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grixm

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Greenland 2020 Melting Season
« on: March 24, 2020, 08:40:12 AM »
Since we clarified that the SMB thread should be for SMB data/discussion only, I am making a general-purpose melting season thread for Greenland like from last year.

I'd like to start by asking wtf is going on in the Freya Glacier webcam? Am my eyes deceiving me or was there a lot of snow melting yesterday despite being March and -20C?

Some resources:

SMB data: http://polarportal.dk/en/greenland/surface-conditions/ (And gerontocrat's thread)
Melt extent data and news: https://nsidc.org/greenland-today/
A webcam: https://www.foto-webcam.eu/webcam/freya1/


Stephan

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Re: Greenland 2020 Melting Season
« Reply #1 on: March 24, 2020, 10:34:59 PM »
Hi grixm,
I detected the same yesterday. It was cold the last days, and if it is -20°C or below at noon it should be colder than that during evening, night and morning. I have two possible explanations: The snow was drifted away by the wind or sublimation took place. I do not believe that the sun could heat up the stones above freezing when it is so cold.
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grixm

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Re: Greenland 2020 Melting Season
« Reply #2 on: April 07, 2020, 07:03:46 PM »
NSIDC has started updating their melt extent graph for the season. https://nsidc.org/greenland-today/greenland-surface-melt-extent-interactive-chart/

Aside from a tiny bit on April 1st, no registered melt yet.

Next week there may be some days of positive temperatures along the southwestern coast.

Stephan

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Re: Greenland 2020 Melting Season
« Reply #3 on: April 12, 2020, 10:00:53 PM »
Melting season has started in Southern Grønland.
www.wetteronline.de presents the following forecast for Narssarssuaq (from 12.-26.4.2020):
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grixm

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Re: Greenland 2020 Melting Season
« Reply #4 on: April 13, 2020, 08:14:23 AM »
Melting season has started in Southern Grønland.
www.wetteronline.de presents the following forecast for Narssarssuaq (from 12.-26.4.2020):

NSIDC also showed surface melt on the 11th:


grixm

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Re: Greenland 2020 Melting Season
« Reply #5 on: April 22, 2020, 04:08:35 PM »
It is 7 degrees in Nuuk today.


Stephan

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Re: Greenland 2020 Melting Season
« Reply #6 on: April 22, 2020, 10:36:09 PM »
A temperature jump also at Freya Gletscher 1053 m a.s.l. from -18°C to -3°C in the last couple of days. And snow is melting in the sun.
Generally much less snow than in 2018, and less snow than in 2017 and 2016 [2019 had no pictures at that time of the year, the camera was broken for a while].

See attached photo from https://www.foto-webcam.eu/webcam/freya1/
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paolo

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Re: Greenland 2020 Melting Season
« Reply #7 on: April 28, 2020, 11:22:46 PM »
In addition to the lack of snow in general, what I find really remarkable is that in the glacier we can already see areas that are no longer white and it's only on the 28/04. At this date it should be spotless!

click twice to zoom in

grixm

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Re: Greenland 2020 Melting Season
« Reply #8 on: April 29, 2020, 08:24:32 AM »
In addition to the lack of snow in general, what I find really remarkable is that in the glacier we can already see areas that are no longer white and it's only on the 28/04. At this date it should be spotless!

click twice to zoom in

It really is odd, not sure what is going on. Although it is discolored, there are no water-filled melting pools as far as I can tell, even though they usually appear before the discoloration does.

After a period of positive temperatures, it will now get cold again for the foreseeable future, so it will be interesting to see if it whitens again. But the sun will keep shining relentlessly so maybe the early drop in albedo will have lasting consequences.

johnm33

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Re: Greenland 2020 Melting Season
« Reply #9 on: April 29, 2020, 10:18:03 AM »
Given that it's timed at noon why are the shaded areas showing more melt? Dry north wind? Sublimation?

paolo

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Re: Greenland 2020 Melting Season
« Reply #10 on: April 29, 2020, 11:45:07 AM »
It is already a normally dry place and this winter there hasn't been much snow.
Little snow that the wind, a little sublimation and a little melting have probably already made disappear in some places of the glacier, probably letting the layer of the previous year appear in some places.
Even if there were only a few days just above 0°, which already seems exceptional to me, the glacier is at 1000 m of altitude, I am talking about a small melting because of the lateral valley, in the foreground, at the bottom of the picture, a valley that loses all the snow at the end of the season and whose gray spot doesn't seem to me to have any other justification.

This camera is very good to show us the dirty state in which the NE coast of Greenland is this year.
The image of the surroundings of the Fraya Glacier below shows us moreover that there was an important melting at sea level (0 m of altitude), as well as deposits of dust carried by the wind on the sea ice.

Attached :
> Reminder of the anomalies
> the surroundings of the Freya Glacier
> a zoom on the Freya Glacier
> a zoom on the area of melting and dust deposition on the sea ice

paolo

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Re: Greenland 2020 Melting Season
« Reply #11 on: April 29, 2020, 02:28:27 PM »
Melting in North Greenland
Image of the 25/04

gerontocrat

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Re: Greenland 2020 Melting Season
« Reply #12 on: April 29, 2020, 04:44:52 PM »
& DMI Polar Portal shows sublimation on 27 & 28 April at the head of Independence fjord.
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Re: Greenland 2020 Melting Season
« Reply #13 on: April 29, 2020, 05:55:45 PM »
PS post 11 :

Origin: lack of snow, wind and sublimation, but can there also be some foehn effect?

The pure ice images are too beautiful, I'll also post two zooms on the lake on the left in the picture of the post and on the small fjord tributary of the Independence Fjord on the top right

click twice to zoom in

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Re: Greenland 2020 Melting Season
« Reply #14 on: May 03, 2020, 11:25:52 PM »
I wanted to check the state of the "Independence Fjord" by comparing it with previous years and so I created an animation with images from the years 2016-2020 (the image of the 2016 is one week later).
This year's exceptionality is clear and the melting may start well in advance because of the albedo!

paolo

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Re: Greenland 2020 Melting Season
« Reply #15 on: May 07, 2020, 11:26:38 PM »
SW coast of Greenland: clear signs of melting

Freegrass

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Re: Greenland 2020 Melting Season
« Reply #16 on: May 08, 2020, 08:37:46 AM »
The NSIDC website is showing melting in the north of Greenland, but I didn't see any positive temperatures there. Could this be an error? Or are those grayed rocks heating up already in the sun?
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paolo

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Re: Greenland 2020 Melting Season
« Reply #17 on: May 08, 2020, 09:04:41 AM »
In my opinion: The area is cold, but not so much because of the lack of snow and therefore a low albedo, it is very dry and there is a lot of sun => sublimation

Freegrass

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Re: Greenland 2020 Melting Season
« Reply #18 on: May 08, 2020, 09:22:05 AM »
In my opinion: The area is cold, but not so much because of the lack of snow and therefore a low albedo, it is very dry and there is a lot of sun => sublimation
Sublimation has been going on there for months now, and never gets registered as "melting". So I'm not sure that's what's going on there.
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paolo

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Re: Greenland 2020 Melting Season
« Reply #19 on: May 08, 2020, 09:41:06 AM »
The current temperature is not the same as in the previous weeks, but above all the sun is non-stop and at a much higher angle!
Moreover in this area and in the previous days the NSIDC map had already reported melting!

EDIT: Regarding the second point I've added the NSIDC map for "Greenland Cumulative Melt Days Jan 1 -May 6", which shows that there have already been several days of sublimation

EDIT2 : "The process of ice changing directly into vapor without any intermediate liquid stage is often described by sublimation. The opposite of sublimation is “deposition,” where water vapor changes directly into ice. The sublimation of ice or snow is driven by an imbalance between the saturation vapor pressure (or vapor density) at a given temperature, and the vapor pressure in the immediate vicinity of an ice surface. Sublimation process in snow controls the grain shape and size. Snow sublimation rate can be defined as the amount of mass lost per unit time and depends on particle surface area to mass ratio, vapor pressure gradients, and rate of air exchange around the snow crystal surface. Typically, these rates are higher when large vapor pressure gradients exist and rapid air exchange occurs.
It is not easy to actually see sublimation occurring, especially for ice. Sublimation occurs more readily when certain weather conditions are present, that is, on a dry and windy day with low relative humidity. Sublimation also occurs more at higher altitudes, where the air pressure is less than at lower altitudes. Sublimation is fairly slow since it takes quite a bit of energy for an ice molecule to escape the solid rigid structure to a gas. Sublimation will be enhanced under direct sunlight since photons of solar energy will add the energy necessary for solid ice molecules to escape. Sublimation will occur even at low sun angles but the amount of sublimation will be very weak. Since sun angle is a minimum at the start of winter and much higher in late winter, the sublimation power of the sun on surface snow will be much higher in late winter as compared to early winter on sunny days. The sublimation rate of ice or snow has important implications on surface energy balance calculations, mass balance calculations, and studies of snow metamorphism."

« Last Edit: May 08, 2020, 10:13:59 AM by paolo »

Niall Dollard

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Re: Greenland 2020 Melting Season
« Reply #20 on: May 12, 2020, 01:34:30 AM »
19.6 C max today in the microclimate that is Kangerlussuaq.

paolo

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Re: Greenland 2020 Melting Season
« Reply #21 on: May 12, 2020, 05:40:23 PM »
For those who like to follow this small glacier (6 km long) in NE Greenland (Clavering Island) :
I just found out that there is a second webcam on the Freya Glacier, towards the upper part of the glacier:
https://www.foto-webcam.eu/webcam/freya2/2020/05/04/1200

I also add the links on two found videos (these two links are not directly related to this season, but can help to put in context the visual information of the Freya Glacier Webcam :
The first one about a catastrophic year for this Glacier: 2013, based on the images from both webcams at the same time:




and the second over two "normal" years (2016 and 2017) :


Freegrass

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Re: Greenland 2020 Melting Season
« Reply #22 on: May 12, 2020, 10:38:59 PM »
Strong melting already.  ???

http://nsidc.org/greenland-today/
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gerontocrat

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Re: Greenland 2020 Melting Season
« Reply #23 on: May 12, 2020, 11:39:49 PM »
"Para a Causa do Povo a Luta Continua!"
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Freegrass

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Re: Greenland 2020 Melting Season
« Reply #24 on: May 13, 2020, 12:51:47 AM »
The Danes disagree - different algorithm
First time I see that Danish graph. I noticed they use different scales. The mean from Denmark goes to around 30% melt at it's maximum, while the NSIDC graph only goes to 18%. Both the Danish and the NSIDC graph give us around 4 to 5% melt right now.

Which model is the better one?
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gerontocrat

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Re: Greenland 2020 Melting Season
« Reply #25 on: May 13, 2020, 10:14:00 AM »
The Danes disagree - different algorithm
First time I see that Danish graph. I noticed they use different scales. The mean from Denmark goes to around 30% melt at it's maximum, while the NSIDC graph only goes to 18%. Both the Danish and the NSIDC graph give us around 4 to 5% melt right now.

Which model is the better one?
Not a clue. If you compare the "Greenland Today" map (attached)with the melt map from DMI you will see that the DMI map is at a much finer resolution.

Does this make it more accurate? Potentially yes, but I avoid arguments about who has the better algorithms like the plague.

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Re: Greenland 2020 Melting Season
« Reply #26 on: May 13, 2020, 10:59:43 AM »

First time I see that Danish graph. I noticed they use different scales. The mean from Denmark goes to around 30% melt at it's maximum, while the NSIDC graph only goes to 18%. Both the Danish and the NSIDC graph give us around 4 to 5% melt right now.

The blue line in the NSIDC graph is the median not the mean. Still some discrepancy between the two though.

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Re: Greenland 2020 Melting Season
« Reply #27 on: May 14, 2020, 11:34:58 AM »
The modis Terra 367 images show the surface wetness to be right inline with NSIDC.

I don't know what to think of dmi they have always reported far less GIS ice mass loss yearly than grace satellites show.

The grace gravity detection is very very precise.
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paolo

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Re: Greenland 2020 Melting Season
« Reply #28 on: May 14, 2020, 12:36:43 PM »
In the calculation of the "Surface mass balance", neither calving nor melting by sea water, as specified in the DMI site, is taken into account:
"The map illustrates how the surface of the Greenland Ice Sheet gains and loses mass on a daily basis. This is known as the surface mass balance. It does not include the mass that is lost when glaciers calve off icebergs and melt as they come into contact with warm seawater."

It should not be confused with the "Total mass balance" as specified in their site, section "Mass and Height Change", where they use GRACE data:
" The map and graph show the gain in the mass of ice when there is precipitation, and how much of this mass is lost when snow and ice melt and when icebergs break off from the ice sheet’s major outlet glaciers. The difference in these mass changes over a glaciological year (September-August) is called the total mass balance of the Greenland Ice Sheet.
The map shows the latest changes in mass derived from data from the GRACE and GRACE-FO satellites'
"

EDIT: It should also be taken into account that melt water can either reach the sea or refreeze.
If the water freezes "Total mass balance" = 0, "Surface mass balance" to be checked.
« Last Edit: May 14, 2020, 12:47:55 PM by paolo »

gerontocrat

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Re: Greenland 2020 Melting Season
« Reply #29 on: May 14, 2020, 01:16:40 PM »
I don't know what to think of dmi they have always reported far less GIS ice mass loss yearly than grace satellites show.

No they don't, because when reporting on the overall Greenland Ice Sheet Mass change, DMI use the GRACE / GRACE-FO data.
http://polarportal.dk/en/home/
http://polarportal.dk/fileadmin/user_upload/polarportal-saesonrapport-2019-EN.pdf

The daily data on the Polar Portal @ http://polarportal.dk/en/greenland/surface-conditions/ is about Surface Mass Balance (SMB). SMB change is a function of snowfall, rain, sublimation, melt, and resulting run-off.

Obviously, SMB excludes ice mass loss from calving of marine-terminating glaciers and melting of marine-terminating glacial tongues by the ocean. DMI consider this separately from SMB.

But yes, the NSIDC melting graph often shows a greater area of melt than the DMI graph and a greater reduction in net SMB gain for the 2018-19 year (NSIDC - 300GT less than average, DMI - about 200GT less than average)

http://nsidc.org/greenland-today/2019/11/large-ice-loss-on-the-greenland-ice-sheet-in-2019/

ps: Even in years with high melting, Greenland SMB increases over the year (September to August) .. snowfall in winter greater than melt in summer. One year in the future that will reverse? (i.e.  melt in summer will be greater than snowfall in winter )
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Freegrass

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Re: Greenland 2020 Melting Season
« Reply #30 on: May 14, 2020, 02:02:37 PM »
ps: Even in years with high melting, Greenland SMB increases over the year (September to August) .. snowfall in winter greater than melt in summer. One year in the future that will reverse? (i.e.  melt in summer will be greater than snowfall in winter )
I'm sure I will be told to put this in the stupid questions section, but where does all that snow come from? All winter I saw high pressure above Greenland, so I've been wondering about that all winter...
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gerontocrat

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Re: Greenland 2020 Melting Season
« Reply #31 on: May 14, 2020, 08:09:45 PM »
ps: Even in years with high melting, Greenland SMB increases over the year (September to August) .. snowfall in winter greater than melt in summer. One year in the future that will reverse? (i.e.  melt in summer will be greater than snowfall in winter )
I'm sure I will be told to put this in the stupid questions section, but where does all that snow come from? All winter I saw high pressure above Greenland, so I've been wondering about that all winter...
ARITHMETIC

Cumulative Snowfall on Greenland this year is just over 500 GigaTons & we are nearly at the maximum as melt from insolation (and rain) will soon exceed precipitation as snow. The area of Greenland is 2.166 million km2.

So the 500 GT equates to a Snow Water Equivalent of 230 mm of rainfall (which is, depending on compaction, anything between 1 to 2 metres thickness of snow).

Quote
"Deserts are dry or arid areas that receive less than 250 mm of rain each year.
Deserts can be hot or cold"
https://www.bbc.co.uk/bitesize/guides/znxsgk7/revision/1

Greenland is a desert but AGW+Polar Amplification could (is) change(ing) all that.
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Freegrass

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Re: Greenland 2020 Melting Season
« Reply #32 on: May 14, 2020, 08:26:12 PM »
Thanks Gerontocrat! That helped me a lot to understand. And I guess both the melting and the snowfall will mostly be located at the edges? I totally get it now. Thanks!
« Last Edit: May 14, 2020, 08:35:58 PM by Freegrass »
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ArcticMelt2

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Re: Greenland 2020 Melting Season
« Reply #33 on: May 14, 2020, 10:19:21 PM »
Wow  :o

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Re: Greenland 2020 Melting Season
« Reply #34 on: May 14, 2020, 10:47:08 PM »
Forecast for Narsarsuaq, S Grønland mid-end May 2020.
Mild, dry and sunny. Melting season.
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Re: Greenland 2020 Melting Season
« Reply #35 on: May 14, 2020, 11:06:41 PM »
FG, Greenland is a mountain of ice that reaches 2700m IIRC. This helps precipitate snow.

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Re: Greenland 2020 Melting Season
« Reply #36 on: May 15, 2020, 12:28:15 AM »
FG, Greenland is a mountain of ice that reaches 2700m IIRC. This helps precipitate snow.
I did some research, and came across this. My apologies if this was discussed here already, but it's the first time I read about this phenomenon...

PUBLISHED SEPTEMBER 18, 2019

Something strange is happening to Greenland's ice sheet
What should be like a snowcone is becoming more like a popsicle, speeding up the runoff from the melting ice sheet.

When the remnants of Europe’s second summertime heat wave migrated over Greenland in late July, more than half of the ice sheet’s surface started melting for the first time since 2012. A study published Wednesday in Nature shows that mega-melts like that one, which are being amplified by climate change, aren’t just causing Greenland to shed billions of tons of ice. They’re causing the remaining ice to become denser.

“Ice slabs”—solid planks of ice that can span hundreds of square miles and grow to be 50 feet thick—are spreading across the porous, air pocket-filled surface of the Greenland ice sheet as it melts and refreezes more often. From 2001 to 2014, the slabs expanded in area by about 25,000 square miles, forming an impermeable barrier the size of West Virginia that prevents meltwater from trickling down through the ice. Instead, the meltwater becomes runoff that flows overland, eventually making its way out to sea.

As the ice slabs continue to spread, the study’s authors predict more and more of Greenland’s surface will become a “runoff zone,” boosting the ice sheet’s contribution to global sea level rise and, perhaps, causing unexpected changes.

“We're watching an ice sheet rapidly transform its state in front of our eyes, which is terrifying,” says lead study author Mike MacFerrin, a glaciologist at the University of Colorado, Boulder.

A ‘turtle shell’ for ice

It’s easy to think of Greenland as a solid, impenetrable hunk of ice. But in reality about 80 percent of the ice sheet’s surface is like a snowcone: A dusting of fresh snowfall covers a thick layer of old snow, called firn, that’s slowly being compressed into glacier ice but still contains plenty of air pockets. When the top of this snow cone melts in the summer, liquid water percolates down into the firn, which soaks it up like a 100-foot-thick sponge.

MacFerrin and his colleagues got their first hint that the firn may be losing its absorbency in the spring of 2012, when they were drilling boreholes through the firn in southwest Greenland. They started finding dense, compacted layers of ice in core after core, just below the seasonal snow layer. It was, MacFerrin says, as if a “turtle shell” had formed over the firn.

MacFerrin and his colleagues immediately wondered whether that shell might be preventing meltwater from percolating into the firn.

“That was May of 2012,” MacFerrin says. “And July was this record-breaking melt year, and we got our answer very quickly.”

That summer, for the first time on record, meltwater from this part of Greenland visibly started to flow away as runoff.

Realizing they had witnessed something significant, the researchers set about drilling more cores over a larger region to see how extensive the ice shell was. They discovered that it spanned a transect 25 miles long and was having widespread effects on local hydrology.

Those findings, published in 2016 in Nature Climate Change, were the springboard for the new study. Using radar data from NASA’s IceBridge airborne campaign, as well as ground-based surveys, MacFerrin and his colleagues have now created a first-of-its-kind map of ice slabs across the entire surface of Greenland.

Based on modelling results, the researchers think the shell began to form and spread widely in the early 2000s. As of 2014, it covered some 4 percent of Greenland’s surface, according to the new analysis. Every summer that extensive melting occurs, it gets thicker and spreads inland to colder, higher ground.

“Every handful of years, these big melt summers are doing a number on the firn,” MacFerrin says. “That’s causing this whole process to grow inland pretty quickly.”

Sea level rise and unexpected consequences

Ice slabs have already caused Greenland’s runoff zone to expand by about 26 percent, according to the new study. So far the additional runoff has only added about a millimeter to global sea levels. Greenland now contributes a little under a millimeter per year to rising sea levels, through a combination of icebergs breaking off glaciers and melt occurring at the surface and base of the ice sheet.

But if Greenland’s surface hardens more, runoff could rise dramatically. Under a worst-case scenario where carbon emissions continue to climb until the end of the century, the researchers calculated that ice slab proliferation could add up to 3 inches of sea level rise by 2100, boosting the ice sheet’s overall sea level rise contribution by nearly a third. In both a middle-of-the-road scenario where emissions peak by mid-century and the high emissions one, the amount of runoff from Greenland’s interior roughly doubles by century’s end.

But more runoff is only one potential consequence of the transformation taking place in Greenland’s ice. Kristin Poinar, a glaciologist at the University of Buffalo who wasn’t involved in the study, pointed out that slabs of solid ice aren’t nearly as reflective as bright white snowfall.

“And so, if we start getting these ice slabs forming near the ice sheet’s surface, it could potentially...cause the ice sheet to absorb more solar radiation and warm up,” she says. “And that would create more ice slabs.”

And runoff from ice slabs doesn’t have to flow into the ocean, said Indrani Das, a glaciologist at Columbia University who wasn’t involved in the study. She worries about how it could seep into the large crevasses that exist at lower elevations on the ice sheet. From there, the runoff could, potentially, flow all the way down to bedrock, lubricating the zone where the ice makes contact with it.

“That could make the ice sheet flow faster,” Das says, which could cause glaciers to spill their contents into the ocean more quickly, like ice cream sliding off a piece of cake.

To Poinar, the most significant contribution of the new study is that it will allow scientists to improve their projections of future sea level rise, giving coastal communities the information they need to prepare. At the same time, the study highlights the fact that the more carbon we spew into the atmosphere, the more we’re likely to transform Earth’s northern ice sheet in insidious and unexpected ways. And that could have consequences that are difficult to anticipate.

“We have never observed an ice sheet behaving this way before,” Poinar says. “It’s unprecedented in human scientific history.”
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Frivolousz21

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Re: Greenland 2020 Melting Season
« Reply #37 on: May 16, 2020, 08:57:33 AM »
I don't know what to think of dmi they have always reported far less GIS ice mass loss yearly than grace satellites show.

No they don't, because when reporting on the overall Greenland Ice Sheet Mass change, DMI use the GRACE / GRACE-FO data.
http://polarportal.dk/en/home/
http://polarportal.dk/fileadmin/user_upload/polarportal-saesonrapport-2019-EN.pdf

The daily data on the Polar Portal @ http://polarportal.dk/en/greenland/surface-conditions/ is about Surface Mass Balance (SMB). SMB change is a function of snowfall, rain, sublimation, melt, and resulting run-off.

Obviously, SMB excludes ice mass loss from calving of marine-terminating glaciers and melting of marine-terminating glacial tongues by the ocean. DMI consider this separately from SMB.

But yes, the NSIDC melting graph often shows a greater area of melt than the DMI graph and a greater reduction in net SMB gain for the 2018-19 year (NSIDC - 300GT less than average, DMI - about 200GT less than average)

http://nsidc.org/greenland-today/2019/11/large-ice-loss-on-the-greenland-ice-sheet-in-2019/

ps: Even in years with high melting, Greenland SMB increases over the year (September to August) .. snowfall in winter greater than melt in summer. One year in the future that will reverse? (i.e.  melt in summer will be greater than snowfall in winter )

Thanks for the info I totally overlooked the glacier loss.

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paolo

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Re: Greenland 2020 Melting Season
« Reply #38 on: May 17, 2020, 06:28:11 PM »
West greenland, it's melting

twice click to zoom in

blumenkraft

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Re: Greenland 2020 Melting Season
« Reply #39 on: May 17, 2020, 06:49:30 PM »
Indeed! Almost all of the west...
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blumenkraft

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Re: Greenland 2020 Melting Season
« Reply #40 on: May 17, 2020, 07:16:56 PM »
NSIDC Greenland Surface Melt Extent
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Frivolousz21

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Re: Greenland 2020 Melting Season
« Reply #41 on: May 18, 2020, 06:05:04 AM »
NSIDC Greenland Surface Melt Extent

The amazing thing is how  before in May there was almost to surface change.

And things have dramatically changed

In 20-30 years May will probably see melt extent by the end of month to what the peak average is now.
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Frivolousz21

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Re: Greenland 2020 Melting Season
« Reply #42 on: May 18, 2020, 06:08:50 AM »
The weather models do bring cloudy cool vortex back soon.

To see GIS have an exceptional melt season a major ridge would have to establish for at least a week sometime between the 20th of May and June 15th.

If it came after the 15th the melt could be big but the overall melt totals probably can't beat 2019 or 2012 without a major early June dipole
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grixm

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Re: Greenland 2020 Melting Season
« Reply #43 on: May 21, 2020, 04:41:53 PM »
Did the first honest-to-god melt pond in the Freya glacier webcam pop up today?

paolo

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Re: Greenland 2020 Melting Season
« Reply #44 on: May 21, 2020, 09:59:15 PM »
The temperature today is -0.7, but we can think that it is the temperature recorded where are the 2 cameras on the crinal which dominates the glacier, and we can therefore think that it is a bit higher at the bottom, on the glacier.  I don't know the temperature of the previous days.
In any case it is in a depression and if it is not the beginning of melt pond, it looks like it. ;)

Stephan

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Re: Greenland 2020 Melting Season
« Reply #45 on: May 21, 2020, 10:17:59 PM »
I just checked the historical pictures from Freya Gletscher webcam and looked for melt pond formation dates:
2016 first melt pond further downstream June 11, no melt pond at that place at all through August
2017 first melt pond further downstream June 1, melt pond at that place June 6
2018 no melt pond in May, and then - camera not working for a while...
2019 melt pond at that place May 26
So in this little race 2020 is the winner for being as early as never since 2016.
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FrostKing70

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Re: Greenland 2020 Melting Season
« Reply #46 on: May 21, 2020, 11:15:54 PM »
And, meanwhile in the bigger picture, another consecutive day of mass loss...

Stephan

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Re: Greenland 2020 Melting Season
« Reply #47 on: May 22, 2020, 05:38:49 PM »
And, meanwhile in the bigger picture, another consecutive day of mass loss...
...in previously untouched territory (knowing that the grey shaded area does not cover the maxima (or minima) that were observed so far).
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FrostKing70

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Re: Greenland 2020 Melting Season
« Reply #48 on: May 22, 2020, 07:40:20 PM »
I am starting to wonder if this is the year that we get well outside the normal, as scary as that is for the planet!

I don't have the software to do this the way I would like (copy the red line and connect to this years) so hand drew a projection which is actually less scary than the red line!