By Ross Nuechterlein

 Convection is the movement of molecules within fluids and is one of the major modes of heat and mass transfer in liquids and gas.

 Buoyancy is an upward acting force exerted by a fluid, that opposes an object's weight.  Buoyancy = weight of displaced fluid.

A change in Temperature, Salinity or Density causes a fluid parcel to have vertical tendencies until a great enough force is achieved. Until then: Transport takes place horizontally till the downward force becomes greater than the rising force below.

 Natural Convection  Gravitational Convection  Forced Convection  Granular Convection  Thermo magnetic convection.

 Occurs due to temperature differences affecting density resulting in buoyancy (more or less dense)  This leads to bulk fluid movement.  More rapid movement between two fluids of large density differences.  Larger acceleration occurs through greater mediums

 Induced by buoyancy variations resulting from material properties other than temperature.  Variable salinity in water is a frequent cause of ocean convection.  Dependant on the effects of gravity and does not occur in micro gravity environments

 Solar radiation warms the oceans near the Equator, driving warm water toward the poles.  Cold polar water replaces displaced warm water at the equator creating circulation.

 Density differences also drive ocean convection due to varying salinity. This is known as Thermohaline convection.  In some cases warm saline water may sink being replaced by cooler fresher water which rises. This reverses the transport of heat.

 Deep Ocean circulation is important because it determines the vertical stratification of the ocean and because it also modulates climate.  This circulation is caused by the convection processes discussed.

 Stewart, R. H., Introduction to Physical Oceanography.  Open ocean convection: observations, theories, models. hing/ocean_dynamics/reading/marshall_scho tt99.pdfhttp:// hing/ocean_dynamics/reading/marshall_scho tt99.pdf