The Sun Shines Brightest in South America’s Atacama Desert


Forget Arizona or Florida. Sun worshippers should head to South America’s Atacama Desert. The sunlight there is more intense than anywhere else on Earth. Its brightness beats super-sunny spots, such as Mount Everest. Sometimes, it even rivals conditions on Venus.

A high-altitude plateau in the Atacama straddles parts of Chile, Bolivia, Peru and Argentina. Satellite data had suggested this area — the Altiplano — gets the most intense sunlight on Earth. But satellites look down from afar. It’s important to check such claims with on-the-ground data, says Raúl Cordero. A physicist, he works at the University of Santiago in Chile. His team wanted to know: “How good are these [satellite] estimates?”

To answer that, the team brought two shipping containers to the Chilean Altiplano and set up a small observatory. It’s been measuring sunlight there since 2016. The team used a pyranometer (Pye-ruh-NAH-muh-ter). This palm-sized instrument can detect not only visible light, but also ultraviolet and near-infrared wavelengths.

The team now reports the observatory’s first five years of data.

On average, some 308 watts of solar energy hits each square meter (about 11 square feet) of land. This amount is what the satellite measurements had suggested. It’s also higher than light recorded near Mount Everest’s summit. The team shared its findings July 3. They appeared in the Bulletin of the American Meteorological Society.

The researchers also noted bursts of especially intense sunlight. Each typically lasted just a few minutes. The researchers think they happen when thin clouds scatter light toward the ground. One event in January 2017 blasted the site with a whopping 2,177 watts per square meter! That was more than seven times the site’s average. It actually rivaled the sunlight hitting Venus. And that’s surprising because Venus is more than 40 million kilometers (25 million miles) closer to the sun than Earth is.

Source: Science News Explores