termoklina

Termoklina, or thermocline, is the layer in a body of water where temperature changes most rapidly with depth. Above this boundary the water tends to be warmer and well mixed, while below it the water is cooler and more stable. In lakes, the thermoklina typically lies within the metalimnion, the middle layer of stratification, separating the epilimnion (the warm surface layer) from the hypolimnion (the deep, cold layer). In the ocean, the thermocline marks a substantial vertical gradient that separates warmer surface waters from deeper, colder waters.

Depth and strength of the termoklina vary with latitude, season, weather, and freshwater input. In tropical regions it can be relatively shallow and persistent year-round, while in temperate zones a seasonal thermocline forms during warmer months and may weaken or vanish in winter. The thermocline can be sharp or gradual; its presence influences the overall stability of the water column and the extent of vertical mixing.

Importance and implications: the thermocline affects nutrient distribution, primary production, and the habitat of aquatic organisms, shaping where plankton, fish, and other life forms are found. It also influences acoustic properties in the water and the storage of heat within the water column. Measurement is typically achieved through vertical temperature profiles obtained by CTD instruments, expendable thermistor probes, or autonomous profiling floats.