Mixing in the ocean occurs on several scales, the smallest scale being molecular. If a layer of warm, salty water lies above a layer of colder, fresher water, the heat and salt will tend to diffuse (spread out) downwards to make a single layer with intermediate temperature and salinity values. However, because heat diffuses faster than salt, the process can lead to local instabilities in the density structure which cause mixing within a layer many meters thick. The best-known example of this process, known as salt fingering, occurs where very salty water from the Mediterranean outflow mixes into the North Atlantic.
Read more: Ocean Mixing - sea, depth, oceans, temperature, salt, source, effect, salinity, Pacific http://www.waterencyclopedia.com/Mi-Oc/Ocean-Mixing.html#ixzz1D4AHmOk3
