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Jim Hunt

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Re: 2017 sea ice area and extent data
« Reply #100 on: February 23, 2017, 12:42:45 PM »
I wouldn't place any bets at the moment, but it's certainly possible.

No crow pie consumed yet!
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DrTskoul

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Re: 2017 sea ice area and extent data
« Reply #101 on: February 23, 2017, 12:46:24 PM »
I wouldn't place any bets at the moment, but it's certainly possible.

No crow pie consumed yet!

Admit it. You must really like crow. Every year you prepare it early ...  ;D ;D ;D
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Jim Hunt

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Re: 2017 sea ice area and extent data
« Reply #102 on: February 24, 2017, 10:27:58 AM »
Admit it. You must really like crow.

Actually last year, with a little help from Wipneus, my alter ego's prognosticatory powers proved to be astonishingly accurate:

http://GreatWhiteCon.info/2016/02/the-2016-arctic-winter-sea-ice-puzzle/#comment-213898

Scoff at this @shubclimate. 2016 maximum CT Arctic sea ice area will be ~12.886 million square kilometers

Getting back to this year, can I be excused my customary crow consumption for another day at least? UH AMSR2 extent is just above the prior high today, but area is still just below it.
« Last Edit: February 24, 2017, 12:54:30 PM by Jim Hunt »
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DrTskoul

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Re: 2017 sea ice area and extent data
« Reply #103 on: February 24, 2017, 12:24:05 PM »
 ;D 8)
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BornFromTheVoid

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Re: 2017 sea ice area and extent data
« Reply #104 on: February 26, 2017, 08:13:23 PM »
Update for the week to February 25th

The current 5 day trailing average is on 14,360,000km2 while the 1 day extent is at 14,362,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -1,102,000km2, an increase from -1,091,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at -293,000km2, a decrease from -330,000km2 last week. We're currently 3rd lowest on record, down from 2nd lowest last week.



The average daily change over the last 7 days was +17.4k/day, compared to the long term average of +19.0k/day, and the 07, 11 and 12 average of +12.1k/day.
The average long term change over the next week is +5.9k/day, with the 07, 11, and 12 average being +19.0k/day.



The extent increase so far this February is the 12th largest on record. To achieve the largest increase, a gain of at least 58.8k/day is required (at least +146.4k/day with with single day values), while the smallest increase requires a loss of at least 191.4k/day (loss of at least 478.9k/day with single day values) and an average increase requires a loss of 31.1k/day (loss of 78.8k/day with single day values)


Wipneus

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Re: 2017 sea ice area and extent data
« Reply #105 on: March 01, 2017, 02:21:20 PM »
Some melting may have started, but how about the Arctic Basin where almost all the remaining ice will have retreated by the time of the minimum?

Attached are detailed graphs of the maximum of area and extent in the Arctic Basin, taken to be Beaufort, Chukchi, East Siberian, Laptev and Central Basin regions.
Included in the graphs is the 10%-90% percentiles range calculated in the 1981-2010 era.

What can be seen:
- through the noise it is clear that the normal date that the maximum in the Basin is reached is in the beginning of April.
- at maximum, less than a handful of years do not reach 100% ice extent.
- 2017 is currently no longer running very low and is more or less found in the middle of the pack.

 

Tor Bejnar

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Re: 2017 sea ice area and extent data
« Reply #106 on: March 01, 2017, 03:16:53 PM »
...
What can be seen:
- through the noise it is clear that the normal date that the maximum in the Basin is reached is in the beginning of April.
- at maximum, less than a handful of years do not reach 100% ice extent.
- 2017 is currently no longer running very low and is more or less found in the middle of the pack.
Thanks for this reality check.  My reading of the second chart says every year has reached 100% extent at some point in April (at least) for the "Arctic Basin".  2017 reached 100% extent coverage briefly already. 

I'm sure there is a deficit of ice volume in the Arctic Basin (but this is OT  :-X).
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Shared Humanity

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Re: 2017 sea ice area and extent data
« Reply #107 on: March 01, 2017, 03:27:50 PM »
The minimum last year was very low and the ice was in horrible condition. This freeze season has been weak, arguably the weakest on record with FDD anomaly that is unbelievable. I would expect that this tendency to reach 100% extent in the Arctic Basin will persist for many years and it would be a great metric to track as it would capture so many changes occurring in the basin. (halocline destruction, increased wave activity due to open water, rapidly growing high humidity environment, ice mobility, etc)

Jim Hunt

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Re: 2017 sea ice area and extent data
« Reply #108 on: March 05, 2017, 11:12:22 AM »
I fear crow is now on my menu:

http://GreatWhiteCon.info/2017/03/facts-about-the-arctic-in-march-2017/

There's unfortunately no avoiding the fact that UH AMSR2 area has posted a new high for the year at a smidgen over 13 million square kilometers:

Reality is merely an illusion, albeit a very persistent one - Albert Einstein

wili

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Re: 2017 sea ice area and extent data
« Reply #109 on: March 05, 2017, 12:03:10 PM »
Apologies if this has been posted already somewhere and if this is not the right spot for it:

http://www.zmescience.com/ecology/climate/arctic-ice-aerosols/?utm_source=ZME+Science+Newsletter&utm_campaign=5f37c44652-ZME_Science_Daily3_6_2015&utm_medium=email&utm_term=0_3b5aad2288-5f37c44652-242645473&ct=t(ZME_Science_Daily11_8_2014)

Aerosol emissions kept climate change in check over the Arctic until Clean Air regulations

Researchers first observed that Arctic ice cover was dwindling in the mid-1970s, and some climate model simulations done since then show that ice loss may have begun as early as 1950. But recently recovered Soviet observations show that between 1950 and 1975, Arctic ice cover actually increased for almost as much as it’s decreased between 1975 to 2005. Which doesn’t fit into our models in any way.

A new study aimed at uncovering the cause behind this expansion found that human-made air pollution is also to blame here. The paper proposes that [p]articles originating primarily from the burning of fossil fuels may have temporarily overshadowed the effects of global warming in the third quarter of the 20th century in the eastern Arctic.
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BornFromTheVoid

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Re: 2017 sea ice area and extent data
« Reply #110 on: March 05, 2017, 05:53:48 PM »
Update for the week to March 4th

The current 5 day trailing average is on 14,377,000km2 while the 1 day extent is at 14,437,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -1,127,000km2, an increase from -1,102,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at -410,000km2, an increase from -293,000km2 last week. We're currently lowest on record, up from 3rd lowest last week.



The average daily change over the last 7 days was +2.2k/day, compared to the long term average of +5.9k/day, and the 07, 11 and 12 average of +19.0k/day.
The average long term change over the next week is -0.1k/day, with the 07, 11, and 12 average being +9.3k/day



The extent change so far this March is the 15th most positive record. To achieve the largest increase, a gain of at least 13.9k/day is required (at least +12.6k/day with with single day values), while the largest drop requires a loss of at least 27.1k/day (loss of at least 31.9k/day with single day values) and an average change requires a loss of 9.1k/day (loss of 12.3k/day with single day values).



The extent increase in February was the 19th smallest on record while the average extent was the lowest on record.




BornFromTheVoid

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Re: 2017 sea ice area and extent data
« Reply #111 on: March 12, 2017, 05:12:35 PM »
Update for the week to March 11th

The current 5 day trailing average is on 14,354,000km2 while the 1 day extent is at 14,420,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -1,148,000km2, an increase from -1,127,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at -498,000km2, an increase from -410,000km2 last week. We're currently 2nd lowest on record, down from lowest last week.



The average daily change over the last 7 days was -3.1k/day, compared to the long term average of -0.1k/day, and the 07, 11 and 12 average of +9.3k/day.
The average long term change over the next week is -7.1k/day, with the 07, 11, and 12 average being -4.8k/day



The extent change so far this March is the 15th most positive record. To achieve the largest increase, a gain of at least 19.7k/day is required (at least +18.3k/day with with single day values), while the largest drop requires a loss of at least 35.4k/day (loss of at least 43.1k/day with single day values) and an average change requires a loss of 11.1k/day (loss of 16.0k/day with single day values).


Tor Bejnar

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Re: 2017 sea ice area and extent data
« Reply #112 on: March 20, 2017, 04:34:32 AM »
BFTV: where are you? I have an addiction to your wonderful weekly summaries, and now I'm going into withdrawals.  'Trust you're just busy!
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Wipneus

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Re: 2017 sea ice area and extent data
« Reply #113 on: March 22, 2017, 04:59:38 PM »
Area from NSIDC sea ice concentration data is again lowest for the day.

Pmt111500

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Re: 2017 sea ice area and extent data
« Reply #114 on: March 22, 2017, 07:07:12 PM »
Thank you Wipneus for the graph, it'll be interesting to see if the curve follows the 2016 line for the next 3 months. It almost looks like something broke the previous winter 2016 february to april since the unique form of the curve late april to midsummer.
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BornFromTheVoid

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Re: 2017 sea ice area and extent data
« Reply #115 on: March 22, 2017, 08:38:40 PM »
Update for the week to March 18th (finally!)

The current 5 day trailing average is on 14,305,000km2 while the 1 day extent is at 14,178,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -1,148,000km2, the same as last week. The anomaly compared to the 07, 11 and 12 average is at -506,000km2, an increase from -498,000km2 last week. We're currently lowest on record, up from 2nd lowest last week.



The average daily change over the last 7 days was -7.0k/day, compared to the long term average of -7.1k/day, and the 07, 11 and 12 average of -4.8k/day.
The average long term change over the next week is -12.3k/day, with the 07, 11, and 12 average being -18.5k/day.



The extent change so far this March is the 19th least negative record. To achieve the largest increase, a gain of at least 34.1k/day is required (at least +52.0k/day with with single day values), while the largest drop requires a loss of at least 50.6k/day (loss of at least 48.4k/day with single day values) and an average change requires a loss of 13.3k/day (loss of 4.2k/day with single day values).


Jim Pettit

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Re: 2017 sea ice area and extent data
« Reply #116 on: March 23, 2017, 03:29:31 PM »
I've added a new graph to my stable, this one plotting year-to-date NSIDC SIE extent anomalies for the current year, alongside the ten previous years with the lowest average annual anomalies, plus decadal average lines for the 80s,90s, and 00s:



This graph does a good job showing just how much more sunlight-absorbing open water there now is during those months with high solar insolation. A few days with less ice-covered water won't change much, obviously, but when that extra sea surface is exposed to the summer sun for months on end, the cumulative effect becomes part of a powerful feedback loop.

A few things really stand out to me:
--the deep 2017 anomaly (red line)
--last year's recordsetting average anomaly (orange)
--2012's wild June-October plunge (violet)

i suspect that 2017 will follow a trajectory similar to last year's through June, then steepen a bit after that through the minimum, though as always there's no way to know. Anyway, you can find it at my climate graphs page, or by the image URL.

jai mitchell

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Re: 2017 sea ice area and extent data
« Reply #117 on: March 23, 2017, 04:41:13 PM »
thanks Jim, that is very informative
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Re: 2017 sea ice area and extent data
« Reply #118 on: March 23, 2017, 04:44:15 PM »
...... showing just how much more sunlight-absorbing open water there now is during those months with high solar insolation. A few days with less ice-covered water won't change much, obviously, but when that extra sea surface is exposed to the summer sun for months on end, the cumulative effect becomes part of a powerful feedback loop.


There is nearly 2 million sq km more open water as of now compared with the 1980's. Being at the fringes of the ice-cap meaningful insolation is already happening on that water. I wonder what is the accumulated  additional heat still in long-term storage in the ocean due to increased insolation caused by reduction in sea-ice area  spatially distributed over the Arctic year by year since 1979.
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BornFromTheVoid

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Re: 2017 sea ice area and extent data
« Reply #119 on: March 26, 2017, 04:21:14 PM »
Update for the week to March 25th

The current 5 day trailing average is on 14,111,000km2 while the 1 day extent is at 14,073,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -1,255,000km2, an increase from -1,148,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at -570,000km2, an increase from -506,000km2 last week. We're currently lowest on record, the same as last week.



The average daily change over the last 7 days was -27.7k/day, compared to the long term average of -12.3k/day, and the 07, 11 and 12 average of -18.5k/day.
The average long term change over the next week is -12.1k/day, with the 07, 11, and 12 average being -5.3k/day.



The extent change so far this March is the 16th most negative record. To achieve the largest increase, a gain of at least 106.4k/day is required (at least +168.9k/day with with single day values), while the largest drop requires a loss of at least 77.4k/day (loss of at least 106.6k/day with single day values) and an average change requires an increase of 3.4k/day (+14.6k/day with single day values).


Tor Bejnar

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Re: 2017 sea ice area and extent data
« Reply #120 on: March 26, 2017, 08:09:18 PM »
... the largest drop requires a loss of at least 77.4k/day (loss of at least 106.6k/day with single day values) ...
Normally I'd say such a rate of loss would be impossible, but I see that in 1979 the rate of loss was nearly this high.  Of course, there was much more southern ice available to melt back then (but less CO2 and H2O [and probably methane] in the Arctic air).

I want to express my continued profound appreciation to BFTV for posting these summaries.
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Neven

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Re: 2017 sea ice area and extent data
« Reply #121 on: March 27, 2017, 09:06:26 PM »
Here's a comment Buddy posted in the wrong thread:

Below is Wip's graphic of COMBINED global sea ice area.  I love Wip's graphic for several reasons....but certainly one of the reasons is that it combines the sea ice and we can see where we are IN TOTAL.  For albedo....and other reasons....that is important.

Global warming over the last few years has been "off the charts" for both sea ice, ocean temps, and air temperature.  And this year it appears to have been attacking the sea ice in a big way.

I'll describe the "interesting things" that I see/wonder about....when I look at Wip's chart.  Note:  I have added some things to the chart:

(1)  There are 4 "legs" to the trends in global sea ice over a years time....and this is true from 1978 through today:

(A) Leg A....is from early-to-mid November and goes through mid February.  That is when the Antarctic is in PEAK MELT season and is losing ice at a faster rate than the Arctic is gaining ice.

(B) Leg B....is from mid February through mid June.  That is when the Antarctic is adding more ice than the Arctic is losing.

(C) Leg C....is from mid June through end of August/early September.  This is where the Arctic is now in PEAK MELT and losing more ice than the Antarctic is adding.

(D) Leg D...is from end of August/early September through the end of October/early November.  This is when the Arctic is adding more ice than the Antarctic is losing. 


(2)  Prior to 2016.....the "slope" of the two "peaks" in sea ice.....WAS UP as you can see by the upward sloping BLUE LINES.   Before 2016....the highest peak was the "early November peak".....which is the time of year when the Arctic is gaining ice at a fast clip AND when the Antarctic is losing ice at a SLOW CLIP, just before the Antarctic really begins to lose serious ice.

But 2016 changed all of that.  In 2016 two things happened from a "mathematical" standpoint:  (a) the Antarctic ice sheet reached a RECORD LOW MAXIMUM in late August of 2016 which is VERY EARLY, and (b) the Antarctic started losing ice in late August when the Arctic was still losing ice itself.  That combination of LOW MAX and EARLY MAX by the Antarctic.....AND....the Arctic still losing ice....created a RECORD LOW PEAK to global sea ice in early October.  That peak was about 17.5 vs the prior record low peak of 20.5.  That low peak in 2016 was about 15% LESS than the prior record low peak.

In "charting".....whether you're dealing with things in nature....or your dealing with things in "markets" (stock market, oil market, etc).....that is called a "DIVERGENCE".  Something changed or reached a tipping point....in order to cause such an immediate and significant change.

The "FUNDAMENTALS" cause the graph....the graph don't cause the fundamentals.  Did currents in the southern oceans shift to allow a greater amount of warm ocean water to attack the ice?  Did the winds coming from the interior of Antarctica blowing OUT towards the sea die down and decrease the amount of area/extent in Antarctica?

OR.....have we reached ANOTHER TIPPING POINT......where several things have slowly been "coming together" to cause the increased melt earlier in the season:  Record setting air temps over the past 3 years, continually warming ocean temps, changing ocean currents, etc.

The SECOND GRAPH BELOW......is a "stab" at what a "worst case scenario" MIGHT look like over the coming year.  If there are enough FUNDAMENTALS that are now coming together to drive the ice levels LOWER....and EARLIER.  It is NOT meant to be "this is what I think will happen."  It is more of a "what IF another significant low happens THIS YEAR AGAIN".....?  The "blue line" for the remainder of 2017 is just a "what if" scenario.

Also....note the "black circle".....that is just shown to highlight where this years line has CROSSED OVER BELOW the record low of the last year.

I KNOW where the ice is going over the next 10 years....LOWER.  What we don't know is WHEN and HOW STEEP the drop will be.  That SECOND GRAPHIC just posts something to "think about"....and ponder.  If anything CLOSE to that DOES HAPPEN this year....then the ramp up in worry will be significant.....although at this point, I'm not sure just how much more worrying can be done going from a "level 8 worry" to a "level 10 worry".           
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Pmt111500

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Re: 2017 sea ice area and extent data
« Reply #122 on: March 28, 2017, 07:44:50 AM »
Well I guess someone had to be the first to speculate on future behavior of Global sea Ice. Thanks Buddy for being the first bold one to spell out the dreaded 't'-word (tipping point).

Some notes.
1) The August 2016 would be very close to the maximum atmospheric effect of El Nino.
2) Large part of the (imo) naturally impossible deviation of last winter (starting from late October) was due to Antarctic ice melting way faster than usual.
3) Thus there could have been a tipping point for some part of Southern Ocean. I remember there was something odd going on on the region of Weddell Gyre.

This would be the Antarctic area to watch this (northern) spring. Has the Antarctic Circumpolar Current moved to an area it's not previously been? Thus the start of the freeze in Antarctic could be abnormal here as well

4) For me, the Arctic lack of growth in the autumn was pretty much what I'd expect of the WACC (and the theory of J. Francis of the diminishing temperature gradient between tropics and arctic).

5) From all of the previous. I'm not even sure we'll even see the first peak of the global graph clearly. The global graph could flat line all through this summer starting from June as the Siberian melt progresses.

An extreme scenario, but on these days they're necessary to be aware of.  Knowing you're much into politics, Buddy, I'm still of the opinion that Russians as people (and especially Siberian Russians) do not much care if their winters get milder. They might get a couple of ten millions of immigrants from south at some point, but that's an issue for the time it happens.

I'm keeping an eye on the spring progress during this post-El Nino year. I think the more pronounced swings in the extent and area of Arctic Sea ice since 2006 allows the speculations of general tipping points, but  for now i'm thinking these more of a local issue. As the weather gets stuck in one position more easily these days, the serious hobbyist of atmospheric science in me could say, the weather induced events unfolding round the northern hemisphere are of note and interest. I'm rather looking forward the time the idjit possessing The Button and his so called
friends get it. Not too much though, as their other views are also quite repulsive.
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Re: 2017 sea ice area and extent data
« Reply #123 on: April 01, 2017, 03:26:42 PM »
NSIDC finished the month back in first place for the day, the month, and the year-to-date. In fact, for the fifth consecutive month--that is, beginning with November-- NSIDC extent has been the lowest monthly average on record, and that's even with the slowdown in extent loss we've seen over the past week. A few helpful graphs:






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Re: 2017 sea ice area and extent data
« Reply #124 on: April 01, 2017, 05:21:55 PM »
Looking at the extent graph above, and at Wipneus's Global sea ice, we're about two weeks away from a new downturn in ice cover, it's happened twice that's coincidence a third time will be a trend.

Wipneus

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Re: 2017 sea ice area and extent data
« Reply #125 on: April 02, 2017, 02:21:00 PM »
Arctic Basin ice area ( total of Beaufort, Chukchi, East Siberian, Laptev and Central Basin regions) calculated from NSIDC sea ice concentration has reached a new maximum for this year. As discussed previously perfectly normal. Extent has been at 100% for a while.
Now waiting for the melting season to start.

Shared Humanity

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Re: 2017 sea ice area and extent data
« Reply #126 on: April 02, 2017, 04:59:03 PM »
The Arctic Basin SIA chart is somewhat encouraging as it clearly shows the basin is in better shape than last year and has been for about 6 weeks. Maybe this has allowed the ice to strengthen relative to 2016 despite the FDD anomaly.

Jim Pettit

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Re: 2017 sea ice area and extent data
« Reply #127 on: April 02, 2017, 05:54:21 PM »
The Arctic Basin SIA chart is somewhat encouraging as it clearly shows the basin is in better shape than last year and has been for about 6 weeks. Maybe this has allowed the ice to strengthen relative to 2016 despite the FDD anomaly.

Possibly--though it should be noted that 2012 was smashed against the ceiling for most of the period between late February and early May, and that doesn't appear to have been of much help in avoiding that year's incredibly low minimum...

Again, this should be an "interesting" year...

BornFromTheVoid

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Re: 2017 sea ice area and extent data
« Reply #128 on: April 02, 2017, 07:10:49 PM »
Update for the week to April 1st

The current 5 day trailing average is on 14,167,000km2 while the 1 day extent is at 14,126,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -1,114,000km2, a decrease from -1,255,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at -477,000km2, a decrease from -570,000km2 last week. We're currently lowest on record, the same as last week.



The average daily change over the last 7 days was +8.0k/day, compared to the long term average of -12.1k/day, and the 07, 11 and 12 average of -5.3k/day.
The average long term change over the next week is -31.5k/day, with the 07, 11, and 12 average being -23.1k/day.



The extent loss so far this April is the 9th smallest record. To achieve the largest loss, a drop of at least 55.9k/day is required (at least -58.5k/day with with single day values), while the smallest drop requires a loss of less than 24.0k/day (loss of less than 24.2k/day with single day values) and an average loss requires a drop of 38.1k/day (-39.4k/day with single day values).



The extent change in March was the 16th least negative on record, while the average extent was the lowest on record.




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Re: 2017 sea ice area and extent data
« Reply #129 on: April 05, 2017, 02:31:06 PM »
Sea ice area calculated for NSIDC sea ice concentration in the Arctic Basin (regions Beaufort, Chukchi, ESS, Laptev and Central Basin) seems to go for a record day max.

It is now at 7.173 Mm2, second behind 4th April 1988: 7.175 Mm2.


Shared Humanity

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Re: 2017 sea ice area and extent data
« Reply #130 on: April 05, 2017, 02:42:56 PM »
This basin push towards a max can only be characterized as encouraging, not in the long term but for the approaching melt season. What it is telling us is that the peripheral seas are the main contributors to the low numbers and the variability in these seas is typical of today's Arctic.

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Re: 2017 sea ice area and extent data
« Reply #131 on: April 05, 2017, 03:20:17 PM »
Not necessarily encouraging, the lower values last year were mainly due to open water north of Spitsbergen, i.e. higher values now are associated with higher transport out of the basin towards destruction.
The high area mainly means ice is compact, but if that means little movement towards the North Greenland coast where it would build thickness by compaction, it means little growth in volume for the few weeks remaining for build up. The best place to grow ice now is in opening leads while surface temperatures are still cold.

magnamentis

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Re: 2017 sea ice area and extent data
« Reply #132 on: April 05, 2017, 10:50:25 PM »
This basin push towards a max can only be characterized as encouraging, not in the long term but for the approaching melt season. What it is telling us is that the peripheral seas are the main contributors to the low numbers and the variability in these seas is typical of today's Arctic.

too much cherry picking IMO, this kind of information is fodder for deniers to interpret it their way. no offense meant, after all it's a simple statement of facts as we know them while i'm not entirely sure whether area and extent still hold too much value as information to describe the state of the ice. the more i read and look at graphs and plots based on old models, based on how it once was, the more i get the feeling that something is not right, i just hope that we won't get too much of a negative surprise if what we got by now wouldn't be bad enough already.

thanks for all the contributions from both of you but still i felt that i have to make that statement, hope it's well taken, because the other side (deniers) are very strategical at times and perhaps we as well need to be a bit smartly using the available input (staying with the borders of truth and/or best knowledge of course)
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Re: 2017 sea ice area and extent data
« Reply #133 on: April 07, 2017, 03:24:58 PM »
... i felt that i have to make that statement, hope it's well taken, because the other side (deniers) are very strategical at times and perhaps we as well need to be a bit smartly using the available input (staying with the borders of truth and/or best knowledge of course)

On the contrary, this makes me very unhappy.

It is bad enough that staying on-topic seems to be less and less respected by a very loud minority.

But being criticized for being on-topic but not being political correct in a pure sea ice thread is a step too far. Please discuss that somewhere else, I am not interested.

The subject here is "2017 sea ice area and extent data", how hard is it to stay with that?

jai mitchell

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Re: 2017 sea ice area and extent data
« Reply #134 on: April 07, 2017, 04:13:25 PM »
I think that the high basin Sea Ice Area this year is extremely interesting considering record low NSIDC sea ice extent and PIOMAS volume. 

It makes me consider the potential impacts of increased sea ice mobility, recent extreme cold (compared to the previous two winters) and the likelihood of changes in dominant wind patterns under the changing regime.

very useful and informative, cause for pause and deep thought.

thank you!
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Re: 2017 sea ice area and extent data
« Reply #135 on: April 07, 2017, 04:21:32 PM »
On the contrary, this makes me very unhappy.

It is bad enough that staying on-topic seems to be less and less respected by a very loud minority.

But being criticized for being on-topic but not being political correct in a pure sea ice thread is a step too far. Please discuss that somewhere else, I am not interested.

The subject here is "2017 sea ice area and extent data", how hard is it to stay with that?

I agree, and would like to add: F*** climate risk deniers and how they may twist words on some obscure Forum.
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gerontocrat

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Re: 2017 sea ice area and extent data
« Reply #136 on: April 07, 2017, 04:27:05 PM »
Dear Neven,
I have to inform you that due to the activities of persons including me this obscure blog is not as obscure as once it was (and nor is your typepad).
Sorry,
Gerontocrat.
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Re: 2017 sea ice area and extent data
« Reply #137 on: April 07, 2017, 05:34:21 PM »
On the contrary, this makes me very unhappy.

It is bad enough that staying on-topic seems to be less and less respected by a very loud minority.

But being criticized for being on-topic but not being political correct in a pure sea ice thread is a step too far. Please discuss that somewhere else, I am not interested.

The subject here is "2017 sea ice area and extent data", how hard is it to stay with that?

I agree, and would like to add: F*** climate risk deniers and how they may twist words on some obscure Forum.

duly noted including the general opinion that it does not matter (ref to f... them) it's a valid possible point of view and hence i'll try to remember. didn't mean to make anyone unhappy ;)
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Re: 2017 sea ice area and extent data
« Reply #138 on: April 07, 2017, 06:13:09 PM »
I'm curious about the effect Nares Strait is having on Baffin Bay.  Specifically, Kane Basin (and the entire Strait) has not had an effective ice arch all winter, so Nares has exported a lot of up-to-about-one-meter-thick (grown in Nares Strait) ice.  The volume (not thickness) of ice created in Nares Strait will be much greater than usual, as new ice with no snow cover is (virtually) continually being created in the northern parts of the Strait, and the first 10 or 50 cm grows much faster (in a given temperature) than the third.  And it is almost constantly being exported to Baffin Bay.  Other years, Nares Strait closes in January or February and gets flushed out in June. Thicker, obviously, but after a great deal of melting happens further south, and nowhere near as much ice area gets exported, in total.
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Re: 2017 sea ice area and extent data
« Reply #139 on: April 08, 2017, 08:18:19 AM »
Meanwhile, commenter Al Roger reported on the blog that NSIDC has decided to change the counter-intuitive way average monthly extent numbers are calculated:

And with all that, NSIDC inform me:-
“We have received similar questions in the recent past about our December numbers, and the science leads have decided to switch the way in which the averaging is completed. The current method is really just a legacy way of doing things as the dataset's original intended purpose was to simply produce coarse resolution figures (c.a. 2007) on a monthly interval for our site. The dataset is now clearly the most popular product we have due to our blog-style publication and thus changes will be made after considering any impact to the community.“

So expect the monthly extent numbers to drop in the near future (Al shows some numbers).

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Re: 2017 sea ice area and extent data
« Reply #140 on: April 08, 2017, 10:05:29 AM »
Wip


Will there be a means of converting from the new numbers to the legacy numbers?


Thanks
Terry

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Re: 2017 sea ice area and extent data
« Reply #141 on: April 08, 2017, 02:49:46 PM »
Wip


Will there be a means of converting from the new numbers to the legacy numbers?


Thanks
Terry

We have to wait what the NSIDC says when they introduce the change. Perhaps some average difference (for the month of year) can be given.

Remember that the problem is that the current (legacy) way is to average concentration first and from that extent. For a grid cell 5 days of ice cover is enough to exceed the 15% and the cell is included for the full 100%. The grid cell in the new way will be counted as about 16% (5 divided by number of days in the month). The net difference will obviously depend a lot on the particular dynamics in sea ice in that particular month.

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Re: 2017 sea ice area and extent data
« Reply #142 on: April 08, 2017, 02:54:02 PM »
Wipneus: will you produce daily and forecasted numbers from NSIDC values?

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Re: 2017 sea ice area and extent data
« Reply #143 on: April 08, 2017, 05:43:16 PM »

On the contrary, this makes me very unhappy.

It is bad enough that staying on-topic seems to be less and less respected by a very loud minority.

But being criticized for being on-topic but not being political correct in a pure sea ice thread is a step too far. Please discuss that somewhere else, I am not interested.

The subject here is "2017 sea ice area and extent data", how hard is it to stay with that?

While I do not know what was said as I blocked this commenter a while back, I want to thank you for this.

Shared Humanity

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Re: 2017 sea ice area and extent data
« Reply #144 on: April 08, 2017, 05:48:21 PM »
Meanwhile, commenter Al Roger reported on the blog that NSIDC has decided to change the counter-intuitive way average monthly extent numbers are calculated:

And with all that, NSIDC inform me:-
“We have received similar questions in the recent past about our December numbers, and the science leads have decided to switch the way in which the averaging is completed. The current method is really just a legacy way of doing things as the dataset's original intended purpose was to simply produce coarse resolution figures (c.a. 2007) on a monthly interval for our site. The dataset is now clearly the most popular product we have due to our blog-style publication and thus changes will be made after considering any impact to the community.“

So expect the monthly extent numbers to drop in the near future (Al shows some numbers).

What I find most awesome about this response is their reference to the "community". There is a growing community (including this blog) of actively engaged persons on the planet. I draw comfort that it exists and is being recognized.

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Re: 2017 sea ice area and extent data
« Reply #145 on: April 08, 2017, 11:41:42 PM »

Wip

It sounds as though NSIDC's new method will be a huge improvement, but unless they run their figures back there will be a huge gap with little connecting the new data to the historic.
A comparison between where we are and where we were in 1979, or 2007, or even 2012 might be lost forever.
Perhaps publishing parallel charts for a few seasons would ameliorate the situation?


Is it possible for you to provide such a comparison, or will the needed data either not be available, or require so much massaging as to make this impracticable. It's not my intent to add to the huge effort you already expend on our behalf.


 Thanks
 Terry

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Re: 2017 sea ice area and extent data
« Reply #146 on: April 09, 2017, 12:13:46 AM »
Terry, I think/hope NSIDC would somehow provide the average for all past years as well. The major strength of NSIDC data is its long record that enables good comparisons. I'm quite sure they are aware of it.

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Re: 2017 sea ice area and extent data
« Reply #147 on: April 09, 2017, 08:32:09 AM »
Wipneus: will you produce daily and forecasted numbers from NSIDC values?

I am not sure what you are asking. NH NSIDC area/extent data are found at the following links (daily updated when NSIDC releases SIC data):

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

In the SH the links are:

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

What "forecasted numbers" and why do you think that I can produce them?




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Re: 2017 sea ice area and extent data
« Reply #148 on: April 09, 2017, 08:37:09 AM »

It sounds as though NSIDC's new method will be a huge improvement, but unless they run their figures back there will be a huge gap with little connecting the new data to the historic.
A comparison between where we are and where we were in 1979, or 2007, or even 2012 might be lost forever.
Perhaps publishing parallel charts for a few seasons would ameliorate the situation?

Hi Terry,

I fully expect that NSIDC will replace the complete (1978-present) monthly data series by the updated one. If not I will.

Not sure if they will archive the old data, so perhaps this is the time to do so (reminder to myself).

Lord M Vader

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Re: 2017 sea ice area and extent data
« Reply #149 on: April 09, 2017, 10:33:53 AM »
Wipneus: I was thinking about these for example CT-area numbers that you posted quite regularly during the melting season last year.  :)

http://forum.arctic-sea-ice.net/index.php/topic,1457.msg87403.html#msg87403

Best regards, LMV