Home (Adiabatic)

 Meteorology 

What is what? Everything you always wanted to know.
  » »
 
   

Adiabatic

Meteorology  Additive data  Adiabatic lapse rate

The Adiabatic lapse rate is the rate of temperature change that occurs in an atmosphere as a function of elevation, assuming that air behaves adiabatically. This term is most commonly used to refer to Earth's atmosphere.


adiabatic - See adiabatic process.
advection - The process of transport of an atmospheric property solely by the mass motion (velocity field) of the atmosphere; also, the rate of change of the value of the advected property at a given point.

Adiabatic process A process that takes place without a transfer of heat between the system (such as an air parcel) and its surroundings. In an adiabatic process compression always results in warming, and expansion results in cooling.

ADIABATIC: Occurring without loss or gain of heat. i.e., "adiabatic expansion of a body of air."
ADVECTION: The horizontal transport of air or atmospheric properties. Commonly used with temperatures, i.e., "warm air advection".

Adiabatic - Referring to a process without the addition or removal of heat. A temperature change may come about as a result of a change in the state of a gas.
...

~ Temperature Change
Warming or cooling of air that happens when air is compressed or expands without heat being added or subtracted.
Air Parcel ...

~ Process- The change of temperature of air without transferring heat. In an ~ process compression results in warming, and expansion results in cooling.

~ - changes in temperature caused by the expansion (cooling) or compression (warming) of a body of air as it rises or descends in the atmosphere.
ADNLY- Additionally ...

~ process—The process by which fixed relationships are maintained during changes in temperature, volume, and pressure in a body of air without heat being added or removed from the body.

~- A process that causes rising air to cool and sinking air to warm
ADNLY- Additionally
ADV- Advisory ...

~ process Expansional cooling or compressional warming of air parcels in which there is no net heat exchange between the air parcels and the surrounding (ambient) air.

~ lapse rate - how quickly the temperature of a moving parcel of air changes, even though no heat enters or leaves it.

~ PROCESS
A thermodynamic change of state in a system in which there is no transfer of heat or mass across the boundaries of the system. In this process, compression will result in warming and expansion will result in cooling.
ADVECTION ...

~ Processes: An ~ process is one in which no heat is exchanged with the surrounding air.
Rising air expands as the pressure of the surrounding air decreases (there is less air above it).
The expansion results in cooling because energy is used to separate the molecules.

~
A thermodynamic process in which no heat is transferred to the surrounding air.
In an ~ process, compression of an air parcel results in an increase in temperature, while expansion results in a decrease in temperature.

~ cooling/heating The rate of cooling (by expansion) as an air parcel rises. It is approximately 1 degrees Celsius per 100 metres. It is also the rate of heating (by compression) as an air parcel descends.

~ Lapse Rate
The rate of decrease of temperature experienced by a parcel of air when it is lifted in the atmosphere under the restriction that it cannot exchange heat with its environment. For parcels that remain unsaturated during lifting, the (dry adiabatic) lapse rate is 9.

dry ~ lapse rate: the rate at which an unsaturated parcel of air will decrease in temperature as it moves through the atmosphere. The rate is a decrease of about 9.767C per kilometer upwards.

Dry Adiabatic Rate The rate of change of temperature in rising or descending unsaturated air parcel. The rate of ~ cooling or warming is 5.5F per 1,000 feet (10C per 1,000 meters).

An ~ process is one in which no heat is removed from, or added to, the parcel. Think of the plastic bag as being thoroughly insulated.

Dry ~ Lapse RateThe rate at which the temperature of a parcel of dry air decreases as the parcel is lifted in the atmosphere. The dry ~ lapse rate (abbreviated DALR) is 5.5F per 1000 ft or 9.8C per km.

moist ~ lapse rate (MALR)The rate at which the temperature of a parcel of saturated air decreases as the parcel is lifted in the atmosphere. The moist ~ lapse rate is not a constant like the dry ~ lapse rate but is dependent on parcel temperature and pressure.

The subsiding air compresses as it descends, causing ~ warming. The eventually warmer and drier air suppresses cloud formation and thus anticyclones are usually associated with fine weather in the summer and dry, cold, and sometimes foggy weather in the winter.

Lifting Condensation Level - the level at which a parcel of moist air becomes saturated when it is lifted dry adiabatically.LDSLightning Detection SystemLDTLocal Daylight Time.LeaderThe streamer which initiates the first phase of each stroke of a lightning discharge.

Moist AdiabatThe line on a Skew T-Log P chart that depicts the change in temperature of saturated air as it rises and undergoes cooling due to ~ expansion. As saturated air rises, the temperature changes at a rate of 0.

Compare to ~ process. Diamond-Hinnman radiosonde A variable audio-modulated radiosonde developed at the Bureau of Standards and used by the United States weather services.

The dry ~ lapse rate is about 5.5 degrees F per 1000 feet, and the wet ~ lapse rate varies between 2 and 5 degrees F per 1000 feet. latent heat Energy transferred from the earth's surface to the atmosphere through the evaporation and condensation processes.

Such ascent/descent is said to be ~, which means that the energy/heat changes are confined to that particular parcel.
Provided the parcel is warmer (less dense) than the environmental air through which it is passing, it is buoyant, and rises.

Upslope Fog: It forms as air is cooled ~ally by blowing up sloping terrain. The upslope cooling may form clouds concurrently with the fog. As is the case with advection fog, upslope fog can form with moderate to strong winds under cloudy skies.

An atmospheric condition that exists when the environmental lapse rate is less than the moist ~ lapse rate.
NOAA National Weather Service - Cite This Source - This Definition ...

The prevailing westerlies lose moisture in climbing the mountains, then warm up and dry out at the dry adiabatic rate on descent from the foothills at 9000 ft to the plains at 5000 ft.

Foehn Winds: Winds descending downslope from mountains which are characteristically warm and dry due to ~ compression. The term originally referred to such winds flowing down the Alpine valleys of Germany and Austria but is now used as the generic term for such airflows.

The lowest temperature that an air parcel would have if cooled ~ally to saturation at constant pressure by evaporation of water into it, assuming that all latent heat required for evaporation would be supplied by the air parcel itself.

Theta-e (or Equivalent Potential Temperature) - The temperature a parcel of air would have if a) it was lifted until it became saturated, b) all water vapor was condensed out, and c) it was returned ~ally (i.e., without transfer of heat or mass) to a pressure of 1000 millibars.

Potential Temperature - The temperature a parcel of dry air would have if brought ~ally (i.e., without transfer of heat or mass) to a standard pressure level of 1000 mb.
Precipitation - Liquid or solid water that falls from the atmosphere and reaches the ground.

Diabatic Heating - A process which occurs with the addition or loss of heat. The opposite of ~. Meteorological examples include air parcels warming due to the absorption of radiation or release of latent heat.

FOHN: A warm dry wind on the lee side of a mountain range. The heating and drying are due to ~ compression as the wind descend downslope.

Adibiatic Temperature Change- A cooling or heating of the air caused by expansion of contraction of air molecules, as opposed to the gain or loss of heat. For example, ~ cooling takes place as air rises.
Advection- Horizontal movement of air, moisture, or heat.

It is then super-heated in an ~ compression process and becomes the "burning wind". A similar phenomenon also takes place in other countries; in the Alps it is called a Foehn, while in the Rocky Mountains, U.S. it is called a Chinook.

Foehn
A warm dry wind on the lee side of a mountain range, whose temperature is increased as the wind descends down the slope. It is created when air flows downhill from a high elevation, raising the temperature by ~ compression. Classified as a katabatic wind.

See also: See also: What is the meaning of Temperature, Weather, Air, Surface, Water?

◄ Additive data   Adiabatic lapse rate ►
 
RSS Mobile