Chapter 1: The Earth and Its Atmosphere

Meteorology

The study of weather variables, the processes that cause weather, and the interaction of the atmosphere with the Earth's surface, ocean, and life.

Climatology

The study of the climate, including past climate conditions and possible climate changes in the future.

Weather

The condition of the atmosphere at any time and place, including variables such as temperature, humidity, pressure, wind speed and direction, cloud cover, precipitation, and visibility.

Climate

The condition of the atmosphere over many years, including the same variables used for weather.

Atmosphere

A gaseous layer enveloping a planetary surface.

Atmospheric Composition

The makeup of Earth’s atmosphere, primarily consisting of 78% nitrogen, 21% oxygen, 1% carbon dioxide, and varying amounts of water vapor.

Water Vapor

Makes up 0-4% of the atmosphere and plays a key role in weather processes like condensation and evaporation.

Condensation

The process of changing water vapor into liquid water.

Evaporation

The process of liquid water becoming water vapor.

Latent Heat

Heat released during phase change, such as from vapor to liquid to ice.

Carbon Dioxide (CO2)

Makes up 0.038% of the atmosphere and enters through various natural processes and human activities.

Ozone

Makes up 0.01% of the atmosphere and absorbs incoming radiation, providing a protective shield.

Aerosols

Suspended solid and liquid particles in the air, some of which are man-made.

Pollutants

Gases and aerosols in concentrations great enough to cause a nuisance or health hazard.

Density

The amount of mass in a given space (volume), calculated as mass divided by volume.

Pressure

The force of the atmosphere acting on an area, calculated as force divided by area.

Lapse Rate

The rate at which temperature decreases with height in the atmosphere.

Troposphere

The lowest layer of the atmosphere, where temperature decreases with height and nearly all weather occurs.

Stratosphere

The layer of the atmosphere above the troposphere, where temperature increases with height due to the ozone layer.

Mesosphere

The layer of the atmosphere above the stratosphere, characterized by decreasing temperatures with height.

Thermosphere

The highest layer of the atmosphere, where temperature increases due to absorption of high-energy radiation.

Ionosphere

A region in the atmosphere capable of reflecting radio waves, also home to the aurora.

Exosphere

The upper limit of the atmosphere where space begins, approximately 350 miles above the Earth.