ENV234H1 Lecture 17: Basic Structure of Aquatic Ecosystems
22 Nov 2016
School
Department
Course
Professor
Document Summary
Non-linear relationship between water temperature and density of water (fresh water) Subtle change in density, but enough to structure water in 3d. The colder the water, the more dense: dense water sinks, and warm water floats on top. Ice floats when it starts forming, it floats to the surface of the water and keeps water below the ice warm - allows aquatic organisms to survive. Isothermal water: same temperature of water as depth increases, no denser water that sinks; water mixes easily. Stratified water (i. e. , sun and warmer temperature: warmer temperature at the surface, heat absorbed at the surface, light lost as depth increases now heat. Deeper stratification by wind: same amount of heat as stratified water, but well-mixed by wind, deeper mixing of water, at lower depth, water is colder. Stratification of water depends on temperature (sun, energy) and wind: determines structure of water. Epilimnion: surface (top) layer of warm water.
