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Evaporation is an essential part of the water cycle. The sun (solar energy) drives evaporation of water from oceans, lakes, moisture in the soil, and other sources of water. In hydrology, evaporation and transpiration (which involves evaporation within plant stomata) are collectively termed evapotranspiration. Evaporation of water occurs when ...
Evaporation is a phase transition from the liquid phase to vapor (a state of substance below critical temperature) that occurs at temperatures below the boiling temperature at a given pressure. Evaporation occurs on the surface. Evaporation only occurs when the partial pressure of vapor of a substance is less than the equilibrium vapor pressure ...
When a net evaporation occurs, the body of water will undergo a net cooling directly related to the loss of water. In the US, the National Weather Service measures the actual rate of evaporation from a standardized "pan" open water surface outdoors, at various locations nationwide. Others do likewise around the world.
Evaporation: the movement of water directly to the air from sources such as the soil and water bodies. It can be affected by factors including heat, humidity, solar radiation and wind speed. [6]: Ch. 1, "Evaporation" Transpiration: the movement of water from root systems, through a plant, and exit into the air as water vapor.
The processes that drive these movements are evaporation, transpiration, condensation, precipitation, sublimation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid and vapor. The ocean plays a key role in the water cycle as it is the source of 86% of global evaporation. [2]
This differs from its meaning in other sciences. [16] According to the American Meteorological Society Glossary of Meteorology , saturation vapor pressure properly refers to the equilibrium vapor pressure of water above a flat surface of liquid water or solid ice, and is a function only of temperature and whether the condensed phase is liquid ...
This evaporation increases the tension on the water menisci in the cell walls and decreases their radius, thus exerting tension in the cells' water. Because of the cohesive properties of water, the tension travels through the leaf cells to the leaf and stem xylem, where a momentary negative pressure is created as water is pulled up the xylem ...
Temperature-dependency of the heats of vaporization for water, methanol, benzene, and acetone. In thermodynamics, the enthalpy of vaporization (symbol ∆H vap), also known as the (latent) heat of vaporization or heat of evaporation, is the amount of energy that must be added to a liquid substance to transform a quantity of that substance into a gas.