Lämpökerroksia

Lämpökerroksia, a Finnish term, translates to "thermal layers" or "heat layers" and refers to distinct stratification of temperature within a body of water. This phenomenon is most commonly observed in lakes, ponds, and other standing bodies of water, particularly during the summer months. The formation of these layers is driven by the density of water, which changes with temperature.

The uppermost layer is known as the epilimnion. It is typically well-mixed by wind and sunlight, resulting in a relatively uniform and warm temperature. Below the epilimnion lies the thermocline, also called the metalimnion. This is a transitional zone where the temperature drops rapidly with increasing depth. The thermocline acts as a barrier, preventing efficient mixing between the upper and lower water layers. The deepest layer is the hypolimnion, which is characterized by cold, dense water that remains relatively undisturbed and isolated from the surface.

The presence and distinctness of thermal layers are influenced by factors such as water depth, size of the water body, wind exposure, and ambient air temperature. In shallow or frequently mixed waters, thermal stratification may be weak or absent. Thermal layering plays a crucial role in the aquatic ecosystem, affecting oxygen distribution, nutrient cycling, and the habitats available for different aquatic organisms. As autumn approaches, the surface water cools, leading to the breakdown of stratification and the mixing of the water column.