Modis (resolution 1km/px), color-overlay is my interpretation of the 'almost solid ice' aka 'mesh pattern' currently present. Estimated area is ~1,3Mkm2.

DavidR

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Re: 2014 sea ice area and extent data
« Reply #909 on: August 20, 2014, 10:34:32 AM »
The CAA should take a huge damage right now as a small but powerful cyclone have entered the area.. The cyclone should remain in this area for about 24 hours before dissipating. We have seen on the Bremen and Wipneus maps that the ice there have shown signs to decent melting. This cyclone may smash the ice and eventually help the Northwest Passage to become ice free before refreezing starts..

Greatdying: I suspect this cyclone to be the reason for the change in Hudson Bay by dispersing the remaining ice there.. Should be zero ice in Hudson Bay before the end of the week...

Yeah, good point, the cyclone might explain it.
A slightly smaller cyclone went through the Greenland Sea on August 12th.

The day before it went  through the area was populated with largish ice floes (up to ~20 k across) afterwards nothing but mush for 300 k in any  direction. Quite an amazing transformation.  Compare the Aug 9th and 16th images for a comparison.

https://earthdata.nasa.gov/labs/worldview/?switch=arctic&products=baselayers,!MODIS_Aqua_CorrectedReflectance_TrueColor,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_graticule_3413,arctic_coastlines_3413&time=2014-08-12&map=-7864320,-3764224,7864320,3764224

You'll have to look hard to  see it, its about  76N, 10W. Drill down to  the 50km level.

According to Wipneus, the extent in the Greenland sea shoots up about by 40K sq, approx 20%,  in the following three days, and then goes back into  a steady decline. 
« Last Edit: August 20, 2014, 11:40:10 AM by DavidR »
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Jim Pettit

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Re: 2014 sea ice area and extent data
« Reply #910 on: August 20, 2014, 12:44:59 PM »
IJIS Extent:
5,614,708 km2 (19 August)
Down 8,833,708 km2 (61.14%) from 2014 maximum of 14,448,416 km2 on 20 March.
2,437,253 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).
Down 60,153 km2 from previous day.
Down 433,728 km2 over past seven days (daily average: -61,961 km2).
Down 1,148,421 km2 for the month of August (daily average: -60,443 km2).
509,224 km2 below 2000s average for this date.
405,152 km2 above 2010s average for this date.
70,894 km2 above 2013 value for this date.
1,388,761 km2 above 2012 value for this date.
Sixth lowest August to-date average.
Seventh lowest value for the date.
11 days this year (4.76% year-to-date) have recorded the lowest daily extent.
14 days (6.06%) have recorded the second lowest.
56 days (24.24%) have recorded the third lowest.
81 days (35.06%) in total have been among the three lowest on record.


CT Area:
4,495,750 km2 (19 August [Day 0.6301])
Down 8,991,588 km2 (66.67%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].
2,261,740 km2 above record minimum area of 2,234,010 km2 (14 September 2012).
Down 36,092 km2 from previous day.
Down 82,228 km2 over past seven days (daily average: -11,747 km2).
Down 648,147 km2 for the month of August (daily average: -34,113 km2).
172,760 km2 above 2000s average for this date.
797,543 km2 above 2010s average for this date.
512,781 km2 above 2013 value for this date.
1,618,291 km2 above 2012 value for this date.
Eighth lowest August to-date average.
11th lowest value for the date.
12 days this year (5.19% year-to-date) have recorded the lowest daily area.
21 days (9.09%) have recorded the second lowest.
17 days (7.36%) have recorded the third lowest.
50 days in total (21.65%) have been among the lowest three on record.

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #911 on: August 20, 2014, 04:27:01 PM »
From area calculated from NSIDC sea ice concentration I expect a CT-area decline next Friday of about -95k.

That is mostly caused to the CAB (-64k), ESS (-27k) and CAA (-20k).

Extent changes are rather small except a big uptick in the Greenland Sea (+27k) and a smaller drop in the CAB (-15k).

All the details:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data
Date: 2014-08-19 12:00  Values in 1000 km^2  Anomalies are from the 1981-2010 mean values

Extent (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  4075.1  -14.5  -268.2    400.8  -10.2  -141.0     13.4   +3.2  -317.0
               Kara Sea             Barents Sea           Greenland Sea
   190.9   +9.1  -112.7    132.8   +4.2   +73.5    209.6  +27.2   -52.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    30.3   +0.2   -57.6      0.0   +0.0    +0.0     69.6   -7.3   -23.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   563.1   +1.3   +79.2    186.0   -2.5  -118.8     30.0   -0.7  -146.8
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0    141.1  -10.4    +6.3
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   5901.7  +10.0 -1086.4

Area (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  3464.6  -63.6  -124.3    176.9  -26.6  -154.5      5.8   +0.9  -193.1
               Kara Sea             Barents Sea           Greenland Sea
    78.6   +4.7   -92.7     62.6   -0.9   +38.8     89.4   +7.3   -30.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    12.5   -0.2   -25.5      0.0   +0.0    +0.0     21.0   -2.2   -11.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   329.7  -19.9   +52.3    107.2   +2.2   -58.6      9.6   -1.4   -79.0
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0     86.2   +2.4   +26.6
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   4358.1  -99.7  -678.6
« Last Edit: August 20, 2014, 04:39:52 PM by Wipneus »

crandles

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Re: 2014 sea ice area and extent data
« Reply #912 on: August 20, 2014, 04:40:25 PM »
CT area with Wipneus' updates:
4.496 - 0.080 - 0.095 = 4.321

If this year has insufficient decline to get below 4.283 then this year would be 16th lowest year for minimum area.

compared with same day of year:
2012.6356  -2.3522015   2.7419870
2007.6356  -2.0302463   3.0704725
2011.6356  -1.8732083   3.2275105
2008.6356  -1.5148966   3.5792918
2010.6356  -1.3520687   3.7486501
2009.6356  -1.2113898   3.8893290
2013.6356  -1.1923628   3.9083560
2005.6356  -0.8409869   4.2597318
2002.6356  -0.8037216   4.2969971
2014
2006.6356  -0.6651670   4.4355516

Remains 10th lowest for day.
Up to 1579k above 2012.

Losses from day .6356 to minimum and where we end if losses from now on are the same
2005   0.168   4.153
2006   0.406   3.915
2007   0.151   4.170
2008   0.576   3.745
2009   0.465   3.856
2010   0.677   3.644
2011   0.323   3.998
2012   0.508   3.813
2013   0.354   3.967
      
07+Average___   0.436   3.885 (8th lowest)
07+Average+3sd   0.962   3.359 (6th lowest)
07+Average+2sd   0.787   3.534 (7th lowest)
07+Average+sd_   0.612   3.709 (8th lowest)
07+Average-sd_   0.261   4.060 (9th lowest)
07+Average-2sd   0.086   4.235 (14th lowest)
07+Average-3sd   -0.090   4.411 (17th lowest, but projecting 4.321 for 16th lowest)
      
Further CT losses for 2007 onwards range is down to 0.15 to 0.7. Typical reductions like years 2007 onwards using 1sd range results in 8th to 9th lowest area, using 2sd range leads to 7th to 14th lowest area, and using 3sd deviation range leads to 6th to 16th lowest area.

greatdying2

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Re: 2014 sea ice area and extent data
« Reply #913 on: August 20, 2014, 06:12:16 PM »
A slightly smaller cyclone went through the Greenland Sea on August 12th.

The day before it went  through the area was populated with largish ice floes (up to ~20 k across) afterwards nothing but mush for 300 k in any  direction. Quite an amazing transformation.  Compare the Aug 9th and 16th images for a comparison.
Thanks. Nothing but swirls of slush now. Quite beautiful, actually.
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.

jdallen

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Re: 2014 sea ice area and extent data
« Reply #914 on: August 21, 2014, 05:58:38 AM »
From over on the blog, Wayne may have just identified a partial source of some of odd CT numbers we've seen.

http://eh2r.blogspot.ca/2014/08/40-ice-resolution-at-cryosphere-today.html

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Re: 2014 sea ice area and extent data
« Reply #915 on: August 21, 2014, 06:08:49 AM »
From over on the blog, Wayne may have just identified a partial source of some of odd CT numbers we've seen.

http://eh2r.blogspot.ca/2014/08/40-ice-resolution-at-cryosphere-today.html

This is known, the SSMIS sensors have a footprint in the order of 50km across. Very bad in the CAA, as so called land spill over will increase apparent concentration, which is only partially corrected for.

This has no consequences for the non-coastal ice and thus very little on total CT numbers. For the CAA is does have an impact, thus my threshold for reporting interesting changes there is a bit higher than most other regions.

jdallen

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Re: 2014 sea ice area and extent data
« Reply #916 on: August 21, 2014, 06:16:58 AM »
From over on the blog, Wayne may have just identified a partial source of some of odd CT numbers we've seen.

http://eh2r.blogspot.ca/2014/08/40-ice-resolution-at-cryosphere-today.html

This is known, the SSMIS sensors have a footprint in the order of 50km across. Very bad in the CAA, as so called land spill over will increase apparent concentration, which is only partially corrected for.

This has no consequences for the non-coastal ice and thus very little on total CT numbers. For the CAA is does have an impact, thus my threshold for reporting interesting changes there is a bit higher than most other regions.

Known to you, new to me ;)
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Wipneus

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Re: 2014 sea ice area and extent data
« Reply #917 on: August 21, 2014, 06:39:34 AM »
From over on the blog, Wayne may have just identified a partial source of some of odd CT numbers we've seen.

http://eh2r.blogspot.ca/2014/08/40-ice-resolution-at-cryosphere-today.html

This is known, the SSMIS sensors have a footprint in the order of 50km across. Very bad in the CAA, as so called land spill over will increase apparent concentration, which is only partially corrected for.

This has no consequences for the non-coastal ice and thus very little on total CT numbers. For the CAA is does have an impact, thus my threshold for reporting interesting changes there is a bit higher than most other regions.

Known to you, new to me ;)

OK, I'l dig up the sensor specs of the SSMIS later ( I've posted the table from a NSIDC page a few times before but can't find it in a hurry).

Better to know that the resolution is primary affecting extent: the higher the resolution the lower extent is calculated. It has little effect on area, there the details of the ice concentration algorithm are of primary importance.

Jim Pettit

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Re: 2014 sea ice area and extent data
« Reply #918 on: August 21, 2014, 12:52:46 PM »
IJIS Extent:
5,551,956 km2 (20 August)
Down 8,896,460 km2 (61.57%) from 2014 maximum of 14,448,416 km2 on 20 March.
2,374,501 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).
Down 62,752 km2 from previous day.
Down 423,789 km2 over past seven days (daily average: -60,541 km2).
Down 1,211,173 km2 for the month of August (daily average: -60,559 km2).
518,587 km2 below 2000s average for this date.
391,875 km2 above 2010s average for this date.
53,633 km2 above 2013 value for this date.
1,408,308 km2 above 2012 value for this date.
Sixth lowest August to-date average.
Seventh lowest value for the date.
11 days this year (4.74% year-to-date) have recorded the lowest daily extent.
14 days (6.03%) have recorded the second lowest.
56 days (24.14%) have recorded the third lowest.
81 days (34.91%) in total have been among the three lowest on record.


CT Area:
4,495,750 km2 (19 August [Day 0.6301])
Down 8,991,588 km2 (66.67%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].
2,261,740 km2 above record minimum area of 2,234,010 km2 (14 September 2012).
Down 36,092 km2 from previous day.
Down 82,228 km2 over past seven days (daily average: -11,747 km2).
Down 648,147 km2 for the month of August (daily average: -34,113 km2).
172,760 km2 above 2000s average for this date.
797,543 km2 above 2010s average for this date.
512,781 km2 above 2013 value for this date.
1,618,291 km2 above 2012 value for this date.
Eighth lowest August to-date average.
Tenth lowest value for the date.
12 days this year (5.17% year-to-date) have recorded the lowest daily area.
21 days (9.05%) have recorded the second lowest.
17 days (7.33%) have recorded the third lowest.
50 days in total (21.55%) have been among the lowest three on record.

CT SIA is now lower than the minimums reached from 1979-1997, and 2001.

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #919 on: August 21, 2014, 05:29:44 PM »
From area calculated from NSIDC sea ice concentration I expect a CT-area decline next Saturday of about -78k.

Mostly CAB again with -55k, small changes in other regions.

Extent changes are much smaller except in the Greenland Sea (-36k).

All the details:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data
Date: 2014-08-20 12:00  Values in 1000 km^2  Anomalies are from the 1981-2010 mean values

Extent (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  4074.5   -0.6  -264.0    402.2   +1.4  -132.1     17.3   +3.9  -307.4
               Kara Sea             Barents Sea           Greenland Sea
   181.8   -9.1  -115.4    145.8  +13.0   +87.4    173.8  -35.8   -85.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    33.2   +2.9   -51.6      0.0   +0.0    +0.0     51.1  -18.6   -38.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   552.6  -10.5   +75.8    196.8  +10.8  -105.8     26.9   -3.1  -147.7
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0    145.0   +3.9   +10.6
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   5856.0  -45.8 -1085.1

Area (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  3409.6  -55.0  -179.0    164.5  -12.5  -163.4      6.6   +0.8  -189.1
               Kara Sea             Barents Sea           Greenland Sea
    74.0   -4.7   -93.2     66.9   +4.2   +43.3     82.0   -7.4   -36.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    11.3   -1.2   -25.7      0.0   +0.0    +0.0     15.1   -6.0   -16.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   326.7   -3.0   +52.3    114.0   +6.8   -51.4      8.5   -1.1   -79.4
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0     87.6   +1.4   +28.4
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   4279.1  -79.0  -738.2

jdallen

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Re: 2014 sea ice area and extent data
« Reply #920 on: August 21, 2014, 05:33:31 PM »
From over on the blog, Wayne may have just identified a partial source of some of odd CT numbers we've seen.

http://eh2r.blogspot.ca/2014/08/40-ice-resolution-at-cryosphere-today.html

This is known, the SSMIS sensors have a footprint in the order of 50km across. Very bad in the CAA, as so called land spill over will increase apparent concentration, which is only partially corrected for.

This has no consequences for the non-coastal ice and thus very little on total CT numbers. For the CAA is does have an impact, thus my threshold for reporting interesting changes there is a bit higher than most other regions.

Known to you, new to me ;)

OK, I'l dig up the sensor specs of the SSMIS later ( I've posted the table from a NSIDC page a few times before but can't find it in a hurry).

Better to know that the resolution is primary affecting extent: the higher the resolution the lower extent is calculated. It has little effect on area, there the details of the ice concentration algorithm are of primary importance.
Only if you cross it whilst pursuing something else.  Please don't waste your time on it.  At my level of expertise, understanding of the limitation at a qualitative level is sufficient.  I can dig if I feel it required for my need, probably more easily than you can. 

I'd rather you spent your time modeling than searching for errata for a duffer like me.
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Wipneus

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Re: 2014 sea ice area and extent data
« Reply #921 on: August 21, 2014, 05:43:31 PM »
Nevertheless this is what I meant:

Quote
Source data grid cells are nominally 25 km by 25 km, but this is not the same as the resolution of the satellite instrument sensor channels used to create source data ice concentration products. That resolution, or field of view (FOV), is an ellipsoid with a long axis that ranges from about 28 to 69 km, depending on channel frequency and instrument series. Table 5 provides the FOV for the SMMR, SSM/I, and SSMIS channels used by the NASA Team algorithm.
Table 5. FOV for SMMR, SSM/I, and SSMIS Instrument    

Frequency (GHz)    FOV (km)
SMMR
   18.0    55 x 41 (1)
   37.0    27 x 18 (1)
SSM/I
    19.35    69 x 43 (2)
   37.0    37 x 28 (2)
SSMIS
    19.35    74 x 45 (3)
   37.0    45 x 28 (3)


SSMIS is the instrument currently used.

deep octopus

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Re: 2014 sea ice area and extent data
« Reply #922 on: August 21, 2014, 05:46:30 PM »
Been out of town for a few days, so here's an overdue update on the recent data in case anyone is following the long-term trend.

One-day NSIDC extent is now below the 1990, 1993, 1995, 2000, and 2003 minima, bringing to 23 the number of years whose minima 2014 has passed: 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 2000, 2001, and 2003.

crandles

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Re: 2014 sea ice area and extent data
« Reply #923 on: August 21, 2014, 06:10:26 PM »
CT area with Wipneus' updates:
4.408 - 0.095 - 0.078 = 4.235

4.408 is lowest so far this year per CT making it 16th lowest minimum area.

If this year has insufficient decline to get below 4.204 and assuming it does get below 4.262 then this projection would be 14th lowest year for minimum area.

compared with same day of year:
2012.6383  -2.2842073   2.7927916
2007.6383  -2.0144956   3.0796928
2011.6383  -1.9141448   3.1800437
2008.6383  -1.5050614   3.5719376
2010.6383  -1.2831190   3.8110695
2013.6383  -1.2026405   3.8915479
2009.6383  -1.1602459   3.9339426
2014
2005.6383  -0.8125021   4.2816863
2002.6383  -0.7956998   4.2984886
2006.6383  -0.7061360   4.3880525

To 8th lowest for day from 10th lowest.
Down to 1442k above 2012.

Losses from day .6383 to minimum and where we end if losses from now on are the same
2005   0.190   4.045
2006   0.358   3.877
2007   0.160   4.075
2008   0.568   3.667
2009   0.509   3.726
2010   0.739   3.496
2011   0.275   3.960
2012   0.559   3.676
2013   0.337   3.898
      
07+Average___   0.450   3.785 (8th lowest)
07+Average+3sd   1.050   3.185 (6th lowest)
07+Average+2sd   0.850   3.385 (6th lowest)
07+Average+sd_   0.650   3.585 (8th lowest)
07+Average-sd_   0.249   3.986 (8th lowest)
07+Average-2sd   0.049   4.186 (1213th lowest)
07+Average-3sd   -0.151   4.386 (16th lowest, but projecting 4.235 for 14th lowest)

Further CT losses for 2007 onwards range is down to 0.15 to 0.7. Typical reductions like years 2007 onwards using 1sd range results in 8th lowest area, using 2sd range leads to 6th to 1213th lowest area, and using 3sd deviation range leads to 6th to 14th lowest area.
« Last Edit: August 22, 2014, 05:14:52 PM by crandles »

Steven

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Re: 2014 sea ice area and extent data
« Reply #924 on: August 21, 2014, 08:23:56 PM »
It looks like the date labeling system on the CT website has changed?  CT area has updated, but the image on the front page of the website is currently labeled "August 19".  That image would normally be labeled "August 20"?

This makes the label of the front page image consistent with the corresponding archive image on the CT website, see here for comparison of those 2 images.

Until recently, that was not the case.  E.g., last Friday the front page image was labeled "August 14" and the corresponding archived image was "August 13", see here for comparison of those 2 images.

epiphyte

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Re: 2014 sea ice area and extent data
« Reply #925 on: August 21, 2014, 08:45:22 PM »
Nevertheless this is what I meant:

Quote
Source data grid cells are nominally 25 km by 25 km, but this is not the same as the resolution of the satellite instrument sensor channels used to create source data ice concentration products. That resolution, or field of view (FOV), is an ellipsoid with a long axis that ranges from about 28 to 69 km, depending on channel frequency and instrument series. Table 5 provides the FOV for the SMMR, SSM/I, and SSMIS channels used by the NASA Team algorithm.
Table 5. FOV for SMMR, SSM/I, and SSMIS Instrument    

Frequency (GHz)    FOV (km)
SMMR
   18.0    55 x 41 (1)
   37.0    27 x 18 (1)
SSM/I
    19.35    69 x 43 (2)
   37.0    37 x 28 (2)
SSMIS
    19.35    74 x 45 (3)
   37.0    45 x 28 (3)


SSMIS is the instrument currently used.

I hadn't realized just how big those pixels are... Maybe we'll get some reality-checking soon from Sentinel one... Looks to my untutored eye as though its SAR IW/EW products can resolve sea-ice down as low as 10x10 meters  - even less in specially-targeted modes...
https://earth.esa.int/web/sentinel/sentinel-1-sar-wiki/-/wiki/Sentinel+One/Level+1b+Products

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #926 on: August 22, 2014, 05:52:19 AM »
NSIDC revised the data some six hours after the initial update.

Here is my revised report:

From area calculated from NSIDC sea ice concentration I expect a CT-area decline next Saturday of about -78k81k.

Mostly CAB again with -55k -38k, small changes in other regions. Lake ice -11k to the loss.

Extent changes are much smaller except in the Greenland Sea (-36k41k). Hudson? mmmm.

All the details:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data
Date: 2014-08-20 12:00  Values in 1000 km^2  Anomalies are from the 1981-2010 mean values

Extent (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  4081.0   +5.9  -257.5    398.9   -1.9  -135.4     17.2   +3.9  -307.4
               Kara Sea             Barents Sea           Greenland Sea
   179.3  -11.6  -117.9    138.1   +5.3   +79.7    168.1  -41.5   -91.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    32.5   +2.2   -52.4      0.0   +0.0    +0.0     36.7  -33.0   -53.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   547.9  -15.2   +71.1    188.6   +2.5  -114.1     30.0   -0.0  -144.6
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0    127.0  -14.2    -7.5
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   5818.2  -83.5 -1122.8

Area (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  3427.1  -37.5  -161.5    168.9   -8.0  -158.9      6.3   +0.5  -189.4
               Kara Sea             Barents Sea           Greenland Sea
    73.5   -5.1   -93.7     65.0   +2.4   +41.5     80.2   -9.2   -38.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    14.3   +1.8   -22.7      0.0   +0.0    +0.0     12.2   -8.8   -18.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   322.7   -6.9   +48.4    108.8   +1.6   -56.6      9.0   -0.7   -78.9
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0     75.1  -11.1   +15.9
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   4288.2  -69.9  -729.1

Jim Pettit

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Re: 2014 sea ice area and extent data
« Reply #927 on: August 22, 2014, 01:23:45 PM »
IJIS Extent:
5,489,997 km2 (21 August)
Down 8,958,419 km2 (62.%) from 2014 maximum of 14,448,416 km2 on 20 March.
2,312,542 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).
Down 61,959 km2 from previous day.
Down 410,159 km2 over past seven days (daily average: -58,594 km2).
Down 1,273,132 km2 for the month of August (daily average: -60,625 km2).
531,917 km2 below 2000s average for this date.
377,465 km2 above 2010s average for this date.
2,127 km2 above 2013 value for this date.
1,416,925 km2 above 2012 value for this date.
Sixth lowest August to-date average.
Sixth lowest value for the date.
11 days this year (4.72% year-to-date) have recorded the lowest daily extent.
14 days (6.01%) have recorded the second lowest.
56 days (24.03%) have recorded the third lowest.
81 days (34.76%) in total have been among the three lowest on record.


CT Area:
4,313,539 km2 (21 August [Day 0.6356])
Down 9,173,799 km2 (68.02%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].
2,079,529 km2 above record minimum area of 2,234,010 km2 (14 September 2012).
Down 94,856 km2 from previous day.
Down 248,664 km2 over past seven days (daily average: -35,523 km2).
Down 830,358 km2 for the month of August (daily average: -39,541 km2).
36,849 km2 above 2000s average for this date.
725,530 km2 above 2010s average for this date.
405,183 km2 above 2013 value for this date.
1,571,552 km2 above 2012 value for this date.
Eighth lowest August to-date average.
Tenth lowest value for the date.
12 days this year (5.15% year-to-date) have recorded the lowest daily area.
21 days (9.01%) have recorded the second lowest.
17 days (7.3%) have recorded the third lowest.
50 days in total (21.46%) have been among the lowest three on record.

deep octopus

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Re: 2014 sea ice area and extent data
« Reply #928 on: August 22, 2014, 04:16:22 PM »
One-day NSIDC extent is virtually tied with 2004's minimum, with a difference of only 130 km2. The 2006 minimum is only 27,440 km2 less than the present 2014 values, and it should not be hard for 2014 to surpass these two years soon. Dropping roughly another 69,000 km2 on top of that, 2014 will land a spot in the 10 lowest years on record.

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #929 on: August 22, 2014, 04:28:13 PM »
From area calculated from NSIDC sea ice concentration I expect a CT-area decline next Sunday of about -44k.

Which is mostly caused by the CAB at -37k.

Extent dropped most in the CAA (-28k), CAB and ESS continue declines of the last few days ( -16k and -15k)

All the details:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data
Date: 2014-08-21 12:00  Values in 1000 km^2  Anomalies are from the 1981-2010 mean values

Extent (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  4065.1  -15.8  -268.3    383.5  -15.4  -143.6     15.9   -1.3  -302.9
               Kara Sea             Barents Sea           Greenland Sea
   170.0   -9.3  -120.9    140.5   +2.3   +82.7    169.9   +1.8   -86.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    27.6   -4.8   -54.4      0.0   +0.0    +0.0     60.6  +23.9   -25.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   519.9  -28.0   +50.2    191.7   +3.2  -108.9     26.7   -3.3  -145.9
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0    131.8   +4.8    -1.9
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   5771.5  -46.8 -1123.8

Area (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  3390.4  -36.6  -198.1    170.5   +1.5  -154.1      5.1   -1.2  -187.1
               Kara Sea             Barents Sea           Greenland Sea
    70.3   -3.2   -92.7     65.6   +0.6   +42.3     81.5   +1.3   -35.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    12.5   -1.8   -23.6      0.0   +0.0    +0.0     20.0   +7.8    -9.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   308.4  -14.3   +36.6    102.2   -6.6   -63.2      7.4   -1.6   -79.9
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0     82.4   +7.2   +23.7
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   4234.0  -54.2  -765.5

crandles

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Re: 2014 sea ice area and extent data
« Reply #930 on: August 22, 2014, 05:13:01 PM »
CT area with Wipneus' updates:
4.314 - 0.081 - 0.044 = 4.189

4.314 is lowest so far this year per CT making it already 16th lowest minimum area.

If this year has insufficient decline to get below 4.171 and assuming it does get below 4.204 then this projection would be 13th lowest year for minimum area.

compared with same day of year:
2012.6411  -2.3084774   2.7505391
2007.6411  -2.0756209   3.0013781
2011.6411  -1.9161577   3.1608412
2008.6411  -1.5202284   3.5387881
2010.6411  -1.3074706   3.7695284
2013.6411  -1.2390854   3.8379135
2009.6411  -1.0698006   4.0071983
2014
2002.6411  -0.8268415   4.2501574
2006.6411  -0.7388932   4.3381057
2005.6411  -0.7368380   4.3401608

Remains 8th lowest for day.
Down to 1438k above 2012.

Losses from day .6411 to minimum and where we end if losses from now on are the same
2005   0.248   3.941
2006   0.308   3.881
2007   0.082   4.107
2008   0.535   3.654
2009   0.583   3.606
2010   0.697   3.492
2011   0.256   3.933
2012   0.517   3.672
2013   0.284   3.905

07+Average___   0.422   3.767 (8th lowest)
07+Average+3sd   1.076   3.113 (6th lowest)
07+Average+2sd   0.858   3.331 (6th lowest)
07+Average+sd_   0.640   3.549 (7th lowest)
07+Average-sd_   0.204   3.985 (8th lowest)
07+Average-2sd   -0.014   4.203 (13th lowest)
07+Average-3sd   -0.232   4.421 (17th lowest, but projecting 4.189 for 13th lowest)

Further CT losses for 2007 onwards range is down to 0.1 to 0.7. Typical reductions like years 2007 onwards using 1sd range results in 7th to 8th lowest area, using 2sd range leads to 6th to 13th lowest area, and using 3sd deviation range leads to 6th to 13th lowest area.

Lord M Vader

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Re: 2014 sea ice area and extent data
« Reply #931 on: August 22, 2014, 06:23:53 PM »
Wipneus: the uptick for Hudson Bay seems quite unrealistic. If one look at both Bremen and your google png-pics you can see an area at W Hudson Bay that must be false. the DMI SST image indicates a SST around 10C...

//LMV

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #932 on: August 23, 2014, 08:13:40 AM »
Wipneus: the uptick for Hudson Bay seems quite unrealistic. If one look at both Bremen and your google png-pics you can see an area at W Hudson Bay that must be false. the DMI SST image indicates a SST around 10C...

//LMV

Yes, that is why I normally don't comment such changes. As you noticed they do have a substantial influence on the day to day NSIDC Sea Ice Extent numbers.

Attached is an delta image shining a light on the extent increase in Hudson region.

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #933 on: August 23, 2014, 08:18:30 AM »
BTW, like yesterday NSIDC had an interim update again yesterday with substantial changes. If this is going to happen every day it is going to take a lot of fun away from pre-posting the CT numbers.

Here is the revised report.

From area calculated from NSIDC sea ice concentration I expect a CT-area decline next Sunday of about -4473k.

Which is mostly caused by the CAB at -3750k.

Extent dropped most in the CAA (-29k), CAB and ESS continue declines of the last few days ( -1619k and -1526k)

All the details:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data
Date: 2014-08-21 12:00  Values in 1000 km^2  Anomalies are from the 1981-2010 mean values

Extent (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  4061.9  -19.1  -271.6    373.3  -25.7  -153.8     12.1   -5.1  -306.8
               Kara Sea             Barents Sea           Greenland Sea
   169.4   -9.9  -121.6    140.5   +2.3   +82.7    169.9   +1.8   -86.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    23.8   -8.6   -58.2      0.0   +0.0    +0.0     60.6  +24.0   -25.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   518.6  -29.2   +48.9    188.6   -0.0  -112.0     25.4   -4.6  -147.2
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0    127.4   +0.4    -6.3
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   5744.1  -74.2 -1151.2

Area (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  3377.4  -49.7  -211.2    169.8   +0.9  -154.8      4.6   -1.7  -187.6
               Kara Sea             Barents Sea           Greenland Sea
    70.2   -3.3   -92.8     65.6   +0.6   +42.3     81.5   +1.3   -35.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    12.3   -2.0   -23.8      0.0   +0.0    +0.0     18.0   +5.8   -11.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   304.7  -18.0   +32.8     99.8   -9.1   -65.7      6.9   -2.1   -80.4
             Bering Sea          Sea of Okhotsk                   Lakes
     0.0   +0.0    +0.0      0.0   +0.0    +0.0     76.3   +1.2   +17.7
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   4210.8  -77.4  -788.7

Jim Pettit

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Re: 2014 sea ice area and extent data
« Reply #934 on: August 23, 2014, 02:23:34 PM »
IJIS Extent:
5,440,376 km2 (22 August)
Down 9,008,040 km2 (62.35%) from 2014 maximum of 14,448,416 km2 on 20 March.
2,262,921 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).
Down 49,621 km2 from previous day.
Down 391,400 km2 over past seven days (daily average: -55,914 km2).
Down 1,322,753 km2 for the month of August (daily average: -60,125 km2).
546,906 km2 below 2000s average for this date.
389,202 km2 above 2010s average for this date.
7,718 km2 below 2013 value for this date.
1,429,510 km2 above 2012 value for this date.
Sixth lowest August to-date average.
Sixth lowest value for the date.
11 days this year (4.7% year-to-date) have recorded the lowest daily extent.
14 days (5.98%) have recorded the second lowest.
56 days (23.93%) have recorded the third lowest.
81 days (34.62%) in total have been among the three lowest on record.


CT Area:
4,230,718 km2 (22 August [Day 0.6383])
Down 9,256,619 km2 (68.63%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].
1,996,708 km2 above record minimum area of 2,234,010 km2 (14 September 2012).
Down 82,821 km2 from previous day.
Down 290,112 km2 over past seven days (daily average: -41,445 km2).
Down 913,178 km2 for the month of August (daily average: -41,508 km2).
32,304 km2 below 2000s average for this date.
649,484 km2 above 2010s average for this date.
339,170 km2 above 2013 value for this date.
1,437,926 km2 above 2012 value for this date.
Eighth lowest August to-date average.
Eighth lowest value for the date.
12 days this year (5.13% year-to-date) have recorded the lowest daily area.
21 days (8.97%) have recorded the second lowest.
17 days (7.26%) have recorded the third lowest.
50 days in total (21.37%) have been among the lowest three on record.

CT SIA has dropped as much over the past three days as it did over the previous 16.
This year's SIA minimum is already lower than the minima recorded from 1979-1998, 2001, and 2004. If the melt season stopped today, 2014 would be in 14th place.
« Last Edit: August 23, 2014, 03:29:04 PM by Jim Pettit »

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #935 on: August 23, 2014, 05:09:17 PM »
From area calculated from NSIDC sea ice concentration I expect a CT-area decline next Monday of about -60k.

The CAB alone is bigger than that: -78k. Other regions have small changes, mostly upticks of course.

In area  the Greenland Sea has a big increase of +26k. ESS and CAB go down (-26k and -11k) and Kara increases (+15k)

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data
Date: 2014-08-22 12:00  Values in 1000 km^2  Anomalies are from the 1981-2010 mean values

Extent (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  4050.6  -11.2  -277.8    347.8  -25.5  -172.2      9.6   -2.5  -303.5
               Kara Sea             Barents Sea           Greenland Sea
   184.6  +15.2  -100.4    142.1   +1.7   +85.3    196.3  +26.3   -56.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    33.2   +9.3   -46.3      0.0   +0.0    +0.0     60.4   -0.2   -22.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   535.3  +16.6   +71.8    194.3   +5.7  -104.1     24.1   -1.3  -146.2
             Bering Sea          Sea of Okhotsk                   Lakes
     0.6   +0.6    +0.6      0.0   +0.0    +0.0    122.8   -4.5   -10.5
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   5778.7  +34.6 -1071.9

Area (value, one day change, anomaly):
           Arctic Basin       East Siberian Sea              Laptev Sea
  3299.3  -78.1  -285.2    161.5   -8.4  -159.6      5.1   +0.5  -183.6
               Kara Sea             Barents Sea           Greenland Sea
    73.5   +3.3   -85.7     67.3   +1.7   +44.3     86.5   +4.9   -29.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
    13.0   +0.7   -22.2      0.0   +0.0    +0.0     18.1   +0.1   -10.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   313.0   +8.3   +43.5    106.5   +6.7   -58.8      6.1   -0.8   -80.4
             Bering Sea          Sea of Okhotsk                   Lakes
     0.1   +0.1    +0.1      0.0   +0.0    +0.0     73.2   -3.2   +14.9
          Other regions       Total (ex. lakes)
     0.0   +0.0    +0.0   4150.0  -60.8  -827.7

viddaloo

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Re: 2014 sea ice area and extent data
« Reply #936 on: August 23, 2014, 05:37:35 PM »
Newbie question: I noticed the NSIDC extent was *up* Friday and also Tuesday of this week ( that would be the first increases in ice extent since July 31th).

What's the reason NSIDC is up, while IJIS Extent is generally down?
[]

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #937 on: August 23, 2014, 06:25:36 PM »
NSIDC and Jaxa/IJIS are different all over, different satellite/instrument, different frequency bands, different calculation, different resolution.

That leads to NSIDC giving different average results but also more day-to-day noise. You could say Jaxa/IJIS is the higher quality product, but NSIDC has the broadest range 1978-present. That is sometimes all that matters.

viddaloo

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Re: 2014 sea ice area and extent data
« Reply #938 on: August 23, 2014, 06:39:26 PM »
OK, thanks, Wipneus! For my use I only need data for the past month (until PIOMAS data arrive). Would you suggest IJIS as a better indicator of probable volume loss than NSIDC? I would at least guess — and 2012 PIOMAS data seem to suggest that 100% — volume data are less noisy (showing a steady decrease in the melting season and increase in the freezing season) than both area and extent.
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Wipneus

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Re: 2014 sea ice area and extent data
« Reply #939 on: August 23, 2014, 06:46:07 PM »
OK, thanks, Wipneus! For my use I only need data for the past month (until PIOMAS data arrive). Would you suggest IJIS as a better indicator of probable volume loss than NSIDC? I would at least guess — and 2012 PIOMAS data seem to suggest that 100% — volume data are less noisy (showing a steady decrease in the melting season and increase in the freezing season) than both area and extent.

PIOMAS seems to use (assimilation) NSIDC sea ice concentration. I would certainly try that first.

Steven

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Re: 2014 sea ice area and extent data
« Reply #940 on: August 23, 2014, 07:29:39 PM »
CT area with Wipneus' estimates for Sunday's and Monday's update.  Currently 8th lowest.  CT area is approaching the threshold of 4 million km2, and the 2014 minimum seems on track to end up somewhere between 3.5 and 4 million km2.


Jim Pettit

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Re: 2014 sea ice area and extent data
« Reply #941 on: August 24, 2014, 02:04:12 PM »
IJIS Extent:
5,392,741 km2 (23 August)
Down 9,055,675 km2 (62.68%) from 2014 maximum of 14,448,416 km2 on 20 March.
2,215,286 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).
Down 47,635 km2 from previous day.
Down 360,427 km2 over past seven days (daily average: -51,490 km2).
Down 1,370,388 km2 for the month of August (daily average: -59,582 km2).
553,421 km2 below 2000s average for this date.
393,759 km2 above 2010s average for this date.
40,557 km2 below 2013 value for this date.
1,475,732 km2 above 2012 value for this date.
Sixth lowest August to-date average.
Sixth lowest value for the date.
11 days this year (4.68% year-to-date) have recorded the lowest daily extent.
14 days (5.96%) have recorded the second lowest.
56 days (23.83%) have recorded the third lowest.
81 days (34.47%) in total have been among the three lowest on record.


CT Area:
4,156,076 km2 (23 August [Day 0.6411])
Down 9,331,261 km2 (69.19%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].
1,922,067 km2 above record minimum area of 2,234,010 km2 (14 September 2012).
Down 74,641 km2 from previous day.
Down 415,404 km2 over past seven days (daily average: -59,343 km2).
Down 987,820 km2 for the month of August (daily average: -42,949 km2).
95,755 km2 below 2000s average for this date.
621,097 km2 above 2010s average for this date.
318,163 km2 above 2013 value for this date.
1,405,537 km2 above 2012 value for this date.
Eighth lowest August to-date average.
Eighth lowest value for the date.
12 days this year (5.11% year-to-date) have recorded the lowest daily area.
21 days (8.94%) have recorded the second lowest.
17 days (7.23%) have recorded the third lowest.
50 days in total (21.28%) have been among the lowest three on record.

CT SIA is now below minima recorded in 2004, plus every year prior to and including 2001.
« Last Edit: August 24, 2014, 02:39:17 PM by Jim Pettit »

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #942 on: August 24, 2014, 04:32:26 PM »
NSIDC have modified yesterday's data again in a major way. As long as this stays this way I don't see much use in the daily regional data.
I will see what I can do, perhaps reporting yesterday's data only, perhaps NSIDC will behave as they did for a long time.
For now I give you the CT-area for the next two days and see how often I have to report that the next day's value was changed.

Mon: -93k (was -60k)
Tue:  -46k

crandles

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Re: 2014 sea ice area and extent data
« Reply #943 on: August 24, 2014, 05:36:33 PM »
CT area with Wipneus' updates:
4.156 - 0.093 - 0.046 = 4.017

4.156 is lowest so far this year per CT making it already 12th lowest minimum area.

If this year has insufficient decline to get below 3.554 and assuming it does get below 4.03 then this projection would be 8th lowest year for minimum area.

compared with same day of year:
2012.6466  -2.2717855   2.7270751
2011.6466  -2.0503592   2.9878161
2007.6466  -1.9108371   3.1273384
2008.6466  -1.6200589   3.3788018
2010.6466  -1.4198390   3.6183364
2009.6466  -1.2972544   3.7409210
2013.6466  -1.1248199   3.9133556
2014
2006.6466  -0.7480453   4.2901301
2002.6466  -0.7109197   4.3272557
2005.6466  -0.6613668   4.3768086

Remains 8th lowest for day.
Down to 1290k above 2012.

Losses from day .6466 to minimum and where we end if losses from now on are the same
2005   0.285   3.732 (8th lowest)
2006   0.260   3.757 (8th lowest)
2007   0.208   3.809 (8th lowest)
2008   0.375   3.642 (8th lowest)
2009   0.316   3.701 (8th lowest)
2010   0.546   3.471 (7th lowest)
2011   0.083   3.934 (8th lowest)
2012   0.493   3.524 (7th lowest)
2013   0.359   3.658 (8th lowest)
      
07+Average___   0.340   3.677 (8th lowest)
07+Average+3sd   0.817   3.200 (6th lowest)
07+Average+2sd   0.658   3.359 (6th lowest)
07+Average+sd_   0.499   3.518 (7th lowest)
07+Average-sd_   0.181   3.836 (8th lowest)
07+Average-2sd   0.022   3.995 (8th lowest)
07+Average-3sd   -0.137   4.154 (12th lowest, but projecting 4.017 for 8th lowest)

Further CT losses for 2007 onwards range is down to 0.1 to 0.55. Typical reductions like years 2007 onwards using 1sd range results in 7th to 8th lowest area, using 2sd range leads to 6th to 8th lowest area, and using 3sd deviation range leads to 6th to 8th lowest area.

BornFromTheVoid

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Re: 2014 sea ice area and extent data
« Reply #944 on: August 24, 2014, 08:20:58 PM »
Update for the week to August 23rd

The current 5 day mean is on 5,809,840km2 while the 1 day extent is at 5,792,660km2.

The daily anomaly (compared to 81-10) is at -1,076,060km2, an increase from -1,052,020km2 last week. The anomaly compared to the 07, 11 and 12 average is at 1,041,190km2, a change from +947,290km2. We're currently 8th lowest on record, down from 7th last week.

The average daily change over the last 7 days was -53.4k/day, compared to the long term average of -50.0k/day, and the 07, 11 and 12 average of -66.8k/day.
The average long term change over the next week is -40.9k/day, with the 07, 11, and 12 average being -50.4k/day.

The loss in the first 23 days of August have been the 15th smallest on record. To achieve the largest August loss on record, a drop of 173.6k/day is required, while an average loss requires -49.7k/day and the smallest loss needs an increase of 17.0k/day.



I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

greatdying2

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Re: 2014 sea ice area and extent data
« Reply #945 on: August 25, 2014, 06:52:53 AM »
Jaxa down to 5th lowest:

Year     Extent    Delta
2012    3819352   
2007    4666029   846677
2011    4834007   167978
2008    5247855   413848
2014    5338658   90803
2010    5347015   8357
2013    5405161   58146
2009    5510409   105248
2005    5738632   228223
2006    5890782   152150
2002    6011288   120506
2004    6027763   16475
2003    6374728   346965
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.

Jim Pettit

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Re: 2014 sea ice area and extent data
« Reply #946 on: August 25, 2014, 01:41:43 PM »
IJIS Extent:
5,338,658 km2 (24 August)
Down 9,109,758 km2 (63.05%) from 2014 maximum of 14,448,416 km2 on 20 March.
2,161,203 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).
Down 54,083 km2 from previous day.
Down 374,500 km2 over past seven days (daily average: -53,500 km2).
Down 1,424,471 km2 for the month of August (daily average: -59,353 km2).
567,242 km2 below 2000s average for this date.
389,819 km2 above 2010s average for this date.
66,503 km2 below 2013 value for this date.
1,519,306 km2 above 2012 value for this date.
Sixth lowest August to-date average.
Fifth lowest value for the date.
11 days this year (4.66% year-to-date) have recorded the lowest daily extent.
14 days (5.93%) have recorded the second lowest.
56 days (23.73%) have recorded the third lowest.
81 days (34.32%) in total have been among the three lowest on record.


CT Area:
4,156,076 km2 (23 August [Day 0.6411])
Down 9,331,261 km2 (69.19%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].
1,922,067 km2 above record minimum area of 2,234,010 km2 (14 September 2012).
Down 74,641 km2 from previous day.
Down 415,404 km2 over past seven days (daily average: -59,343 km2).
Down 987,820 km2 for the month of August (daily average: -42,949 km2).
95,755 km2 below 2000s average for this date.
621,097 km2 above 2010s average for this date.
318,163 km2 above 2013 value for this date.
1,405,537 km2 above 2012 value for this date.
Eighth lowest August to-date average.
Eighth lowest value for the date.
12 days this year (5.08% year-to-date) have recorded the lowest daily area.
21 days (8.9%) have recorded the second lowest.
17 days (7.2%) have recorded the third lowest.
50 days in total (21.19%) have been among the lowest three on record.

CT SIA is now lower than all minima recorded for any year prior to 2006 with the lone exception of 2002.
If the melt season ended today, 2014 would finish in 10th place. At this stage, an 8th place finish is by far the most likely, though given the right conditions 7th place is slightly possible. A finish in 6th place or lower is all but impossible.

deep octopus

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Re: 2014 sea ice area and extent data
« Reply #947 on: August 25, 2014, 04:00:37 PM »
One-day NSIDC extent is now below the 1999, 2004, and 2006 minima, bringing to 26 the number of years whose minima 2014 has passed: 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, and 2006.

2014 has now clinched a spot in the ten lowest years on record. It is in good position to slide below 2002 (which has a delta of about 11,000 km2) rather soon.

Wipneus

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Re: 2014 sea ice area and extent data
« Reply #948 on: August 25, 2014, 04:44:42 PM »
From area calculated from NSIDC sea ice concentration I expect the following changes of  CT-area:

Tue:  -46k (same as yesterday)
Wed: -76k

Quite a spectacular extent drop of -157k. The attached delta map shows that at least part is due to disappearing false ice.

crandles

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Re: 2014 sea ice area and extent data
« Reply #949 on: August 25, 2014, 05:11:48 PM »
CT area with Wipneus' updates:
4.068 - 0.046 - 0.076 = 3.946

4.068 is lowest so far this year per CT making it already 10th lowest minimum area.

If this year has insufficient decline to get below 3.554 and assuming it does get below 4.03 then this projection would be 8th lowest year for minimum area.

compared with same day of year:
2012.6493  -2.3315191   2.6431620
2011.6493  -2.0152636   2.9835970
2007.6493  -1.9684652   3.0303955
2008.6493  -1.7360137   3.2386675
2010.6493  -1.3553942   3.6434665
2009.6493  -1.2665972   3.7322636
2013.6493  -1.1420041   3.8568566
2014_______________3.946
2006.6493  -0.7043117   4.2945490
2002.6493  -0.6971157   4.3017449
2005.6493  -0.6890767   4.3097839

Remains 8th lowest for day.
Up to 1303k above 2012.

Losses from day .6493 to minimum and where we end if losses from now on are the same
2005   0.218   3.728 (8th lowest)
2006   0.265   3.681 (8th lowest)
2007   0.111   3.835 (8th lowest)
2008   0.235   3.711 (8th lowest)
2009   0.308   3.638 (8th lowest)
2010   0.571   3.375 (6th lowest)
2011   0.079   3.867 (8th lowest)
2012   0.409   3.537 (7th lowest)
2013   0.302   3.644 (8th lowest)
      
07+Average___   0.288   3.658 (8th lowest)
07+Average+3sd   0.797   3.149 (6th lowest)
07+Average+2sd   0.628   3.318 (6th lowest)
07+Average+sd_   0.458   3.488 (7th lowest)
07+Average-sd_   0.118   3.828 (8th lowest)
07+Average-2sd   -0.052   3.998 (projected 3.946 8th lowest)
07+Average-3sd   -0.222   4.168 (projected 3.946 8th lowest)

Further CT losses for 2007 onwards range is down to 0.08 to 0.57. Typical reductions like years 2007 onwards using 1sd range results in 7th to 8th lowest area, using 2sd range leads to 6th to 8th lowest area, and using 3sd deviation range leads to 6th to 8th lowest area.