ATOC 184 Lecture Notes - Lecture 3: Antarctic Convergence, Current Meter, Maxima And Minima
9 Jul 2018
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Document Summary
Thermohaline circulation: water circulation produced by differences in temp and or salinity (therefore density) Including at depth where wind energy cannot penetrate. Co-exists with wind driven circulation at the surface. Reduction of density occurs when precipitation diminishes salinity and heating by the atmosphere raise temperature. Increase of density occurs when evaporation increases salinity and decreases temp. Direct conduction with the colder atmosphere decreases temp. Freezing of seawater inc salinity just below where sea ice formed (ejected from ice) Density variations produce horizontal pressure gradients at all depths. Gravity pulls water down the slope (against pressure gradient) Pressure gradient force drives a movement of water down slope. Process responsible for large-scale vertical movement of ocean water and the circulation of the global oceans as a whole. Water mass: body of water identified by its salinity and temperature (density) Through processes occurring at the ocean surface (heating/cooling, evaporation/precipitation) They reach their depth at equilibrium according to their density.
