Earth's Atmosphere and Weather Glossary

Absorption

The process when one thing becomes part of another thing. The Earth absorbs the sun’s energy and this is represented on Earth’s energy budget

Air Mass

A large “bubble” of air that has about the same temperature and humidity throughout it.

Air Pressure

The force exerted by the weight of air on everything around it.

Altitude

The height above sea level. Sometimes this is referred to as elevation.

Atmosphere

The blanket of gases that surrounds a planet held in place by gravity. Earth’s atmosphere is primarily a mixture of nitrogen (78%) and oxygen (21%), and trace amounts of other gases (Argon, Carbon Dioxide, and Water Vapor).

Barometer

A weather instrument that measures air pressure.

Carbon Dioxide (C02)

A gas made up of one carbon atom and two oxygen atoms. Carbon dioxide is a greenhouse gas.

Climate

The long-term pattern of weather conditions in a particular region.

Cold Front

The leading edge of a moving mass of cooler air that pushes under a mass of warm air.

Conduction

The transfer of heat energy or electricity between objects due to direct contact between the atoms in those objects.

Convection

The transfer of heat energy through the movement of liquids or gases.

Convection Current

The circular movements of liquids or gases as a result of convection. Convection currents form because warm liquids and gases rise while cool liquids and gases sink.

Drought

A period of time with abnormally low rainfall. Droughts can last weeks, months, or even years.

Earth’s Energy Budget

The balance between the Earth energy receives from the sun and energy Earth radiates back into outer space.

Emission

The release or discharge of something, especially gas or radiation.

Front

The transition zone between two air masses at the Earth’s surface.

Greenhouse Effect

is the process of Earth’s atmosphere trapping heat near Earth’s surface.

Greenhouse Gases

gases in Earth’s atmosphere that trap the sun’s heat. Greenhouse gases are essential to maintaining the temperature on Earth, but an imbalance in emissions and uptake have led to global warming and climate change.

High Pressure System

Places where the atmospheric pressure is higher than the surrounding area. These systems are usually associated with clear skies, calm conditions, and drier weather.

Humidity

The amount of water vapor present in the air.

Hurricane

A very large and violent tropical storm. The sustained winds of this storm are at least 74 miles per hour. The most severe hurricanes can have sustained winds of more than 157 miles per hour.

Infrared Radiation

A type of electromagnetic radiation (invisible energy from the sun that transfers heat).

Low Pressure System

Places where the atmospheric pressure is lower than the surrounding area. These systems are usually associated with cloudy skies, precipitation, and sometimes stormy weather.

Mesosphere

The third layer from Earth’s crust in the atmosphere. In this layer, temperature decreases with altitude. The mesosphere is the coldest layer of the atmosphere and air pressure is lower than the stratosphere.

Ozone Layer

A layer in Earth’s atmosphere at an altitude of about 6.2 miles containing a high concentration of ozone, which absorbs most of the ultraviolet radiation reaching Earth from the sun.

Pattern

A consistent, recurring characteristic or trait that helps in the identification of a phenomenon and serves as an indicator for predicting future behavior or events.

Precipitation

Water that falls to Earth’s surface as rain, snow, sleet, or hail.

Radiation

The movement of energy through space as electromagnetic waves.

Reflection

The bouncing back of light rays from a surface.

Solar Energy

Energy from sunlight.

Stratosphere

This is the second layer from Earth’s crust in the atmosphere. Temperature increases with altitude in this layer and air pressure is lower than in the troposphere. Planes fly in the lower part of this layer.

Temperature

The degree or intensity of heat present in a substance or object.

Thermal Energy

The energy of moving particles in a substance.

Thermosphere

This is the fourth layer from the Earth’s crust in the atmosphere. This is the hottest layer and temperature increases with altitude. Air pressure is lower than the mesosphere, and satellites are found in this layer.

Thunderstorm

A storm with lightning, thunder, rain, and sometimes hail. Severe thunderstorms can lead to tornadoes.

Tornado

A violently rotating column of air touching the ground, usually attached to the base of a thunderstorm.

Troposphere

This is the layer closest to the Earth’s crust in the atmosphere. Virtually all weather takes place in this layer. Temperature decreases as altitude increases and air pressure is highest in this layer.

Ultraviolet Radiation

A type of electromagnetic radiation; Energy from the sun that can cause damage to living tissue.

Warm Front

The leading edge of a moving mass of warmer air that pushes into a cooler mass of air.

Weather

The condition of the atmosphere at a place for a short period of time.

Weather Map

A map showing weather conditions over an area.

Wind Speed

The rate at which air is moving past a given point. This is commonly measured in miles per hour (mph) or kilometers per hour (km/h).