Epilimnion
Epilimnion is the top-most layer in a thermally stratified Lake, occurring above the deeper Hypolimnion. It is warmer and typically has a higher pH and dissolved oxygen concentration than the hypolimnion.
Being exposed at the surface, it typically becomes turbulently mixed as a result of surface wind-mixing. It is also free to exchange dissolved gases (ie O2 and CO2) with the atmosphere.
See also: Lake stratification
External link
- http://wow.nrri.umn.edu/wow/teacher/thermal/teaching.html