Which of the following best describes thermal stratification?

Thermal stratification refers to the formation of distinct layers of water in a body of water, primarily lakes and reservoirs, where each layer has a different temperature. This phenomenon occurs when warmer water, which is less dense, sits atop cooler, denser water, creating a temperature gradient. During stratification, these layers remain relatively separated from each other because of the differences in temperature and, consequently, density.

This process is important for understanding aquatic ecosystems, as it affects oxygen distribution, nutrient cycling, and the overall health of the water body. In contrast, uniform temperature distribution would suggest that there is no layering, and mixing due to wind or high turbulence would indicate a lack of separation between layers. Thus, the separation of water layers based on temperature accurately encapsulates the essence of thermal stratification.