Condensation
Condensation is the change of water vapor into liquid water. It occurs when water vapor cools or otherwise reaches saturation.
Saturation vapor pressure: The equilibrium pressure of a vapor above its liquid at a given temperature. Cooling lowers this pressure, so air can become saturated with water vapor.
Cloud formation: The formation of visible clouds from droplets or ice crystals suspended in the atmosphere. Cloud droplets form when rising, cooling air condenses water vapor.
Water vapor: Water in its gaseous state, present in the atmosphere and other environments. It is the gaseous starting state that becomes liquid during condensation.
Water cycle: The continuous movement of water among Earth's atmosphere, land, oceans, and living things. Condensation returns atmospheric water to liquid forms within this global cycle.
Dew point: The temperature to which air must cool, at constant pressure and water-vapor content, to reach saturation. It marks the temperature at which condensation can begin in air.
Dew: Liquid water droplets deposited on cool surfaces when nearby air reaches its dew point. It is a familiar surface example of atmospheric water vapor condensing.
Evaporation: The transformation of a liquid into vapor from its surface. It is the reverse surface process, moving water from liquid into gas.
Atmospheric convection: Vertical transport in the atmosphere driven by buoyancy and differences in air density. Heat released by condensation can strengthen buoyant air currents.
Latent heat of vaporization: The energy required to convert a unit mass of liquid into vapor without changing temperature. Water releases this energy when vapor condenses, warming the surrounding air.
Fog: A cloud of tiny water droplets or ice crystals at ground level that reduces visibility. Fog forms when air near the ground cools enough for condensation.