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I have captured for La Vanguardia Readers' Photos this spectacular image of the morning fog front following the profile of the Barcelona coastline,
The snapshot with this perspective is taken from the Turó del Reig, above the town of Tiana, in the Maresme region, on the crest of the Serralada de Marina.
Turó del Reig is a 368-meter mountain that is located between the municipalities of Tiana, in the Maresme region, and Sant Fost de Campsentelles, in the Vallès Oriental region.
The coastal fog has nothing to do with the fogs in the interior of Catalonia. They are currents of relatively warm and humid air that move over a cold sea.
This mass of air cools at its lower part, the one closest to the sea, which increases its humidity until it condenses in the form of fog, called “advection”.
The fact is that this fog cannot progress inward, because once in contact with the earth, the temperature increases again and it dissolves.
Therefore, advection fog forms due to the movement (advection) of relatively warm, moist air over a lower temperature surface and the cooling of the air by contact with that cold surface until it reaches saturation temperature.
