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Sculptural products from Dark Snow 2014 campaign

In August of 2014 I was honored and privileged to be a team member of Dark Snowʼs terminal rotation of the season in the ablation belt of Greenlandʼs Ice Cap. This would not be of particular note, except that I am not a scientist, but an artist.

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Well, maybe not just any artist. I like to think that I have one foot in the world of science, and that one of my roles is to attempt to bridge the gaps between the two disciplines. I believe that the flash of creativity— the “something” where there was nothing— is identical in  process in science and art. Indeed, to me, at their best both are derived from the same approach: looking very, very closely at the world, and then making some kind of interpretative sense of it. Of course there are mediocre practitioners of both, who create science about science or art about art, or other lacks of inspiration, but that is inevitable in any human endeavor.

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My residence with Project Dark Snow was my fourth polar sojourn. When the NSF sent me in 1999 to The Ice (Antarctica) I became the first sculptor from any country to be sent to the “last continent” (7 weeks). They sent me again in 2006 (4 weeks). I also spent the last rotation of 2001 on Canadaʼs largest icebreaker (Louis S. St-Laurent) (5 weeks). All of these trips included a significant airborne component, in fixed and rotary wing aircraft.

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On the Greenland Cap I assisted with the science work, but I also engaged in my usual observations when in the field. I get asked frequently if I sculpt on these trips: of course not. I am out there as a researcher, gathering “data” in a manner somewhat parallel to what the science folks do. For them, the data will be analyzed and interpreted back at the lab, and for me there is plenty of time to carve, weld and grind when back at my studios. On ice I photograph, sketch, observe, make notes, converse. It is imperative to keep an open mind: it is very often the unexpected that turns out to be the real prize.

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After these and other trips to nourish my work, at first I am artistically stunned. Slowly, some art begins, usually fairly illustrative since I am still in thrall to the majesties I have witnessed; often this takes the form of works on paper, but not this time. Somehow, sheet marble called, and seemed a logical first step. Eventually, LED illumination wormed into things as well. Gradually, as a bit of time and labor pass, I slowly am able to inject metaphorical meaning into the work, and as it thus matures I become more and more comfortable applying my signature.

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In every case, this visual, intellectual, metaphorical infusion is added to everything previous, and the entire additive structure of all my trips and other nourishment becomes enriched.

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I hope that the provided images  show this progression, consequent over more than a year, a normal time for these gellings to occur.

 

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BLACK and BLOOM: Microbial processes darken and accelerate the melting of the Greenland Ice Sheet

The UK Natural Environment Research Council (NERC) has funded a consortium of UK scientist to work together with their international collaborators on issues related to why the melting of the Greenland Ice Sheet is accelerating. 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 large research project is based on our hypothesis that microbes thrive and bloom on melting snow and ice surfaces, and darken the ice sheet surface as a consequence.

Life exists wherever there is liquid water on the Earth’s surface, and ice sheet surfaces are no exception (see Figures 1). Just one drop of ice melt contains up to 10,000 microbes. Many of these are tiny organisms have green chlorophyll, similar to plants, to capture sunlight and grow va photosynthesis. They also develop their own dark-coloured sun block, often coloured red, purple or brown, which protects them from damage by the fierce sunlight which shines for 24 hr per day in the height of the Arctic summer. The microbes can turn the surface of the ice sheet purple to black when they multiply rapidly and bloom, which means that the ice sheet surface warms and melts much faster than if the surface were white and lifeless. Microbiologists have long known that snow is discoloured by the growth of snow algae. Indeed, water melon snow looks and smells like water melons. It is only recently that microbiologists have shown that dark-coloured microorganisms grow in melting ice.

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Figure 1. Examples of coloured snow algae from the Greenland Ice Sheet [1]. Clean, fresh snow has an albedo of ~90%. This means that ~90% of the incoming solar radiation is reflected back into the atmosphere, and that only 10% is used for melting the surface snow. The snow and ice algae give rise to albedos of 35-49%, which means that 51-65% of the incoming solar radiation is used to melt the surface snow.

Scientists at the Universities of Bristol (Martyn Tranter, Alex Anesio, Jon Bamber, Jo Laybourn-Parry, Nicholas Roberts, Jemma Wadham and Marian Yallop), Leeds (Liane Benning and Jim McQuaid), Sheffield (Edward Hanna and Andy Hodson) and Aberystwyth (Tris Irvine-Fynn) have been awarded over £3 million during the next five years to study these microbes and to evaluate how their distribution and growth combine with the other factors to darken the ice surface and enhance the melting of the Greenland Ice Sheet . They are joined by a talented team of international partner scientists, including Carl BØggild (Copenhagen, Denmark), Jason Box (GEUS, Denmark), Michiel van den Broeke (Utrecht, Netherlands), Brent Christner (Louisianna State, USA), Gianfelice Cinque and Burkhard Kaulich (Diamond Light Source, UK), Xavier Fettweis (Liege, Belgium), Paolo Formenti (Paris, France), Alex Gardner (NASA JPL, USA), Stef Lhermitte (Leuven, Belgium), Martin Sharp (Alberta, Canada), Marek Stibal (Prague, Czech Republic) and Nozomu Takeuchi (Chiba, Japan).

Our goal will be to understand what controls the growth and blooming of the microorganisms. We want to know how they stick to the small amounts of dark particles present in the snow and ice, including dust and black soot, and if they retain those particles at the surface for long periods.

We will be making some of the first detailed measurements of how the surface or the ice sheet darkens over the whole spring, summer and autumn, starting with cold snow, going through slush, then ice as the snow melt drains away, and finally to rotten ice, a mix of ice and water. At the moment, we lack detailed field measurements that take account of all the different factors that darken the ice sheet surface. Our detailed field measurements will do just this. Importantly, few measurements of coloured microbes have been made alongside the other factors, which include how wet the snow and ice is and the size of the snow and ice crystals. Wet snow and ice and bigger crystals are usually darker. Details of fieldwork already undertaken on the Greenland Ice Sheet by our partners at GEUS as part of the Dark Snow Project can be found at http://darksnow.org/ .

Finally, we will put all our information on surface darkening into a melt model of the whole ice sheet that will be used to predict how much sea level rise will occur in the future. Currently, sea level is rising by about 1cm per decade, but there are real concerns that this could accelerate in the future. In addition, there are concerns that the input of more fresh water into the seas south of Greenland may decrease the flow of the Gulf Stream, which is responsible for the temperate climate of the UK. Warming leads to greater melting of the ice sheet interior, which is quite flat, and so holds melt water at the surface for longer. This will lead to more growth of microbes, which will darken the surface and increase the amount of melt. We need to be able to predict with more certainty than we can do at present just how much more melting will arise as a consequence, so that we can be confident that our predictions of sea level rise are more accurate.

[1] Lutz, S., Anesio, A. M., Jorge Villar, S. E. & Benning, L. G. Variations of algal communities cause darkening of a Greenland glacier. FEMS Microbiology Ecology 89, 402-414, doi:10.1111/1574-6941.12351 (2014).

 

About the August, 2014 dark Greenland photos

Photos and video I took during an August 2014 south Greenland maintenance tour of promice.org climate stations and an extreme ice survey time lapse camera went viral, featuring a surprisingly (to me and others) dark surface of Greenland ice.

What we know, the southern Greenland ice sheet hit record low reflectivity in the period of satellite observations since 2000 due to a ~2 month drought affecting south Greenland…
2014_August_record_map
map with colors indicating when record low albedo was observed. The photos are from the blue patch near the southern tip of Greenland.
Snowfall summer 2014  for south Greenland would have kept the melt rates down by brightening up the surface. Summer 2014, at the PROMICE.org QAS_A site, we recorded ice loss from the surface at a place we thought was above equilibrium line altitude, where the surface would lose no ice in an ‘average climate’. The higher than normal melt rates allowed the impurities to concentrate near the surface in a process documented for snow surfaces by Doherty et al. (2013).
To avoid misinterpretation, black carbon is only part of the darkness, the rest is dust and microbes (See Dumont et al. 2014 and Benning et al. 2014). The photos are from the lowest part of the ice sheet’s elevation. The upper elevations do not get nearly this dark. This satellite image illustrates for west Greenland how dark the surface gets, down to 30% reflectivity.
Work Cited
  • Benning, L.G. A.M. Anesio, S. Lutz & M. Tranter, Biological impact on Greenland’s albedo, Nature Geoscience 7, 691 (2014) doi:10.1038/ngeo2260
  • Doherty, S. J., T. C. Grenfell, S. Forsstro¨ m, D. L. Hegg, R. E. Brandt, and S. G. Warren (2013), Observed vertical redistribution of black carbon and other insoluble light-absorbing particles in melting snow, J. Geophys. Res. Atmos., 118, 5553–5569, doi:10.1002/jgrd.50235.
  • Dumont, M., E. Brun, G. Picard, M. Michou, Q. Libois, J-R. Petit, M. Geyer, S. Morin and B. Josse, Contribution of light-absorbing impurities in snow to Greenland’s darkening since 2009, Nature Geoscience, 8 June, 2014, DOI: 10.1038/NGEO2180
Photo by Jason Box

Photos by Jason Box

 

The Stars of the Show

For almost two months we endured (and let’s face it, enjoyed) camp life at its fullest; sleeping on the ice every night, falling into countless water filled holes, enduring the discomforts of cold-numbed toes and keeping up with the seemingly endless treadmill of camp maintenance… But at the end of the day, it was these guys, the “Ice Algae”, that were the true stars of the show!

The picture above is an image of what we see when we look down the microscope at our surface ice samples. Dark-coloured ice algae clearly dominate the sample. Typically we estimated that there were tens of thousands of algal cells in every milliliter of sample. When you bulk these samples up to liters and gallons, and then to the volume of surface ice found within biologically active area of the Greenland Ice Sheet (currently estimated at >400,000 km2), we’re looking at some serious cell numbers. As Marek Stibal explained previously, these guys are packed with a dark purple-brown pigment that protects them from sunlight, but also causes the darkening of the ice surface.

So, were we pleased with our field season? Definitely! Once we had figured out the best way to interpret the environment, we set about to amass as much data as we could, so that any conclusions that are drawn are as robust as possible. Overall we took around 600 samples for biological analysis, over 2000 close range spectral readings and, most amazingly, we individually counted around 94,000 algal cells in the field. This, on top of keeping a well-oiled camp going, kept us more than busy over the summer.

Now that we are back from our field work, our next mission is to interpret just how much albedo change is due to the darkening effect of algal growth on the ice surface, and furthermore, how much this darkening is contributing towards ice melt. In addition, we also intend to use laboratory analyses in Copenhagen to look into some of the more intricate components of the surface ice ecology that we have been living alongside all summer.

 

 

Whodunit? Glacier Crime Scene Investigation in the Himalaya

High up in the Himalaya, it lurks. It is hard to spot with the naked eye. Yet we see the damage it leaves in its wake. No, this is not the elusive Himalayan yeti (though I do have camera traps set out). Rather, I am referring to black carbon or soot – resulting from incomplete combustion of fossil fuels, as well as biofuels and biomass – which deposits on snow and ice in the Himalaya. These dark particles absorb sunlight, warming snow and ice, leading to faster glacier mass loss.  These particles are smaller than a strand of hair. Small but mighty, so it seems. Yet, black carbon isn’t the only culprit. Locally and regionally derived dust also can impact snow melt. While dust is a natural occurrence on the planet, recent land use changes, such as road and trail construction can add to the amount. Thus, it is important to consider the combined effect of soot and dust.

As in the Arctic, dark particles on Himalayan snow are a concern as they lead to enhanced heating, melting and sublimation. While melting ice on Greenland can directly contribute to sea level increases, in the Himalaya ice loss affects people on a more local and regional scale – by disrupting water resources, as well as cutting off climbing routes. The Nepalese Himalaya are home to eight of the world’s 8000-meter peaks. As climate continues to change and conditions become more treacherous for climbing, this may affect the local communities who rely on trekkers and mountaineers for income.

From October 2013 – end of May 2014, my team and I collected snow samples across the Khumbu valley in the Everest region (eastern part of Nepal), including Island Peak, Lobuche East, Khumbu glacier, Ngozumpa glacier, Cho La and Renjo La. In central Nepal, we collected samples from Annapurna South and Mt. Himlung in the remote NarPhu valley, on the border with Tibet. Out in the field, the technique is straight-forward: wash your hands (or ice axe) in the snow first, then collect a gallon-size bag of snow from the top few centimeters and the subsurface. The former represents dry deposition from the air while the latter represents deposition in the last snowfall event. You then quickly come back down to camp to melt the samples and run the water through filters, capturing pollutants and other contaminants, which later are analyzed in the lab. The technique I am using was developed by Dr. Carl Schmitt at the National Center for Atmospheric Research, with whom I am collaborating (http://www2.ucar.edu/atmosnews/just-published/8856/measuring-pollutants-andean-glaciers).  He developed this while working with the American Climber Science Program throughout the Cordillera Blanca in Peru (http://climberscience.wordpress.com).

Preliminary results show a dominance in relative mass concentration of dust in samples, with particularly high levels of black carbon/dust in more frequented regions such as the high mountain passes and climbing peak high camps. Whodunit? Well, that’s more complicated, but a few suspects are in custody:

  • dust from eroding trails at the lower altitudes, due to frequent human and animal traffic during the high trekking seasons in the autumn and spring
  • black carbon from wildfires
  • soot from yak dung burning stoves in local villages
  • dust from road construction in Kathmandu
  • black carbon from diesel-belching buses and trucks
  • soot from brick factories, though farther geographically, may be carried to the mountains by the wind.

It is clear we are dealing with anthropogenic changes and that needs to be addressed at the local and national government levels. Understanding the sources better and developing mitigation efforts where possible will be key, as well as understanding the effects on the water supply in the region in order to facilitate adaptation.

Acknowledgments Funding for my work includes: National Science Foundation (NSF); USAID; the US Fulbright Program; Geological Society of America (GSA); the Explorers Club; National Snow and Ice Data Center’s (NSIDC) CHARIS project; Rice Space Institute; and individual sponsors/donors through the University of Colorado Boulder and crowd-funding from Petrishdish.org and Rockethub.com.

Team members: Passang Nuru Sherpa, Kami Sherpa, Ang Tendi Sherpa, Nima Sherpa, Dr. John All, Jake St. Pierre, Chris Cosgriff, David Byrne, Marty Coleman, Michael Coote