Greenland - What Do We Know, What Is The Long Term Future And Is There Any Evidence Of A Melt Out?

[iapennell]

https://www.iceagenow.info/greenland-ice-sheet-growing-record-rate/

Possibly as a result of above-normal temperatures of surrounding ocean surfaces (and less sea-ice around this winter gone)- leading to more moisture in the atmosphere over Greenland; the Greenland Icecap has had record snowfall amounts over this last autumn and winter (2016/17) with almost double the normal amounts of winter snowfall on the Ice-cap. If that is so, it will have to be record warm summer on the Icecap to give rise to continued net loss. Much depends on whether open and warmer-than-usual waters in the Greenland Sea- from where some of Greenland's most prevalent winds come results in a repeat scenario for the next few winters. If then, in summer, lower pressure occurs over the Arctic and adjacent areas leads to more cloud-cover and substantial summer snowfall on the higher parts of the Ice-cap (possibly due to less Arctic ice leading to sub-polar depressions regularly penetrating deep into the Arctic or the record Westerly QBO this year repeating in later years- leading to lower pressure in high latitudes) then the net annual accumulation of the snow and ice may well turn positive with more winter snowfall than melting in spite of higher annual mean temperatures on the Icecap.

[BornFromTheVoid]

Iceagenow is a spoof site, not to be taken seriously.

Snowfall has been increasing over Greenland for a while now (as is to be expected when the air temps increase but are still cold enough for snow), but it's nowhere near outpacing the melt.

[iapennell]

@BornFromTheVoid, Whatever you think about the Ice Age Now site references to the Greenland Icecap's record snowfall accumulations over the autumn and winter just gone come from several sources:

http://polarportal.dk/nyheder/nbsp/nyheder/heavy-snowfall-in-greenland/

and here:

https://realclimatescience.com/2017/01/greenland-blowing-away-all-records-for-ice-growth-3/

and these here:

https://www.longroom.com/discussion/264182/greenland-enters-2017-adding-extraordinary-amounts-of-ice-and-snow

https://steemit.com/globull-wurming/@everittdmickey/greenland-ice-sheet-growing

 

Whilst I do not deny that Greenland has been losing mass due to global warming over recent years, you have here information from a number of sources that suggest that there has been excessively high snowfall totals this last autumn and winter over the Greenland Icecap (because of record warmth in the Greenland Sea just to the east and the northwards passage of far North Atlantic depression-tracks). The amount of snow- over 20 cm above normal in terms of water equivalent for the season over a wide area- will require sustained warmth and melting *along with glacier calving into the surrounding seas) to get the Greenland Icecap back to the state it was in at the end of August last year.

However, some of these reports emphasise that for north-west Greenland only, snowfall amounts were below normal last winter but not by much, hence it is likely that these areas of the ice-sheet will see a net loss of snow and ice (but not by much, because the NW of Greenland remains cold during most summers being so far north). This does not detract from the fact that, over east and SE Greenland but also into the interior where little melting happens, snowfall over the last six months has been well above the long-term normal and this will have implications for the local mass-balance of the ice-sheet.

[knocker]

I'm not sure what point you are trying to make, if any. A quote from the Polar Portal site which is by far the most reliable of the sites you have chosen.

Quote

As we have stated before, the surface mass budget of the ice sheet is best viewed over a year or longer to get a sense of what is happening to the ice sheet – it is the difference between looking at weather and climate. When viewed over the year the three most important months for the annual surface mass balance budget are the summer ones of June, July and August. The amount of melting in the summer is much more important in determining the mass budget over the ice sheet than the winter months.  It is therefore still far too early to suggest that the Greenland ice sheet will not lose more mass than it gains this year.

 

[Methuselah]

5 hours ago, BornFromTheVoid said:

Iceagenow is a spoof site, not to be taken seriously.

Snowfall has been increasing over Greenland for a while now (as is to be expected when the air temps increase but are still cold enough for snow), but it's nowhere near outpacing the melt.

Blimey BFTV, I counted 13 'recoveries' in there!

[Gael_Force]

A lot more icebergs coming off Greenland than is usual for this time of year.

http://www.cbc.ca/news/technology/icebergs-affecting-shipping-lanes-atlantic-1.4058032

Experts are attributing it to uncommonly strong counter-clockwise winds that are drawing the icebergs south, and perhaps also global warming, which is accelerating the process by which chunks of the Greenland ice sheet break off and float away.

As of Monday, there were about 450 icebergs near the Grand Banks of Newfoundland, up from 37 a week earlier, according to the U.S. Coast Guard's International Ice Patrol in New London, Connecticut. Those kinds of numbers are usually not seen until late May or early June. The average for this time of year is about 80.

 

[iapennell]

The possible implications of heavier snowfall over Greenland (as this winter past) and more melting in summer, combined with heavier rainfall and snowfall over the far North Atlantic (as storm-tracks move northwards with the shrinking seasonal Arctic ice-cover) could freshen the North Atlantic Ocean to such an extent that the Thermohaline Circulation, otherwise known as the North Atlantic Drift, could shut down before the end of the 21st Century. This possibility is spelt out in the following article:

https://article.wn.com/view/2017/02/01/Is_the_North_Atlantic_headed_for_an_ice_age/

If the North Atlantic Drift weakens drastically or shuts down completely before this century is out the impact on the climate of Britain, much of north-west Europe and the eastern US will not be one of warming but quite a sharp cooling that would more than counteract the CO₂-induced warming by the end of the Century. heavier snowfall with more melting that more than removes accumulated winter snow-cover over the entire Greenland Ice-cap has some serious implications. It could indeed be what is responsible for the record calving of ice-bergs in the NW Atlantic (see reference above) and the presence of the so-called "North Atlantic Cold Blob", a large patch of substantially colder-than-normal water in the North Atlantic which is about the size of western Europe: See article about it here:

http://blogs.reading.ac.uk/weather-and-climate-at-reading/2017/an-update-on-the-north-atlantic-cold-blob-january-2017/

 

[Gray-Wolf]

We've seen the recent uptick in Bergs flowing out of Baffin and a recent paper announcing the end of the shore-fast ice around Greenland so we know Greenland has now fully entered its 'melt out' phase so this WACCy snow pasting, it took over winter, just leads us to bigger issues like slope stability.

With a saturated layer below the snow any scarring , by avalanche, could lead to areas draining this layer if channels form during the movement. This would lead to further instability and begin the process of lowering the ice cap via catastrophic collapse ( and not a slow 'drip, drip' ablation?).. If we see a continuation of grounding line retreat of all the ocean terminating Glaciers then we should expect an uptick in berg formation and , after what just occur in Baffin, we know those bergs will be shunted out into the N.Atlantic in short order!

Once we see ocean water breach the lip into the central basin we must expect the failure of the ice above and rapid 'sadlle/lobe' melt of the ice so denatured? If that doesn't lead to a cold ,fresh, melangel delighter pulse of a scale to block the NAD I do not know what will!

We will , of course, be battling on so many fronts by that point that it will probably go un-noticed!!!

 

[knocker]

 

[knocker]

Is Petermann Gletscher Breaking Apart this Summer?

Quote

I am disturbed by new ocean data from Greenland every morning before breakfast these days. In 2015 we built a station that probes the ocean below Petermann Gletscher every hour. Data travels from the deep ocean via copper cables to the glacier surface, passes through a weather station, jumps the first satellite overhead, hops from satellite to satellite, falls back to earth hitting an antenna in my garden, and fills an old computer.

https://icyseas.org/2017/06/16/is-petermann-gletscher-breaking-apart-this-summer/

[knocker]

 

[stewfox]

13 hours ago, knocker said:

 

Does show seasonal variation clearly. Not sure the comment re sea level rise ? Land ice/snow will melt in summer and will add 0.001mm to sea levels (taking into account southern hemisphere) but will come back in the winter.  Nothing to report really apart from below average.

 

Edited June 24, 2017 by stewfox

[knocker]

The increasing rate of global mean sea-level rise during 1993–2014

Quote

Global mean sea level (GMSL) has been rising at a faster rate during the satellite altimetry period (1993–2014) than previous decades, and is expected to accelerate further over the coming century1. However, the accelerations observed over century and longer periods2 have not been clearly detected in altimeter data spanning the past two decades3, 4, 5. Here we show that the rise, from the sum of all observed contributions to GMSL, increases from 2.2 ± 0.3 mm yr−1 in 1993 to 3.3 ± 0.3 mm yr−1 in 2014. This is in approximate agreement with observed increase in GMSL rise, 2.4 ± 0.2 mm yr−1 (1993) to 2.9 ± 0.3 mm yr−1 (2014), from satellite observations that have been adjusted for small systematic drift, particularly affecting the first decade of satellite observations6. The mass contributions to GMSL increase from about 50% in 1993 to 70% in 2014 with the largest, and statistically significant, increase coming from the contribution from the Greenland ice sheet, which is less than 5% of the GMSL rate during 1993 but more than 25% during 2014. The suggested acceleration and improved closure of the sea-level budget highlights the importance and urgency of mitigating climate change and formulating coastal adaption plans to mitigate the impacts of ongoing sea-level rise.

https://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3325.html

[knocker]

Greenland's summer ocean bloom likely fueled by iron

Quote

Iron particles catching a ride on glacial melangel delighter washed out to sea by drifting currents is likely fueling a recently discovered summer algal bloom off the southern coast of Greenland, according to a new study.

https://www.sciencedaily.com/releases/2017/07/170705164458.htm

[Gray-Wolf]

Well it had been a record slow melt year with the largest snow accumulation on record..... then this;

There was a lot of rain over S/SW Greenland from the 19th so maybe we're seeing runoff and snow melt ......and there's a lot of snow to go at esp down the East of the island?

[jvenge]

On 21.07.2017 at 15:54, Gray-Wolf said:

Well it had been a record slow melt year with the largest snow accumulation on record..... then this;

There was a lot of rain over S/SW Greenland from the 19th so maybe we're seeing runoff and snow melt ......and there's a lot of snow to go at esp down the East of the island?

Looks like it was a two day weather system event and it has gone now. It would take something quite spectacular to stop this season being one of the highest growth years in the past 35 years, but one season is meaningless to look at with a view of drawing conclusions, of course, no matter which direction it is.

 

[knocker]

 

[knocker]

Huge landslide triggered rare Greenland mega-tsunami - caused a 100 m high wave

Scientists hope studying last month’s deadly event will improve modelling of rockslides that could become more frequent with climate change.

http://www.nature.com/news/huge-landslide-triggered-rare-greenland-mega-tsunami-1.22374

[jvenge]

Curious to see what the end result is. DMI only provide graphs and I can't see the raw numbers. NOAA won't update until December.

Still, I think it is likely that the ice sheet would have grown this season, although probably by sub 200 Gt. One year is meaningless to draw conclusions, though.

 

[knocker]

How the Greenland ice sheet fared in 2017

Quote

Dr Ruth Mottram, Dr Peter Langen and Dr Martin Stendel are climate scientists at the Danish Meteorological Institute (DMI) in Copenhagen, which is part of the Polar Portal.

Yesterday saw the final day of the Greenland ice sheet melt season. This marks the traditional point of the year where scientists look back at the past 12 months and see how the ice sheet is faring.

https://www.carbonbrief.org/guest-post-greenland-ice-sheet-2017?utm_content=bufferf42ce&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

[knocker]

More snow + rain for E Greenland - where there is also a large warm temperature anomaly

http://polarportal.dk/en/weather/

[jvenge]

Didn't seem to impact the mass. Melting sitting on the mean for the time of year and new mass gained seems at a high for September and slightly above two standard deviations.

[knocker]

Glacier Calving in Greenland

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n combination, the breakaway of icebergs (calving) and submarine melting at marine-terminating glaciers account for between one third and one half of the mass annually discharged from the Greenland Ice Sheet into the ocean. These ice losses are increasing due to glacier acceleration and retreat, largely in response to increased heat flux from the oceans. Behaviour of Greenland’s marine-terminating (‘tidewater’) glaciers is strongly influenced by fjord bathymetry, particularly the presence of ‘pinning points’ (narrow or shallow parts of fjords that encourage stability) and over-deepened basins (that encourage rapid retreat). Despite the importance of calving and submarine melting and significant advances in monitoring and understanding key processes, it is not yet possible to predict the tidewater glacier response to climatic and oceanic forcing with any confidence. The simple calving laws required for ice-sheet models do not adequately represent the complexity of calving processes. New detailed process models, however, are increasing our understanding of the key processes and are guiding the design of improved calving laws. There is thus some prospect of reaching the elusive goal of accurately predicting future tidewater glacier behaviour and associated rates of sea-level rise.

https://link.springer.com/article/10.1007/s40641-017-0070-1

[knocker]

 

[knocker]