text: Stratification is commonly seen in the planetary sciences.
  Solar energy passes as visible radiation through the air, and is absorbed by the ground, to be re-emitted as heat radiation. The lower atmosphere is therefore heated from below (UV absorption in the ozone layer heats that layer from within). Outdoor air is thus usually unstably stratified and convecting, giving us wind. Temperature inversions are a weather event which happens whenever an area of the lower atmosphere becomes stably-stratified and thus stops moving.
  Oceans, on the other hand, are heated from above, and are usually stably stratified. Only near the poles does the coldest and saltiest water sink. The deep ocean waters slowly warm and freshen through internal mixing (a form of double diffusion), and then rise back to the surface.
  Examples:
  * Ocean stratification, the formation of water layers based on temperature and salinity in oceans
  * Lake stratification, the formation of water layers based on temperature, with mixing in the spring and fall in seasonal climates.
  * Atmospheric instability
  * Atmospheric stratification, the dividing of the upper reaches of the Earth's atmosphere into stably-stratified layers
  * Atmospheric circulation, caused by the unstable stratification of the atmosphere
  * Thermohaline circulation, circulation in the oceans despite stable stratification.
  * Stratified flows (such as the flow through the Straits of Gibraltar)