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Author Topic: Latest PIOMAS update (mid July update)  (Read 532559 times)

magnamentis

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Re: Latest PIOMAS update (February)
« Reply #1300 on: February 04, 2017, 11:32:47 AM »
Insane...

Not you, Wipneus, I mean PIOMAS.  ;)

just for fun, i think you mean neither WIP nor PIOMAS but the ICE-VOLUME LOL :-)
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crandles

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Re: Latest PIOMAS update (February)
« Reply #1301 on: February 04, 2017, 01:47:49 PM »
2013 31 17.733
2017 31 16.162  1.571 below previous lowest for date

2012 365 13.921
2016 365 13.078 0.843 below previous lowest for date

2012 335 10.235
2016 335  9.511 0.724 below previous lowest for date

2012 305   6.547
2016 305   6.534 0.013 below previous lowest for date

So gap grew:
0.711 in Nov
0.119 in Dec
0.728 in Jan

Seems a little puzzling to me. Why so little growth (edit in the gap) in Dec and so much in Jan?
(when compared to temp diffs. Export?)
« Last Edit: February 04, 2017, 01:54:34 PM by crandles »

DrTskoul

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Re: Latest PIOMAS update (February)
« Reply #1302 on: February 04, 2017, 01:50:57 PM »

2013 31 17.733
2017 31 16.162  1.571 below previous lowest for date

2012 365 13.921
2016 365 13.078 0.843 below previous lowest for date

2012 335 10.235
2016 335  9.511 0.724 below previous lowest for date

2012 305   6.547
2016 305   6.534 0.013 below previous lowest for date

So gap grew:
0.711 in Nov
0.119 in Dec
0.728 in Jan

Seems a little puzzling to me. Why so little growth in Dec and so much in Jan?

It was a stolen freezing season.. All those lows have done their damage?
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crandles

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Re: Latest PIOMAS update (February)
« Reply #1303 on: February 04, 2017, 02:01:02 PM »

It was a stolen freezing season.. All those lows have done their damage?

Certainly storms do damage. But do they show up as higher temps? Nov & Dec 16 compared 12 were much warmer and if anything Jan 17 compared Jan 13 warmer but not by as much. If Dec 16 was much warmer but didn't have storms maybe that has less effect ... perhaps but were there really few storms Dec 16?

Wipneus

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Re: Latest PIOMAS update (February)
« Reply #1304 on: February 04, 2017, 02:10:24 PM »
Animated thickness for January. Map format changed (using common PS projection with Greenland pointing down),

Tigertown

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Re: Latest PIOMAS update (February)
« Reply #1305 on: February 04, 2017, 03:04:12 PM »
That's gonna hurt the numbers, when that thicker patch turns the corner, and eventually melts out.

Wipneus

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Re: Latest PIOMAS update (February)
« Reply #1306 on: February 04, 2017, 03:11:49 PM »
The average thickness for January map, followed comparisons with previous years.

Flocke

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Re: Latest PIOMAS update (February)
« Reply #1307 on: February 04, 2017, 03:36:44 PM »
Seems a little puzzling to me. Why so little growth (edit in the gap) in Dec and so much in Jan?
Higher temperatures might have more impact on growth of thicker ice.

ktonine

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Re: Latest PIOMAS update (February)
« Reply #1308 on: February 04, 2017, 04:28:25 PM »
So gap grew:
0.711 in Nov
0.119 in Dec
0.728 in Jan

Seems a little puzzling to me. Why so little growth (edit in the gap) in Dec and so much in Jan?
(when compared to temp diffs. Export?)

Crandles, I think the answer comes in two parts - the actual temperature at which ice begins to form on the sea and the non-linearity of ice formation as a function of temperature.

DMI N80 for Nov. 2016 was 7.88°C warmer than Nov. 2012 while Dec 2016 was 6.15°C.  While this difference is significant it is not enough to account for the disparity in volume growth.  It's only a difference of 52 FDDs.

What this calculation doesn't show is the absolute Nov. 2016 average temperature; which was just -11.93°C for N80. For N70 to N80 it was warmer still. In realistic sea conditions ice isn't expected to form until temperatures reach approximately -10°C.  For much of the arctic temperatures were barely reaching that level in Nov. This shows up in the record low extent numbers.

In December, despite a smaller difference in monthly temperatures between 2016 and 2012, the absolute temperatures were well below those needed for ice formation.  And once ice begins to form the non-linear nature of ice formation meant that 2016 would actually form more ice because it was starting from a thinner ice thickness.

Remember that volume increase is essentially a function of temperature times extent.  By the time we get to January 2016's N80 average temperature is nearly 3°C warmer than 2012.  While this is still only 90 FDDs difference when combined with the difference in extent I think the numbers become much less puzzling.

The final piece that I think would make the numbers completely understandable is wind.  I suspect 2016-17 was much windier than 2012-13.  This would retard ice formation when and where it's windy and possibly lead to export of ice into "killing zones" of warm ocean waters.

oren

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Re: Latest PIOMAS update (February)
« Reply #1309 on: February 04, 2017, 04:30:53 PM »
Not sure whether to believe PIOMAS or not, but it claims this year is unique in the location of the 4+ meter ice, and the animation shows it moving slowly but surely towards Svalbard and the Fram. If/when it does, there will be an additional source of volume loss, as if the current situation wasn't enough.

Attached an end-of-month chart, which I feel brings the latest crash in numbers to a better focus.

magnamentis

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Re: Latest PIOMAS update (February)
« Reply #1310 on: February 04, 2017, 05:39:41 PM »
if i see this correctly this is around the volume we had in AUGUST 1989

and is lower than the volume in September 1979 & 1984

there are more examples, just sayin'
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iceman

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Re: Latest PIOMAS update (February)
« Reply #1311 on: February 04, 2017, 05:46:03 PM »
So gap grew:
0.711 in Nov
0.119 in Dec
0.728 in Jan

Seems a little puzzling to me. Why so little growth (edit in the gap) in Dec and so much in Jan?
(when compared to temp diffs. Export?)
   ....
Remember that volume increase is essentially a function of temperature times extent.  By the time we get to January 2016's N80 average temperature is nearly 3°C warmer than 2012.  While this is still only 90 FDDs difference when combined with the difference in extent I think the numbers become much less puzzling.
   ....

I followed your explanation up to here.  From eyeballing NSIDC and other graphs, though, it's not clear that average extent anomaly during January was much different than December.  Based only on extent and the 2012 vs. 2016 temperature comparisons, we might expect a drop-off in the volume anomaly (a smaller gap as Crandles puts it) in January.  Your point about freezing dynamics partly covers why December should have a smaller gap vs. 2012, but not why January's would be larger than both Nov and Dec..

ktonine

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Re: Latest PIOMAS update (February)
« Reply #1312 on: February 04, 2017, 06:15:47 PM »
I followed your explanation up to here.  From eyeballing NSIDC and other graphs, though, it's not clear that average extent anomaly during January was much different than December.  Based only on extent and the 2012 vs. 2016 temperature comparisons, we might expect a drop-off in the volume anomaly (a smaller gap as Crandles puts it) in January.  Your point about freezing dynamics partly covers why December should have a smaller gap vs. 2012, but not why January's would be larger than both Nov and Dec..

Jan. is definitely the weakest part of the analysis.  Which is why I my last paragraph said:

The final piece that I think would make the numbers completely understandable is wind.  I suspect 2016-17 was much windier than 2012-13.  This would retard ice formation when and where it's windy and possibly lead to export of ice into "killing zones" of warm ocean waters.

If export and wind fields were equal in Jan 2017 and Jan 2013, then the rationale for January is a mystery to me as well.  Actually, with a smaller, thinner ice pack even the same winds would lead to a decrease in growth - so even equal wind fields would lead to some discrepancy.  But for my January analysis I would expect a noticeable difference.

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Re: Latest PIOMAS update (February)
« Reply #1313 on: February 04, 2017, 07:27:20 PM »

It was a stolen freezing season.. All those lows have done their damage?

Certainly storms do damage. But do they show up as higher temps? Nov & Dec 16 compared 12 were much warmer and if anything Jan 17 compared Jan 13 warmer but not by as much. If Dec 16 was much warmer but didn't have storms maybe that has less effect ... perhaps but were there really few storms Dec 16?
The answer lies in heat transfer.  Look at the FDD's.  Each lost degree of freezing translates directly into less ice.

You can also look at the starting conditions.  The previous seasons being measured started with less ice and caught up more, whereas last fall, growth and thickening stalled most of the fall with those astonishing temperatures.

The whole thermal exchange mechanism in the Arctic has been convulsively disrupted by changes in atmospheric circulation and exposed high-latitude open water.  It's not settling down either.
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Re: Latest PIOMAS update (February)
« Reply #1314 on: February 04, 2017, 07:36:40 PM »
.

Seems a little puzzling to me. Why so little growth (edit in the gap) in Dec and so much in Jan?
(when compared to temp diffs. Export?)

There was a strong recovery in Jan 2013 but the anomaly stayed level in 2017. Its Jan 2013 thats generating this effect rather than Jan 2017. (and if there's no 2013 style recovery in the next couple of months, its not going to take all that strong a summer melt to take a big chunk out of the record minimum)


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Re: Latest PIOMAS update (February)
« Reply #1315 on: February 04, 2017, 07:57:00 PM »
Here's the up to date version of Andy Lee Robinson's alternative visualisation of the PIOMAS numbers:

http://GreatWhiteCon.info/2017/02/facts-about-the-arctic-in-february-2017/
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FishOutofWater

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Re: Latest PIOMAS update (February)
« Reply #1316 on: February 04, 2017, 07:59:33 PM »
.

Seems a little puzzling to me. Why so little growth (edit in the gap) in Dec and so much in Jan?
(when compared to temp diffs. Export?)

There was a strong recovery in Jan 2013 but the anomaly stayed level in 2017. Its Jan 2013 that's generating this effect rather than Jan 2017. (and if there's no 2013 style recovery in the next couple of months, its not going to take all that strong a summer melt to take a big chunk out of the record minimum)

There was a sudden stratospheric warming in early Jan 2013 and intense high pressure over the Arctic ocean that led to clear skies, subsidence, intense long wave radiation of heat to space and Ekman convergence of ice in the central Arctic. January 2013 was quite exceptional.

That said when ice is very thin as it was this fall and in fall 2012, it normally thickens rapidly because ice is an insulator. When ice was thicker decades ago heat transfer from the ocean to the atmosphere was slowed by the insulating properties of ice. This year's build up of thickness was very slow given how thin it was initially.

Lord M Vader

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Re: Latest PIOMAS update (February)
« Reply #1317 on: February 04, 2017, 08:22:06 PM »
Crossposting here from the thread "2017 ENSO":

"When next bigger El Niño arrives, the Arctic will be in tremendeous trouble. Latest U_Albany forecast depicts a weak-moderate WWB which should strengthen the weak downwelling Kelvin wave. And MJO will move into phase 7 in about 5-7 days with a fairly high amplitude according to both GFS an ECMWF.

The WWB will be limited to 120-150oE while strong easterlies initially will hover around the Dateline but are forecasted to weaken in about a week or so. Worth to mention is that the last time we saw a WWB was by New Year 2015/1016 which is about 13 months ago now."

Addition to the above: If a new El Niño would be underway (subsurface temps are about 1o warmer than normal in the West Pacific with a small pool of +2o) and if it's of a decent strength I think we might reach the tipping point very soon. By then, the race to the bottom will be quick. If the ice is growing so slow as it has done this winter, I don't want to think about howslow it will grow if a new major El Niño blows up the temperatures to a new record level.

Blizzard92

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Re: Latest PIOMAS update (February)
« Reply #1318 on: February 04, 2017, 08:40:28 PM »
I've updated all of my PIOMAS sea ice thickness and volume figures here: http://sites.uci.edu/zlabe/arctic-sea-ice-volumethickness/
UC Irvine - Earth System Science Ph.D. Student
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Jim Hunt

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Re: Latest PIOMAS update (February)
« Reply #1319 on: February 04, 2017, 09:00:35 PM »
I've updated all of my PIOMAS sea ice thickness and volume figures here


Thanks Zack. Would it be OK if "Snow White" reproduced one or two of those, with appropriate attribution?

Whilst you're around, can you offer any tips & tricks over here?

http://forum.arctic-sea-ice.net/index.php/topic,1871.0.html

P.S. I just scrolled down to the small print at the bottom, so I'll take that as a "Yes" to my first question!
« Last Edit: February 04, 2017, 09:10:38 PM by Jim Hunt »
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Blizzard92

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Re: Latest PIOMAS update (February)
« Reply #1320 on: February 04, 2017, 09:29:26 PM »
Sure thing! :)
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meddoc

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Re: Latest PIOMAS update (February)
« Reply #1321 on: February 04, 2017, 09:54:27 PM »
Looking at those graphs and projecting into 1st May- there's little chance we'll end up above 20.000 km3
In that case, prepare for Nuclear Winter

Neven

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Re: Latest PIOMAS update (February)
« Reply #1322 on: February 04, 2017, 10:58:57 PM »
Certainly storms do damage. But do they show up as higher temps? Nov & Dec 16 compared 12 were much warmer and if anything Jan 17 compared Jan 13 warmer but not by as much. If Dec 16 was much warmer but didn't have storms maybe that has less effect ... perhaps but were there really few storms Dec 16?

Crandles, I don't know if this answers your question, but I had a look at SLP for Jan 2013 and Jan 2017 (for the latest PIOMAS update). The difference couldn't be larger. A lot of high pressure in 2013, and thus outward radiation. A lot of low pressure in 2017, and thus clouds. I don't know about transport. High pressure means Beaufort Gyre means Fram export, but this past January a lot of the low pressure was caused by storms coming in via the Atlantic, and this also caused a lot of export, I believe.
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Pmt111500

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Re: Latest PIOMAS update (February)
« Reply #1323 on: February 05, 2017, 05:50:32 AM »
Certainly storms do damage. But do they show up as higher temps? Nov & Dec 16 compared 12 were much warmer and if anything Jan 17 compared Jan 13 warmer but not by as much. If Dec 16 was much warmer but didn't have storms maybe that has less effect ... perhaps but were there really few storms Dec 16?

Crandles, I don't know if this answers your question, but I had a look at SLP for Jan 2013 and Jan 2017 (for the latest PIOMAS update). The difference couldn't be larger. A lot of high pressure in 2013, and thus outward radiation. A lot of low pressure in 2017, and thus clouds. I don't know about transport. High pressure means Beaufort Gyre means Fram export, but this past January a lot of the low pressure was caused by storms coming in via the Atlantic, and this also caused a lot of export, I believe.

The route of export is different for lows and highs I guess. I wouldnt be surprised if the Beaufort gyre had changed direction duringn these continuing low pressure intrusions. They don't let the ice stay in the Arctic Basin for as long as high pressure would.
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OSweetMrMath

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Re: Latest PIOMAS update (February)
« Reply #1324 on: February 05, 2017, 10:11:32 AM »
Well, this is terrifying. I'm attaching my volume anomaly graph, which I've been producing on and off for the last year. As before, this shows the anomaly (or residuals) after accounting for both the linear trend and the seasonal variation in ice volume. The anomaly decreased (became more negative) through October and November, which is highly unusual. It trended slightly down in January, meaning that the current volume is 2 thousand cubic km below what would have been expected based on the downward linear trend for January.

The graph doesn't have a key, so every year since 1979 is shown as a thin black line. Years starting in 2010 are in thicker colored lines, in rainbow order, so red is 2010 and the purplish color is 2016. The colors are changed from previous graphs because of the new year. January 2017 is the thick black line. The volume anomaly is in thousand of cubic km.

I have sometimes posted about the time series model I use to predict ice volume. The prediction from last January for this January's volume was 16.4 thousand cubic km. Since the actual value is 14.6 thousand cubic km, I think we can call that a miss. Most of the error was due to the November volume, which came in 900 cubic km below my prediction based on the October data. Looking forward, the model predicts a monthly volume of 20.8 thousand cubic km for April and 3.6 thousand cubic km for September. If these hold, that would be a record low maximum by over 1.5 thousand cubic km, and also a record low minimum, barely edging out the minimum in 2012.

This is a little unnerving, because the model is generally somewhat conservative. When observed values are lower than predicted, as they have been, future predicted values generally discount the low observations and continue to predict higher values. In order to currently predict a new record low, recent observations must be far below the predictions.

The predictions have a substantial uncertainty, especially for September since it's 8 months in advance. While this means that the actual ice volume could come in well larger than these predictions, the volume could also be substantially smaller than the predictions.

gerontocrat

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Re: Latest PIOMAS update (February)
« Reply #1325 on: February 05, 2017, 10:55:57 AM »
NOT reported by the BBC, The Guardian or anywhere else that I can find. The message is not getting out there.

Paddy

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Re: Latest PIOMAS update (February)
« Reply #1326 on: February 05, 2017, 12:50:40 PM »
NOT reported by the BBC, The Guardian or anywhere else that I can find. The message is not getting out there.

Nothing on a news.google.com search either. I suspect a lot of the usual outlets feel they've given their coverage to sea ice for this season back when wipneus' global extent chart was all over Twitter :S

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Re: Latest PIOMAS update (February)
« Reply #1327 on: February 05, 2017, 12:59:38 PM »
I know this is serious, but can't help laughing, wondering if most media people who are not meteorologist know what PIOMAS is or that volume of sea ice is even monitored.

Neven

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Re: Latest PIOMAS update (February)
« Reply #1328 on: February 05, 2017, 01:05:30 PM »
Latest PIOMAS update on the ASIB is up.
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iceman

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Re: Latest PIOMAS update (February)
« Reply #1329 on: February 05, 2017, 05:22:07 PM »
I've updated all of my PIOMAS sea ice thickness and volume figures here: http://sites.uci.edu/zlabe/arctic-sea-ice-volumethickness/

Hey Zack, you could use the "Angry Roc" graphic from January as a T-shirt logo or something.

Arctic Sea Ice Thickness Jan 2017_ZLabe
« Last Edit: February 06, 2017, 01:38:33 AM by iceman »

Jim Pettit

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Re: Latest PIOMAS update (February)
« Reply #1330 on: February 05, 2017, 06:38:52 PM »
The "death spiral" continues to tighten and constrict:



Meanwhile, the anomaly grows:



...And again (still?) we are headed into uncharted waters:



While I'm at it, a few more alarming graphs (click for interactive versions):








RikW

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Re: Latest PIOMAS update (February)
« Reply #1331 on: February 06, 2017, 08:48:36 AM »
There has been some news about it on the website of the dutch state television with title "The decrease in sea ice is accelerating" though the graphs are really alarming, especially the death spiral graph

Wipneus

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Re: Latest PIOMAS update (February)
« Reply #1332 on: February 06, 2017, 09:12:15 AM »
There has been some news about it on the website of the dutch state television with title "The decrease in sea ice is accelerating" though the graphs are really alarming, especially the death spiral graph


Thanks Rik, for those speaking Dutch::

http://nos.nl/op3/artikel/2156592-de-afname-van-het-zee-ijs-gaat-steeds-sneller.html

Neven

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Re: Latest PIOMAS update (February)
« Reply #1333 on: February 06, 2017, 03:22:13 PM »
That's very nicely done. My compliments to Dutch TV.
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iceman

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Re: Latest PIOMAS update (February)
« Reply #1334 on: February 06, 2017, 05:06:01 PM »
   .... I'm attaching my volume anomaly graph ....
   ....
The predictions have a substantial uncertainty, especially for September since it's 8 months in advance. While this means that the actual ice volume could come in well larger than these predictions, the volume could also be substantially smaller than the predictions.

Thanks for the updated graph.  (Suggestion: add an orange line to get an extra year into the color scheme.  Wouldn't want 2010 to go to black in next year's edition.)

Curious about your time series model.  Under what conditions do you think it has greatest predictive accuracy?

liefde

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Re: Latest PIOMAS update (February)
« Reply #1335 on: February 09, 2017, 10:07:41 AM »
Well, this is terrifying. [...]
You may want to consider adding a legend with the graph, because the thin line at the bottom seems to indicate a lower record anomaly exists, which I doubt is true, making the graph less impactful than it should be. Or just remove that thin line.

liefde

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Richard Rathbone

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Re: Latest PIOMAS update (February)
« Reply #1337 on: February 09, 2017, 01:45:29 PM »
Well, this is terrifying. [...]
You may want to consider adding a legend with the graph, because the thin line at the bottom seems to indicate a lower record anomaly exists, which I doubt is true, making the graph less impactful than it should be. Or just remove that thin line.

Its 1982, which is accurately depicted as the record on this measure.

Herfried

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Re: Latest PIOMAS update (February)
« Reply #1338 on: February 09, 2017, 01:56:13 PM »
@ liefde: No, these Impact on the earths rotation are really tiny.

Way too small for any feedback onto the clinate. These impacts are way smaller than e.g. the slow but constant shifts due to the Milankovich cycles - which do start and end glacial and interglacial periods - still their effect is outshined by our direct contribution via greenhouse gasses.

Here you see longer term effects of a warming, melting arctic ocean. WACCy situations are becoming more and more standard - a new normal. This changes positions of lows and highs, wind directions and oceanic streams.

Additionally the ice becomes less stable.

Thats what you see. Wind and.oceabic streams are grabbing weakened old ice, pushing it out through the Fram strait.

RoxTheGeologist

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Re: Latest PIOMAS update (January)
« Reply #1339 on: February 09, 2017, 04:13:15 PM »
I must say the PIOMAS location of the thick ice is very strange.
Indeed.
Could that be related to https://www.washingtonpost.com/news/energy-environment/wp/2016/04/08/the-melting-of-greenland-and-antarctica-isnt-just-raising-seas-its-changing-the-earths-rotation/ perhaps?


Unlikely. The earth will slow down as the mass from the poles gets distributed across the oceans.  Think of an ice skater in a fast tight spin holding out their arms and slowing down. It's simple conservation of angular momentum.

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Re: Latest PIOMAS update (February)
« Reply #1340 on: February 09, 2017, 06:43:51 PM »
Unlikely. The earth will slow down as the mass from the poles gets distributed across the oceans.  Think of an ice skater in a fast tight spin holding out their arms and slowing down. It's simple conservation of angular momentum.


Yes, but I don't think it will be evenly distributed because of the the topology of the planet. So, yes it will slow down , but more like an ice skater "squiggling" their arms,  or so I imagine. I believe that like everything else like sea ice, glaciers and plate tectonics, the planetary movements will change at an accelerated rate proportional to the speed of warming. It could still be too slow to be significant, but that's something that I have not ruled out yet.

Sorry for the offtopic, maybe take this to the thread "Milankovitch Cycles doubts" http://forum.arctic-sea-ice.net/index.php/topic,1868.msg101892.html#msg101892
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Re: Latest PIOMAS update (January)
« Reply #1341 on: February 09, 2017, 09:28:29 PM »
I must say the PIOMAS location of the thick ice is very strange.
Indeed.
Could that be related to https://www.washingtonpost.com/news/energy-environment/wp/2016/04/08/the-melting-of-greenland-and-antarctica-isnt-just-raising-seas-its-changing-the-earths-rotation/ perhaps?


Unlikely. The earth will slow down as the mass from the poles gets distributed across the oceans.  Think of an ice skater in a fast tight spin holding out their arms and slowing down. It's simple conservation of angular momentum.
I believe we are looking at micro-second level variations here, as there are several effects here https://en.m.wikipedia.org/wiki/Day_length_fluctuations has a reasonable summary of observed variations in day length. I believe Greenland is capable of causing an effect, but not sea ice, as the sea ice (like the ocean it floats on)  is already at a gravitationally neutral position.

RoxTheGeologist

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Re: Latest PIOMAS update (January)
« Reply #1342 on: February 09, 2017, 09:44:29 PM »
I believe we are looking at micro-second level variations here, as there are several effects here https://en.m.wikipedia.org/wiki/Day_length_fluctuations has a reasonable summary of observed variations in day length. I believe Greenland is capable of causing an effect, but not sea ice, as the sea ice (like the ocean it floats on)  is already at a gravitationally neutral position.

Yes, it's not going to make a lot of difference. The mass of ice is tiny compared to the mass of the planet. Only ice overlaying land, and only until the earths geoid resets. All the ice is isostatically compensated on around a 10000 year timescale. Post glacial rebound transfers the mass.

VeliAlbertKallio

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Re: Latest PIOMAS update (January)
« Reply #1343 on: February 25, 2017, 02:39:45 AM »
Another observation reported (besides the angular momentum change from the loss of ice on the both Poles to the Equatorial oceans) was an accumulating deviation in the laser beam returns from mirrors the Apollo astronauts placed on moon (water on the Equator is a tiny bit closer to the moon than the ice which resided on the poles). On the other hand, mountain glaciers fall backward but the amount of ice lost from them is less than the Polar ice migrating to the bulging geoid latitudes of the Equator. Polar gravity distance is thousands of kilometers from pole, but just a few kilometers down and away from mountain heights (the earth's curvature being the more significant element). The volume growth of available mass for tidal movements is still yet another phenomenon when the Polar ice caps and mountain glaciers melt and disappear.

I must say the PIOMAS location of the thick ice is very strange.
Indeed.
Could that be related to https://www.washingtonpost.com/news/energy-environment/wp/2016/04/08/the-melting-of-greenland-and-antarctica-isnt-just-raising-seas-its-changing-the-earths-rotation/ perhaps?


Unlikely. The earth will slow down as the mass from the poles gets distributed across the oceans.  Think of an ice skater in a fast tight spin holding out their arms and slowing down. It's simple conservation of angular momentum.
I believe we are looking at micro-second level variations here, as there are several effects here https://en.m.wikipedia.org/wiki/Day_length_fluctuations has a reasonable summary of observed variations in day length. I believe Greenland is capable of causing an effect, but not sea ice, as the sea ice (like the ocean it floats on)  is already at a gravitationally neutral position.
« Last Edit: February 25, 2017, 03:26:14 AM by VeliAlbertKallio »

Wipneus

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Re: Latest PIOMAS update (March)
« Reply #1344 on: March 01, 2017, 04:15:57 PM »
While waiting for PIOMAS update, here is an animation of the ADS/Jaxa sea ice thickness map for February.


StopTheApocalypse

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Re: Latest PIOMAS update (March)
« Reply #1345 on: March 01, 2017, 06:33:15 PM »
While waiting for PIOMAS update, here is an animation of the ADS/Jaxa sea ice thickness map for February.

Hmm you can see what the shape of what hycom thinks is thicker ice pretty clearly in the ESS and Laptev seas, but JAXA thinks it's the same thickness/thinner than the areas around it, which doesn't make sense to me.

Neven

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Re: Latest PIOMAS update (March)
« Reply #1346 on: March 02, 2017, 09:41:44 AM »
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Wipneus

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Re: Latest PIOMAS update (March)
« Reply #1347 on: March 03, 2017, 10:36:57 AM »
PIOMAS gridded thickness data has updated. From the thickness I calculate 18.609 [1000 km3] for day 59. That would be about 1850 km3 lower than the previous record for the day in 20102011.

Thickness maps will be posted later.
« Last Edit: March 03, 2017, 02:16:23 PM by Wipneus »

Wipneus

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Re: Latest PIOMAS update (March)
« Reply #1348 on: March 03, 2017, 10:45:55 AM »
Here is the animation for February.

« Last Edit: March 03, 2017, 11:45:53 AM by Wipneus »

Wipneus

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Re: Latest PIOMAS update (March)
« Reply #1349 on: March 03, 2017, 11:00:57 AM »
This month I present the thickness maps for the last day of the month, instead of the mean monthly map. Should be more relevant.
Here the thickness map for 28 Feb 2017, comparison with previous years and differences with previous years.