Marine layer
From Wikipedia, the free encyclopedia
A marine layer is a cool, moist, foggy layer of air that can be several hundred feet to as much as three thousand feet thick associated with offshore weather patterns.
[edit] How a marine layer develops
The marine layer is formed as cold ocean water such as is found on the Pacific Coast in Southern California cools the air just above it. Warmer air above that layer acts like a seal, and keeps the air below it from mixing and dispersing.
In the case of Southern California, a steady west wind often brings the marine layer ashore overnight, blanketing coastal communities in a cool, thick fog. This can last until midday when the heat of the sun is frequently strong enough to break the inversion layer and dissipate the effects. In California, the marine layer is most common from spring through to fall.
Drizzle or light rain can also be associated with a particularly wet marine layer.
[edit] Effect on pollution
The inversion that caps the marine layer also traps pollutants in cities such as Los Angeles which exacerbates the development of smog.