Water in the Atmosphere
This invisible gas is the starting point for all condensation and precipitation.
What is water vapor?
The amount of water vapor in the air.
What is humidity?
All clouds begin to form when air reaches this condition.
What is saturation (or the dew point)?
These clouds are puffy, white, and resemble cotton balls.
What are cumulus clouds?
This type of air resists rising and results in fog or flat clouds.
What is stable air?
This phase change releases latent heat and leads to cloud formation.
What is condensation?
This term describes how close air is to being saturated.
What is relative humidity?
The temperature change that happens when rising air expands without added heat.
What is adiabatic cooling?
High-level clouds composed of ice crystals, often wispy or featherlike.
What are cirrus clouds?
This rate measures how quickly temperature drops with height.
What is the environmental lapse rate?
Water must always pass through this state in the atmosphere during the water cycle.
What is water vapor?
The temperature to which air must cool to become saturated.
What is dew point?
The lifting of air caused by mountain ranges.
What is orographic lifting?
This low-level cloud brings steady precipitation and appears as a thick gray layer.
What is nimbostratus?
A parcel of air that’s warmer than its surroundings will do this.
What is rise?
The amount of energy it takes to evaporate 1 gram of water.
What is 2258 joules?
This tool uses a dry bulb and wet bulb thermometer to calculate humidity.
What is a sling psychrometer?
This heating process slows cooling once condensation starts.
What is release of latent heat (wet adiabatic rate)?
These clouds have vertical growth and are capable of producing thunderstorms.
What is cumulonimbus?
This lifting mechanism occurs when warm and cold air masses collide.
What is frontal wedging?
These two phase changes are responsible for frost and dry ice fog.
What are deposition and sublimation?
As air temperature rises, relative humidity does this (assuming no change in water vapor).
What is decreases?
The four ways air can be lifted into the atmosphere.
What are orographic lifting, frontal wedging, convergence, and localized convective lifting?
“Alto-” is a prefix for this cloud height range.
What is middle-level clouds?
Rising parcels of warm air on sunny days—used by birds and gliders.
What are thermals (localized convective lifting)?