sunset on la palma island during calima sahara dust
Some sunsets on the Canary Islands are eerily subdued. They look as if the sun were hiding behind a thin veil of gauze. This situation is known by the designation Calima, its Spanish name, which has crossed the language barriers as the weather condition crosses the borders of countries and sometimes even continents. What causes this meteorological phenomenon? The Calima emanates from the endless dunes of the Sahara desert, where storms of enormous proportions lift tiny particles of sand into high layers of the atmosphere. The Sirocco wind then carries these fine dust grains over the western Maghreb countries and passes the Canary Islands, where it saturates the otherwise crispy clear skies with hot, dry haze. During the day, the sky looks milky-white or even brownish-gray. In the night only the brightest stars are visible, hardly better than light-polluted city skies. However, as dusk approaches the Calima turns a sunset into an unforgettable otherworldly experience. The sun hovers above the horizon like a ghostly disk, a sight that leaves one gaping at our home star in stunned awe. The sunset was imaged by project nightflight from an altitude of 1300 meters on La Palma island on June 7, 2015. The two comparison pictures below show the effect the Calima haze has on the sky. The pictures were shot from exactly the same spot on La Palma on two different days in the summer of 2014. The left picture is the typical clear blue La Palma sky with everything gleaming in bright sunlight. In the picture on the right the Calima scenery is of low contrast, the colors are faded and the sky’s blue has turned white. [Released September 2, 2016]
comparison calima and fair weather on la palma island