PHASE CHANGE
) A transition from one state to another, such as from solid to liquid or liquid to gas (see phase change cooler). It often refers to the transition between an unstructured "amorphous" atomic state and a structured "crystalline" atomic lattice (see phase change disc and phase change memory).
SUBLIMATION
In physics, the change of state of a substance from a solid to a gas without first becoming liquid. One example is the vaporization of frozen carbon dioxide, or dry ice, at ordinary atmospheric pressure and temperature. The phenomenon occurs at pressures and temperatures (both relatively low) where solid and vapour phases coexist in equilibrium. Preservation of food by freeze-drying involves sublimation of water from the food in a frozen state under vacuum.
LATENT HEAT
Characteristic amount of energy absorbed or released by a substance during a change in physical state that occurs without a change in temperature. Heat of fusion is the latent heat associated with melting a solid or freezing a liquid. Heat of vaporization is the latent heat associated with vapourizing a liquid or condensing (see condensation) a vapour. For example, when water reaches its boiling point and is kept boiling, it remains at that temperature until it has all evaporated; all the heat added to the water is absorbed as latent heat of vaporization and is carried away by the escaping vapour molecules.
LATENT HEAT OF CONDENSATION
heat liberated by a unit mass of gas at its boiling point as it condenses into a liquid; "the heat of condensation is equal to the heat of vaporization"
heat of transformation, latent heat - heat absorbed or radiated during a change of phase at a constant temperature and pressure
heat of transformation, latent heat - heat absorbed or radiated during a change of phase at a constant temperature and pressure
HUMIDITY
Amount of water vapour in the air. One of the most variable characteristics of the atmosphere, humidity is an important factor in climate and weather: it regulates air temperature by absorbing thermal radiation both from the Sun and the Earth; it is directly proportional to the latent energy available for the generation of storms; and it is the ultimate source of all forms of condensation and precipitation. Humidity varies because the water-holding capacity of air is determined by temperature. When a volume of air at a given temperature holds the maximum amount of water vapour possible, the air is said to be saturated. Relative humidity is the water-vapour content of the air relative to its content at saturation. Saturated air has a relative humidity of 100%; near the Earth the relative humidity rarely falls below 30%.
VAPOR PRESSURE
The pressure exerted by a vapor in equilibrium with its solid or liquid phase.
1. The pressure exerted by a vapor on the solid or liquid phase with which it is in equilibrium. At pressures lower than the vapor pressure, more atoms or molecules of the liquid or solid vaporize and escape from the surface of the liquid or solid than are absorbed from the vapor, resulting in evaporation. At the vapor pressure the exchange is equal and there is no net evaporation. Also called evaporation pressure.
2. The pressure exerted by water vapor in the atmosphere.
1. The pressure exerted by a vapor on the solid or liquid phase with which it is in equilibrium. At pressures lower than the vapor pressure, more atoms or molecules of the liquid or solid vaporize and escape from the surface of the liquid or solid than are absorbed from the vapor, resulting in evaporation. At the vapor pressure the exchange is equal and there is no net evaporation. Also called evaporation pressure.
2. The pressure exerted by water vapor in the atmosphere.
SLING PSYCHROMETER
A psychrometer in which the wet- and dry-bulb thermometers are mounted upon a frame connected to a handle at one end by means of a bearing or a length of chain; the psychrometer may be whirled in the air for the simultaneous measurement of wet- and dry-bulb temperatures.
MOIST ADIABATIC RATE (MAR)
(Earth Sciences / Physical Geography) the rate of change of any meteorological factor with altitude, esp atmospheric temperature, which usually decreases at a rate of 0.6°C per 100 metres (environmental lapse rate). Unsaturated air loses about 1°C per 100 m (dry adiabatic lapse rate), whereas saturated air loses an average 0.5°C per 100 m (saturated adiabatic lapse rate)
CLOUD
1.
a. A visible body of very fine water droplets or ice particles suspended in the atmosphere at altitudes ranging up to several miles above sea level.
b. A mass, as of dust, smoke, or steam, suspended in the atmosphere or in outer space.
2. A large moving body of things in the air or on the ground; a swarm: a cloud of locusts.
3. Something that darkens or fills with gloom.
4. A dark region or blemish, as on a polished stone.
5. Something that obscures.
6. Suspicion or a charge affecting a reputation.
7. A collection of charged particles: an electron cloud.
v. cloud·ed, cloud·ing, clouds
v.tr.
1. To cover with or as if with clouds: Mist clouded the hills.
2. To make gloomy or troubled.
3. To obscure: cloud the issues.
4. To cast aspersions on; sully: Scandal clouded the officer's reputation.
v.intr.
To become cloudy or overcast: The sky clouded over.
Idiom:
in the clouds
1. Imaginary; unreal; fanciful.
2. Impractical.
a. A visible body of very fine water droplets or ice particles suspended in the atmosphere at altitudes ranging up to several miles above sea level.
b. A mass, as of dust, smoke, or steam, suspended in the atmosphere or in outer space.
2. A large moving body of things in the air or on the ground; a swarm: a cloud of locusts.
3. Something that darkens or fills with gloom.
4. A dark region or blemish, as on a polished stone.
5. Something that obscures.
6. Suspicion or a charge affecting a reputation.
7. A collection of charged particles: an electron cloud.
v. cloud·ed, cloud·ing, clouds
v.tr.
1. To cover with or as if with clouds: Mist clouded the hills.
2. To make gloomy or troubled.
3. To obscure: cloud the issues.
4. To cast aspersions on; sully: Scandal clouded the officer's reputation.
v.intr.
To become cloudy or overcast: The sky clouded over.
Idiom:
in the clouds
1. Imaginary; unreal; fanciful.
2. Impractical.
CLOUD CONDENSATION NUCLEI
Cloud condensation nuclei
Aerosol pollution over Northern India and Bangladesh - NASA
Cloud condensation nuclei or CCNs (also known as cloud seeds) are small particles (typically 0.2 µm, or 1/100 th the size of a cloud droplet [1]) about which cloud droplets coalesce. Water requires a non-gaseous surface to make the transition from a vapour to a liquid. In the atmosphere, this surface presents itself as tiny solid or liquid particles called CCNs. When no CCNs are present, water vapour can be supercooled below 0 °C (32 °F) before droplets spontaneously form (this is the basis of the cloud chamber for detecting subatomic particles). In above freezing temperatures the air would have to be supersaturated to around 400% before the droplets could form. The concept of cloud condensation nuclei has led to the idea of cloud seeding, that tries to encourage rainfall by seeding the air with condensation nuclei. It has further been suggested that creating such nuclei could be used for marine cloud brightening, a geoengineering technique.
Size, abundance, and composition
Aerosol pollution over Northern India and Bangladesh - NASA
Cloud condensation nuclei or CCNs (also known as cloud seeds) are small particles (typically 0.2 µm, or 1/100 th the size of a cloud droplet [1]) about which cloud droplets coalesce. Water requires a non-gaseous surface to make the transition from a vapour to a liquid. In the atmosphere, this surface presents itself as tiny solid or liquid particles called CCNs. When no CCNs are present, water vapour can be supercooled below 0 °C (32 °F) before droplets spontaneously form (this is the basis of the cloud chamber for detecting subatomic particles). In above freezing temperatures the air would have to be supersaturated to around 400% before the droplets could form. The concept of cloud condensation nuclei has led to the idea of cloud seeding, that tries to encourage rainfall by seeding the air with condensation nuclei. It has further been suggested that creating such nuclei could be used for marine cloud brightening, a geoengineering technique.
Size, abundance, and composition
Flashcard set info:
Author: CoboCards-User
Main topic: Geography
Topic: Earth
Published: 09.02.2012
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