Marine stratocumulus is a type of
stratocumulus cloud
A stratocumulus cloud, occasionally called a cumulostratus, belongs to a genus-type of clouds characterized by large dark, rounded masses, usually in groups, lines, or waves, the individual elements being larger than those in altocumulus, and the ...
that form in the stable air off the west coast of major land masses. The Earth spins on its axis, which results in the
Coriolis force
In physics, the Coriolis force is an inertial or fictitious force that acts on objects in motion within a frame of reference that rotates with respect to an inertial frame. In a reference frame with clockwise rotation, the force acts to the ...
pushing the ocean surface water away from the coast in the
mid-latitudes
The middle latitudes (also called the mid-latitudes, sometimes midlatitudes, or moderate latitudes) are a spatial region on Earth located between the Tropic of Cancer (latitudes 23°26'22") to the Arctic Circle (66°33'39"), and Tropic of Caprico ...
. This results in
upwelling
Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nutr ...
of cold water from below that creates a pool of cool water at the surface, which in turn cools the air directly above it. The surface cooling results in a large
temperature inversion
In meteorology, an inversion is a deviation from the normal change of an atmospheric property with altitude. It almost always refers to an inversion of the air temperature lapse rate, in which case it is called a temperature inversion. No ...
at the top of the
marine layer
A marine layer is an air mass that develops over the surface of a large body of water, such as an ocean or large lake, in the presence of a temperature inversion. The inversion itself is usually initiated by the cooling effect of the water on th ...
. As the temperature is cooled to the
dewpoint
The dew point is the temperature to which air must be cooled to become saturated with water vapor, assuming constant air pressure and water content. When cooled below the dew point, moisture capacity is reduced and airborne water vapor will cond ...
, water vapor condenses upon available cloud condensation nuclei, and forms a cloud. The stability of the marine layer prevents deep convection, and thus
stratiform
Stratiform may refer to:
* Any of the stratus family of clouds (fog, stratus clouds, altostratus clouds, cirrostratus clouds, nimbostratus clouds) and the precipitation coming from them.
* Any occurrence of layered strata (see stratigraphic unit). ...
clouds are formed.
Climate scientists are currently investigating the detailed structure of marine stratocumulus clouds in an attempt to understand their effect on the climate.
See also
*
Oceanic climate
An oceanic climate, also known as a marine climate, is the humid temperate climate sub-type in Köppen classification ''Cfb'', typical of west coasts in higher middle latitudes of continents, generally featuring cool summers and mild winters ( ...
*
Actinoform cloud
An actinoform or actiniform describes a collection of marine low clouds that takes a distinct shape. They are named after the Greek word for "ray" due to their radial structure. Actinoform clouds can spread out over across and thus cannot be eas ...
References
Cumulus
Stratus
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