Ch.3 Introduction to the Atmosphere

Air Composition

Air is a mixture of gases, primarily 71% nitrogen, 21% oxygen, and 2% other gases.

Density and Altitude

Density of air decreases with increasing altitude due to gravity.

Early Atmosphere

Earth's early atmosphere was altered by volcanic eruptions, comets, and early life.

Oxygen Production

Early bacteria and plants consumed CO2 and released oxygen through photosynthesis.

Permanent Gases

The two most abundant permanent gases in the atmosphere are nitrogen and oxygen.

Water Vapor

Water vapor varies by location and is more abundant over warm, moist surfaces.

Carbon Dioxide

Carbon dioxide is evenly distributed in the lower atmosphere and affects climate.

Ozone Layer

The ozone layer filters ultraviolet radiation from the sun.

Particulates

Particulates are non-gaseous particles in the air, mainly liquid or ice water that forms clouds.

Troposphere

The troposphere is the lowest layer of the atmosphere, where temperature decreases with altitude.

Stratosphere

The stratosphere contains the ozone layer and has increasing temperatures with altitude.

Mesosphere

In the mesosphere, temperature decreases with increasing altitude.

Thermosphere

The thermosphere experiences increasing temperatures with altitude.

Exosphere

The exosphere transitions into interplanetary space.

Air Pressure

Air pressure is highest at sea level and decreases with altitude.

Homosphere

The homosphere is the lower part of the atmosphere with a uniform composition.

Heterosphere

The heterosphere is layered by atomic weight above the homosphere.

Ionosphere

The ionosphere is a deep layer of electrically charged molecules or atoms.

Weather

Weather refers to short-term atmospheric conditions in a specific area.

Climate

Climate is the aggregate of daily weather conditions over a long period.

Latitude

Latitude influences the distribution of solar energy and temperature.

Maritime Climates

Maritime climates have milder temperatures and typically less humidity.

Continental Climates

Continental climates have more extreme seasonal temperature ranges.

General Circulation

The general circulation of the atmosphere and oceans influences weather and climate.

Altitude

Altitude affects temperature, pressure, and moisture content, decreasing with height.

Topographic Barriers

Mountains and hills can divert wind flow and affect local climates.

Windward

Windward refers to the side of a mountain facing the wind.

Leeward

Leeward is the side of a mountain sheltered from the wind.

Coriolis Effect

The Coriolis effect is the deflection of moving objects due to Earth's rotation.

Ozone Depletion

The ozone layer is thinning due to chlorofluorocarbons and other chemicals.

Montreal Protocol

The Montreal Protocol is an agreement to ban CFCs to protect the ozone layer.

UV Index

The UV Index informs the public about the intensity of UV radiation.

Air Pollution

Air pollution includes harmful substances released into the atmosphere.

Carbon Monoxide

Carbon monoxide is a primary pollutant released directly into the air.

Nitrogen Compounds

Nitrogen compounds are natural byproducts in water and soil, often from fuel use.

Sulfur Compounds

Sulfur compounds have natural origins but increase with fossil fuel consumption.

Photochemical Smog

Photochemical smog forms from reactions with UV light and includes secondary pollutants.

Temperature Inversions

Temperature inversions limit air circulation and can trap pollutants.

Anthropogenic Pollution

Anthropogenic air pollution leads to health issues and environmental damage.

Alternative Energy

There is growing support for alternative energy sources to reduce environmental impact.