U6: Lesson 1 Atmospheric Variables

Temperature

A measure of the average energy of motion of the particles of a substance.

air pressure

A force that is the result of the weight of a column of air pushing down on an area.

thermometer

An instrument used to measure temperature

wind speed

how fast the air is moving

anemometer

An instrument used to measure wind speed

wind vane

measures wind direction

humidity

The amount of water vapor in the air

relative humidity

The percentage of water vapor in the air compared to the maximum amount of water vapor that air can contain at a particular temperature

station model

indicates weather conditions at a specific location, using a combination of symbols on a map

sling psychrometer

tool made of a wet and dry thermometer that measures relative humidity and requires a table to interpret the two temperatures

dewpoint temperature

The temperature to which air has to cool , in order for condensation to take place, air becomes saturated, clouds, dew, fog forms

saturated air

air that contains as much water vapor as is possible for that temperature

hygrometer

measures humidity

barometer

An instrument that measures atmospheric pressure

wet bulb thermometer

The thermometer in a psychrometer that is used to measure the wet-bulb temperature

dry-bulb thermometer

normal thermometer that measures the current air temperature

wet bulb temperature

The lowest temperature that can be obtained by evaporating water into the air. Must be lower than the dry bulb temperature

Dry Bulb Temperature

The temperature of air measured by a thermometer freely exposed to the air

water vapor

water in the form of a gas

water droplets

water in liquid form, clouds and fog

absorb

to take in

reflect

to bounce back

altitude

Elevation above sea level

Evaporation

The change of a substance from a liquid to a gas

Condensation

The change of state from a gas to a liquid