Climate scientists go above and beyond
It was the end of an 11-day trek from Lukla, Nepal, mainly following river valleys with a team of scientists, a film crew and their porters and guides. The snow fell hard on the final leg into Base Camp at Mount Everest, and Heather Clifford had a bad headache. Worried it may be the onset of altitude sickness, she let a Sherpa take her pack and she struggled into camp.
Clifford, a 2011 Sandwich High School graduate and 2015 Clemson University graduate with a degree in environmental engineering, flew to Nepal last April to be part of an expedition, organized and funded by National Geographic and Rolex, to establish the world’s highest weather station on the summit of Mount Everest.
While the capstone was the weather station, the approach was to gather much-needed information across many disciplines and the team included geologists, glaciologists, biologists, cartographers and climate scientists. Climate change researchers fear the mountain regions of the world are taking a disproportionately big hit from global warming, but in these remote and hard-to-access areas there’s little solid information. A 2015 study by the Mountain Research Institute found that the density of weather stations above 14,763 feet is one-tenth what it is below that elevation and that long-term data doesn’t exist for areas above 16,400 feet.
The Mountain Research Institute report also showed that over the past 20 years, areas above 13,000 feet on the Tibetan Plateau warmed at a rate nearly 75% faster than those below 6,500 feet in elevation. A warming planet is believed to be the primary cause in shrinking ice caps and glaciers where nearly 70% of the world’s fresh water is locked in ice, according to the United States Geological Service.
The thousands of Himalayan glaciers that lace these lofty peaks and are a water source for millions are under siege. The Hindu Kush Himalaya Assessment, a five-year study by 350 researchers and experts released last January, forecast that glacier mass could decline by 9% to 32% in the Himalayas, depending on the region, by 2030. Within 80 years, the eastern Himalayan glaciers would have virtually disappeared, with other areas suffering as much as a 35% loss of mass.
Conversely, computer models predicted glaciers on the western side are expected to increase in size due to higher snowfalls forecast in those areas, but the Himalaya Assessment also worried that those computer models were weak due to a lack of fine-scale data.
Clifford, a first-year doctoral student at the University of Maine’s Climate Change Institute, was on the expedition to collect ice cores from the Khumbu Glacier. She had been invited by the expedition’s lead scientist Paul Mayewski, director of the institute.
In a long career, Mayewski has led over 55 expeditions to practically anywhere on the planet that was remote and cold, including the Arctic, Antarctic, the Andes and Himalayas. In 2018, Clifford was on one of his expeditions to the Andes in Peru.
In Nepal, the party of 20 slept in lodges along the way, gradually gaining altitude, allowing their bodies time to adjust to the elevation. They drank sweet milk tea, ate yak meat, and her personal favorite, momos, a kind of steamed dumpling.
Along the way, the landscape changed from green to gray, from fields, trees and living things, to drab cobble and sand, rocks and boulders. Close up, the mountains seemed primordial, a place where the planetary, earth-creation forces were still at work.
The Himalayas are the product of a cyclopean collision of the Eurasian and Indian continental plates that began 225 million years ago and continues today. This is the land of year-round snow that has piled up for tens of thousands of years. As snow accretes in the mountains, the hexagonal shape of the flakes is compressed into the round sugar-sized grains that then pack tightly into a river of ice blocks that respond to the tug of gravity. The glacier creaks, groans and snaps as it slides inexorably downhill and over millions of years, this has ground down the Himalayan Mountains to one-tenth their original mass.
In the snow and darkness of that first night on Everest, base camp — essentially a tent village pitched on sand, gravel, ice and dirty snow just below a sweeping bend in the Khombu Glacier — had seemed a tentative outpost perched precariously on the verge of the outsized wilderness that surrounded it.
But the next morning, Clifford exited her tent to a sunny day, and the camp seemed more like a bustling village. Climbers gathered for the spring season were busy with preparations, and her expedition had its tasks. The headache was gone and she was surrounded by mountain peaks that pierced the sky.
They seemed so close, she said, that you could almost reach out and touch them, but watching a helicopter take off and become a small dot, flying up to Camp 2, nearly 4 miles distant and 4,000 feet up the mountain, gave her a sense of the massive scale.
Clifford, 26, felt a long way from the high school science labs in biology, chemistry and physics that challenged her and made her doubt she could ever be a scientist.
“You can’t really assess your own situation by saying, ‘I’ll work for an insurance company because I’m not good at biology.’ If you’re passionate about something, work towards that,” she said.
Clifford found her passion in an ecology class her junior year of high school, and an independent study project in which she read the United Nation’s Independent Panel on Climate Change report. “It made me want to build my future around studying climate change,” she said.
The opportunity at Everest was unique. With peaks that approach the cruising altitude of jetliners, the Himalayan mountain range is the only place in the world where mountain peaks pierce the jet stream. Generally found between 20,000 to 50,000 feet, jet streams exist at the boundaries of massive warm and cold fronts with the pressure differential creating rivers of wind that race at speeds approaching 300 mph. They move in a snaky circle around the earth and can cause large changes in local weather and climate.
Scientists worry that climate change has destabilized these rivers of wind leading to wild extremes of weather. Last August, a kink in the North Atlantic jet stream trapped warm air over Greenland, causing a record-breaking heat wave that pushed the air temperature over the ice cap to nearly 39 degrees, initiating melting of over 60% of the ice sheet, according to a report in the London Financial Times.
While the jet streams are monitored by instruments on both commercial and military aircraft, as well as other sampling methods like wind balloons and satellites, a permanent weather station would give instantaneous and continuous data on wind speed, temperature, barometric pressure and humidity that would make computer models forecasting weather or forecasting our climate change future, more accurate.
“There is no substitution for having high temporal resolution of those data sets, and located where they are gives you so much more,” said Baker Perry, a geographer and climate scientist at Appalachian State University.
“We know that the subtropical jet stream is critical to the onset and end of the monsoon season in Asia,” Perry said. “It’s a huge player in the lives of so many people.”
Changes in the monsoon season can affect billions in Southeast Asia. Dry seasons with little rain mean farmers don’t plant crops; too much rain and there’s flooding and disease. One-third of India’s electricity is generated by hydropower.
“The behavior of the polar and subtropical jet streams is a lot more erratic in recent years, presumably climate change. Having direct observation as to what’s happening in the jet stream would be very beneficial,” said Perry.
On this expedition, Perry was chosen to be one of the scientists to install three weather stations along the Everest climbing route, including one on the summit. For the vast majority of climbers, just climbing Everest is all they can handle.
The mountain was thought to be unclimbable until Sir Edmund Hillary and Tenzing Norgay reached the summit in 1953. Using bottled oxygen and guides, the odds have dramatically improved: 76% of those who left base camp reached the top in 2018, a total of 802 summits. But there were also five deaths that year, according to Himalayan Database archives. The database found that 72 climbers have died of the nearly 8,000 who departed for the top from base camp between 2010 and 2019.
Overall, there’s about a 1 in 100 chance of dying, and the first obstacle mere feet from the tent village is formidable, the Khumbu Icefall, a massive frozen waterfall of enormous glacial blocks of ice.
“It was probably my favorite part,” Clifford said of walking around the edges of the icefall taking ice core samples. Glacial peaks, known as penitents, towered 20 feet overhead. Created when the snow goes straight from solid to gas, vaporizing in low humidity and a dew point below freezing, these fields of pinnacles are named for their resemblance to the pointed white hoods worn by Spanish religious orders during Holy Week.
“If you are walking through it, it’s as though you are in an ice forest,” said Clifford, who was not part of the climbing expedition.
But climbers have many more dangers ahead. They leave in the predawn hours to get through the icefall before the ice and snow on the glacier is weakened by the sun and begins to shift. Climbers have been killed when towering pillars of ice known as seracs collapse without warning. The glacier is moving and deadly crevasses sometimes open up underfoot. Others must be crossed using long ladders over a yawning abyss.
More crevasses and avalanches await climbers beyond Camp 1 in the snowbound Valley of Silence. From Camp 2, there’s an icy 4,000 foot high steep slope known as the Lhotse Face. One slip and you fall thousands of feet. When you hit Camp 4 at 26,000 feet, you’re in what is known as the Death Zone.
At sea level, the oxygen concentration in the atmosphere is approximately 21%. At 17,000 feet, there’s roughly half that amount. Perry would spend over a day near the summit, at around 29,000 feet where the oxygen was less than 7%, a third of what the inhabitants of Clifford’s home town of Sandwich took in with each breath.
During the long slow trek into base camp from Lukla, the climbers’ bodies adjusted to more efficiently harvest the available oxygen from the air. They breathed more deeply, using more of their lungs, and their bodies produced more red blood cells capable of absorbing and transporting oxygen and an enzyme that helps release it into body tissues.
Even so, in the Death Zone, the air pressure is so low that fluid can leak from capillaries and builds up in your lungs and/or your brain. Either can be fatal.
“It’s like being on another planet. Such a barren, inhospitable landscape. So windswept. Really cold,” Perry recalled.
Twenty-two climbers from the National Geographic/Rolex expedition left for the climb to the top on May 17 and didn’t return to base camp until a week later. They would spend three days above 21,000 feet, breathing bottled oxygen, but every step required extraordinary effort. Even though thirst and hunger are suppressed, it’s important to stay hydrated and to eat, but just melting snow to drink took most of the day.
“Everything feels like slow motion. My mind seemed always to be a little foggy,” Perry said.
But the ultimate foe proved to be the crowds. The desire for a bucket list achievement is not limited to Everest, but the sight of long lines at one of the world’s most dangerous places, waiting like a queue for popular movie, was mind-boggling.
It started early in the trip. Traveling with traffic through the Khumbu Icefall, Perry crested a big block of ice and saw 75 to 100 climbers standing in line waiting to climb a ladder up a vertical ice face.
“That’s when it became apparent there’s a lot of people up there that could cause major traffic jams,” he said.
Still, they were able to install two weather stations, one at Camp 2 at 21,207 feet, and a second near Camp 4, at a feature known as the Southern Col, at over 26,000 feet.
Another University of Maine researcher and Polish climate scientist Mariusz Potocki had built a special lightweight drill for the expedition that had enough power to drill into glacial ice at the South Col to successfully extract a 32-foot long ice core, the highest such sample ever taken.
By 12:30 p.m. on that afternoon, the party retreated to tents for the final push, the last 1,000 feet in elevation to the summit. They left for the top at 11 that night, climbing by the light of their headlamps. After a few hours, the pace slowed to a crawl as the line of people attempting to reach the roof of the world had created yet another traffic jam.
The lead, Panuru Sherpa, with 17 successful summits of Everest, made the case for abandoning the quest for the top. Climbers were getting cold and it would be another 7 to 8 hours before they’d get to the summit at this pace. It would leave them little time to work and they may not have enough oxygen for the descent.
“Everest is such an iconic peak, the highest place in the world, and there’s certainly that part of you that has that desire to get up there,” Perry said. “But those on this expedition understood that the primary mission was to do science and research.”
The team retreated to a small overhanging cornice known as The Balcony to set up the final weather station at 27,658 feet, which is still the highest such facility. It is powered by solar panels and has instruments that measure wind speed, air temperature and humidity and visible, ultraviolet and infrared radiation. Data is collected in 3-second intervals and transmitted by satellite.
Once assembled, the weather station is a little over 6 feet tall without the lightning rod, and weighs about 110 pounds. Because every pound adds to the burden of physiologically and physically overtaxed climbers, the pieces for the three weather stations were parceled out among five Sherpas.
The Balcony is small, and made for cramped working conditions. The first problem the team encountered was that the extreme cold had sucked the life out of the batteries for Potocki’s drill that was needed to sink screws into rock to hold the station in place.
“One of our largest Sherpas stuffed the batteries into his crotch and armpits and we sat there and waited in 10 below F,” Perry said. After an hour, the batteries warmed up enough to drill the holes for a mountain-climbing bolt that expands in the rock and holds when tightened.
Problem solved, but the crew soon found out they were missing two vital parts. The short tubes that attached the wind sensors to the frames had not been packed.
“When I realized that, I just sat down and put my hands on my helmet,” Perry said. But somehow, despite brains fogged by the high altitude, the team was able to hammer shovel handles into the right shape and, using duct tape, attach the sensors.
“When we got a text from a satellite phone from a colleague waiting for the data to show up and we had confirmation that it was transmitting as designed, that was the real sense of accomplishment,” Perry said. The sensors have since transmitted wind speeds up to 148 mph.
The climbers were in daily contact with those at base camp. But during the night and a few times daily, Clifford would be jolted by the roar of avalanches. One made it close enough that it sent a giant cloud of snow throughout the camp.
“It was nerve-wracking worrying about their safety,” she said. It was not all worry and work however. Clifford and University of Maine undergraduate Laura Mattas realized they had missed their May 11 graduation for Clifford’s master’s degree and Mattas’ bachelor’s degree, so they improvised a ceremony that included a cake and caps made from cardboard and tape and trash bags for gowns. Berry said the return to base was somewhat anticlimactic. Many of the climbers who had stood in line to reach the summit the day before had already departed. The Sherpas were still there packing and he celebrated with them.
“It was a celebratory atmosphere back there for sure,” he said.
The ice cores were already on their way to the University of Maine, each 3-foot section fitted with a temperature sensor and placed into a protective tube. They were walked back down the mountain, and then flown by helicopter to a freezer facility in Kathmandu for transport back to the U.S.
The ice cores are now in the Climate Change Institute’s walk-in freezer that keeps them at -13F. Clifford said the ice is a clearish-blue color, like hazy ice cubes. She will use a customized table saw to cut them into long thin slices, and then do a chemical analysis and Carbon 14 dating to find when the ice formed.
Like the amber that trapped prehistoric insects and pollen, the ice cores are time capsules of the conditions that existed tens of thousands, or more, years ago when they first fell as snow on Everest. Tests will look for isotopes that indicate the temperature at the time, and for dust, sea salt and other contaminants in the atmosphere, traveling back through time along the various layers of deposits in the ice core.
It’s lab work, and she’s good at that now, but the thrill of field work is still a big draw and she’d love to go to Antarctica to do more research.
“I would like to take a step outside my comfort zone and try something in science communication and policy,” Clifford said of her plans after she gets her doctorate. “It seems like that is very much needed in today’s climate.”
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