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PhillipS

Greenland Melt Discussion

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We're doomed. Northern Hemisphere Ice cap was fun while it lasted. Tell your grandkids about it.

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Interesting new study out on Greenland melt.

 

http://jasonbox.net/more-greenland-melt-under-cloudy-conditions/

 

 

Our new study reveals that under warm and wet conditions, atmospheric heat can melt the lower 1/3 of the Greenland ice sheet elevations more than under sunny conditions. This was especially so during the 2012 heat wave when a record warm North America loaded the air with heat and moisture that drifted to Greenland.

We recorded the largest ever observed daily and annual surface melt rates on Greenland under PROMICE. The 8-11 July, 2012 heat wave produced 0.9 m (3 ft) of ice melt for a yearly total of 8.5 m (28 ft), actually 9% less than the 2010 annual value of 9.2 m (30 ft). The peak daily melt rate was 0.28 m (11 inches) occurred on 11 July. To capture such high melt rates, we use a 12.4 m (40 ft) long ruler.

 

A persistent air flow that drove air up and over west Greenland prevailed for 6 summers (2007 to 2012), parts of 2015, and in other years. This is the same kind of “atmospheric river” that can replenish California’s moisture deficit and cause flooding. In the case of Greenland, if it’s summer and air temperatures are high enough, there will be no snow, just rain and atmospheric heat delivered to the ice surface can do untold damage to the surface.

The study decomposes the ice melt energy into contributions. Together, atmospheric heat and condensation delivered more energy to the lower elevations of the ice sheet than absorbed sunlight during pulses in July and August 2012. It’s counterintuitive that under cloudy conditions there can be more melting, especially because the surface is so dark in this lower 1/3 of the ice sheet elevations. It  goes to show that the ice sheet melt does not get a break just because the sun is blocked.

Climate models under-represent this effect, by our estimate by a factor of two, and with the frequency of warmer air masses driven over Greenland expected to increase with climate change (Collins et al., 2013), the impact of atmospheric heat and condensation will probably bring Greenland ice melt loss faster than forecast.

 

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-20C 850s moving in...

Another strong ridge will develop by day 7.

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Yeah totally nuts.

NPQ40Dg.jpg

Not good. Still a long time to go but this is getting ugly fast.

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18 minutes ago, chubbs said:

Here is a summary of the modeled surface mass balance of the Greenland ice sheet for the 2015/16 melting season. Strong melting was partially compensated for by above average snowfall.

http://climato.be/cms/index.php?climato=the-2016-melt-season-over-greenland-as-simulated-by-marv3-5-2

greenlandSMB-1D201516.png

Keeping in mind that SMB is only half of the mass balance equation, it looks like 2016 was the fifth worst melt season of the instrumental period, and the second greatest season for runoff.  Just eyeballing the graph it looks like there is a long-term decline in snowfall but I don't know if that's due to less precipitation overall or more precip falling as rain.

Here's the GRACE plot of total mass balance since 2003.  I expect that 2016 will have a net mass loss of around 300 Gtons (300 km3).  

Grace_curve_La_EN_20160300.png

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6 hours ago, PhillipS said:

Keeping in mind that SMB is only half of the mass balance equation, it looks like 2016 was the fifth worst melt season of the instrumental period, and the second greatest season for runoff.  Just eyeballing the graph it looks like there is a long-term decline in snowfall but I don't know if that's due to less precipitation overall or more precip falling as rain.

Here's the GRACE plot of total mass balance since 2003.  I expect that 2016 will have a net mass loss of around 300 Gtons (300 km3).  

 

The figure below from a recent paper below shows how glacier discharge (D) has increased and surface mass balance has decreased since 1990 causing an increasingly negative Greenland mass balance (MB). Comparing the SMB estimates in the chart below to the chart posted above, the long term trends are similar but there are some differences in the relative ranking of individual years.

http://www.the-cryosphere.net/10/1933/2016/

Greenlandvandenbroekefig9.png

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On 4/16/2016 at 9:59 AM, bluewave said:

Interesting new study out on Greenland melt.

 

http://jasonbox.net/more-greenland-melt-under-cloudy-conditions/

 

 

Our new study reveals that under warm and wet conditions, atmospheric heat can melt the lower 1/3 of the Greenland ice sheet elevations more than under sunny conditions. This was especially so during the 2012 heat wave when a record warm North America loaded the air with heat and moisture that drifted to Greenland.

We recorded the largest ever observed daily and annual surface melt rates on Greenland under PROMICE. The 8-11 July, 2012 heat wave produced 0.9 m (3 ft) of ice melt for a yearly total of 8.5 m (28 ft), actually 9% less than the 2010 annual value of 9.2 m (30 ft). The peak daily melt rate was 0.28 m (11 inches) occurred on 11 July. To capture such high melt rates, we use a 12.4 m (40 ft) long ruler.

 

A persistent air flow that drove air up and over west Greenland prevailed for 6 summers (2007 to 2012), parts of 2015, and in other years. This is the same kind of “atmospheric river” that can replenish California’s moisture deficit and cause flooding. In the case of Greenland, if it’s summer and air temperatures are high enough, there will be no snow, just rain and atmospheric heat delivered to the ice surface can do untold damage to the surface.

The study decomposes the ice melt energy into contributions. Together, atmospheric heat and condensation delivered more energy to the lower elevations of the ice sheet than absorbed sunlight during pulses in July and August 2012. It’s counterintuitive that under cloudy conditions there can be more melting, especially because the surface is so dark in this lower 1/3 of the ice sheet elevations. It  goes to show that the ice sheet melt does not get a break just because the sun is blocked.

Climate models under-represent this effect, by our estimate by a factor of two, and with the frequency of warmer air masses driven over Greenland expected to increase with climate change (Collins et al., 2013), the impact of atmospheric heat and condensation will probably bring Greenland ice melt loss faster than forecast.

 

Bit of an "intuitive no-brainer" really ...

I mean it's always good to corroborate common-sense based supposition with empirical evidence, ... but liquid water has more energy per unit volume compared to free air - liquid on ice is a more effective delivery of energy to the ice than would be the ice-conditioned air/environment immediately in contact in the glacial basal regions.  This is like after-school Mr Wizard's fun physical sciences for 4th grader material.... I know, but that conceptually can be blown up to the scale of these magnificent systems - physical rules don't change just because a Greenland's ice is awesome.   not that you think so... just sayn' 

 

 

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Things we do not regularly see are the warming of the base of the ice sheet and the amount of liquid water held in the snow pack. Both these physical realities could lead to rapid and catastrophic changes to the ice sheet and treat us to the 'saddle & lobe' type of melt that took the last ice sheets at the end of the last glaciation.

The 'swiss cheese' nature of the base of the pack must pose a threat of internal collapse and so hasten further basal erosion of the ice as more surface area is presented to the inundating, pressurised, melt waters?

The weight of liquid water in the snow layer must pose a threat of collapse under gravity if its weight becomes unsustainable bringing large amounts of snow down to lower, melt region, areas?

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https://mobile.twitter.com/mikarantane/status/1156248654883229697

Weather balloon released from Danmarkshavn, #Greenland E-coast (77°N) recorded today 850 mb temperature of 14.4°C, which is their all-time record high. 500 mb geopotential height was 5860 gpm, which is also a new record. Soundings began in 1950.

https://mobile.twitter.com/mikarantane/status/1156258216575213573

This warmth in Greenland originates from Europe. The blocking high located last week in Scandinavia has propagated west and dragged the hot air mass along with it towards Greenland.

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I warned people last week ...  

not that it matters - wasn't like it could be stopped.  

But the models could not have been more clear about sending that terminating planetary wave event ( waa off Europe's heat wave) right over those lat/lons...  

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https://mobile.twitter.com/xavierfettweis/status/1156848174599942144

1/4 The last MAR based numbers for the current heat wave over Greenland are 31-JUL: Record of ice sheet temperature! T2m=+0.55°C (vs -0°C in 11-JUL-2012). Anomaly:6.8°C 01-AUG: Record of ablation rate (minimum SMB)! -12.5 GT/day (vs 11.7 in 2012)

https://mobile.twitter.com/xavierfettweis/status/1156848178819411975

2/4 31-JUL: melt extent (2nd record) -> using 5 mm/day as melt threshold as on my Fig5: 61% (vs 79% in 2012) -> using 1mm/day as HARMONIE on

: 81% (vs 97%) -> using 0.1mm/day: 90% (vs 99%) 31-JUL: meltwater production (2nd record) 24Gt/day (vs 26 in 2012)

 

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It’s going to be interesting to see what happens when all that coastal property becomes worthless and the inland ones may actually increase in value.

 

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2 hours ago, Bhs1975 said:

It’s going to be interesting to see what happens when all that coastal property becomes worthless and the inland ones may actually increase in value.

 

Catch -22...

Most people ... they don't really respond.  Not beyond nods and brow raises around water coolers, and social functions ...when it comes to these sort of macro-threats.

Part of the problem? ...well, most of it actually ... is that it's just too big to be mentally tenable.  It's fascinating dystopian novel work and akin to Hollywood cinema ... more so than anything anyone has seen.

Therein in is another aspect to the general peril.  Humans primary only respond to threats directly perceived via the corporeal senses... Taste, touch, smell, sound and sight... if we don't taste the acid, feel the heat ( though that's changing), smell the rotting carcasses, hear burning woods or see the tsunamis coming over the horizon... meh.  We give those polite head nods and acknowledging brow raises...but no one is going to amend their ways without seeing these calamities actually unfolding,.

There's the catch-22...by the time they see, them... it's too late.

And what makes this catch-22 extraordinarily textured ( ...if ironic), evolution provide the human species with this incredible power of ingenuity... to master its domain and manipulate the environment. It brought us out of the primordial dependency on just the ecological provisions ( like all other animal species on this planet ), to supplant those guiding proxies over our survival prospects. Now...  those inventions that were made to do so?  Will end said species -

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Why is this Greenland melt event a JFC moment? Sure it was forecasted for 2070 but that's such a small amount of time on geological scales. At any rate we should expect more melt events in the future on our journey to the inevitable future of restored order and stability in the Earth System and that implies the end of overpopulation and consuming 1.8 Earth's per year of resources.

Weird flex and not how I would choose to fix the problem. Maybe there is some latent masochism or guilt complex inside of civilization or more likely ... nobody is in control.

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4 hours ago, Typhoon Tip said:

Catch -22...

Most people ... they don't really respond.  Not beyond nods and brow raises around water coolers, and social functions ...when it comes to these sort of macro-threats.

Part of the problem? ...well, most of it actually ... is that it's just too big to be mentally tenable.  It's fascinating dystopian novel work and akin to Hollywood cinema ... more so than anything anyone has seen.

Therein in is another aspect to the general peril.  Humans primary only respond to threats directly perceived via the corporeal senses... Taste, touch, smell, sound and sight... if we don't taste the acid, feel the heat ( though that's changing), smell the rotting carcasses, hear burning woods or see the tsunamis coming over the horizon... meh.  We give those polite head nods and acknowledging brow raises...but no one is going to amend their ways without seeing these calamities actually unfolding,.

There's the catch-22...by the time they see, them... it's too late.

And what makes this catch-22 extraordinarily textured ( ...if ironic), evolution provide the human species with this incredible power of ingenuity... to master its domain and manipulate the environment. It brought us out of the primordial dependency on just the ecological provisions ( like all other animal species on this planet ), to supplant those guiding proxies over our survival prospects. Now...  those inventions that were made to do so?  Will end said species -

Science gives people the tools to break out of the vast limitations of their five senses. Scientific knowledge has been accepted albeit with periods of difficulty across history. The science is now all but unequivocal in its general conclusions. Residual uncertainties persist, but no plausible science-based alternative explanation exists.

Over time, even as the small number of vocal resisters to science try to thwart public understanding, attribution studies are eroding that point of resistance. In Europe, a critical threshold of public opinion has already been achieved. The United States is lagging, but opinion polls taken over the past five years show a decided move toward the scientific conclusion. 

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27 minutes ago, donsutherland1 said:

Science gives people the tools to break out of the vast limitations of their five senses. Scientific knowledge has been accepted albeit with periods of difficulty across history. The science is now all but unequivocal in its general conclusions. Residual uncertainties persist, but no plausible science-based alternative explanation exists.

Over time, even as the small number of vocal resisters to science try to thwart public understanding, attribution studies are eroding that point of resistance. In Europe, a critical threshold of public opinion has already been achieved. The United States is lagging, but opinion polls taken over the past five years show a decided move toward the scientific conclusion. 

I'm noticing this too...  small but perhaps the beginnings to a modality that... frankly, humanity has no choice but to become massively committed to - yeah...long way to got. 

I'm not mincing words... There are two choice my friends, either control yourselves, or, Nature will impose that control.

How do we want it. 

If it's continued profligate management and selfish lording over the environment in this disposable, selfish entitled attitude?  This will all inexorably lead to a forced population correction -  

In fact... one is probably more necessary ...whether we control that ... or, it happens to us, in spite of us. 

I hope we're right. These 'warnings' ...they are now being met with a growing database of empirical evidences... And I argue that is the impetus behind this ... call it evolving sentiment we're discussing - for now I'm only giving it that much.  40 C at 40 N in Europe's developed industrial societies has a way of lifting chins. 

 

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Sadly many folk are now accepting the NeoLib capitalism is responsible for our wasteful assaults on our natural world and its resources but also that that global economics holds no solutions for our climate crisis either?

Those with most to gain from the current system are also the ones who have the most power over our world under this planet killing system?

They will not go anywhere near far enough to helping mitigate the woes to come but appear almost welcoming of it as a way to 'slim down' global population whilst leaving them firmly in control of a world that will then resume its consuming ways post the 'great dying'?

If you still have not seen enough to show you that only a globally concerted effort will be enough to start solving this nightmare then you do not have long to wait to find yourself so convinced.

 

Just hope it's not your hometown that is targeted by Mother N. in the next big advert for how bad things already are (with 35 yrs 'worsening ' already dialed into the climate system even it we halt polluting tomorrow!)

 

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