Understanding the Atacama Desert: The Driest Non-Polar Place on Earth
Explore the meteorological reasons behind Atacama's hyper-aridity, including rain shadows and cold ocean currents.
The Meteorology of Aridity
The Atacama Desert in northern Chile covers a 1,000-kilometer strip of land. Some weather stations here have never recorded a single drop of rain in history.
1. The Double Rain Shadow Effect
Atacama is locked between two mountain ranges. The Andes block moist air from the Amazon basin to the east, while the Chilean Coast Range blocks moisture from the Pacific to the west.
2. The Humboldt Current and Inversion Layers
The cold ocean Humboldt Current cooling the Pacific coast stabilizes the air, preventing the formation of rain clouds. Instead, it creates a thick coastal fog called camanchaca.
3. Astrophotography and Clear Skies
Because of its extreme dryness, high altitude (averaging 8,000 feet), and lack of light pollution, Atacama offers the clearest night skies on the planet, hosting major astronomical observatories.
