Greenland has a 'heat wave'?

Totally Random?
It occurs every 150 years.
Greenland Ice Melt every 150 years is ‘right on time’ | Watts Up With That?

 

Just as an aside, "watts up with that" is a site promulgated by a TV weather man,, with no climate expertise at all.

 

Bob,

God's Zamboni, indeed.

The prior record melt years in the satellite data were 2010 (1) and 2011 (2). So this is just best viewed as continuation of short-term trend. I think what made news is that the interior surface flipped from frozen to melting in just a few days. That seems to be an entirely new phenomenon in the satellite era.

Related:

Ice-albedo feedback - Wikipedia, the free encyclopedia
Greenland Ice Albedo Monitoring - Byrd Polar Research Center - Research Wiki


Apparently the albedo reduction is now about twice what the average general circulation model anticipated. So add warm air temps to the sunshine falling on the darker surface, and you get more melt.

The second article talks about the large 2012 albedo anomaly in the interior/higher elevations. There was this really unusual darkening of the interior portions of the ice sheet surface in 2012 (look at the first spaghetti graph in that article), now there's unexpectedly rapid surface-wide melt. Maybe concidence, maybe not. Maybe I have causality reversed here. But two off-the-chart events, seems plausible these would be related.

Here's the albedo graph. This is higher elevations, black line is 2012. So the albedo change preceded the unusually widespread and rapid conversion of the frozen surface to melting surface.



I've seen it written (without having seen any research to verify it) that the greater incidence of North American wildfires is depositing enough additional soot to make a difference. No idea whether that's true. (It's true that wildfires deposit soot there, it's unknown if that's enough additional soot to matter.) But if true, it's a feedback from persistently high wildfire years to persistently higher melting.

As the snow melts, it differentially leaves the soot, so the surface gets progressively darker with more melt, independent of the effects that the melt lakes have.

Ice-albedo feedback is one of the things Hansen points to when he suggests that the scientific consensus substantially underestimates likely sea-level rise for this century.

 

Mojo, there defiantly are natural cycles, just as there have always been natural forest fires.
Just because something in the past has a natural influence doesn't mean mankind isn't currently having an influence.

The most telling statistic to me is the ratio of record high temperatures to record low temperatures.

As to this thawing, it is being studied to see if we can figure out what is happening. This is good news,isn't it?

 

The quote about the arithmetic is from the Nasa Goddard press release and is on the Nasa website.
Pretty funny those dumb nice person scientists cant do the math.
NASA - Satellites See Unprecedented Greenland Ice Sheet Surface Melt
""Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time," says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data."

 

"UNPRECEDENTED" but occurs naturally every 150 years.The current melt must be due to CO2 levels.
Pure FUD from NASA.

Heres a critique from the NYT.Revkin is an avid AGW cheerleader,but shows some sense here.

'Unprecedented' Greenland Surface Melt - Every 150 Years? - NYTimes.com

 

Unprecedented means in this interglacial this is the most warming we have seen in greenland. There was more of a melt in the last interglacial, but that was long ago.

mean means average, as in a statistical average. The variance of these cycles accounts for the 18% off this time. That 150 year cycle is from nasa, and it is a word problem. The reporting should be more clear that the period is statistical and not fixed.

 

These things do cluster. That is not a statistical anomaly.

We would not expect an event that happened in 1889 to appear in the satelite record. That would truely be unprecidented.

 

Hoping we might sort this out w/o rancor, but I'm still confused. Revkin helpfully shows a figure from Science 1994

Some of those other “unprecedented” melt events at...

In the GISP2 core, a low annual accumulation is 0.23 m (firn or snow?) per year, and a high year is 0.265. If this is the basis of the 150-year cycle, that is 150 +/- LARGE.

I don't know how to relate that annual accumulation to the current situation in Greenland. I know there is fast surface melting now, but what about the previous season's input?

Also I had hoped to post a link to annual forest burn area in US, but the NPS website is inaccessible to me just now. Perhaps because it ends with .gov From time to time, US gov websites are blocked for me here It comes and goes.

What I recall is that about 1910 there was a big fire and some fire fighters got toasted. This (in part) led to the policy of extensive fire fighting. This has led to more dry surface fuels and 'ladder fuels', such that when you have a dry year and some ignition source, the chance has increased that the fire will get very large. As we have seen (but not every year) over the recent decades.

In the longer term, annual burn area seems to relate to ENSO phase. In some regions, ENSO + is dry while for others, ENSO - is dry. Fires happened then. Fire-scar studies in the southerstern US also show big burns in the mideval climate anomaly. Recently re-renamed the mideval warm period based on Lappland trees. Both topics discussed here earlier.

The last few decades have put a lot of soot in the air, but I cannot say that it is unusual in context of prehistoric fire.

 

I dont know exactly what NASA means by "unprecedented" .But I do know its an exaggeration meant to fool the media and the public.
There is certainly evidence that there has been greater warming during most of the past 10,000 years.Thus a melt every 150 years would virtually guarantee a greater melting precedent .It would be greater melting occurring very many times over the past 10,000 years.

 

if anyone here is more interested in fires than 'today in Greenland'...

http://www.fs.fed.us/psw/publications/skinner/psw_2012_skinner001.pdf

New, but regional. You have to connect the other dots (open circles) figure 2, to see the annual burn are, only since 1987. Also, note the logarithmic axis.

Figure 4 is also increasting, with >50 year fire rotation intervals in pre-settlement times. Interesting stuff - those old-growth forests had frequent, low intensity fires. The rest of Figure 4 is kinda scary, presuming that I understand it. Older and older forests having massive burns until 1985. Then? ? We finished buring off the (few, heavily protected) old growth and now burning younger trees? In any case the 1985 transition looks remarkable.

 

I dont particularly mind off topic posts,but since you scolded me in the past for supposedly being off topic,I will point out that fires were already off topic in a different thread.
At least you could keep the off topic posts to the same originating thread.

 

I wonder what it will take for Mojo to realize that human action is causing dramatic climate change? Will it take two more years,, or ten, or twenty? How far down the road will we be by then?

Icarus

 

OMG you are in deep doodoo dude,like over your head in doodoo.
The article you originally posted, gave reference to the 150 year occurance.
The woman scientist quoted gives a reference to a peer reviewed study by Alley as her source.
Ill give links if you are to lame to find them.
Jeesh.

 

"2:10 p.m. | Updated | Lora Koenig of NASA just sent this note providing the reference underlying her comment about past summer melting episodes at the summit (the spot on the giant ice sheet least vulnerable to melting):

The study I am citing is Alley and Anandakrishnan, 1995, “Variations in melt-layer frequency in the GISP2 ice core: implications for Holocene summer temperatures in central Greenland” published in the Annals of Glaciology for establishing the long-term frequency of melt events at Summit , Greenland. And Clausen et al., 1988 Glaciological Investigations in the Crete area, Central Greenland: A search for a new deep-drilling site also published in Annals of Glaciology for an early reference to the 1889 melt event though as mentioned in the press release Kaitlin Keegan and her advisor Mary Albert at Dartmouth University have more recent research on this event and please contact them for additional specific information.​

My comment shows that melt events have occurred at Summit in the past and I have quoted the longest-term average frequency of ~150 years (exactly 153 from the paper) over the past 10,000. Since this is an ice core record that frequency is for the location of Summit only. The frequency ranges from ~80 to 250 years over different sections of the GISP2 ice core, please see the paper for specifics."​