What occurs when two bodies of water at different temperatures meet?

When two bodies of water at different temperatures meet, thermal equilibrium occurs, which is the process of energy transferring until the temperatures of the two bodies of water equalize. This means that the warmer water transfers heat to the cooler water, leading to an overall uniform temperature between the two.

Thermal equilibrium is driven by the second law of thermodynamics, which states that heat will naturally flow from areas of higher temperature to areas of lower temperature until equilibrium is reached. This phenomenon can be observed in various scenarios, such as when a warm stream flows into a cooler lake, or when you mix hot and cold water in a bath.

In contrast, convection refers to the movement of heat through fluids (liquids or gases) caused by motion of the fluid itself, which is not the direct result of two different temperatures meeting but rather a process that can occur within a single body of fluid. Osmosis involves the movement of solvent molecules through a semi-permeable membrane from an area of lower solute concentration to higher concentration, which is unrelated to temperature. Filtration is a physical or mechanical process that separates solids from liquids or gases using a filter, which also does not apply in this context of temperature exchange between two bodies of water.