epilimnion
/ˌɛpəˈlɪmniən/
noun
- The warm, upper layer of water in a lake, above the thermocline (the layer where temperature changes rapidly).
- Scientists measured oxygen levels in the epilimnion to study algae growth.
- Fish that prefer warm water often stay in the epilimnion.
- In summer, the epilimnion of the lake can reach 25 degrees Celsius.
Antonyms