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Climbing Mount Everest: My Search for Dirty Snow

Editor's note: This April, geologist and Ph.D. candidate Ulyana Horodyskyj will be climbing Mount Everest to determine how much soot is settling on snow at the top of mammoth glaciers, which could slow their growth at the top, even as they melt at much lower elevations.

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Editor’s note: This April, geologist and Ph.D. candidate Ulyana Horodyskyj will be climbing Mount Everest to determine how much soot is settling on snow at the top of mammoth glaciers, which could slow their growth at the top, even as they melt at much lower elevations. She will post updates to this blog as she and her team climb higher and higher in ever-tougher conditions, detailing what they are finding and how they are surviving. In past treks up the Himalaya, Horodyskyj, based at the University of Colorado, Boulder, has captured surprising video showing how quickly glacial lakes empty and refill, one basis for her current research.

KATHMANDU — As I sit here in the capital of Nepal at about 1,400 meters (4,600 feet) elevation, I am surrounded by a mountain of gear that threatens to topple over. Everything I will need to climb up safely beyond 8,000 meters (26,000 feet) on Mt. Everest and Mt. Lhotse this month and through the end of May is in this pile. Or so I hope! Amidst the expected sleeping bag, down suit, over-mitts, mountaineering boots and ice axes is an assortment of gadgets from lasers and temperature sensors to 7-kilogram (15-pound) tripods and weather station components—seemingly odd hardware for climbing a mountain.

Most of the tech stuff is for my research. We often hear about how glaciers are melting. But how fast do they grow from new snowfall? The balance between melt and growth is what significantly affects water supply as well as climate-change feedback across large regions of the Earth.


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Since 2011 I have been working in the Nepalese Himalaya, studying how supraglacial lakes evolve and change the surface of a glacier near its termini (end). These lakes, perched on the surface of the ice, effectively eat away at the glacier through melting and calving (ice wall collapses), sometimes partially draining overnight and refilling multiple times during the melt season. This all occurs on a glacier’s ablation (melt) zone and contributes to glacier demise in the vertical direction. But what about the other end of the glacier—the accumulation zone—where the glacier is fed by seasonal snowfalls? How is that part of the glacier faring? Does it counteract the effects lower down? This question crossed my mind on multiple occasions while working in 2011 and 2012 on the Ngozumpa glacier, one of Nepal’s largest. Until now, however, I had neither the time nor the money to attempt to climb up and answer these questions.

In June 2013 my field assistant Sam Ecenia from the University of Colorado, Boulder and I trekked up to the base of Cho Oyu, the sixth highest peak in the world and the source of the Ngozumpa glacier. Imagery from then and in August revealed a lot of dirty snow and ice as the melt season progressed. The contamination is partly natural dust and partly man-made soot from incomplete combustion of fossil fuels, biofuels and biomass.

Then in October 2013 a cyclone from the Bay of Bengal moved toward the Himalaya and dumped over a meter of snow in just two days. I set up a temporary weather station to track air temperatures and snow albedo (reflectivity) changes, and physically sampled snow with another field assistants, Emma Marcucci, a recent Ph.D. from Boulder, and Martin Coleman, a retired Lockheed Martin engineer. Just days after the storm, the snow was already quite dirty. Although it appeared white to the naked eye, we found plenty of contaminants after melting down the samples and running them through a filter. The samples are currently in the lab so it remains to be determined how much is due to natural dust and how much is man-made pollution or debris from road construction in Kathmandu or from extensive trail erosion along the route to base camp.

Over the course of three weeks, as the snow melted despite decreasing temperature, instruments called pyranometers recorded a reflectivity decrease of nearly 20 percent. You know how you feel much warmer in the sun if you wear a dark shirt rather than a light-colored shirt? That’s because the dark material absorbs more solar radiation. Dark particles on the white snow do the same thing, melting the snow faster.

Sampling on nearby 6,000-meter (20,000-foot) peaks with local field assistants Jas Bahadur, Passang Nuru Sherpa and Ang Tendi Sherpa through the fall and winter revealed contaminants up at these altitudes as well. A bit surprised, we now want to know: How high do pollutants deposit on the snow pack, and what kind of effect might they be having up to 7,000 or 8,000 meters, if any? Mt. Everest is our new site, where a good base camp and solid logistical support from Himalayan Ecstasy, a Kathmandu-based company, will keep us safe as we attempt to climb high for science.

Our team of climber-scientists consists of volunteers recruited through the American Climber Science Program, run by John All, who summited Everest from the north in 2010. This April and May we will be slowly making our way up the mountain, acclimatizing and collecting data as we climb. We will have an advanced camp (camp 2) in the Western Cwm, the so-called Valley of Silence of Everest, from where we will launch day trips into the glacial valley. A temporary weather station will record air temperature, snow temperature and albedo changes over the two months we will be climbing and researching. With careful negotiation and navigation through the crevasse fields within the cwm we will collect snow samples at the surface and subsurface as well as make reflectivity measurements using a handheld spectrometer.

As we go higher the equipment will definitely feel heavier given the lower oxygen levels. Our goal is to collect data and samples from the Western Cwm from 6,000 up to 8,500 meters to reveal the altitudinal distribution of soot on snow. Along the way, we will work together with Sherpa Scientist Initiative trainees, hoping to teach them data-collection techniques so that they can continue to generate snow data on their own treks in coming years.

All of the information we collect over eight long, cold weeks should provide insight into how much impact pollution may be making at the roof of the world. Given a recent article noting that Kathmandu’s pollution levels and air quality are ranked among the worst in the world, this is a timely study.

The expedition officially kicked off on April 3 when two of us headed to base camp ahead of the others to acclimatize and set up instrumentation. The rest of the team will follow a week later. I will post when I can as we climb higher and higher for science. Thanks for following.

Ulyana Horodyskyj received a B.S. in earth science at Rice University and M.Sc. in planetary geology at Brown University. Currently, she is a Ph.D. candidate in geosciences at the University of Colorado, Boulder. For the past few years, she has traveled to Nepal to study how glacial lakes evolve with time. She is currently spending a year abroad on a Fulbright scholarship and has expanded her project to study the effects of black carbon on snow melt.

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