Where does the energy come from to evaporate the esti- mated 425,000 km3 of water that annually leaves the oceans, as illustrated here? [Section 18.3]

Key Concepts

Evaporation

Evaporation is the process by which liquid water transforms into vapor, occurring at the surface of the liquid. This phase change requires energy, typically in the form of heat, which is absorbed from the surrounding environment. Factors such as temperature, humidity, and wind speed influence the rate of evaporation, making it a critical component of the water cycle.

Energy Sources for Evaporation

The energy required for evaporation primarily comes from solar radiation, which heats the surface of the oceans. This energy increases the kinetic energy of water molecules, allowing them to overcome intermolecular forces and escape into the atmosphere as vapor. Additionally, heat from the atmosphere and ocean currents can also contribute to the energy needed for this process.

Water Cycle

The water cycle describes the continuous movement of water within the Earth and atmosphere, encompassing processes such as evaporation, condensation, precipitation, and runoff. Evaporation plays a vital role in this cycle, as it transfers water from the oceans to the atmosphere, where it can later condense and fall back to the surface as precipitation, thus sustaining ecosystems and weather patterns.