temperaturstratifikasjon

Temperaturstratifikasjon refers to the layering of water bodies, such as lakes or oceans, based on temperature. This phenomenon is primarily driven by the density of water, which is maximum at approximately 4 degrees Celsius. In lakes, this stratification typically occurs during the summer months. The sun's energy heats the surface layer, creating a warmer, less dense epilimnion. Below this, a transitional layer called the thermocline exists, where the temperature drops rapidly with increasing depth. The deepest, coldest, and densest layer is known as the hypolimnion.

This stratification has significant ecological implications. The epilimnion is often rich in dissolved oxygen due to atmospheric exchange and photosynthesis, but can become nutrient-poor. The hypolimnion, being isolated from the atmosphere, can experience oxygen depletion as organic matter decomposes. In autumn, as surface waters cool, the density differences decrease, leading to a mixing event called turnover, which redistributes oxygen and nutrients throughout the water column. In winter, ice formation can lead to a different stratification, with colder water at the surface and warmer water just above 0 degrees Celsius at the bottom. Understanding temperature stratification is crucial for managing aquatic ecosystems, predicting water quality, and studying the behavior of aquatic organisms.