More than 21,000 feet above sea level, a dormant volcano called Tupungato rises on the border of Chile and Argentina. Amid volcanic rocks and what little snow doesn’t get blown away by intense winds sits a six-foot tall weather station recently installed by a National Geographic expedition. Though it’s a remote area with “certainly no vegetation,” says mountain climatologist Baker Perry, understanding the weather that happens at this height—and how it transforms over time amid climate change—is crucial for those who live below its peak.
Tupungato is what’s known as a water tower, a high mountain with snow and ice that slowly melts to provide critical water resources downstream. “As a result of climate change, glaciers are shrinking, their volume is decreasing, and in some cases, in many parts of the Andes and Himalayas, they’re disappearing completely,” Perry says. But experts still don’t fully understand what’s happening at these elevations, which is why its crucial to install weather stations at such heights.
These water towers are threatened by climate change across the planet, and Tupungato is one of the most vulnerable in the Andes mountains. Chile is in its tenth year of extreme drought, which experts say is a result of climate change. The weather station that now sits just below its summit is the highest weather station in the Southern and Western hemispheres. To install it, Perry and his team recently completed a 15-day expedition, a collaboration between National Geographic and the Chilean government (with support from Rolex).
The weather station will monitor temperature, relative humidity, moisture, barometric pressure, incoming solar radiation—which has a big influence on glacier mass, balance, and change, Perry says—and reflected solar radiation. They also drilled three feet into the ground to install temperature sensors that will track the permafrost, the ground that remains frozen throughout the year, over time.
All this data will help the researchers, and Chilean officials, understand how glaciers and the snow in these water towers is responding to climate change, which can then help them improve the models they use to forecast how much water from these sources will be available in the future. “Meltwater is incredibly important,” Perry says. “Add in a drought and climate change in there, and it becomes highly significant. It’s so important to understand what’s happening to make reliable projections for the future.”
Perry was also part of expeditions that placed other weather stations, including on Mount Everest—at more than 27,000 feet, the highest weather station in the world. The researchers haven’t compared the results yet, but Perry says the solar radiation levels on Tupungato may be more extreme than what’s been measured so far on Everest, “and those were exceptionally high, higher than we anticipated.”
Researchers will also compare this new station’s data to two lower weather stations recently installed by the Chilean government to answer questions like how similar are the precipitation patterns in valleys and the summit? Right now, they don’t know, and they hope to operate the weather station just below the summit for as long as possible, so they can collect data over multiple winter and summer seasons. “The big story,” Perry says, “is Chile has been in this mega drought for a decade now and we don’t have long term observations from high elevations.”