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Arctic Sea Ice Extent, Area, and Volume


ORH_wxman
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21 hours ago, WxUSAF said:

Ooof.  Holy shi-t.  

 

 

CxbPIgCXAAAwIOC.jpg

Does that main max in the late part of the year happen because the Antarctic sea ice is just passed its max plus the Arctic is supposed to be rapidly freezing up?  If so, I'd wager this is a combo of the wholesale lack of sea ice in the Arctic plus a paltry (relative to normal) level in the Antarctic.

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IJIS extent has opened up a huge lead. Down 46k yesterday (biggest drop in Nov in 10 years), which puts it about 750k behind 2012. 2012 rockets away shortly and is replaced by 2006 for previous lowest (which was the 2nd warmest winter behind last year). I suspect we'll get pretty close to 1M below the record before closing later in the month (2006 had quite the slowdown in Nov before speeding back towards the pack).

Anomalies look to "revert" back to +10C above 80N and +6C over the Arctic Ocean as a whole, so we should see some resumption of freezing, if at a somewhat sluggish pace. The real story is the continuing lack of decent freezing degree day totals, which if it continues to be sustained, will put the hurt on spring thickness. Last year was a -650 anomaly (above the Arctic Circle) and -1075 (above 80N) or about 800 overall. A doubling of that anomaly to -1300/-2150 puts us in striking range of near ice-free conditions by summer's end as it causes thickness gains to drop below the critical ~1.7m threshold. I'm far from convinced that we'll get a doubling of those anomalies, but with the way it is going, it might get somewhat close.

Speaking of which, there's another strat PV split forecasted in the medium range.

Edit: My numbers are a bit off.

Ice thickness growth= sqrt(FDD/804)

Normal for the Arctic Ocean is 4500 FDD (5500 north of 80N). This equals about 2.2m of thickness growth overall (a bit more at the pole/near Greenland).

A -1300 anomaly would drop this to 2.0m of thickness growth.

A -2000 anomaly would drop this to 1.7m, which is where you would need to be to get ice-free conditions at the end of summer assuming a normal melt year. A 2007 or 2012 style melt year would require quite a bit less, of course.

To achieve a 2500 FDD total for 1.7m of average thickness growth, the average temperature during the freezing season (Sept 15-April 15) would need to average -13 to -14C. That's the number we need to watch. If we keep getting crazy bursts of periodic warmth through say... February, I'd be worried. If it finally mean-reverts and gets closer to normal for a while, it won't be so bad.

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17 hours ago, Bacon Strips said:

good thing Trump isn't president yet , gives him some more time to flip-flop.

I was thinking the same thing.  This departure from normal in global sea ice has really blown up on social media and I'd expect the mainstream media to pick it up really soon.  Be curious to see what the Trump admin. would have to say about this, especially if we don't see a sizable shift in the winter months for the artic and the melt season come Spring starts off really bad.

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On 11/16/2016 at 11:50 AM, skierinvermont said:

You're right it doesn't exaggerate it as much as I thought. But I think it does still exaggerate it somewhat. The area of Russia is 6.6 million square miles. The area of the arctic ocean including the Kara, Barents, Hudson and the seas on either side of Greenland is 5.4 million. Probably around 4 million if looking just at the high arctic ocean.

There was an article on this recently... How distorted maps are versus reality.

The arctic is in a world of sh-t right now, but the global anomaly is still sitting around +0.5C above the 30 year moving average. That Russia cold is insane. We need that cold on top of the planet.

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On 11/17/2016 at 10:56 AM, stadiumwave said:

Anyone know where GlobalWarmer poster is? I figured he'd be all over this.  Kind of concerns me he's not posting. 

I believe he was previously named frivolous.

Something happened to him in his life I believe. He checked in and said he didn't have time for this anymore.

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3 hours ago, Jonger said:

Something happened to him in his life I believe. He checked in and said he didn't have time for this anymore.

MIB ?   all in all, I hope he's well ..   It was fun seeing him and ORH go at it at times, over the years.    Guess I gotta take over and keep the pressure on now.  (jk) 

I learned a lot from both him and ORH regarding the arctic...and others here.    

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This departure from normal in global sea ice has really blown up on social media and I'd expect the mainstream media to pick it up really soon. 

when pigs fly.  Mainstream media is so owned by the Republican agenda, so I highly doubt it.   We'll have to wait until ALL ice is gone , or once things start looking like this.  

then maybe...just maybe there'll be a story or 2. 

 

slr-sea-level-rise1.jpg

 

 

 

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On November 18, 2016 Arctic Sea Ice Extent (JAXA) was 8,320,714 square kilometers. That was a decline of 97,385 square kilometers from the previous day. It is also 948,831 square kilometers below the previous record minimum for the date of 9,269,545 square kilometers, which was set in 2012.

The biggest 1-day declines in the October 1-December 31 timeframe:

1. 97,385 sq. km., 11/18/2016 (exceeded the biggest 2-day decline for this timeframe).

2. 54,064 sq. km., 12/25/2011

3. 53,292 sq. km. 12/1/2007

4. 51,274 sq. km. 12/17/2011

5. 48,440 sq. km. 10/25/2009

The November 17, 2016 decline of 46,717 square kilometers ranked 6th biggest for this timeframe. The 11/17-18/2016 2-day decline of 144,102 square kilometers exceeded the previous record of 81,804 square kilometers, which was established on 12/1-2/2007.

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9 hours ago, pazzo83 said:

Wait - we lost nearly 100,000 sq km of ice coverage in ONE day?

Also, all those records are within the last decade.  Man, we are f*cked.

 

Important to remember methodology here. It's done by satellite imaging so, measurements are intermittent (depending on orbit) not to mention accurate record history might be difficult for before 1990ish. As with all optical remote sensing, these measurements are prone to occlusion error (in this case  by clouds/sea water.) Also, I don't know what technically constitutes a "loss," true melting (calving events [breaks "up])  or just the loss of continuity of the Antarctic ice mass (meaning a large but complete ice shelf breaks "off") . Neabulous but important issues that probably get glazed over in non-scientific journal reporting and clickbait). 

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1 hour ago, zenmsav6810 said:

Important to remember methodology here. It's done by satellite imaging so, measurements are intermittent (depending on orbit) not to mention accurate record history might be difficult for before 1990ish. As with all optical remote sensing, these measurements are prone to occlusion error (in this case  by clouds/sea water.) Also, I don't know what technically constitutes a "loss," true melting (calving events [breaks "up])  or just the loss of continuity of the Antarctic ice mass (meaning a large but complete ice shelf breaks "off") . Neabulous but important issues that probably get glazed over in non-scientific journal reporting and clickbait). 

Given this decline has been persistent and today's value is 160k lower than the value 3 days ago it's not due to cloud cover or measurement error. If we saw a 100k blip down and then it went right back up the next day then a big portion of the dip could have been measurement error. But when the measurement is consistent across 3 days, and in fact just keeps getting lower, it's not measurement error. 

A calving event or ice shelf breaking off would have no effect on sea ice area. If anything land ice or ice shelves calving would increase sea ice area because previously land bound ice would now be afloat and thus newly within the sea ice boundary area.

Nor does an area of sea ice separating from (IE getting blown away from) the rest of the sea ice pack, decrease sea ice area. The resolution of the satellites measurements is such that this separated ice would still be included in the total. Obviously small icebergs would go unnoticed. But 100,000 sq km is several orders of magnitude bigger than what might go unnoticed.

Sea ice decreases this time of year are probably largely due to wind compaction. We could also be seeing newly formed ice from the last week or two melting. When it first freezes it would be very thin and then if the weather changes it might melt again.

Normally any compaction would be compensated for by the rapid freezing going on elsewhere. The ice area and volume should be exploding this time of year. So what we're really likely seeing is a general arctic-wide lack of rapid freezing combined with either compaction and/or melting of newly formed ice. 

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