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

[Gray-Wolf]

I was not referring to albedo changes in Arctic sea ice just volume losses as modeled and measured stew? The thinning of the ice will mean a loss of albedo across the basin over melt season with differences in snow and ice and open water?

[keithlucky]

Very slow melt in Greenland this year about 1 month late

[knocker]

The ebb and flow of Greenland’s glaciers New study could improve understanding of Greenland’s contribution to sea-level rise

 

WASHINGTON, D.C. – In northwestern Greenland, glaciers flow from the main ice sheet to the ocean in see-sawing seasonal patterns. The ice generally flows faster in the summer than in winter, and the ends of glaciers, jutting out into the ocean, also advance and retreat with the seasons.

Now, a new analysis shows some important connections between these seasonal patterns, sea ice cover and longer-term trends. Glaciologists hope the findings, accepted for publication in the June issue of the American Geophysical Union’s Journal of Geophysical Research-Earth Surface and available online now, will help them better anticipate how a warming Greenland will contribute to sea level rise.

 

http://news.agu.org/press-release/the-ebb-and-flow-of-greenlands-glaciers/

[knocker]

Sudden draining of glacial lakes explained

 

In 2008 scientists from Woods Hole Oceanographic Institution (WHOI) and the University of Washington documented for the first time how the icy bottoms of lakes atop the Greenland Ice Sheet can crack open suddenly--draining the lakes completely within hours and sending torrents of water to the base of the ice sheet thousands of feet below. Now they have found a surprising mechanism that triggers the cracks.

 

http://www.eurekalert.org/pub_releases/2015-06/whoi-sdo060315.php

[BornFromTheVoid]

Current AMA on the science sub reddit: https://www.reddit.com/r/science/comments/38nt2y/science_ama_series_pulling_the_plug_melting_ice/

 

Science AMA Series: Pulling the plug: Melting ice and draining lakes on the Greenland Ice Sheet. We’re Laura Stevens and Dr. Sarah Das, glaciologists at MIT and the Woods Hole Oceanographic Institution, here to talk about all things ice! AMA!

 

Yesterday we published a paper in Nature on supraglacial lake drainages on the Greenland Ice Sheet[1] . Supraglacial lakes form on the surface of the ice sheet during the summer, when temperatures get above freezing in the daytime. In a 2008 study, we discovered that these lakes, some of which are miles wide, can drain in a matter of hours through long cracks known as hydro-fractures that open in the lakebed. These drainage events send a flood of meltwater comparable to Niagra Falls thousands of feet straight down to the bottom of the ice sheet. The meltwater causes the ice to temporarily speed up, moving more ice to the edge of the ice sheet where it calves off into the ocean as icebergs. It’s important to know where and when lakes will drain in order to predict how fast the ice sheet is moving and how much the ice sheet contributes to sea level rise.

Since that study in 2008 we have been working hard to figure out what triggers these hydro-fractures, and what that might mean for the future of the ice sheet (and for people elsewhere on the planet) in a warming climate. We do this by traveling every summer to lakes on the ice sheet via helicopter, setting up GPS stations around the lakes, and then using our measurements to observe how the ice sheet surface moves during lake drainage events. We found that enough meltwater gets down to the bottom of the ice sheet before the lake drains to cause the ice sheet surface to be pushed up and stretched. This stretching causes new fractures to form, and once one of those fractures intersects the lake, water from the lake drives the crack open and the lake is history.

We will be back at 1:00 pm EDT (10:00 am PDT, 5:00 pm UTC) to answer your questions about Greenland lakes, global warming, or the life of a scientist doing research on the ice sheet. AMA!

Edited June 5, 2015 by BornFromTheVoid

[knocker]

Greenland melt season kicks off slowly in 2015; the new abnormal

 

http://www.meltfactor.org/blog/greenland-melt-season-kicks-off-slowly-in-2015/

[knocker]

£3 million NERC award for research into melting ice sheet

 

Global warming alone is not enough to account for the increasingly rapid melting of the ice sheet. Other factors are darkening the ice sheet surface, which results in greater rates of melting. The main focus of this collaborative research project is based on the hypothesis that microbes thrive and bloom on melting snow and ice surfaces, and darken the ice sheet surface as a consequence.

 

http://www.bristol.ac.uk/news/2015/june/nerc-grant.html

[stewfox]

Greenland melt season kicks off slowly in 2015; the new abnormal

 

http://www.meltfactor.org/blog/greenland-melt-season-kicks-off-slowly-in-2015/

 

 

Most folk would call it weather, colder then average summer season forecast, its shows we have had a few warmer ones in recent years so overdue. 

 

If you take the view this cold weather is due to global warming and is 'abnormal' , like whats happening in the Antarctica I guess that is another view. Your on a win win, ie if its colder its global warming if its warmer it global warming. 

Edited June 28, 2015 by stewfox

[Gray-Wolf]

Jason Box appears more concerned as to the mega melt we should expect once it does warm there? We will see. More JCB's in rivers come Aug.

[keithlucky]

Jason Box appears more concerned as to the mega melt we should expect once it does warm there? We will see. More JCB's in rivers come Aug.

Record cold continues in Greenland the reason is cold sea in north Atlantic

[knocker]

Externally forced fluctuations in ocean temperature at Greenland glaciers in non-summer months

 

Enhanced submarine melting of outlet glaciers has been identified as a plausible trigger for part of the accelerated mass loss from the Greenland ice sheet^{1, 2, 3}, which at present accounts for a quarter of global sea level rise⁴. However, our understanding of what controls the submarine melt rate is limited and largely informed by brief summer surveys in the fjords where glaciers terminate. Here, we present continuous records of water properties and velocity from September to May in Sermilik Fjord (2011–2012) and Kangerdlugssuaq Fjord (2009–2010), the fjords into which the Helheim and Kangerdlugssuaq glaciers drain. We show that water properties, including heat content, vary significantly over timescales of three to ten days in both fjords. This variability results from frequent velocity pulses that originate on the shelf outside the fjord. The pulses drive rapid water exchange with the shelf and renew warm water in the fjord more effectively than any glacial freshwater-driven circulation. Our observations suggest that, during non-summer months, the glacier melt rate varies substantially and depends on externally forced ocean flows that rapidly transport changes on the shelf towards the glaciers’ margins.

 

http://www.nature.com/ngeo/journal/v7/n7/full/ngeo2186.html

 

Article

 

Understanding the ocean's role in Greenland glacier melt

http://phys.org/news/2014-06-ocean-role-greenland-glacier.html#inlRlv

[4wd]

Jason Box appears more concerned as to the mega melt we should expect once it does warm there? We will see. More JCB's in rivers come Aug.

What a strange post.

Some 'folk' are falling for the usual alarmist (clap)trap of assuming a graph trend line can only go one way.

 

[knocker]

Greenland ice sheet melt area shoots up 19-21 June, above 95% occurrence

 

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

Edited June 22, 2015 by knocker

[knocker]

Greenland melting shoots up in June.

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

[knocker]

Greenland continuing to spike

 

[Gray-Wolf]

What a strange post.

Some 'folk' are falling for the usual alarmist (clap)trap of assuming a graph trend line can only go one way.

 

 

Looks very much like Jason Box , a scientist I respect, was bang on with his concerns about the rapid melt to come 4? Any retraction ?

 

With H.P. looking to set up over Greenland we should expect more of this exceptional melt.

[Interitus]

Most folk would call it weather, colder then average summer season forecast, its shows we have had a few warmer ones in recent years so overdue. 

 

 

That was not the best of forecasts. At Søndre Strømfjord (Kangerlussuaq) 67°N the maximum temperature has reached over 20°C every day for the past fortnight and looks like doing so again today. The town benefits from fohn winds and the June and July average maxima are a fairly respectable 14 and 16.5°C. But while 20°C has been achieved a few times each summer in recent years, the record maximum is only 25.5°C and such a prolonged warm spell looks unprecedented.

 

Record cold continues in Greenland the reason is cold sea in north Atlantic

 

The average maximum temperatures for Nuuk / Godthaab in June and July are 7 and 9.9°C. It has been in double figures for each of the last 16 days averaging 14.84°C. The cold spring is rapidly becoming a warm summer.

[knocker]

20th day in a row with clear sky conditions along W Greenland is driving low albedo and high melt especially across North Greenland more melting than normal

http://nsidc.org/news/

 

[knocker]

Quite a good piece in Discover mag.

As Parts of Three Continents Bake, Greenland Sees Sudden Spike in Surface Melting

[knocker]

Latest

 

http://polarportal.dk/en/groenlands-indlandsis/nbsp/isens-overflade/

[stewfox]

Greenland melting shoots up in June.

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

 

 

And now its on the way down as the brief melt season comes to an end

 

We often see the 'refreeze'  start by mid July in Greenland.

[Interitus]

And now its on the way down as the brief melt season comes to an end

 

We often see the 'refreeze'  start by mid July in Greenland.

 

Hold your horses, July is the warmest month of the year. The melt has come down from extremely high levels to 'only' 2 sd above average.

[knocker]

Russell Glacier, Greenland Rapid Snowline Rise K-Transect 2015

 

It was 30 years ago I first participated in Greenland Ice Sheet research, there was not much of it at the time.  However, there was the recognition of the importance for sea level rise with global warming, and this was driving an increase in research at that time. The level of research has increased exponentially in the last decade. One long standing and remarkable program that indicates the long term thinking that has helped us develop an understanding of ice sheet changes, is the K-Transect of ablation stakes emplaced in the Russell Glacier Catchment.  Here we examine the changing snowline from Mid-June to early July of 2015, as well as the longer term record.  The Institute for Marine and Atmospheric Research Utrecht has maintained the best long term field based ablation record on the GIS, the K-Transect. This resulted in  van de Wal  et al., (2012) reporting on 21 years of surface mass balance in the region.  At one site, S9 (1520 m) near the equilibrium line altitude (ELA), the long term record indicates a rise in the ELA in recent years, see figure below, and a more negative surface mass balance. This record has also been crucial in helping to build surface mass balance models for the GIS. The results updated daily from one such model, is at the Polar Portal, maintatined by the DMI – Danish Meteorological Institute, GEUS – The Geological Survey of Denmark and Greenland and DTU Space – National Space Institute. This summer the Automatic Weather Station on this transect Kan M, at 1270 m did not experience temperatures above 0 C until June 19th and they have been consistently above that since, (PROMICE, 2015).  At S9 temperatures have been reaching 4 C most days in July (IMAU, 2015).

[knocker]

Greenland ice reflectivity reaches new low in satellite data

 

[Interitus]

That was not the best of forecasts. At Søndre Strømfjord (Kangerlussuaq) 67°N the maximum temperature has reached over 20°C every day for the past fortnight and looks like doing so again today. The town benefits from fohn winds and the June and July average maxima are a fairly respectable 14 and 16.5°C. But while 20°C has been achieved a few times each summer in recent years, the record maximum is only 25.5°C and such a prolonged warm spell looks unprecedented.

The spell of >20°C ended yesterday with a maximum of 18.4°C after 17 consecutive days - only a handful of stations in the southeast of the UK have managed that this summer.