Atmospheric Stability Flashcards
Evaporation
Requires heat/latent heat
Condensation
Releases latent heat
States of Moisture
Three States
Gas/Vapor (Invisible)
Liquid (Visible)
Solid (Visible)
Adiabatic Process
When the temperature of a gas is changed without the addition or deletion of heat energy
Adiabatic Process
Cooling Rates
(1) Dry– approximately 3°C per 1,000 feet occurs when the air is rising and is not saturated (no condensation is occurring).
(2) Moist–approximately 1.5°C per 1,000 feet occurs after saturation takes place in rising air.
Standard temperature lapse rate
2°C/1,000 feet
Lifted Condensation Level (LCL)/Level of Condensation
is an altitude where the temperature equals the dew point.
Level of Free Convection (LFC)
is an altitude where the temperature of the rising air equals the ambient air that is not being lifted. The air will continue to lift after this point, because of the latent heat released inside the forming clouds.
Stability conditions (three)
Stable–air that resists vertical movement.
Unstable–air that starts moving vertically and will continue without any outside force.
Conditionally unstable (convectively unstable)–air that may be stable under one set of conditions and unstable under another.
Weather hazards are related to water in one of its three states. Name the three states of water.
vapor
liquid
solid
A change of state from a vapor to a liquid (visible moisture) is called
condensation
What term describes the process of vapor turning directly to solid?
deposition
What process occurs when a solid changes directly to a gas, without going through the liquid stage?
sublimation
Evaporation is a change of state from a_____ to a _____.
liquid to a vapor
Dew point temperature
The temperature to which air must be cooled to become saturated
Generally, condensation will take place when the spread is __°C or less.
2°
A large temperature/dewpoint spread indicates ____ relative humidity.
low
How do you express relative humidity when reporting it?
as a percentage
The amount of water vapor a given volume of air can contain depends upon the
temperature of the air
Air being lifted over a mountain range will cool on the windward side and heat up as it moves downslope on the leeward side. This temperature change is a result of the
adiabatic process
The dry adiabatic cooling rate per 1,000 feet is
3°
The moist adiabatic cooling rate is approximately
1.5°
The Level of Free Convection is the level
Where the rising air temperature is the same as the ambient air temperature
The Level of Condensation can be described as when the
rising air temperature is the same as the dew point temperature and clouds are formed
