Greenland 2020 Melting Season

[paolo]

The images available today from Sentinel-2 (and thus relative to yesterday) are not the best, but I wanted to give an image of the melt ponds in West Greenland and this image of the Nordenskiold Glacier, West Greenland (southern neighbor of Jakobshavn Isbræ), with a melt pond of almost two kilometers seemed interesting to me.

[Stephan]

New melt ponds on Freya Gletscher. After a short period of new snow (all of it has already melted) in the beginning of this week new melt ponds are visible further upstream (circled in red). The older one (circled in green) is still present.
Note that the temperature is above +1°C, although the webcam is located at 1,053 m above sea level.

[Gerntocratis#1]

Boom

[grixm]

Update on our favourite webcam. It has been quite warm the last two days at the Freya glacier, and we see more melt ponds, as well as exposed dirt layers everywhere. At the base of the valley there is way less snow than there were any other recent June 12th that the webcam has been operative.

[Stephan]

Melting continues on Freya Gletscher, E Grønland. It appears that most of the snow on the glacier has already gone. Incredibly mild (> 10°C in 1.053 m asl). Several smaller melt ponds.
I compared with the last years. Only 2016 comes close to what we observe today. 2017 and 2019 had more snow and less warmth.

[paolo]

Attached the image of the second webcam of the Freya glacier, the one showing its upstream part.
It's in very bad state...

[Stephan]

Melting continues on Freya Gletscher, although today it is below freezing.
A lot of snow has gone, the most visible changes compared to the last days (loss of snow / greying / melt ponds / melt streams) are circled in green.
I checked the same day in previous years. Not even 2016 showed the disastrous state the glacier is in. 2017 and 2019 had much more snow.

Edit: Added the picture of Cam2 - the ice is in a bad state also in the upper part of Freya Gletscher.

[VeliAlbertKallio]

Melville Bay's Coastal Depression section showing ice discharges and drained melt water lakes 27.07.2020. The region has very active Greenland Ice sheet edge because the width of Greenland's perimeter shield fades away and descends below sea level - part of GIS edge more akin to ice shelf.

This area interests SRS due to its broken geology that is also subsiding contrary to the rest of Greenland. Besides Petermann's fjord this is potentially one of the most dangerous parts due to its huge erratic boulders and unstable sea bed, east-west tilting, and north-south bending point stressing its rocks, and turbidic rock falls on its broken seabed. Its edges are often licked also by warm sea water.

Sea Research Society's evidence-giving in Parliament pointed out risks from this region after the Arctic Ocean becomes regularly ice-free in summer time. After exhaustive surface melt in north Greenland, post summer sea ice, this region will accumulate even more wet and slushy ice against its perimeter barrier obstacles. This risk is growing and these land subsidences will become major hazard one day: https://www.academia.edu/37157851/Our_Changing_Climate_in_Action_the_Risk_of_Global_Warming_and_the_Environmental_Damage_from_the_Rising_Ocean_Water_Table_Sustainable_Seas_Enquiry_Written_evidence_submitted_by_Veli_Albert_Kallio_FRGS_SSI0121_Ordered_to_be_published_23_May_2018_by_the_House_of_Commons
 

[nukefix]

This area interests SRS due to its broken geology that is also subsiding contrary to the rest of Greenland.

The area is question is NOT subsiding but is undergoing rapid uplift, see:

https://www.pnas.org/content/pnas/109/30/11944.full.pdf

[VeliAlbertKallio]

I love your post! It appears that I originally referred to the downward anomaly found within the ground uplift when the ice melting (ablation) effect was assessed with this I meant the reduction in the uplift (due to the 2mm deduction by the landslip occurring on the area). As melting lightens the ground, it rises. Yet as the ground slips deeper into the ocean, the ground rises less: anomaly emerges

I referred uplift anomaly to the GNET stations uplift anomaly -2mm deduction in the uplift in the area. My memory is a bit wide but short, the anomaly graph appears I referred on p. 17 here: https://www.academia.edu/33000316/MPs_to_review_UKs_role_in_Arctic_sustainability_-_24th_April_2017.docx and has been taken from SRS Parliament evidence from source :
Bevis, M. et. al.: "Bedrock displacements in Greenland manifest ice mass variations, climate cycles and climate change" Proceedings of the National Academy of Sciences of the United States of America (PNAS)     vol. 109 no. 30, pages 11944–11948, doi: 10.1073/pnas.1204664109. Figure 5. 11 June 2012. Figure 5: https://www.pnas.org/content/109/30/11944

I hope above clarifies my position why I think this region is very problematic when Greenland surface melt becomes exhaustive across the north parts of GIS after the summer sea ice is no longer there.

Arctic has seen a small scale coastal rock collapses. Similar but much larger scale events will happen when the rocks begin to melt further and further thus clearing pathway for ice to slide to sea. This is my view of Heindrich Zero ice berg calving event when the barrier on the Hudson Strait gave away to the ice dome. Its replication, we indicated the structural similarities of the two coastlines and their weaknesses. I see the Hudson Strait as the older sister of the Melville Bay which collapsed, while Melville Bay almost collapsed but was arrested by rising sea water table, more northernly position of Greenland's ice to that of the Fixe-Laurentide ice dome on the Hudson Bay, and the new equilibrium.

This area interests SRS due to its broken geology that is also subsiding contrary to the rest of Greenland.

The area is question is NOT subsiding but is undergoing rapid uplift, see:

https://www.pnas.org/content/pnas/109/30/11944.full.pdf

[paolo]

This is the upper part of the glacier,
but where's the accumulation zone ? ! ? ! ?

  

Click to zoom in

[lurkalot]

With the large number of melting days (and counting) in the SW and NE of Greenland, one might expect the total area of the ice sheet to be reducing on an absolute basis, not just a seasonal one. Also, if the altitude of the ice sheet reduces, then that presumably creates a positive feedback loop, as the temperature will tend to be lower at reduced altitude. In particular, I believe there is a 'saddle' between the northern and southern ice sheets that is of interest in this regard.
Does anyone have data on area and altitude?

[FrostKing70]

Let's not forget that due to the mass loss on the ice sheet, the sea level around Greenland is falling.

https://climate.nasa.gov/news/2626/evidence-of-sea-level-fingerprints/
 

[Tor Bejnar]

from Wikipedia:

The total area of Greenland is 2,166,086 km2 (836,330 sq mi) (including other offshore minor islands), of which the Greenland ice sheet covers 1,755,637 km2 (677,855 sq mi) (81%) and has a volume of approximately 2,850,000 km3 (680,000 cu mi).

image from https://www.flickr.com/photos/66103993@N00/130597590 (click to enlarge a little)

[sidd]

Re: saddle 67N

ELA (equilibrium line altitude) rose above the saddle in 2012. I have seen melt on the saddle but no lakes yet. But i may have missed some.

sidd

[lifeblack]

This is the upper part of the glacier,
but where's the accumulation zone ? ! ? ! ?

  

Click to zoom in

It looks even worse today, if that's possible.  It almost looks as if something started the 'defrost' cycle in their freezer and left the door open

[paolo]

You're right, just catastrophic, and there's still August.

And you're quite right not to show pictures ...

[nukefix]

Arctic has seen a small scale coastal rock collapses. Similar but much larger scale events will happen when the rocks begin to melt further and further thus clearing pathway for ice to slide to sea.

The ice sheet in the area is grounded on bedrock that is rising, and that is already above sea-level, so there is no possibility of a marine-grounded ice-sheet collapse like in parts of WAIS.

[NotaDenier]

I have a question regarding how this mass gain/loss is calculated. Is this a model based upon precipitation? Or is this using date from GRACE data?

How much of this precipitation is falling as rain? If you look a lot of the mass gain is right on the edge of the ice sheet. Isn’t it possible that a lot of moisture in the summer months is rain and that it may not actually add to the mass of the ice sheet long term? Is this taken into account when the calculate the yearly gain/loss?

Also is it possible that some of the mass gain on the outside of the ice sheet is due to the glacier slumping slightly? For example if the glacier sped up slightly and caused the area nearest the sea to rise by say 5 meters would that not show up on GRACE?

Maybe these are separate topics but I’ve been wondering about them for a few years.

TIA

[grixm]

I have a question regarding how this mass gain/loss is calculated. Is this a model based upon precipitation? Or is this using date from GRACE data?

How much of this precipitation is falling as rain? If you look a lot of the mass gain is right on the edge of the ice sheet. Isn’t it possible that a lot of moisture in the summer months is rain and that it may not actually add to the mass of the ice sheet long term? Is this taken into account when the calculate the yearly gain/loss?

Also is it possible that some of the mass gain on the outside of the ice sheet is due to the glacier slumping slightly? For example if the glacier sped up slightly and caused the area nearest the sea to rise by say 5 meters would that not show up on GRACE?

Maybe these are separate topics but I’ve been wondering about them for a few years.

TIA

It is a model based on lots of input, including precipitation. You can read all about it in this paper: https://www.frontiersin.org/articles/10.3389/feart.2016.00110/full

But GRACE data is not used. It does not update fast enough and is probably not good enough resolution for a near-real-time product.

[oren]

You could say Grace data is the control for the model, once you factor in calving and marine melting.

[Stephan]

Please have a look at the sad state Freya Gletscher is in at the moment.
And please check the temperature (+ 8.6°C at an altitude of 1.053 m above sea level).
Never before on an August 1^st since this webcam has been installed this glacier has looked so vulnerable and damaged.

[grixm]

What is the large black splotches on the webcam ice? Rock/dirt on the bottom of the glacier? In that case I didn't realize the valley was so shallow. Or is it just a dirty ice layer of the glacier?

[oren]

I wish someone would put such a webcam above Jakobshavn. The same spot where Chasing Ice was filmed from.

[Stephan]

What is the large black splotches on the webcam ice? Rock/dirt on the bottom of the glacier? In that case I didn't realize the valley was so shallow. Or is it just a dirty ice layer of the glacier?

I would say this is dirty old ice and not the bedrock beneath it.
You can zoom into the photograph by clicking on it:
https://www.foto-webcam.eu/webcam/freya1/

[Stephan]

Another sad picture from Freya 2 on a mild and rainy summer day.

[FrostKing70]

SMB gain in mid august, I don't think that happens very often!

[Sebastian Jones]

What is the large black splotches on the webcam ice? Rock/dirt on the bottom of the glacier? In that case I didn't realize the valley was so shallow. Or is it just a dirty ice layer of the glacier?

I would say this is dirty old ice and not the bedrock beneath it.
You can zoom into the photograph by clicking on it:
https://www.foto-webcam.eu/webcam/freya1/

This is almost certainly dirt (silt) left behind by water that had pooled on the glacier until it suddenly drained away.

[gerontocrat]

I have a question regarding how this mass gain/loss is calculated. Is this a model based upon precipitation? Or is this using date from GRACE data?

How much of this precipitation is falling as rain? If you look a lot of the mass gain is right on the edge of the ice sheet. Isn’t it possible that a lot of moisture in the summer months is rain and that it may not actually add to the mass of the ice sheet long term? Is this taken into account when the calculate the yearly gain/loss?

Also is it possible that some of the mass gain on the outside of the ice sheet is due to the glacier slumping slightly? For example if the glacier sped up slightly and caused the area nearest the sea to rise by say 5 meters would that not show up on GRACE?

Maybe these are separate topics but I’ve been wondering about them for a few years.

TIA

It is a model based on lots of input, including precipitation. You can read all about it in this paper: https://www.frontiersin.org/articles/10.3389/feart.2016.00110/full

But GRACE data is not used. It does not update fast enough and is probably not good enough resolution for a near-real-time product.

I can answer that a bit using my mobile phone.

The GRACE-FO satellites measure the mass of Greenland, i.e. everything.

Afrer a lot of extremely hairy processing the data is analysed down to the mass of each of 7 drainage basins & the total mass of Greenland..

Then Germany once a month produces the change in mass of Greenland and its basins, which is assumed to be the sum of additional precipitation less run-off (i.e the change in SMB) less mass loss from glacial calving and melting of marine-terminating glaciers. The JPL only produce a text file of the total for each month.

The DMI data is the surface mass balance. - SMB. It is a model based on measurements of precipitation and estimated melt from the the weather adjusted for assumptions on how much melt actually runs off and how much precipitation as rain will run off.

Not so long ago they increased the number of weather stations, still very few, so I presume they test their model against field observations when and where they can. In my backup files I have a paper that suggests RAIN will become more important, even in winter, as global heating continues.

I bet there are a lot of discussions every year on whether the model needs tweaking.

The GRACE data is real, but is NOT SMB. With luck I will be back online this weekend, it is infuriating following the data but not being able to process it.

[Tor Bejnar]

The 'black' within the glacier's boundaries ("Freya 2") would be moraine or landslide debris (or rockfall debris if the wall is steep around the corner we cannot see).  When a glacier goes around a corner, all sorts of deformation can occur to lateral or medial moraine debris, without the textbook look of a ribbon (like a couple segments upstream appear to have).  The blotch on the right might be the toe of a recent 'old fashioned' landslide which flowed onto the glacier.  The two blotches near the bend might be from older landslides.

In the Petermann Glacier thread, recently calved icebergs (as well as still-part-of-the-glacier ice) includes black streaks that were (or are) certainly bits of medial moraine quite solidly frozen into the ice.

[JMP]

How much of this precipitation is falling as rain? If you look a lot of the mass gain is right on the edge of the ice sheet. Isn’t it possible that a lot of moisture in the summer months is rain and that it may not actually add to the mass of the ice sheet long term? Is this taken into account when the calculate the yearly gain/loss?

Excellent Question!!! 
My assumption has been that precipitation here only refers to accumulative precipitation no matter the form it takes before accumulation.   But, I do not see this particular definition pinned down or explained.   In this day and age this sort of data needs to be defined most precisely for the broadest selection of the consumers of the information imho. 

[FredBear]

A general darkening of a glacier may be due to cryoconite - a mix of soot, dust and bacterial/biological materials - which tends to accumulate on the surface when the ice there melts. It starts off by being distributed over the surface but may become concentrated in some areas, where it absorbs radiant energy and melts the ice more rapidly creating depressions.

"If you want to learn more about what is making glaciers melt, and what cryoconite holes look like, check out James Balog’s documentary film “Chasing Ice.” The film is both beautiful and horrific, showing how glaciers of enormous proportions are being melted largely by human influences."

[grixm]

Both GFS and ECMWF predicts a heatwave over Greenland starting in around Wednesday.

[Stephan]

A short cool intermezzo during the melting season or the first sign of the coming freezing season?

[grixm]

A short cool intermezzo during the melting season or the first sign of the coming freezing season?

Certainly looks like the former.

[grixm]

A short cool intermezzo during the melting season or the first sign of the coming freezing season?

Certainly looks like the former.

On second look, maybe not. Significant portions of the glacier is still covered in white over two weeks after the snowfall, despite there being sunny weather and above-freezing temperatures. No clear melt ponds visible any more. During peak insolation season the glacier would have cleared of the snow and looked awful after just a few days.

[Stephan]

Seems like the melting season is finished - at least in higher altitudes. Freya Gletscher Webcam, East Grønland, from today.

[glennbuck]

An enormous chunk of Greenland's ice cap has broken off in the far northeastern Arctic, a development that scientists say is evidence of rapid climate change.

The glacier section that broke off is 110 square kilometers (42.3 square miles). It came off of the fjord called Nioghalvfjerdsfjorden, which is roughly 80 kilometers (50 miles) long and 20 kilometers (12 miles) wide, the National Geological Survey of Denmark and Greenland said Monday.

https://phys.org/news/2020-09-big-chunk-greenland-ice-cap.html

[be cause]

News ? .. not here ... https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=400.0;attach=273358;image ..

more here ..
Re: Zachariae Isstrøm / Nioghalvfjerdsfjorden / NE Greenland
« Reply #1026 on: July 01, 2020, 06:25:27 PM »
LikeQuote
Quote from: anaphylaxia on July 01, 2020, 05:36:19 PM
Does the movement of the large slab in the Spaltegletscher area count as calving?

https://apps.sentinel-hub.com/eo-browser/?zoom=9&lat=79.78214&lng=-20.35217&themeId=DEFAULT-THEME&datasetId=S2L1C&fromTime=2020-06-30T00%3A00%3A00.000Z&toTime=2020-06-30T23%3A59%3A59.999Z&layerId=1_TRUE_COLOR&visualizationUrl=https%3A%2F%2Fservices.sentinel-hub.com%2Fogc%2Fwms%2F42924c6c-257a-4d04-9b8e-36387513a99c&gain=0.6

Yes it is a calving, after an ongoing proces for yearssssss suddenly between June 29 and June 30 2020, something happened, thanks for your observation!! Espen