Foehn Effect in La Palma, Canary Islands
November 03, 2021
Photographer: David del Rosario
Summary Authors: David del Rosario; Cadan Cummings
The spectacular photo above shows an atmospheric phenomenon called the Foehn Effect taken on the island of La Palma, in the Canary Islands. Foehn Effect is a type of wind pattern that pushes a warm, unstable air mass upwards over mountains where it cools and condenses into a low cloud layer. This effect is usually accompanied on the leeward side by a strong adiabatic warming when the dry air separates out as it descends down the mountainside. The adiabatic warming occurs as a result of the air mass being compressed by increasing atmospheric pressure as it descends down the mountain. Following the ideal gas law, this compressing force translates to an increase in the temperature of the air mass. These strong wind patterns are known to worsen wildfires by fanning their flames with dry, high speed air masses. Photo taken August 1, 2021.