Study: 'accelerated melting of the lower Greenland ice sheet' due to bacteria darkening the surface albedo


Factors promoting growth of cryoconite granule formation and glacial/ice sheet melting

Cryoconite granules (see Figure 1) are dark, millimeter-sized aggregations of bacteria and algae, mineral particles and organic matter that form on the surface of glaciers. They are also known to be a significant factor responsible for the acceleration in glacial and ice sheet melting. Research on Greenland’s glaciers has revealed that cryoconite granule formation increases in areas on the glacier surface containing higher amounts of fine (250 μm or smaller) mineral particle sediment. Research findings were recently published in the journal FEMS Microbiology Ecology.

This image shows cryoconite granules (Scale: yellow line = 1mm). CREDIT NIPR
Figure 1 This image shows cryoconite granules (Scale: yellow line = 1mm). CREDIT NIPR

Cryoconite granules – these tiny aggregation of cold-loving microbes (also known as cryophiles or psychrophiles) and mineral particles – are very dark in color. Because they are dark, they easily absorb heat and light energy from the sun. This additional heat energy in turn leads to accelerated melting of ice sheets and glaciers (see Figure 2).

This image shows a darkened glacial surface. CREDIT NIPR
Figure 2 This image shows a darkened glacial surface. CREDIT NIPR

The accelerated melting of the lower Greenland ice sheet in recent years is reportedly due in large part to the increasing abundance of cryoconite granules and pigmented algae. However, how many types of microbe inhabiting in this tiny granule and what kind of environment factors promoting the activities of cold-loving microbes are still unclear.

Dr. Jun Uetake and his team at the National Institute of Polar Research, Japan employed a variety of analytical methods including microscopic observation, genetic analysis and nutrients analysis to study samples of cryoconite granules taken from five different locations on Qaanaaq Glacier in Greenland.

Results of his analysis show that cryoconite granules were most highly concentrated in the middle area of the glacier. Also, notably, particularly large amounts of filamentous cyanobacteria were found from same sampling area.

Thorough review of the environmental factors, including data taken such as altitude of and inclination at the sampling location, nutrient (phosphate, nitrate and ammonium ion) concentration, amount and composition of mineral particles, revealed a singular correlation between the amount of fine mineral particles (diameter of 250μm or smaller) and the presence of cryoconite granules in the area. Dr. Uetake says “higher concentrations of fine mineral particles are conducive to cyanobacterial growth and ultimately, cryoconite granule formation.”

Ribosomal RNA analysis confirmed that filamentous cyanobacteria Phormidesmis priestleyi, also found in Antarctic lakes and marshes, is the predominant species contributing to granule formation and growth. Analysis also showed that granule diameter surpassing 250μm due to growth of P. priestleyi leads to change of bacterium species inhabiting cryoconite granules.

Dr. Uetake concludes “As cryoconite granule formation is spreading throughout Greenland, our continuing research must be required.”


The study:

Microbial community variation in cryoconite granules on Qaanaaq Glacier, NW Greenland

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Cryoconite granules are aggregations of microorganisms with mineral particles that form on glacier surfaces. To understand the processes by which the granules develop, this study focused on the altitudinal distribution of the granules and photosynthetic microorganisms on the glacier, bacterial community variation with granules size and environmental factors affecting the growth of the granules. Size-sorted cryoconite granules collected from five different sites on Qaanaaq Glacier were analyzed. C and N contents were significantly higher in large (diameter greater than 250 μm) granules than in smaller (diameter 30–249 μm) granules. Bacterial community structures, based on 16S rRNA gene amplicon sequencing, were different between the smaller and larger granules. The filamentous cyanobacterium Phormidesmis priestleyi was the dominant bacterial species in larger granules. Multivariate analysis suggests that the abundance of mineral particles on the glacier surface is the main factor controlling growth of these cyanobacteria. These results show that the supply of mineral particles on the glacier enhances granule development, that P. priestleyi is likely the key species for primary production and the formation of the granules and that the bacterial community in the granules changes over the course of the granule development.

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Alan Robertson
November 1, 2016 7:09 am

Why has fine mineral deposition been increasing? It must be the result of increased agricultural activities and other surface disturbances by mankind. It’s all our fault. Limit farming! save the planet. Think of the children.

Reply to  Alan Robertson
November 1, 2016 8:13 am

I’m guessing that it is from soot being released from Chinese coal fired power plants.
As these are cleaned up, the ice should get cleaner.

Reply to  MarkW
November 1, 2016 9:49 am

The earliest scientific arctic expeditions by Scoresby in the 1820’s was sanctioned by Banks of the Royal Society as numerous reports came in from the early 1800’s of substantial arctic melting. Scoresby and others recorded a number of interesting things.
Amongst them is the comment about the blackened state of large swathes of ice. The expeditions put it down to industrialisation of America.
Whatever the cause was it seems to have parallels with these current findings.
Darkened ice and snow is also evident in many of the on the spot reports over the last fifty years.
How much this darkening actually effects melt rate is probably un-quantified as yet.

Bryan A
Reply to  MarkW
November 1, 2016 10:13 am

Sounds like the Greenland Ice Sheet could use a spaying of Chlorine Bleach to kill the bacteria and whiten the ice

Samuel C Cogar
Reply to  MarkW
November 2, 2016 2:52 am

Looking at the above picture I wasa wondering if the winter snowfall(s) on the lower Greenland ice sheet has failed to occur in recent years?
Those dudes on the glacier are all dressed in “winter” clothing so it must be winter but no winter snowfall on the ice.

Reply to  MarkW
November 3, 2016 5:57 am

climatereason – that melting in 1817 was due to the effects of the huge S hemisphere eruption of 1816.

Reply to  MarkW
November 3, 2016 10:41 am

A foot of snow and problem solved.

Bruce Cobb
November 1, 2016 7:30 am

Uh-oh. No connection was made between these cold-loving microbes and that nasty, evil “carbon pollution”. No future “climate” funding for you!

Steven F
Reply to  Bruce Cobb
November 1, 2016 12:34 pm

Bacteria an algae need minerals to survives. Mainly phosphorus, potassium, calcium, magnesium, iron and sulfur and about 8 others but in lower quantities. If these were not present the microbes and algae would not survive. All of those elements are delivered by dust in the air. If there is no dust in the air the microbes would not survive and the snow would gradually clear and reflect more light. Today most of the dust is due to human activity. In the past most of it was from natural causes, volcanoes, dust storms in desert areas.

Michael 2
Reply to  Steven F
November 1, 2016 5:34 pm

“In the past most of it was from natural causes, volcanoes, dust storms in desert areas.”
Well then it’s a darn good thing we’ve stopped volcanoes and dust storms!

Kelvin Duncan
Reply to  Michael 2
November 1, 2016 7:52 pm

Yep! And we should hold our breath at both ends and make sure cows and termites do the same.

Reply to  Steven F
November 2, 2016 4:09 am

Since when are Humans not part and product of the nature?
There is 97% consensus: Earth needs plastic.

Tom Halla
November 1, 2016 7:33 am

How much of the bacterial layer is associated with a lack of precipitation? It would seem that continuing snow would bury the layer, and reduce melting from lower albedo.

Reply to  Tom Halla
November 1, 2016 8:47 am

Have any other bacterial layers been found in the ice cores ???

george e. smith
Reply to  Tom Halla
November 1, 2016 10:50 am

And this microbial stuff is different from last year/century/millennium for what reason ??

Reply to  george e. smith
November 1, 2016 11:16 am

It isn’t. It was first described by Nordenskiöld in 1870’s. He was the first scientist ever to visit the Greenland Icecap, so older reports are non-existent.

george e. smith
Reply to  Tom Halla
November 1, 2016 10:55 am

Reflection coefficient or “reflectance” is NOT “Albedo”
Earth’s albedo is 0.35 or thereabouts. There is only ONE value for the whole planet.
PS The bacterially darkened snow will also radiate better in the LWIR. So it might be a cooling influence instead.
Old snow traps solar radiation by TIR, and doesn’t really need any e-coli enhancement.

November 1, 2016 7:45 am

Second last para., “Antarctic lakes and marshes”?

Joel O’Bryan
Reply to  Oldseadog
November 1, 2016 7:24 pm

I had the same comment. Puzzling comment. There are deep sub-glacial lakes that have been drilled into and microbes found. Marshes though?

Les Fee
November 1, 2016 8:29 am

Its probably from a volcano a million or two years ago and due to some melting,
its now exposed! It’ll get covered again during the next ice age.

Kelvin Duncan
Reply to  Les Fee
November 1, 2016 4:10 pm

There are natural causes for this phenomenon. There have been plenty of much more recent volcanoes that could cause this effect. Dust from deserts can deposit heaps of “nutrients.” Ask anyone in Beijing. So, the grey discoloration of NZ glaciers could be due to dust blowing over from Australia thousands of km away. And wind blown glacial “flour” can deposit on snow and ice. Human influences are very obvious when you fly from the Southern Hemisphere to the Northern: the Sun becomes redder, the sunsets more spectacular, and the heating effect of the sun becomes less. And the sky ain’t so blue (except in Wyoming).

November 1, 2016 8:45 am

It’s yet another funding bid –
“As cryoconite granule formation is spreading throughout Greenland, our continuing research must be required.”

Reply to  1saveenergy
November 1, 2016 11:22 am

It isn’t spreading “throughout Greenland”. It only occurs on the lower parts of the icecap where there is melting in summer.
The wording is (deliberately?) deceptive. “In the middle” means “in the middle of the Qaanaaq glacier” not “in the middle of the icecap”.

Walter Sobchak
November 1, 2016 8:57 am

Next up for Greenland: The Yellow Snow problem:

Reply to  Walter Sobchak
November 1, 2016 11:06 am

If Frank Zappa had not died at age 52 from prostate cancer we would probably have heard his take on weather and the climate by now.

Pop Piasa
Reply to  gringojay
November 1, 2016 6:39 pm

Maybe Moon Unit could have a baby and name it “Solar Panel”?

November 1, 2016 9:01 am

Amusing that the researchers were surprised to find the distribution of particles more concentrated towards the center. If something were causing melt water run-off it would seem logical to me that one would find the lower concentrations where the run-off and hence flushed surface was the greatest, namely the periphery.
I await with bated breath their next profound observations.
I also find amusing the lament regarding the greening of ….Greenland.

Reply to  rocketscientist
November 1, 2016 11:24 am

See comment above. There is no summer melting and no cryoconite in the middle of the icecap.

Reply to  rocketscientist
November 1, 2016 1:02 pm

The dark material absorbs and thermalizes e-m radiation and heats up melting ice in situ. Especially on relatively flat snow/ice gravity will have the black stuff sink (heavier than water). Quite large/deelp sink holes can form this way.

November 1, 2016 10:59 am

“” Dr. Uetake concludes “As cryoconite granule formation is spreading throughout Greenland, our continuing research must be required.” “”
More funds please.

November 1, 2016 11:50 am

Here is Nordenskiölds “Redogörelse för en expedition till Grönland 1870” (unfortunately in Swedish)
This and the following five pages describes the discovery of cryoconite, outlines its’ importance for the melting of the glaciers, describes the microorganisms in the cryoconite and gives a detailed analysis of the mineral content. All written in 1870.
If those heroic climate scientists had at least compared their results with the 1870 data they might even have learned something new.

James at 48
November 1, 2016 3:20 pm

Eradicate the Asian Brown Cloud.

Bill Illis
November 1, 2016 5:45 pm

Here are all the old Viking settlements on the far south-west of Greenland (right near the very southern tip of Greenland).
Hvalsey Church was the main settlement here and is the most recognized building of the Vikings. The very last marriage was recorded here for example.
Here is what this location looks like on satellite as of September 26, 2016. More-or-less at the period of maximum melting of the glaciers and the snow and just before the snow starts to come back.
Yeah right. The glaciers are melting back so far, they are at the exact same position they were around the year 1300. Garbage science.
Hvalsey is right in the middle of this satellite pic and the old settlements extend right to where they would have been possible 816 years ago.
Glaciers melting? BS.comment image

Bill Illis
Reply to  Bill Illis
November 1, 2016 5:46 pm
November 1, 2016 6:24 pm

Japanese style “Desperately Seeking Funding”, and I know and have worked with some of the “co-authors”.
A typical non sense conclusion, “As cryoconite granule formation is spreading throughout Greenland, our continuing research must be required.”
Someone could then observe, “as you have shown no connection of cryoconite granule formation to even any kind of energy balance melting of ice (snow, firn or glacier), we can conclude that curtailing your “research” will have no effect on cryoconite granule formation, and in fact could just the opposite as that would reduce cryocnite formation on the sites you visited (lacking latrine facilities and following usual standard procedures of … ‘Japanese Science Army’).”
Ja ja

November 2, 2016 3:28 am

Damn LIFE that keeps growing everywhere you wouldn’t want it (if your a green activist, that is). Where is Monsanto when you need them to eradicate buggers ?

Reply to  paqyfelyc
November 2, 2016 4:16 am

Monsanto had betrayed The Cause: they produce seeds now.

Svend Ferdinandsen
November 2, 2016 2:50 pm

Whenever a climateer finds something he has not seen before (and he hasn’t seen much before) it is likely devastating at some time in the future. It is like quantum mechanics, if you have not measured it, it does not exist.
Like when he sees a methane bubble, it is all doom and gloom. He never thinks that it might have happened all the time before he noticed.

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