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Tensor

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Re: IJIS
« Reply #2600 on: June 24, 2016, 09:33:14 PM »
IJIS:

Will not be updated by me, due to a visit to an internet remote island during the weekend! 8)

OK, I picked a good weekend to be out of touch myself....
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jplotinus

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Re: IJIS
« Reply #2601 on: June 25, 2016, 05:35:40 AM »
The format is not the best, Espen will be missed this weekend, but...


.and 'Have a nice day'of course.

DavidR

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Re: IJIS
« Reply #2602 on: June 25, 2016, 05:39:47 AM »
IJUS drops to 9331851 a 94K drop, still not a century break. But slowly creeping ahead of 2010.
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Tigertown

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Re: IJIS
« Reply #2603 on: June 25, 2016, 05:40:39 AM »
That's another big one. Had a few lately.

Rob Dekker

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Re: IJIS
« Reply #2604 on: June 25, 2016, 09:13:45 AM »
Enjoy your time off, Espen, and thanks for your work !
IJIS clocked in an 'almost' century drop today, from 9.43 to 9.33.
« Last Edit: June 25, 2016, 09:20:20 AM by Rob Dekker »
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Milret2

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Re: IJIS
« Reply #2605 on: June 25, 2016, 12:33:43 PM »
For all that Espen and Werther do for this site I would just like to say, as I float around St. Petersburg Russian on my own vacation, I feel that I can speak for all and hope that you have a great time.

jplotinus

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Re: IJIS
« Reply #2606 on: June 26, 2016, 05:35:08 AM »


"Have a nice day"

be cause

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Re: IJIS
« Reply #2607 on: June 26, 2016, 05:43:23 AM »
    you too ! :) .. and all the crew  :-*   just because  ;)
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Re: IJIS
« Reply #2608 on: June 26, 2016, 06:15:12 AM »
And 2012 drops back to fourth lowest, behind 2016, 2010 and 2011 a position it will hold for a few more days.
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Re: IJIS
« Reply #2609 on: June 27, 2016, 05:25:06 AM »
IJIS:

 9,203,166 km2
(June 26, 2016)
Have a ice day!

Espen

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Re: IJIS
« Reply #2610 on: June 28, 2016, 05:21:53 AM »
IJIS:

9,155,466 km2(June 27, 2016)
Have a ice day!

Sleepy

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Re: IJIS
« Reply #2611 on: June 28, 2016, 05:57:49 AM »
.

Rob Dekker

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Re: IJIS
« Reply #2612 on: June 28, 2016, 08:57:22 AM »
Yeah !
For the first time in this year's melting season, 2016 IJIS extent is actually matched by another year (2010).
Also, Sleepy's graph shows how year-after-year, Arctic ice extent seems to reduce, quite consistently.
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pauldry600

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Re: IJIS
« Reply #2613 on: June 28, 2016, 10:14:35 AM »
Even though 2012 is unlikely to be beaten I think the ice is trying to trick us.

Its in a bad state and a stormy mild winter like last coould do irrepairable damage for the coming years

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Re: IJIS
« Reply #2614 on: June 28, 2016, 12:54:16 PM »
Yeah !
For the first time in this year's melting season, 2016 IJIS extent is actually matched by another year (2010).

Rounded, yes, 2010 and 2016 are even, though 2016 is, technically, still in first by a few thousand square kilometers. But that's really a moot point: 2016 will have a very difficult time keeping up with the pack if it doesn't start disappearing quickly over the next week. 2013 began a 10-day tear today that resulted in 1.27 M km2 of loss, while 2014 lost over a million during the same period.

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Re: IJIS
« Reply #2615 on: June 28, 2016, 02:15:26 PM »
2010 drops 140K tomorrow so 2016 will need a similar drop if it is to continue its 90 day run holding the record.  Its definitely  time for a few 100K + drops.
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Lord M Vader

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Re: IJIS
« Reply #2616 on: June 28, 2016, 05:21:36 PM »
According to Wipneus in the thread http://forum.arctic-sea-ice.net/index.php/topic,1457.msg81622.html#new, the area numbers should see a big fat century break today. The question is however if the extent numbers will do the same or not.

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Re: IJIS
« Reply #2617 on: June 28, 2016, 07:05:59 PM »
I would think Espen is on an expedition up in the north of western Greenland to be the first person to reach a newly exposed bit of land newly revealed as an island. He may not have blogging capability during the adventure but I'm sure we will hear all about it in due course.

Lord M Vader

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Re: IJIS
« Reply #2618 on: June 28, 2016, 07:12:03 PM »
Speaking about Greenland, rather high melting rate there right now... Hope Espen is doing fine :)

Espen

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Re: IJIS
« Reply #2619 on: June 29, 2016, 05:23:28 AM »
IJIS:

9,084,133 km2(June 28, 2016)
Have a ice day!

gregcharles

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Re: IJIS
« Reply #2620 on: June 29, 2016, 05:52:04 AM »
Well, 2016 had a good long run as the minimum. Maybe it will regain the title, but it's looking unlikely.

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Re: IJIS
« Reply #2621 on: June 29, 2016, 06:39:00 AM »
Well, 2016 had a good long run as the minimum. Maybe it will regain the title, but it's looking unlikely.
I'm not sure why people think this is a race.

Now, 2016 is *still*  ahead of every other year in extent loss, and has far worse over all sea ice conditions than 2012, 2007, 2011 and 2015.  Whether or not we reach or pass 2012 is pretty immaterial as far as I'm concerned.  We've got ice conditions so bad that major cruise lines are willing to risk their treasure on Arctic cruises through the NW Passage.

*bozhe moi*

Every year from this point on is a dice roll.  On a bad one, we drop below 1 million KM2 of area, which *will* change how the global weather system operates.  I'm rather disturbed.
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bbr2314

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Re: IJIS
« Reply #2622 on: June 29, 2016, 06:52:32 AM »
Well, 2016 had a good long run as the minimum. Maybe it will regain the title, but it's looking unlikely.
I'm not sure why people think this is a race.

Now, 2016 is *still*  ahead of every other year in extent loss, and has far worse over all sea ice conditions than 2012, 2007, 2011 and 2015.  Whether or not we reach or pass 2012 is pretty immaterial as far as I'm concerned.  We've got ice conditions so bad that major cruise lines are willing to risk their treasure on Arctic cruises through the NW Passage.

*bozhe moi*

Every year from this point on is a dice roll.  On a bad one, we drop below 1 million KM2 of area, which *will* change how the global weather system operates.  I'm rather disturbed.

I agree 100% with what you said and I am becoming increasingly convinced this year will drop below 1M KM2. The extent #s are still sliding yet we can see per area maps that the bulk of the recent June heat (yes, there *has* been heat despite the assertions to the contrary) has been resolved via losses in the CAB. These are not apparent in any of the figures yet, but they will be within a few weeks.... there is an enormous cliff coming!

The CAA should decompose rapidly over the next week or so allowing more open water and heat from North America direct access to the CAB as well. 90s!


Darvince

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Re: IJIS
« Reply #2623 on: June 29, 2016, 08:07:30 AM »
The temperature in the Northwest Territories and Nunavut on Victoria Island and in other areas nearby is in the 80s Fahrenheit, which is indeed very far above normal for the time of year, but on the other side of this the ice is cooling the temperatures above the seas in the area to at the warmest 10C, favoring cooler temperatures. Additionally, the ice there, per all of Wipneus's volume graphs is still thicker than 1 meter through much of CAA, so it should take ten days to melt out at the least.



http://icdc.zmaw.de/1/daten/cryosphere/l3c-smos-sit.html

Sleepy

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Re: IJIS
« Reply #2624 on: June 29, 2016, 09:26:31 AM »
Yeah !
For the first time in this year's melting season, 2016 IJIS extent is actually matched by another year (2010).
Also, Sleepy's graph shows how year-after-year, Arctic ice extent seems to reduce, quite consistently.
And now it's number two after 2010.

The ASI will reduce further, no doubt about that. A slightly odd comment in here?

Acts5v29

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Re: IJIS
« Reply #2625 on: June 29, 2016, 09:29:45 AM »
Well, 2016 had a good long run as the minimum. Maybe it will regain the title, but it's looking unlikely.
I'm not sure why people think this is a race.

Now, 2016 is *still*  ahead of every other year in extent loss, and has far worse over all sea ice conditions than 2012, 2007, 2011 and 2015.  Whether or not we reach or pass 2012 is pretty immaterial as far as I'm concerned.  We've got ice conditions so bad that major cruise lines are willing to risk their treasure on Arctic cruises through the NW Passage.

*bozhe moi*

Every year from this point on is a dice roll.  On a bad one, we drop below 1 million KM2 of area, which *will* change how the global weather system operates.  I'm rather disturbed.

True - while the data is important in analysis, we shouldn't forget what the crisis actually means.

abbottisgone

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Re: IJIS
« Reply #2626 on: June 29, 2016, 10:37:13 AM »
Yeah !
For the first time in this year's melting season, 2016 IJIS extent is actually matched by another year (2010).

Rounded, yes, 2010 and 2016 are even, though 2016 is, technically, still in first by a few thousand square kilometers. But that's really a moot point: 2016 will have a very difficult time keeping up with the pack if it doesn't start disappearing quickly over the next week. 2013 began a 10-day tear today that resulted in 1.27 M km2 of loss, while 2014 lost over a million during the same period.
..you're saying both those years averaged century drops over a ten day period?

I've been looking for the answer to that question ever since I signed up: CHEERS!
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Re: IJIS
« Reply #2627 on: June 29, 2016, 10:45:23 AM »
Well, 2016 had a good long run as the minimum. Maybe it will regain the title, but it's looking unlikely.
I'm not sure why people think this is a race.

Now, 2016 is *still*  ahead of every other year in extent loss, and has far worse over all sea ice conditions than 2012, 2007, 2011 and 2015.  Whether or not we reach or pass 2012 is pretty immaterial as far as I'm concerned.  We've got ice conditions so bad that major cruise lines are willing to risk their treasure on Arctic cruises through the NW Passage.

*bozhe moi*

Every year from this point on is a dice roll.  On a bad one, we drop below 1 million KM2 of area, which *will* change how the global weather system operates.  I'm rather disturbed.

How factual is such a number?

Are there any published ideas on what magnitude of extent/area loss is required to alter the global weather system in a substantial way??

I have of course been saying that ice extent anywhere near 2Mil in September would presumably lead to Global Panic so these numbers will have to be looked at very seriously very soon.
..
But I left school and grew my hair
They didn't understand
They wanted me to be respected as
A doctor or a lawyer man
But I had other plans..........

magnamentis

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Re: IJIS
« Reply #2628 on: June 29, 2016, 11:09:26 AM »
there is an enormous cliff coming!

once more i think in a similar direction and expect a steep decline (cliff) like you do. right now relative cool temps above 80N and the distance between the fragments are  somehow fooling area and extent data and beyond a certain point that will have some flip over effect IMO. unlike others i don't feel fit to put up numbers (going out on a limb haha.. ) but the effect could be similar like a very thin layer (the last mm) going "poof" within the hour.
similar things happened in kimmirut a few days ago when a solid ice cover, in spots turned into open water within 1 hour, and i don't talk about a 1 square meter whole :-)
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Re: IJIS
« Reply #2629 on: June 29, 2016, 01:33:17 PM »
Are there any published ideas on what magnitude of extent/area loss is required to alter the global weather system in a substantial way??

As for a strict 1 km2 threshold, probably not, but Jennifer Francis et al. have published extensively on the topic.  And the next time the weather really aligns for a very big melt season, it is reasonable to assume that the dynamics she describes will only be enhanced. 

FWIW, I tend to believe that whether or not this year is the year, and it may still be, a huge melt out is likely all but inevitable in the next few years.  Following the day to day minutia is fascinating and in a way addictive, but in all honesty I don't think it amounts to much.  We are at the mercy of the weather (no one predicted the GAC until it was all but upon us) and the weather will provide the knockout punch when it wants to.

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Re: IJIS
« Reply #2631 on: June 30, 2016, 05:26:03 AM »
IJIS:

9,033,729 km2(June 29, 2016)
Have a ice day!

oren

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Re: IJIS
« Reply #2632 on: June 30, 2016, 07:06:01 AM »
Moment of truth coming up fast - accelerate or be left behind.

pauldry600

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Re: IJIS
« Reply #2633 on: June 30, 2016, 10:18:58 AM »
I think it will be near the record but not quite.

July will see a lot of melt.

But Junes been a "disaster" for record seekers

epiphyte

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Re: IJIS
« Reply #2634 on: June 30, 2016, 10:40:02 AM »
Speaking about Greenland, rather high melting rate there right now... Hope Espen is doing fine :)

For now at least all that melting is (to some extent) shielding the CAB North of Svalbard from being rapidly demolished by Atlantic energy welling up from the South. Unfortunately it won't last forever, and even while it does, there's a price to be paid in rising sea level.

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Re: IJIS
« Reply #2635 on: June 30, 2016, 10:44:07 AM »
Sea level only rises when land ice melts, but not in case of sea ice.
Bright ice, how can you crack and fail? How can the ice that seemed so mighty suddenly seem so frail?

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Re: IJIS
« Reply #2636 on: June 30, 2016, 01:53:26 PM »
As AmbiValent rightly points out, the melting of floating sea ice does not materially impact sea level. For anyone who doesn't understand this, can I suggest having a look at Archimedes' Principle?

(NB Sometime during the last 12-24 months, I was engaged in an online debate about this over at SkS. When sea ice melts, there is indeed a very, very minor effect on SLR due to the differing densities of fresh water and sea water, but, to all intents and purposes, this can safely be ignored.)

However, there is a mechanism whereby the loss of sea ice will cause an acceleration in SLR. Sea ice that is in-situ at the exit of a glacier provides invaluable buttressing: when that goes, the whole glacier is going to speed up. One classic example of this is the Petermann Glacier which debouches into the Nares Strait. The longer Nares is ice-free, the more the Petermann is going to contribute to SLR.

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Re: IJIS
« Reply #2637 on: June 30, 2016, 02:11:31 PM »
Not sure that sea ice has much of a buttressing effect on a glacier.  The glacier is ~20x as thick as sea ice at the calving front, and 200x as thick as sea ice at the grounding line.  It's like saying you can stop a train with a mattress.

The buttressing effect comes largely from floating ice shelves, which are of comparable thickness to the glaciers that feed them. Not from seasonal sea ice.

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Re: IJIS
« Reply #2638 on: June 30, 2016, 02:44:40 PM »
Perhaps the absence of sea ice for longer periods of time each year raises the adjacent water temperatures above normal (contributing indirectly to glacier ice degradation)?

Shared Humanity

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Re: IJIS
« Reply #2639 on: June 30, 2016, 03:24:15 PM »
Not sure that sea ice has much of a buttressing effect on a glacier.  The glacier is ~20x as thick as sea ice at the calving front, and 200x as thick as sea ice at the grounding line.  It's like saying you can stop a train with a mattress.

The buttressing effect comes largely from floating ice shelves, which are of comparable thickness to the glaciers that feed them. Not from seasonal sea ice.

I don't believe sea ice has any buttressing effect. Visit the Zachariae Isstrom thread and watch the animations as the glacier plows ahead through the winter, shoving sea ice forward as if it doesn't exist.

magnamentis

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Re: IJIS
« Reply #2640 on: June 30, 2016, 03:34:49 PM »
for those denying such buttressing effect i recommend to read through various antarctica threads where that is very well explained, even though on a much larger scale.

once sea ice situated at the "exit" of glaciers is absent (has gone) glaciers indeed accelerate and therefore add to SLR in shorter time, hence are speeding it up.

as we probably all know there are a few quite savvy members on that topic which then would belong to
one of the SLR threads if i'm not totally mistaken.
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Tor Bejnar

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Re: IJIS
« Reply #2641 on: June 30, 2016, 03:44:51 PM »
Not sure that sea ice has much of a buttressing effect on a glacier.  ...

from NSDIC's September 2011 Icelights: Greenland’s glaciers and the Arctic climate

Quote
...Winter sea ice also acts as a buttress against glacier ice flow, seasonally slowing the flow speed. An earlier break-up and later freeze-up of sea ice in the fjords may play a role in the ice sheets' mass balance. ...
Arctic ice is healthy for children and other living things.

magnamentis

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Re: IJIS
« Reply #2642 on: June 30, 2016, 03:55:50 PM »
Not sure that sea ice has much of a buttressing effect on a glacier.  ...

from NSDIC's September 2011 Icelights: Greenland’s glaciers and the Arctic climate

Quote
...Winter sea ice also acts as a buttress against glacier ice flow, seasonally slowing the flow speed. An earlier break-up and later freeze-up of sea ice in the fjords may play a role in the ice sheets' mass balance. ...

yep, thanks for confirming while i thought that the buttressing effect of ice shelves in antarctica are so famous
"WAIS" etc, that even the last one having doubts would see the error. hope that's not too bold because i'm really not a glaciologist but i'm confident that this will be further confirmed by one of the pros here.
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Re: IJIS
« Reply #2643 on: June 30, 2016, 06:25:31 PM »
First off, I apologise for inadvertently dragging this IJIS (or ADS/Vishop) thread off-topic. :-[

The presence of ice shelves indisputably provides the primary buttressing mechanism at the outflow point of tidewater glaciers.
https://nsidc.org/cryosphere/glaciers/questions/types.html

However, the mass balance of the shelf is determined largely by the relationship between two factors:
i) the rate at which the glacier discharges to the shelf, and
ii) the loss rate at the periphery, which is a function of factors such as the calving rate and the sub-surface melt rate

It was not by chance that I happened to briefly mention Petermann in my original post. An example of the field work there can be found at...
http://www.geo.su.se/index.php/en/expedition-logs/1276-petermann-glacier-2015

The introduction to this offers some explanation as to why Petermann was chosen for study...
"... The Petermann Glacier is a well-suited target because it terminates in an extensive floating ice shelf that is sensitive to ice/ocean interactions. Furthermore, the glacier has a relatively simple geometry that can be resolved by realistic field programs. Finally, the Nares Strait is a conduit for southward flow of low-salinity waters, with oceanographic impacts..."

Perhaps this would all have passed without comment had I simply used the suggestion made by Seaicesailor, and described the effect of sea ice as providing an indirect buttressing effect. The ice shelf losses mass (and hence the mechanical inertia needed to provide buttressing) at its periphery. The presence of sea ice at said periphery has the following effects...

i) it has a higher albedo than open water, and hence reduces solar heating
ii) it helps reduce ablation caused by wave action
iii) it does provide some (direct) buttressing on the periphery of the ice shelf, thus reducing the magnitude of calving events  (To the best of my knowledge, the various Petermann Ice Islands - 2008, 2010, 2012 for example - have occurred during periods of minimal sea ice around the boundary of the ice shelf.)


If there is a wish to discuss this further, might I suggest that we do it at (say) ...
https://forum.arctic-sea-ice.net/index.php/topic,53.400.html


Apologies again for being responsible for some off-topic stuff. :-[

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Re: IJIS
« Reply #2644 on: June 30, 2016, 06:32:46 PM »
Sea level only rises when land ice melts, but not in case of sea ice.

I wasn't talking about sea ice. I was talking about runoff from the Greenland ice-cap, taking the edge off warm systems coming up from the Atlantic, which seems to my eyes at least to be preventing more dramatic mixing from happening over the CAB on that side.

[Edit - oops. I guess I followed up without reading the subsequent posts.

... what they all said :) ]
« Last Edit: June 30, 2016, 06:37:56 PM by epiphyte »

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Re: IJIS
« Reply #2645 on: June 30, 2016, 11:45:13 PM »
Not sure that sea ice has much of a buttressing effect on a glacier.  ...

from NSDIC's September 2011 Icelights: Greenland’s glaciers and the Arctic climate

Quote
...Winter sea ice also acts as a buttress against glacier ice flow, seasonally slowing the flow speed. An earlier break-up and later freeze-up of sea ice in the fjords may play a role in the ice sheets' mass balance. ...

yep, thanks for confirming while i thought that the buttressing effect of ice shelves in antarctica are so famous
"WAIS" etc, that even the last one having doubts would see the error. hope that's not too bold because i'm really not a glaciologist but i'm confident that this will be further confirmed by one of the pros here.

The WAIS (West Antarctica Ice Sheet) is far different than seasonal sea ice. Ice shelves such as the Ross Ice Shelf have an enormous buttressing effect and their disintegration results in a dramatic acceleration. I may have not understood what was meant by sea ice but I consider sea ice to be the rubble floating around in the CAB and the seasonal ice that forms in front of glaciers including portions of these glaciers that are floating. While this seasonal ice may have some buttressing effect on glacier speeds, if you watch the wonderful animations that are posted on the Greenland section, these glaciers move forward all year long, pushing the sea ice forward and all of the free floating ice bergs with it.
« Last Edit: June 30, 2016, 11:52:49 PM by Shared Humanity »

oren

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Re: IJIS
« Reply #2646 on: July 01, 2016, 12:14:08 AM »
I don't believe sea ice has any buttressing effect. Visit the Zachariae Isstrom thread and watch the animations as the glacier plows ahead through the winter, shoving sea ice forward as if it doesn't exist.
I know this is far off-topic but must comment that ZI calving rate increased dramatically in August 2014 when the sea ice cleared up. It does continue moving and calving during the winter, but sea ice absence does have an effect.

jdallen

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Re: IJIS
« Reply #2647 on: July 01, 2016, 05:10:07 AM »
I don't believe sea ice has any buttressing effect. Visit the Zachariae Isstrom thread and watch the animations as the glacier plows ahead through the winter, shoving sea ice forward as if it doesn't exist.
I know this is far off-topic but must comment that ZI calving rate increased dramatically in August 2014 when the sea ice cleared up. It does continue moving and calving during the winter, but sea ice absence does have an effect.

I wouldn't confuse correlation with cause.  The calving increased while ice was low, but it may be they *both* were result of an entirely different cause.
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Espen

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Re: IJIS
« Reply #2648 on: July 01, 2016, 05:27:42 AM »
IJIS:

8,973,708 km2(June 30, 2016)
Have a ice day!

seaicesailor

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Re: IJIS
« Reply #2649 on: July 01, 2016, 10:33:14 AM »
Thanks for the explanation, aig.  :)

I wonder if there will be a century break this month (none so far). Last year there was just one, and none in 2008 and 2009.

Yes I put my money of it too :) Easy bet (low return), given the NSDIC numbers.

So much for my 2 cents  :)