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Neven

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Greenland 2017 melt season
« on: May 22, 2017, 01:50:16 PM »




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Darvince

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Re: Greenland 2017 melt season
« Reply #1 on: May 22, 2017, 02:03:04 PM »
Thanks Neven for opening this thread!

DMI has updated their melting algorithms for this year and also added data back to 1980 to their system, so now their average and their melting percentage much more closely matches NSIDC's while being higher resolution:

http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/

prokaryotes

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Re: Greenland 2017 melt season
« Reply #2 on: May 22, 2017, 03:53:41 PM »
In retrospect (and to give some background information), this was just released last week

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gerontocrat

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Re: Greenland 2017 melt season
« Reply #3 on: May 25, 2017, 01:14:33 PM »
The melt continues though confined to southern coasts, and according to cci-reanalyzer temperatures should allow the melt to continue  on southern coastal region for the next few days.





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gerontocrat

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Re: Greenland 2017 melt season
« Reply #4 on: May 27, 2017, 02:02:30 PM »
bbr2314 has pointed out (on 2017 melting season) that Greenland accumulated an amazing additional weight of snow last winter (700 million gt?). I show the graph again. It is from http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/.
Well worth a read.

If, as many have suggested, this massive increase in snowfall is likely to become frequent in future years, this must have consequences. One could easily imagine a warming world where Greenland accumulates vast additional mass through snowfall in winter and correspondingly greatly increased melt in summer.  Sea level rise would reduce or increase depending on the change in net SMB over the years, while surely a vastly increased melt flooding into the Atlantic could change just about everything.

Trying to think it through has given me brain-ache.



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Thomas Barlow

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Re: Greenland 2017 melt season
« Reply #5 on: May 27, 2017, 04:41:40 PM »

bbr2314

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Re: Greenland 2017 melt season
« Reply #6 on: May 28, 2017, 05:10:26 AM »
bbr2314 has pointed out (on 2017 melting season) that Greenland accumulated an amazing additional weight of snow last winter (700 million gt?). I show the graph again. It is from http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/.
Well worth a read.

If, as many have suggested, this massive increase in snowfall is likely to become frequent in future years, this must have consequences. One could easily imagine a warming world where Greenland accumulates vast additional mass through snowfall in winter and correspondingly greatly increased melt in summer.  Sea level rise would reduce or increase depending on the change in net SMB over the years, while surely a vastly increased melt flooding into the Atlantic could change just about everything.

Trying to think it through has given me brain-ache.

It should be noted that the blue line seems to directly correspond to 2017's lead over other years in terms of lack of sea ice, and the gap had narrowed to merely record-setting (instead of hugely record-setting) since extent fell back in line with the more "normal" recent years. Seems to be a direct correlation?

FishOutofWater

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Re: Greenland 2017 melt season
« Reply #7 on: May 29, 2017, 10:09:06 PM »
This year Greenland melting started in May, thus the decline in snow volume.

The high snowfall correlates with warm winter season temperatures and very strong far north Atlantic storms and blocking highs that transported heat towards the pole.

gerontocrat

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Re: Greenland 2017 melt season
« Reply #8 on: June 08, 2017, 02:34:28 PM »
Greenland melting after a couple of May surges is very quiet and confined totally to the coasts. The graphs below also indicate that some really high melting would be required to dispose of last winters massive snowfalls. This does not seem likely in the next few days at least. 'Tis June 8th and no sign of a June cliff in the data anywhere.

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gerontocrat

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Re: Greenland 2017 melt season
« Reply #9 on: June 10, 2017, 01:36:09 PM »
I have just read DMI's webpage re the Greenland melt properly for the first time. (http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/).

As usual I just looked at the melt graph - melt going up again.
Then I looked at the surface mass budget graph - going up. A contradiction?
Then I read properly and saw todayssmb graph. A big increase in surface mass on the east coast.

Would I be right in thinking that perhaps a significant event is in progress in Greenland?


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johnm33

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Re: Greenland 2017 melt season
« Reply #10 on: June 10, 2017, 02:28:07 PM »
I was looking at this earlier wondering the same thing, melt/rain? Inland from 79N/Z
http://www.polarview.aq/images/106_S1jpgsmall/201706/S1A_IW_GRDH_1SDH_20170608T183001_29B7_N_1.jpg
full
 http://www.polarview.aq/images/105_S1jpgfull/S1A_EW_GRDM_1SDH_20170609T142007_83AB_N_1.final.jpg
added Plus Jacobshavn, south branch, looks like it has advanced as far as the bend on its southern shore.
« Last Edit: June 10, 2017, 02:38:37 PM by johnm33 »

Andreas T

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Re: Greenland 2017 melt season
« Reply #11 on: June 10, 2017, 08:24:03 PM »
I don't find this very confusing if you look at what those graphs and charts actually show. If some area in the west is melting (12% of the total area) another area can of course recieve snowfall and gain mass (loss though glaciers dumping ice into the sea is not included into these figures)
The blue areas are larger than the pink (I can't distinguish the pale shades of pink well, but either way the chart shows more gain than loss) The blue area is showing clouds coming in from the east, with the altitude of those areas, snow is the most likely form of precipitation.

gerontocrat

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Re: Greenland 2017 melt season
« Reply #12 on: June 10, 2017, 09:12:55 PM »
The point I was trying to make is that it is the difference in surface mass that matters. As of today mass is constant or rising from an already unusual high. This I would suggest is of interest.
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gerontocrat

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Re: Greenland 2017 melt season
« Reply #13 on: June 17, 2017, 01:01:24 PM »
Greenland melt has woken up. It will be interesting to see how much of the unusually high increase in surface mass over the 2016-2017 winter will melt away in the next three months or so.

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georged

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Re: Greenland 2017 melt season
« Reply #14 on: June 20, 2017, 05:13:17 AM »
Greenland melt has woken up. It will be interesting to see how much of the unusually high increase in surface mass over the 2016-2017 winter will melt away in the next three months or so.

It's back down below normal again. This is an interesting year for Greenland melt. We may end up with a positive mass balance this year, excluding accelerated calving.

Darvince

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Re: Greenland 2017 melt season
« Reply #15 on: June 21, 2017, 05:38:10 PM »
It seems to me that the amount of mass loss from calving has just begun to accelerate, as it is a violent physical process taking place, so other violent physical processes must be required for calving to accelerate. Such as tsunamis, earthquakes, and landslides, caused by permafrost melting, mantle uplift underneath Greenland, and large calving events.

Calving did seem to have accelerated, though, to our eyes, because the glaciers have already begun thinning due to basal melt and surface melt, so the glaciers had to speed up and calve a greater quantity of icebergs into the sea in order for them to keep calving at the same speed.


Note the dynamic mass loss has only just begun to increase due to global warming since 2000.
« Last Edit: June 21, 2017, 05:43:50 PM by Darvince »

TerryM

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Re: Greenland 2017 melt season
« Reply #16 on: June 21, 2017, 07:43:29 PM »
Darvince


Is your above true for this year?
I had thought that the large snowfalls actually increased the mass balance in Greenland.


Terry

Darvince

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Re: Greenland 2017 melt season
« Reply #17 on: June 21, 2017, 09:10:16 PM »
I don't know, I fried my brain so badly that I became unable to use reason for a while, so I have to reread everything on this forum to finally actually, legitimately understand things.

gerontocrat

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Re: Greenland 2017 melt season
« Reply #18 on: June 22, 2017, 12:48:21 PM »
A problem:-
Herewith NSIDC's (http://nsidc.org/greenland-today/) graph of greenland melt so far:
And secondly is the DMI version (http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/:-

I thought they were looking at the same event, i.e. surface melting, but the difference is just too great. Has anyone out there the explanation of such divergent views of the same event?
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gerontocrat

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Re: Greenland 2017 melt season
« Reply #19 on: June 22, 2017, 01:13:47 PM »
Hullo Darvince, Hullo TerryM,

Hope this post makes sense. Suffering from brain-fade.

Quote from http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/

"Over the year, it snows more than it melts, but calving of icebergs also adds to the total mass budget of the ice sheet. Satellite observations over the last decade show that the ice sheet is not in balance. The calving loss is greater than the gain from surface mass balance, and Greenland is losing mass at about 200 Gt/yr."

Looking at the graph below it would seem that in an average year surface mass increases by a net amount of 400 gt. Given that Greenland loses around 200 Gt mass per annum, that means in an average year calving is dumping around 600 Gt of ice into the oceans. That is about double the average annual volume loss of arctic sea ice of 300 Gt quoted by PIOMAS. When my brain finally did the arithmetic it was quite a shock.

The graph below shows that the surface mass gain in winter 2016-2017 was somewhat more than 100 gt in excess of the average, and surface mass loss through melting has been very sluggish. It is possible that Greenland's  net mass loss by the end of September will not be 200 gt but maybe zero or even negative (i.e. a net mass gain).


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gerontocrat

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Re: Greenland 2017 melt season
« Reply #20 on: June 24, 2017, 03:26:44 PM »
The difference between the NSIDC Greenland Today Melting Graph and the DMI Greenland Melting Graph continues to increase.

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diablobanquisa

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Re: Greenland 2017 melt season
« Reply #21 on: June 24, 2017, 08:32:35 PM »
It's a striking difference indeed:




Dr. Xavier Fettweis' Greenland melt season model simulations are available as well: http://climato.be/cms/index.php?climato=the-2017-melt-season-over-greenland-as-simulated-by-marv3-7

It seems that the modelled surface melt closely agrees with NSIDC's observations:




I have noticed that DMI has been showing widespread surface melting at NE Greenland for weeks, whereas, according to NSIDC, the surface melting at NE Greenland has been much more reduced. For instance, these are the maps for June 23rd, NSIDC (left) vs. DMI (right):




Albedo anomalies don't seem to support the widespread surface melting at NE Greenland either:




It seems that the difference between the two graphs is due to NE Greenland. And it looks like something is wrong with DMI's data.


« Last Edit: June 24, 2017, 08:41:59 PM by diablobanquisa »

magnamentis

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Re: Greenland 2017 melt season
« Reply #22 on: June 25, 2017, 02:12:36 AM »
The difference between the NSIDC Greenland Today Melting Graph and the DMI Greenland Melting Graph continues to increase.

well observed & thx 4 pointing it out.

i find many dmi-sources way off, mostly i base my impression on comparisons with sat-imagery and of the kind you just posted. woud not matter if not for causing unnessesary discussions.;)
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diablobanquisa

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Re: Greenland 2017 melt season
« Reply #23 on: June 25, 2017, 03:07:56 AM »
I have noticed that DMI's model and the simulations by Fettweis are using different tresholds: 1mm/day vs. 5mm/day. That could explain the difference between DMI (left, 1mm treshold) and Fettweis' MAR model (right, 5mm treshold):



It makes sense, since the melt area >1mm is larger than the area >5 mm.

However, it's also a bit puzzling, because the area with melt >1 mm is above the 1981-2010 average whereas the area with melt >5mm is below the same climatological mean. That should imply a wider but weaker melt than average. It looks somewhat strange.

In addition, it becomes even more puzzling it we look at NSIDC's data. Instead of using a model, NSIDC's data are based on an analysis of passive microwave observations.  Their algorithm is sensitive to the presence of wet snow on the surface, in any amount, whereas the threshold for DMI's mapping is 1mm liquid water produced -- this is actually a significant amount of melting, surely more than the amount needed to trigger the passive microwave signal. 
In summary, NSIDC data should be closer to DMI (1mm) than to Fettweis' MAR model (5mm). But their graph shows just the opposite: NSDIC data are much more closer to Fettweis' results than to DMI's ones.

Moreover, it's even more puzzling if we compare DMI's 'daily contribution to the surface mass balance' map (right) with their own 'areas where melting has taken place' map (left):



The divergence at NE Greenland is apparent even if we compare DMI data vs. DMI data!

Taking all this into account, I stand by my previous statement: it seems that something is wrong with DMI's 'area where melting has taken place' graph:




And NSIDC's and Fettweis' graphs look like the correct ones:





« Last Edit: June 25, 2017, 03:17:27 AM by diablobanquisa »

diablobanquisa

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Re: Greenland 2017 melt season
« Reply #24 on: June 26, 2017, 11:06:40 AM »
According to DMI, their graph is right. They told me that NSIDC maybe is not seeing the areas with very low melt amounts. (http://images.meteociel.fr/im/191/nsidcvsdmi_wgu2.png)

However, two years ago I sent a question to NSIDC and they told me that their algorithm is sensitive to the presence of wet snow on the surface, in any amount.  ??

According to DMI, the difference between their own two charts (http://images.meteociel.fr/im/2133/dmi_vs_dmi_18_jun_fte9.png )  is due to the fact that surface melt >1mm can happen without negative mass balance there (for instance, the melt water can trickle down the snow and refreeze below).

If DMI is right, the point should be that this year NSIDC's algorithm could be less sensitive to melt than it used to be...

Who knows...


gerontocrat

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Re: Greenland 2017 melt season
« Reply #25 on: June 26, 2017, 11:20:59 AM »
The conclusion seems to be that any statement regarding Greenland melting has to have a great big caveat attached ? What a shame.
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diablobanquisa

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Re: Greenland 2017 melt season
« Reply #26 on: June 26, 2017, 12:12:58 PM »
I don't know if the conclusion should be that.

According to DMI, their products are right. And they also told me that we should focus on the surface mass balance product instead of on the 'areas where melt has taken place' product, because the former includes all processes (surface melt, sub-surface refreezing, condensation, sublimation, snow, rain, etc.) and thus it gives more information about the health of the ice sheet.

(Of course, in order to know the overall mass balance we should take into account the mass loss through iceberg calving too; however, only GRACE and Cryosat-2 are able to track the overall mass balance and, unfortunately, GRACE data are updated only up to July 2016 (http://polarportal.dk/fileadmin/polarportal/Polar-portal-saeson-rapport-UK.pdf , p.4) )

NSIDC's algorithm must be recalibrated every year. That could explain why some years it is very sensitive to any amount of melt, and other years not so much. I have submitted a question to NSIDC as well. If they confirm that their algorithm could be matching the 5mm treshold (at least this season) everything would be OK.

By the way, the updated Surface Mass Balance according to DMI:


Left: Map of the surface mass balance today (in mm water equivalent per day). Right: The average surface mass balance for today’s calendar date over the period 1981-2010.


Map of the accumulated surface mass balance (in mm water equivalent) from September 1st to now.



Top: The total daily contribution to the surface mass balance from the entire ice sheet (blue line, Gt/day). Bottom: The accumulated surface mass balance from September 1st to now (blue line, Gt) and the season 2011-12 (red) which had very high summer melt in Greenland. For comparison, the mean curve from the period 1981-2010 is shown (dark grey). The same calendar day in each of the 30 years (in the period 1981-2010) will have its own value. These differences from year to year are illustrated by the light grey band. For each calendar day, however, the lowest and highest values of the 30 years have been left out.

http://polarportal.dk/en/home/

http://beta.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/



diablobanquisa

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Re: Greenland 2017 melt season
« Reply #27 on: June 26, 2017, 12:30:35 PM »
Regarding GRACE:








gerontocrat

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Re: Greenland 2017 melt season
« Reply #28 on: June 26, 2017, 01:48:21 PM »
Hullo "devil floe". (Verdade ?)
Your posts have convinced me to rely on the DMI analysis, and especially on the progression of the smb.
Muchas gracias for the explanations.
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magnamentis

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Re: Greenland 2017 melt season
« Reply #29 on: June 26, 2017, 06:09:57 PM »
Hullo "devil floe". (Verdade ?)
Your posts have convinced me to rely on the DMI analysis, and especially on the progression of the smb.
Muchas gracias for the explanations.

while everyone is free to choose (of course) i just want to point out that:

"they say" is to be expected and proves nothing.

on the other hand DMI data if one takes a close look over YEARS has been proven (by sat images) wrong and not just a bit, basically they had repeatedly ice, even thick ice, in places where the satellites showed open water. this for me is as close to proof for errors as it can get.

similarly it's with the temps above 80N, 4-5 sources have been showing either obove or on average dtemps over weeks during which only DMI was showing below average temps.

of course in this case it's less clear because one can be right and all others wrong but that with the ice showing where was open water is a clear case o matter what "THEY SAY" in defending their own work. after all most people there have a carrier and get funded and admitting they're wrong is simply out of anything that one could expect.

all this is an opinion based on impressions/observations over several years while i gladly would learn about anything that proves otherwise, just not seen yet
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Benje

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Re: Greenland 2017 melt season
« Reply #30 on: June 28, 2017, 10:05:53 AM »
Thanks Gerontis for this:

Looking at the graph below it would seem that in an average year surface mass increases by a net amount of 400 gt. Given that Greenland loses around 200 Gt mass per annum, that means in an average year calving is dumping around 600 Gt of ice into the oceans. That is about double the average annual volume loss of arctic sea ice of 300 Gt quoted by PIOMAS. When my brain finally did the arithmetic it was quite a shock.

It always seems to me that we would understand the severity (or otherwise) of the Arctic sea ice  melt much better if we considered the input (to the sea ice) from Greenland as an additional volume of ice to be melted. I assume (although I certainly haven't dipped into the PIOMASS model) that PIOMASS includes the "extra" ice from Greenland. It would be nice to undestand what the PIOMASS loss was excluding the (growing) Greenland contribution. That exclusive higher loss better represents the heat gain (in units of GT of ice) that the Arctic is suffering.
It also represents the heat gain that may impinge on Greenland, in addition to Greenland's own growing heat burden, when the long tortured ice cap is effectively lost.

Does anyone calculate and track the "exclusive" higher gross PIOMASS loss?

georged

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Re: Greenland 2017 melt season
« Reply #31 on: June 28, 2017, 11:41:14 AM »
Thanks Gerontis for this:

Looking at the graph below it would seem that in an average year surface mass increases by a net amount of 400 gt. Given that Greenland loses around 200 Gt mass per annum, that means in an average year calving is dumping around 600 Gt of ice into the oceans. That is about double the average annual volume loss of arctic sea ice of 300 Gt quoted by PIOMAS. When my brain finally did the arithmetic it was quite a shock.

It always seems to me that we would understand the severity (or otherwise) of the Arctic sea ice  melt much better if we considered the input (to the sea ice) from Greenland as an additional volume of ice to be melted. I assume (although I certainly haven't dipped into the PIOMASS model) that PIOMASS includes the "extra" ice from Greenland. It would be nice to undestand what the PIOMASS loss was excluding the (growing) Greenland contribution. That exclusive higher loss better represents the heat gain (in units of GT of ice) that the Arctic is suffering.
It also represents the heat gain that may impinge on Greenland, in addition to Greenland's own growing heat burden, when the long tortured ice cap is effectively lost.

Does anyone calculate and track the "exclusive" higher gross PIOMASS loss?

That's a very good point. Each square km of Greenland ice transported into Arctic waters is a very large heat sink.

gerontocrat

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Re: Greenland 2017 melt season
« Reply #32 on: June 28, 2017, 01:06:44 PM »
NSIDC Greenland Today seemed to have made some changes to both the graph presentation and content..  See below, new one first, old one second.
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Shared Humanity

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Re: Greenland 2017 melt season
« Reply #33 on: June 28, 2017, 02:50:07 PM »
Looks as if they've reduced or eliminated entirely the smoothing of the 1981 to 2010 median.

oren

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Re: Greenland 2017 melt season
« Reply #34 on: June 28, 2017, 05:04:13 PM »
That's a very good point. Each square km of Greenland ice transported into Arctic waters is a very large heat sink.
The thing is, I would hazard to say that due to prevailing current all Greenland calvings are actually exported into Atlantic waters and do not enter the Arctic Basin proper. Calvings go either into Baffin Bay - where they are swept south, or into the Greenland Sea - swept south, or rarely into Nares Strait - where they may cause an ice jam and somewhat affect the melting season before being swept south as well. Icebergs may linger quite a while among the sea ice in those areas, and slightly retard the melt, but these are peripheral regions so it would not be very informative to combine this process with PIOMAS. Any ice exported into the Atlantic is basically toast, you don't need much of a model or energy balance for that.
In very large amounts these calved icebergs could cause macro changes to the Atlantic region near Greenland (and even more so near Antarctica), as postulated by Hansen, but that belongs in another thread.

sidd

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Re: Greenland 2017 melt season
« Reply #35 on: June 29, 2017, 10:21:26 PM »
Greenland mass loss is less due to calving than melt. I have not the time to find the reference, I have posted it previously, i believe the authors were Enderlin and Howat.

Tor Bejnar

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Re: Greenland 2017 melt season
« Reply #36 on: June 30, 2017, 12:57:34 AM »
Is this the post, sidd?
RE: GIS  ice loss.

is now predominantly due to SMB, See Enderlin(2014) http://dx.doi.org/10.1002/2013GL059010

Re: SLR

Thermal expansion contribution  is about the same ag that from grounded ice melt
Arctic ice is healthy for children and other living things.

sidd

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Re: Greenland 2017 melt season
« Reply #37 on: June 30, 2017, 06:49:53 AM »
I believe so. There are some subsequent papers also, a citation search should find them.

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Re: Greenland 2017 melt season
« Reply #38 on: June 30, 2017, 03:39:07 PM »
Greenland mass loss is less due to calving than melt. I have not the time to find the reference, I have posted it previously, i believe the authors were Enderlin and Howat.

Hullo sidd.
Melting or calving, if the sluggish progress of SMB loss continues, it looks very much as if at Sept 30th there will be a net addition to Greenland Ice Sheet Mass this year, rather than the "usual" 200 gt loss. Expect crap from Trolls? Also note the ridiculous contrast with the 2011-2012 year.
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Re: Greenland 2017 melt season
« Reply #39 on: July 01, 2017, 05:05:52 AM »
http://www.tropicaltidbits.com/analysis/models/?model=cfs-avg&region=namer&pkg=T2maMean&runtime=2017063012&fh=174&xpos=0&ypos=0

CFS says expect early July to continue to be slow but for it to speed up once late July comes, with possibly a significant August contribution to ice sheet mass loss.

Coffee Drinker

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Re: Greenland 2017 melt season
« Reply #40 on: July 02, 2017, 01:15:31 AM »
Most of Greenland has below average temps the coming week. There won't be much melting going on during peak insulation period. 

http://pamola.um.maine.edu/fcst_frames/GFS-025deg/5-day/GFS-025deg_ARC-LEA_T2_anom_5-day.png

gerontocrat

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Re: Greenland 2017 melt season
« Reply #41 on: July 04, 2017, 03:13:20 PM »
Greenland melt continues to be "The Dog That Did Not Bark". Greenland's cold spell set to continue for several days yet. As previous posts have pointed out that the majority of net mass loss of Greenland's ice sheet is from melt as opposed to calving does this mean the chances are for a net mass gain this year after the amazing snowfall over winter /spring?Any signs of calving being somewhat slow so far this year?

DMI's analysis not updated since June 30 so NSIDC image as at July 2 shown.


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magnamentis

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Re: Greenland 2017 melt season
« Reply #42 on: July 04, 2017, 05:27:53 PM »
Greenland melt continues to be "The Dog That Did Not Bark". Greenland's cold spell set to continue for several days yet. As previous posts have pointed out that the majority of net mass loss of Greenland's ice sheet is from melt as opposed to calving does this mean the chances are for a net mass gain this year after the amazing snowfall over winter /spring?Any signs of calving being somewhat slow so far this year?

DMI's analysis not updated since June 30 so NSIDC image as at July 2 shown.

chances are there IMO, as you say, but this can change within short time, we probably have to wait another few weeks to make a meaningful assessment for seasonal results.
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gerontocrat

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Re: Greenland 2017 melt season
« Reply #43 on: July 06, 2017, 03:17:43 PM »
http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/ has not been updated since 30th June. Do they have a problem?

http://nsidc.org/greenland-today/ continues to show very low melt.

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Re: Greenland 2017 melt season
« Reply #44 on: July 07, 2017, 02:14:22 PM »
From DMI's Greenland Surface Mass Balance webpage :=
"We are experiencing some temporary operational problems and hope to get the ice sheet surface mass balance back online soon.".

These days always a slight panic - is yet another satellite working beyond its design life with no replacement in sight? One hopes not.
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gerontocrat

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Re: Greenland 2017 melt season
« Reply #45 on: July 09, 2017, 03:03:38 PM »
http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/ is back after  8 days of no updates.

There has actually been a little loss of surface mass. Greenland is a bit warmer than of late. But nothing to write home about.
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Thomas Barlow

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Re: Greenland 2017 melt season
« Reply #46 on: July 13, 2017, 02:48:50 PM »
''Low surface ice loss on Greenland this year due to heavy snowfall – consistent with climate warming''
- Jason Box

http://jasonbox.net/low-surface-ice-loss-greenland-year-due-heavy-snowfall-consistent-climate-warming/

gerontocrat

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Re: Greenland 2017 melt season
« Reply #47 on: July 15, 2017, 02:25:49 PM »
"The Dog That Did Not Bark" continues not to bark. Greenland staying cool and will do for at least a few days more according to cci-reanalyzer. Looking more possible that in the DMI year Sept 1 2016 to Aug 30th 2017 surface mass balance may increase by around 200 gigatonne more than the 30 year average (and even more compared with recent years?) Impact on current sea level rise?
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Re: Greenland 2017 melt season
« Reply #48 on: July 19, 2017, 08:06:41 AM »
Fast Ice in NORD un-fastens (after a click).

gerontocrat

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Re: Greenland 2017 melt season
« Reply #49 on: July 20, 2017, 04:13:55 PM »
Forgot to post that https://nsidc.org/greenland-today/ on July 10 has a discussion on the melting season to June 30. Confirms that melting has been really slow, and last winter saw circa 150 gigatonne of mass gain more than usual.

Also says that the question of whether 2017 sees a net mass gain or loss for the Greenland ice sheet will be looked at later in the year. (On the DMI sight a mass gain looks more likely every day).
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