Unit 1 Exam Study Guide

Key terms and concepts from the lecture notes covering weather, climate, atmospheric phenomena, and water in the atmosphere.

Weather

The day-to-day state of the atmosphere, including temperature, humidity, precipitation, and wind.

Climate

The long-term average of weather patterns in a particular area over a significant time period.

Atmosphere

A layer of gases surrounding a planet.

Aerosols

Tiny particles or droplets suspended in the atmosphere.

Thermometer

An instrument used to measure temperature.

Hygrometer

An instrument used to measure humidity.

Barometer

An instrument used to measure atmospheric pressure.

Absolute Zero

The lowest possible temperature, where molecular motion ceases, defined as 0 Kelvin or -273.15°C.

Conductor

A material that allows heat to pass through easily.

Insulator

A material that does not allow heat to pass through easily.

Perihelion

The point in the orbit of a planet where it is closest to the sun.

Aphelion

The point in the orbit of a planet where it is farthest from the sun.

Albedo

The fraction of solar energy reflected from the earth back into space.

Raleigh Scattering

Scattering of light by particles that are much smaller than the wavelength of light.

Mie Scattering

Scattering of light by particles that are comparable in size to the wavelength of light.

Evaporation

The process where liquid water changes into water vapor.

Condensation

The process by which water vapor becomes liquid water.

Precipitation

Any form of water, liquid or solid, that falls from the atmosphere (e.g., rain, snow).

Sublimation

The transition of a substance directly from solid to gas without passing through a liquid phase.

Dewpoint

The temperature at which air is saturated with moisture and dew forms.

Wet-bulb temperature

The lowest temperature that can be achieved by evaporating water into the air at a constant pressure.

Mixing Ratio

The mass of water vapor per unit mass of dry air.

Specific Humidity

The mass of water vapor in a given mass of air.

Vapor Pressure

The pressure exerted by water vapor in the air.

Relative Humidity

The ratio of the current amount of water vapor in the air to the maximum amount it can hold at that temperature.

Condensation Nuclei

Small particles in the atmosphere around which cloud droplets can form.