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Author Topic: 2016 sea ice area and extent data  (Read 364538 times)

Tor Bejnar

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Re: 2016 sea ice area and extent data
« Reply #200 on: May 07, 2016, 04:43:26 PM »
Down 1,956,149 km2 (14.03%) from 2016 maximum of 13,942,507 km2 on 29 February.
(emphases added)

I'm curious how this relates to other years.  2016 started from a lower place than other years, so if decline matched another year (with a similar start date, at least), 2016's extent would stay below it.  But 1980 (as a random selection) started its melt season with a lot more ice, and I don't have much clue as to which year lost more ice between max and today.  I believe someone else was asking about percent decline, perhaps a more meaningful guage.
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DavidR

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Re: 2016 sea ice area and extent data
« Reply #201 on: May 07, 2016, 05:11:43 PM »
Down 1,956,149 km2 (14.03%) from 2016 maximum of 13,942,507 km2 on 29 February.
(emphases added)

I'm curious how this relates to other years.  2016 started from a lower place than other years, so if decline matched another year (with a similar start date, at least), 2016's extent would stay below it.  But 1980 (as a random selection) started its melt season with a lot more ice, and I don't have much clue as to which year lost more ice between max and today.  I believe someone else was asking about percent decline, perhaps a more meaningful guage.
Based on the IJIS record since 2003, this is the third biggest decline in the record. The two declines that were bigger, 2003 and 2004 had more than 750,000 km^2 more ice at the maximum.  They declined  300 - 400K km^2 more.

Another way to look at it is that, based on todays figures, extent will need to decline from now, by the smallest amount since 2006  for it not to be the lowest or second lowest minimum on record.
« Last Edit: May 08, 2016, 06:41:44 AM by DavidR »

anotheramethyst

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Re: 2016 sea ice area and extent data
« Reply #202 on: May 08, 2016, 07:56:57 AM »
We've had a lot of days in a row that were the lowest on record.  What's the most consecutive "lowest IJIS extent on record" days?  How many days with it take to beat that record?

jdallen

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Re: 2016 sea ice area and extent data
« Reply #203 on: May 08, 2016, 08:02:20 AM »
We've had a lot of days in a row that were the lowest on record.  What's the most consecutive "lowest IJIS extent on record" days?  How many days with it take to beat that record?
We're looking at it right now.  We beat it every day. 2012 might be an exception, but I don't have the data in front of me.  That would have been on the front end rather than back end - after we'd passed other years heading towards the minimum.  Even then, I doubt it made 90+ days worth.
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DavidR

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Re: 2016 sea ice area and extent data
« Reply #204 on: May 08, 2016, 09:12:45 AM »
We've had a lot of days in a row that were the lowest on record.  What's the most consecutive "lowest IJIS extent on record" days?  How many days with it take to beat that record?
We're looking at it right now.  We beat it every day. 2012 might be an exception, but I don't have the data in front of me.  That would have been on the front end rather than back end - after we'd passed other years heading towards the minimum.  Even then, I doubt it made 90+ days worth.
In the period leading up to 2007 long record runs were commonplace in IJIS because of the very short record. 2007 had 132 continuous record breaking days from Jul 3rd.

Since 2007 the longest record breaking run was 2012's 83 days from July 25th.  2010 had 40 record breaking days from May 31st.  2015 had 31 days from May 11th and 2011 had 30 days from Dec 18th  2010.

2016 currently has 39 consecutive record days and little prospect of losing the record in the next three weeks. We are currently  255 K km^2 below the previous record and the record declines very slowly over the next week compared to the average decline in that  period until 2015 takes over from 2006 as the record holder on May 11th.

To break the 2012 run, 2016 would have to retain the record until June 21 when the record is held by 2010 with 9,727,850. This would need a loss of 2,184,729 Km^2 between now and then.  Since 2007 only 2013 has lost less than that over that  period and both 2010 and 2012 lost more than 3,000,000 km^2.


anotheramethyst

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Re: 2016 sea ice area and extent data
« Reply #205 on: May 08, 2016, 08:13:02 PM »
Thanks!  That's so fascinating.  I never thought about how the early years of the satellite would have a bias.  Haha I guess JAXA's first year, 365 days were lowest (and highest) on JAXA's record. Haha :)

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Re: 2016 sea ice area and extent data
« Reply #206 on: May 11, 2016, 02:11:18 PM »
ADS-NIPR Extent:
11,633,343 km2 (10 May)
Down 2,309,164 km2 (16.56%) from 2016 maximum of 13,942,507 km2 on 29 February.
8,455,888 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).
Down 49,817 km2 (-.43%) from previous day.
Down 511,104 km2  (-4.21%) over past seven days (daily average: -73,015 km2).
Down 660,104 km2  (-5.4%) for May (daily average: -66,010 km2).
1,022,807 km2 below 2000s average for this date.
687,388 km2 below 2010s average for this date.
479,473 km2 below 2015 value for this date.
1,039,956 km2 below 2012 value for this date.
Lowest year-to-date (01 January - 10 May) average.
Lowest May to-date average.
Lowest value for the date.
76 days this year (58.46% year-to-date) have recorded the lowest daily extent.
27 days (20.77%) have recorded the second lowest.
14 days (10.77%) have recorded the third lowest.
117 days in total (90.%) have been among the lowest three on record.

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #207 on: May 11, 2016, 06:12:36 PM »
Unfortunately neither NSIDC publishes real time  sea ice extent nor does CT appear to have switched to the preliminary F18 sea ice concentration data.

If CT would have, I could have reported a -180k drop is expected for coming Friday.:

day  CT-date       NH               SH                Global
Mon 2016.3479  -75.3 10.917531  +95.8  7.285143   +20.5 18.202674
Tue 2016.3507  -11.6 10.905968  +45.0  7.330120   +33.4 18.236088
Wed 2016.3534  -35.6 10.870406  +79.9  7.410037   +44.4 18.280443
Thu 2016.3562  -39.3 10.831096 +143.9  7.553953  +104.6 18.385049
Fri 2016.3589 -181.9 10.649181  +42.4  7.596343  -139.5 18.245524


The net drop is partly due to widespread sea ice concentration loss in Chukchi (-78k), made visible in the attached delta map. Nothing similar is visible in sea ice concentration maps produced from Uni Hamburg or Jaxa sea ice concentration. Sea ice concentration calculated by NSIDC is sensitive to not just to melt ponds, but to the beginning of melting. So perhaps we see here the beginning of the surface melt, expected by some. It could be a sensor fluke from the F18 as well of course.

For completeness, NSIDC extent dropped -103k. Nothing in Chukchi, but -51k in Baffin and the remainder in Bering and Okhotsk regions.

Juan C. García

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Re: 2016 sea ice area and extent data
« Reply #208 on: May 11, 2016, 06:39:34 PM »
Unfortunately neither NSIDC publishes real time  sea ice extent nor does CT appear to have switched to the preliminary F18 sea ice concentration data.

If CT would have, I could have reported a -180k drop is expected for coming Friday.:


You should be hire by CT, NSIDC or other, Wipneus. You are doing better work than them!
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Juan C. García

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Re: 2016 sea ice area and extent data
« Reply #209 on: May 11, 2016, 06:56:01 PM »
Unfortunately neither NSIDC publishes real time  sea ice extent nor does CT appear to have switched to the preliminary F18 sea ice concentration data.

If CT would have, I could have reported a -180k drop is expected for coming Friday.:



You should be hire by CT, NSIDC or other, Wipneus. You are doing better work than them!


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« Last Edit: May 11, 2016, 07:03:36 PM by Juan C. García »
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Tealight

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Re: 2016 sea ice area and extent data
« Reply #210 on: May 11, 2016, 11:49:29 PM »
If CT would have, I could have reported a -180k drop is expected for coming Friday.:

day  CT-date       NH               SH                Global
Mon 2016.3479  -75.3 10.917531  +95.8  7.285143   +20.5 18.202674
Tue 2016.3507  -11.6 10.905968  +45.0  7.330120   +33.4 18.236088
Wed 2016.3534  -35.6 10.870406  +79.9  7.410037   +44.4 18.280443
Thu 2016.3562  -39.3 10.831096 +143.9  7.553953  +104.6 18.385049
Fri 2016.3589 -181.9 10.649181  +42.4  7.596343  -139.5 18.245524


Do you have calculated CT area values for all of April until today available for download? I'm working on some Albedo calculations which are based on CT data and the sensor error screws the current year over. I would really appricate it if you could provide the daily area values. Then I can post the results here on the forum before CT switches to F18 in a few weeks or months.

I can't switch to AMSR2 because they don't have any data before 2012.

seaicesailor

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Re: 2016 sea ice area and extent data
« Reply #211 on: May 12, 2016, 12:10:37 AM »

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #212 on: May 12, 2016, 08:05:45 AM »
Yes. ADS-Jaxa melt map also indicates the first signs of melt here. Even the Uni Hamburg shows a drop in  sea ice concentration where Jaxa shows melt.
« Last Edit: May 12, 2016, 09:19:59 AM by Wipneus »

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #213 on: May 12, 2016, 09:16:31 AM »
If CT would have, I could have reported a -180k drop is expected for coming Friday.:

day  CT-date       NH               SH                Global
Mon 2016.3479  -75.3 10.917531  +95.8  7.285143   +20.5 18.202674
Tue 2016.3507  -11.6 10.905968  +45.0  7.330120   +33.4 18.236088
Wed 2016.3534  -35.6 10.870406  +79.9  7.410037   +44.4 18.280443
Thu 2016.3562  -39.3 10.831096 +143.9  7.553953  +104.6 18.385049
Fri 2016.3589 -181.9 10.649181  +42.4  7.596343  -139.5 18.245524


Do you have calculated CT area values for all of April until today available for download? I'm working on some Albedo calculations which are based on CT data and the sensor error screws the current year over. I would really appricate it if you could provide the daily area values. Then I can post the results here on the forum before CT switches to F18 in a few weeks or months.

I can't switch to AMSR2 because they don't have any data before 2012.

I put something together here. Will that do for you?

https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/AreaCalculatedLikeCryosphereToday.txt

Tealight

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Re: 2016 sea ice area and extent data
« Reply #214 on: May 12, 2016, 10:18:54 AM »
Thats perfect, thanks.  :)

The F18 values almost perfectly match the official data for the first days of April and give a smooth transitioning.

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #215 on: May 12, 2016, 04:24:37 PM »
The Chukchi apparent drop in concentration travels forward into the interior (recovery in the wake).

Virtual CT area report:

day  CT-date       NH               SH                Global
Tue 2016.3507  -11.6 10.905968  +45.0  7.330120   +33.4 18.236088
Wed 2016.3534  -35.6 10.870406  +79.9  7.410037   +44.4 18.280443
Thu 2016.3562  -39.3 10.831096 +143.9  7.553953  +104.6 18.385049
Fri 2016.3589 -182.2 10.648849  +42.4  7.596343  -139.9 18.245192
Sat 2016.3616 -162.6 10.486256  +52.7  7.649043  -109.9 18.135299


Extent (virtual NSIDC extent) dropped about -130k. Okhotsk and Bering -40k, remainder in Hudson, Baffin, StLawrence and Greenlands Sea.


crandles

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Re: 2016 sea ice area and extent data
« Reply #216 on: May 12, 2016, 04:48:55 PM »
The Chukchi apparent drop in concentration travels forward into the interior (recovery in the wake).

Virtual CT area report:

day  CT-date       NH               SH                Global
Tue 2016.3507  -11.6 10.905968  +45.0  7.330120   +33.4 18.236088
Wed 2016.3534  -35.6 10.870406  +79.9  7.410037   +44.4 18.280443
Thu 2016.3562  -39.3 10.831096 +143.9  7.553953  +104.6 18.385049
Fri 2016.3589 -182.2 10.648849  +42.4  7.596343  -139.9 18.245192
Sat 2016.3616 -162.6 10.486256  +52.7  7.649043  -109.9 18.135299



Lowest .3616 day is 2006 11.091
So if no major adjustments needed, 2016 is currently looking to be around 605k below lowest year on record  :o :o :o

DoomInTheUK

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Re: 2016 sea ice area and extent data
« Reply #217 on: May 12, 2016, 05:59:11 PM »
Come September Wipneus will be struggling to find any ice to count at this rate, but we can be pretty sure he'll count what little is left properly.

No end in sight.

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #218 on: May 13, 2016, 04:27:16 PM »
Sea ice concentration drop progresses further into Beaufort and the CAB (-25k and -49k SIA), while behind the front the concentration is Chukchi recovers (+50k).

The shadow CT-area report:

day  CT-date       NH               SH                Global
Wed 2016.3534  -35.6 10.870406  +79.9  7.410037   +44.4 18.280443
Thu 2016.3562  -39.3 10.831096 +143.9  7.553953  +104.6 18.385049
Fri 2016.3589 -182.2 10.648849  +42.4  7.596343  -139.9 18.245192
Sat 2016.3616 -162.7 10.486125  +52.7  7.649055  -110.0 18.135180
Sun 2016.3644  -68.3 10.417814  +47.1  7.696178   -21.2 18.113992

Shadow NSIDC extent dropped another century (-101k5). No surprises: Okhotsk, Bering, Barents, Greenland Sea and Hudson took their share.

Alphabet Hotel

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Re: 2016 sea ice area and extent data
« Reply #219 on: May 14, 2016, 05:09:39 AM »
AMSR2 images from uni-bremen.de are missing for May 12 and May 13. Anyone know what happened?

Juan C. García

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Re: 2016 sea ice area and extent data
« Reply #220 on: May 14, 2016, 07:22:53 AM »
Someone knows what is happening with AMSR2 Arctic maps of Bremen's University? I haven't been able to see them for a couple of days...
I miss them!  ;)
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #221 on: May 14, 2016, 04:39:17 PM »
Time for an uptick in my shadow CT-area calculation:

day  CT-date       NH               SH                Global
Thu 2016.3562  -39.3 10.831096 +143.9  7.553953  +104.6 18.385049
Fri 2016.3589 -182.2 10.648849  +42.4  7.596343  -139.9 18.245192
Sat 2016.3616 -162.7 10.486125  +52.7  7.649055  -110.0 18.135180
Sun 2016.3644  -67.5 10.418575  +47.2  7.696227   -20.4 18.114802
Mon 2016.3671  +29.2 10.447775 +152.6  7.848805  +181.8 18.296580


The attached delta map shows that yesterday's concentration drop is today's recovery.

Shadow NSIDC extent dropped -28k. Mostly Barents with increases in Baffin and Sea of Okhotsk.

crandles

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Re: 2016 sea ice area and extent data
« Reply #222 on: May 14, 2016, 05:23:38 PM »
Wonderful work you do.


The attached delta map shows that yesterday's concentration drop is today's recovery.

Does this seem odd? I don't remember seeing such pronounced behaviour but maybe I wasn't paying appropriate attention to notice and it is normal? Could there be some calibration adjustments required with new sensor to reduce such overshoot behaviour? Or is what is happening just unusual for this early in season and this somehow causes such swings? or some other explanation?

Probably rather difficult to answer without a lot of time and data which we don't yet have with new sensor, so sorry for asking so soon. Asking for any gut feelings might also be too early a question to ask so I hope you don't mind me canvassing any views there might be.

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #223 on: May 14, 2016, 05:54:47 PM »
Wonderful work you do.


The attached delta map shows that yesterday's concentration drop is today's recovery.

Does this seem odd? I don't remember seeing such pronounced behaviour but maybe I wasn't paying appropriate attention to notice and it is normal? Could there be some calibration adjustments required with new sensor to reduce such overshoot behaviour?

I do not recall seeing this before. I see the same in UH AMSR2 sea ice concentration, and Jaxa's surface melt map. So it is not likely a sensor calibration issue.

Or is what is happening just unusual for this early in season and this somehow causes such swings? or some other explanation?

Probably rather difficult to answer without a lot of time and data which we don't yet have with new sensor, so sorry for asking so soon. Asking for any gut feelings might also be too early a question to ask so I hope you don't mind me canvassing any views there might be.

I can speculate. Look at the attached UH AMSR2 animation, not as pretty but you can clearly see the blotch of darkening moving from the Bering Strait into Chukchi, turning into and crossing the Beaufort and now going into the CAA. That is so fast and unlike other torching phenomena that I have been observing. Those movement where going with the ice, much much slower.
So I come to weather, could it be a rain front, wetting the surface temporary, and since the conditions are not ready for melt yet the surface quickly dries after the rain stops?

ktonine

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Re: 2016 sea ice area and extent data
« Reply #224 on: May 14, 2016, 06:20:17 PM »
Wonderful work you do.


The attached delta map shows that yesterday's concentration drop is today's recovery.

Does this seem odd? I don't remember seeing such pronounced behaviour but maybe I wasn't paying appropriate attention to notice and it is normal? Could there be some calibration adjustments required with new sensor to reduce such overshoot behaviour? Or is what is happening just unusual for this early in season and this somehow causes such swings? or some other explanation?

Probably rather difficult to answer without a lot of time and data which we don't yet have with new sensor, so sorry for asking so soon. Asking for any gut feelings might also be too early a question to ask so I hope you don't mind me canvassing any views there might be.

It might be interesting to check a buoy - if there's one in the path - or a land station to see if the concurrent weather (temp., rain, fog, snow ?) can tell us what the sensors are seeing (and confused by).  Of course it could be something at a higher atmospheric altitude that is confounding the sensors and this wouldn't necessarily be apparent at the surface.

plinius

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Re: 2016 sea ice area and extent data
« Reply #225 on: May 14, 2016, 08:05:22 PM »
isn't that quite exactly what obuoy 14 has seen?
http://obuoy.datatransport.org/monitor#buoy14/weather

About 1 day above freezing temperature, and then a very sudden drop to temperatures ensuring that the surface freezes up again. Given that there is porous snow and no melt ponds, the surface layer/thin film of water would have disappeared almost instantly.



oren

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Re: 2016 sea ice area and extent data
« Reply #226 on: May 14, 2016, 08:58:48 PM »
Yeah my thinking too, something (probably the high temps that were forecast) made the snow wet and the sensor thought it was water, then everything froze up again. With lower albedo though.

BornFromTheVoid

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Re: 2016 sea ice area and extent data
« Reply #227 on: May 15, 2016, 11:49:03 AM »
I'm gonna update the missing weekly NSIDC extent reports from April 9th, so sorry for the spamming to follow!

Update for the week to April 9th

The current 5 day mean is on 13,969,500km2 while the 1 day extent is at 13,870,000km2.

The daily anomaly (compared to 81-10) is at -1,057,960km2, a decrease from -1,063,590km2 last week. The anomaly compared to the 07, 11 and 12 average is at -477,130km2, an increase from -453,470km2 last week. We're currently lowest on record, the same as last week.



The average daily change over the last 7 days was -32.3k/day, compared to the long term average of -32.7k/day, and the 07, 11 and 12 average of -28.5k/day.
The average long term change over the next week is -40.4k/day, with the 07, 11, and 12 average being -29.1k/day.



The extent drop so far this April is the 12th largest record. To achieve the largest monthly loss, a drop of at least 60.6k/day is required, while the smallest loss requires a drop of less than 16.7k/day and an average loss requires a drop of 35.8k/day.


BornFromTheVoid

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Re: 2016 sea ice area and extent data
« Reply #228 on: May 15, 2016, 12:03:55 PM »
Update for the week to April 16th

The current 5 day mean is on 13,859,600km2 while the 1 day extent is at 13,822,000km2.

The daily anomaly (compared to 81-10) is at -885,320km2, a decrease from -1,063,590km2 last week. The anomaly compared to the 07, 11 and 12 average is at -383,550km2, a decrease from -453,470km2 last week. We're currently second lowest on record, down from lowest last week.



The average daily change over the last 7 days was -15.7k/day, compared to the long term average of -32.7k/day, and the 07, 11 and 12 average of -28.5k/day.
The average long term change over the next week is -36.6k/day, with the 07, 11, and 12 average being -23.2k/day.



The extent drop so far this April is the 13th smallest on record. To achieve the largest monthly loss, a drop of at least 83.1k/day is required, while the smallest loss requires a drop of less than 17.2k/day and an average loss requires a drop of 45.9k/day.


BornFromTheVoid

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Re: 2016 sea ice area and extent data
« Reply #229 on: May 15, 2016, 12:23:03 PM »
Update for the week to April 23rd

The current 5 day mean is on 13,549,700km2 while the 1 day extent is at 13,492,000km2.

The daily anomaly (compared to 81-10) is at -939,230km2, an increase from -885,320km2 last week. The anomaly compared to the 07, 11 and 12 average is at -530,830km2, an increase from -383,550km2 last week. We're currently the lowest on record, up from second lowest last week.



The average daily change over the last 7 days was -44.3k/day, compared to the long term average of -36.6k/day, and the 07, 11 and 12 average of -23.2k/day.
The average long term change over the next week is -43.2k/day, with the 07, 11, and 12 average being -49.4k/day.



The extent drop so far this April is the 17th smallest on record. To achieve the largest monthly loss, a drop of at least 121.8k/day is required, while the smallest loss requires an increase of at least than 9.9k/day and an average loss requires a drop of 47.5k/day.


BornFromTheVoid

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Re: 2016 sea ice area and extent data
« Reply #230 on: May 15, 2016, 12:38:24 PM »
Update for the week to April 30th

The current 5 day mean is on 13,142,400km2 while the 1 day extent is at 12,990,000km2.

The daily anomaly (compared to 81-10) is at -1,044,140km2, an increase from -939,230km2 last week. The anomaly compared to the 07, 11 and 12 average is at -592,380km2, an increase from -530,830km2 last week. We're currently the lowest on record, the same as last week.



The average daily change over the last 7 days was -58.2k/day, compared to the long term average of -43.2k/day, and the 07, 11 and 12 average of -49.4k/day.
The average long term change over the next week is -60.6k/day, with the 07, 11, and 12 average being -61.1k/day.



The extent loss in April was the 15th largest on record, while the average extent was the lowest on record.




BornFromTheVoid

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Re: 2016 sea ice area and extent data
« Reply #231 on: May 15, 2016, 12:56:07 PM »
Update for the week to May 7th

The current 5 day mean is on 12,580,300km2 while the 1 day extent is at 12,455,000km2.

The daily anomaly (compared to 81-10) is at -1,182,030km2, an increase from -1,044,140km2 last week. The anomaly compared to the 07, 11 and 12 average is at -726,560km2, an increase from -592,380km2 last week. We're currently the lowest on record, the same as last week.



The average daily change over the last 7 days was -80.3k/day, compared to the long term average of -60.6k/day, and the 07, 11 and 12 average of -61.1k/day.
The average long term change over the next week is -42.6k/day, with the 07, 11, and 12 average being -41.1k/day.



The extent drop so far this May is the 7th largest on record. To achieve the largest monthly loss, a drop of at least 65.6k/day is required, while the smallest loss requires a drop of less than 11.3k/day and an average loss requires a drop of 37.3k/day.


Tor Bejnar

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Re: 2016 sea ice area and extent data
« Reply #232 on: May 15, 2016, 02:29:22 PM »
Thanks, BFTV.  I've sure missed these postings - glad they are back from the void!  ;)
Arctic ice is healthy for children and other living things.

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #233 on: May 15, 2016, 05:45:42 PM »
The shadow CT-area calculations:

day  CT-date       NH               SH                Global
Fri 2016.3589 -182.2 10.648849  +42.4  7.596343  -139.9 18.245192
Sat 2016.3616 -162.7 10.486125  +52.7  7.649055  -110.0 18.135180
Sun 2016.3644  -67.5 10.418575  +47.2  7.696227   -20.4 18.114802
Mon 2016.3671  +29.9 10.448430 +152.7  7.848879  +182.5 18.297309
Tue 2016.3699  -62.7 10.385694 +120.6  7.969448   +57.8 18.355142


Biggest decliners where ESS and Hudson (both about -20k).

Shadow NSIDC extent dropped -68k9. Sea of Okhotsk (-37k) and Barents (-26k) dropped most.

The usual delta map is attached.
In the Chukchi and Beaufort region the situation seems to stabilise. The remaining darker patches may indicate where the surface is most wet from rain/melting/sea water or where perhaps it is due to open water in unresolved leads.

Sourabh

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Re: 2016 sea ice area and extent data
« Reply #234 on: May 15, 2016, 05:55:39 PM »
BFV,

I also missed your updates. Given the recent IJIS drops, your next update would be more interesting.

Sourabh

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Re: 2016 sea ice area and extent data
« Reply #235 on: May 15, 2016, 06:36:56 PM »
Wipneus,

I should have asked this here, and not in the melting season thread.

If possible and if it is not too much to ask, could you also make an updated CAPIE chart to show how this year is doing as compared to previous years? Generally, Neven does that, but just like arctic ice, he has disappeared from this forum lately ( ;D).

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #236 on: May 15, 2016, 07:05:43 PM »
Wipneus,

I should have asked this here, and not in the melting season thread.

If possible and if it is not too much to ask, could you also make an updated CAPIE chart to show how this year is doing as compared to previous years? Generally, Neven does that, but just like arctic ice, he has disappeared from this forum lately ( ;D).

Sourabh, I really think CAPIE is Neven's thing. If I remember correctly he announced to be away for one or two weeks, so he should be back soon enough.

If you are interested in area by extent ratio I can recommend my graph from the "home brew" thread because this is called by (some) scientists "compactness". Area and extent are of course from the same source, CAPIE uses different sources.

https://sites.google.com/site/arctischepinguin/home/amsr2/grf/amsr2-compact-compare.png



There is a regional version as well:

https://sites.google.com/site/arctischepinguin/home/amsr2/grf/amsr2-compact-regional.png


Sourabh

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Re: 2016 sea ice area and extent data
« Reply #237 on: May 15, 2016, 07:19:23 PM »
Thanks Wipneus,

Neven generally divides CT area with IJIS extent to get CAPIE.

In your graph, three different sources of compactness are telling different stories. In NSIDC compactness, 2016 is lower range as compared to other years. But, in Uni Hamburg, it is in upper range.

I was thinking if compactness is also low during May with already lower extent, then this year is likely to be extraordinary. With open skies and lots of melt ponds, there could be possibility of a significant melting momentum. But, I leave the intellectual interpretation of the data to you, Chris, and Neven.

BornFromTheVoid

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Re: 2016 sea ice area and extent data
« Reply #238 on: May 15, 2016, 08:51:33 PM »
Update for the week to May 14th

The current 5 day mean is on 12,083,300km2 while the 1 day extent is at 11,945,000km2.

The daily anomaly (compared to 81-10) is at -1,380,810km2, an increase from -1,182,030km2 last week. The anomaly compared to the 07, 11 and 12 average is at -935,880km2, an increase from -726,560km2 last week. We're currently the lowest on record, the same as last week.



The average daily change over the last 7 days was -71.0k/day, compared to the long term average of -42.6k/day, and the 07, 11 and 12 average of -41.1k/day.
The average long term change over the next week is -45.4k/day, with the 07, 11, and 12 average being -45.5k/day.



The extent drop so far this May is the 3rd largest on record. To achieve the largest monthly loss, a drop of at least 63.3k/day is required, while the smallest loss requires an increase of at least 13.4k/day and an average loss requires a drop of 23.5k/day.


Tealight

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Re: 2016 sea ice area and extent data
« Reply #239 on: May 15, 2016, 11:10:22 PM »
As it seems today is offical graph posting day. So I contribute a Cryosphere Today area graph based on Wipneus calculations.

Currently 2016 is exactly 500,000 km2 below the previous record low from 2011.

Jim Pettit

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Re: 2016 sea ice area and extent data
« Reply #240 on: May 16, 2016, 02:39:19 PM »
ADS-NIPR Extent:
11,262,361 km2 (15 May)
Down 2,680,146 km2 (19.22%) from 2016 maximum of 13,942,507 km2 on 29 February.
8,084,906 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).
Down 31,365 km2 (-.28%) from previous day.
Down 519,805 km2  (-4.41%) over past seven days (daily average: -74,258 km2).
Down 1,031,086 km2  (-8.43%) for May (daily average: -68,739 km2).
1,166,219 km2 below 2000s average for this date.
773,876 km2 below 2010s average for this date.
604,920 km2 below 2015 value for this date.
1,107,042 km2 below 2012 value for this date.
Lowest year-to-date (01 January - 15 May) average.
Lowest May to-date average.
Lowest value for the date.
81 days this year (60% year-to-date) have recorded the lowest daily extent.
27 days (20%) have recorded the second lowest.
14 days (10.37%) have recorded the third lowest.
122 days in total (90.37%) have been among the lowest three on record.


CT Area*:
10,448,430 km2 (15 May [Day 0.3671])
Down 2,472,928 km2 (19.14%) from 2016 maximum of 12,921,358 km2 on 29 March [Day 0.2384].
8,214,421 km2 above record minimum area of 2,234,010 km2 (14 September 2012).
Up 29,855 km2 (.29%) from previous day.
Down 469,101 km2 (-4.3%) over past seven days (daily average: -67,014 km2).
Down 768,902 km2 (-6.9%) for May (daily average: -51,260 km2).
1,047,044 km2 below 2000s average for this date.
628,854 km2 below 2010s average for this date.
665,033 km2 below 2015 value for this date.
906,254 km2 below 2012 value for this date.
Lowest year-to-date (Day 0.0000 - Day 0.3671) average.
Lowest May to-date average.
Lowest value for the date.
* -Due to ongoing satellite issues, multiple days in the Cryosphere Today 2016 dataset are missing and/or invalid; for that reason, these numbers include Wipneus's calculated area numbers instead of the actual published numbers
   

mmghosh

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Re: 2016 sea ice area and extent data
« Reply #241 on: May 16, 2016, 03:43:31 PM »

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #242 on: May 16, 2016, 04:35:35 PM »
The shadow CT-area report:

day  CT-date       NH               SH                Global
Sun 2016.3644  -67.5 10.418575  +47.2  7.696227   -20.4 18.114802
Mon 2016.3671  +29.9 10.448430 +152.7  7.848879  +182.5 18.297309
Tue 2016.3699  -62.6 10.385816 +120.6  7.969487   +58.0 18.355303
Wed 2016.3726  -64.4 10.321439  +68.4  8.037935    +4.1 18.359374

Hudson Bay contributed most (-31k), followed by the CAB (-19k).

Shadow NSIDC extent declined only -25k, Baffin and Barents doing the job.

In the delta map from the NSIDC sea ice concentration, the drop in Hudson is clear. Except for the East Siberian Sea,  most of the Arctic Basin saw small changes.

LRC1962

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Re: 2016 sea ice area and extent data
« Reply #243 on: May 16, 2016, 09:40:07 PM »

The extent drop so far this May is the 3rd largest on record. To achieve the largest monthly loss, a drop of at least 63.3k/day is required, while the smallest loss requires an increase of at least 13.4k/day and an average loss requires a drop of 23.5k/day.
The scary part is that it is the 3rd largest drop and at the same time the lowest extent we have ever had. Put the 2 together and by percentages the Arctic is dropping very fast.
"All truth passes through three stages: First, it is ridiculed; Second,  it is violently opposed; and Third, it is accepted as self-evident."
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abbottisgone

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Re: 2016 sea ice area and extent data
« Reply #244 on: May 17, 2016, 11:10:18 AM »

The extent drop so far this May is the 3rd largest on record. To achieve the largest monthly loss, a drop of at least 63.3k/day is required, while the smallest loss requires an increase of at least 13.4k/day and an average loss requires a drop of 23.5k/day.
The scary part is that it is the 3rd largest drop and at the same time the lowest extent we have ever had. Put the 2 together and by percentages the Arctic is dropping very fast.
I don't know anything about the concept of hysteresis so tried to use it over at skeptical science and quickly got told there is, as yet, no hysteresis as regards the discussion of the worlds sea ice at the moment but the concept does have a valid place when discussing land ice.

I remain willing to accept the word of others with better knowledge but feel the idea should probably get a guernsey somewhere along the line as we are talking about a potentially very serious point in time about now.

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Wipneus

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Re: 2016 sea ice area and extent data
« Reply #245 on: May 17, 2016, 04:16:49 PM »
The shadow CT area report:

day  CT-date       NH               SH                Global
Mon 2016.3671  +29.9 10.448430 +152.7  7.848879  +182.5 18.297309
Tue 2016.3699  -62.6 10.385816 +120.6  7.969487   +58.0 18.355303
Wed 2016.3726  -64.6 10.321244  +68.4  8.037935    +3.9 18.359179
Thu 2016.3753  -33.3 10.287978 +129.6  8.167545   +96.3 18.455523


CAB dropped -20k, Laptev -14k.

Shadow NSIDC extent went down just -8k8, CAB -16k, StLawrence +18k changed most.

The little change can be seen in the attached delta map. Hudson sees some drops in concentration and increases elsewhere.

Jim Pettit

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Re: 2016 sea ice area and extent data
« Reply #246 on: May 18, 2016, 01:19:22 PM »
ADS-NIPR Extent:
11,144,719 km2 (17 May)
Down 2,797,788 km2 (20.07%) from 2016 maximum of 13,942,507 km2 on 29 February.
7,967,264 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).
Down 53,190 km2 (-.47%) from previous day.
Down 488,624 km2  (-4.2%) over past seven days (daily average: -69,803 km2).
Down 1,148,728 km2  (-9.39%) for May (daily average: -67,572 km2).
1,188,821 km2 below 2000s average for this date.
777,532 km2 below 2010s average for this date.
606,845 km2 below 2015 value for this date.
1,033,524 km2 below 2012 value for this date.
Lowest year-to-date (01 January - 17 May) average.
Lowest May to-date average.
Lowest value for the date.
83 days this year (60.58% year-to-date) have recorded the lowest daily extent.
27 days (19.71%) have recorded the second lowest.
14 days (10.22%) have recorded the third lowest.
124 days in total (90.51%) have been among the lowest three on record.


CT Area*:
10,287,978 km2 (18 May [Day 0.3754])
Down 2,633,380 km2 (20.38%) from 2016 maximum of 12,921,358 km2 on 29 March [Day 0.2384].
8,053,969 km2 above record minimum area of 2,234,010 km2 (14 September 2012).
Down 33,266 km2 (-.32%) from previous day.
Down 543,118 km2 (-5.1%) over past seven days (daily average: -77,588 km2).
Down 929,354 km2 (-8.34%) for May (daily average: -51,631 km2).
1,029,512 km2 below 2000s average for this date.
599,767 km2 below 2010s average for this date.
568,373 km2 below 2015 value for this date.
782,051 km2 below 2012 value for this date.
Lowest value for the date.
* - Due to ongoing satellite issues, multiple days in the Cryosphere Today 2016 data are missing and/or invalid; for that reason, this table incorporates sea ice area figures as calculated by Wipneus using NSIDC's numbers.




Wipneus

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Re: 2016 sea ice area and extent data
« Reply #247 on: May 18, 2016, 05:20:01 PM »
The shadow CT-area report:


day  CT-date       NH               SH                Global
Tue 2016.3699  -62.6 10.385816 +120.6  7.969487   +58.0 18.355303
Wed 2016.3726  -64.6 10.321244  +68.4  8.037935    +3.9 18.359179
Thu 2016.3753  -33.3 10.287944 +129.6  8.167545   +96.3 18.455489
Fri 2016.3781  -72.1 10.215845 +144.5  8.312020   +72.4 18.527865


The Kara (-24k) and ESS (-21k) and Beaufort (-11k) were contributors. Hudson increased by (+18k).

Shadow NSIDC dropped over a century (-130k). Here Baffin (-33k), Greenland Sea (-23k) and StLawrence (-16k) were contributors. There is also a large drop (-29k) outside the well known regions, from the delta map I guess that is mostly the Baltic.

In that delta map we can see a drop along the cracked zone in the East Siberian Sea.

Sebastian

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Re: 2016 sea ice area and extent data
« Reply #248 on: May 18, 2016, 10:17:17 PM »
The drop in the baltic was false ice going away again as the sea is about 10 degrees warm in the gulf of finland http://en.ilmatieteenlaitos.fi/ice-conditions

Wipneus

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Re: 2016 sea ice area and extent data
« Reply #249 on: May 19, 2016, 04:34:49 PM »
Shadow CT-area report:


day  CT-date       NH               SH                Global
Wed 2016.3726  -64.6 10.321244  +68.4  8.037935    +3.9 18.359179
Thu 2016.3753  -33.3 10.287944 +129.6  8.167545   +96.3 18.455489
Fri 2016.3781  -72.1 10.215796 +144.5  8.312095   +72.4 18.527891
Sat 2016.3808  -73.3 10.142537  +29.9  8.341968   -43.4 18.484505


The drop is shared over many regions, none stand out, but see attached delta map for  some activity in Hudson and Kara.

Shadow NSIDC extent dropped -61.8. The Sea of Okhotsk managed to squeeze another -37k, Chukchi did -12k.