AP Environmental Science Unit 4 Guide: Atmospheric Systems and Climate

Atmosphere

The blanket of gases surrounding Earth, held in place by gravity.

Composition of the Atmosphere

The relative abundance of primary gases such as Nitrogen, Oxygen, Argon, and Trace Gases.

Nitrogen (N2)

The most abundant gas in the atmosphere, making up about 78%.

Oxygen (O2)

A vital gas that constitutes about 21% of the atmosphere and is essential for respiration.

Argon (Ar)

An inert noble gas that makes up approximately 0.9% of the atmosphere.

Trace Gases

Gases like CO2, CH4, O3, and H2O that are present in small amounts but play significant roles as greenhouse gases.

Troposphere

The lowest layer of the atmosphere where weather occurs, containing 99% of the atmosphere's water vapor.

Stratosphere

The layer above the troposphere that contains the ozone layer, which absorbs harmful UV radiation.

Mesosphere

The atmospheric layer where most meteors burn up; it is the coldest layer.

Thermosphere

An atmospheric layer that absorbs X-rays and UV radiation and is known for the aurora borealis.

Exosphere

The outermost layer of the atmosphere where satellites orbit and transitions into space.

Insolation

The amount of solar radiation reaching a specific area, measured in Watts/m2.

Angle of Incidence

The angle at which solar rays hit the Earth, affecting the distribution of solar energy.

June Solstice

The time when the Northern Hemisphere is tilted toward the sun, resulting in summer.

December Solstice

The time when the Northern Hemisphere is tilted away from the sun, leading to winter.

Equinoxes

Dates when day and night are approximately equal in duration, occurring in March and September.

Albedo

The percentage of incoming sunlight reflected by a surface, influencing local temperatures.

Hadley Cells

Convection cells that rise at the equator and sink at 30° N/S, creating hot, dry deserts.

Ferrel Cells

Mid-latitude convection cells that are influenced by the movements of Hadley and Polar cells.

Polar Cells

Convection cells at the poles where cold air sinks and moves toward lower latitudes.

Coriolis Effect

The deflection of an object's path due to Earth's rotation, affecting wind direction.

Prevailing Winds

Consistent wind patterns resulting from convection cells and the Coriolis effect.

Rain Shadow Effect

The phenomenon where mountains block moisture-laden air, creating wet and dry climatic zones.

Specific Heat Capacity

A measure of how much energy is required to raise the temperature of a substance, affecting climate.

Lake Effect Snow

Heavy snow that occurs when cold air moves over warm bodies of water, picking up moisture.

Common Mistakes in Climate Science

Misconceptions such as conflating the ozone hole with global warming or misunderstanding the cause of seasons.

High Pressure

A situation where air descends, leading to dry conditions, opposite of low pressure.