Atmosphere - Composition and Structure

Vocabulary flashcards covering the composition, layered structure, and pollution of Earth's atmosphere.

Atmosphere

The gaseous envelope surrounding Earth, derived from Greek word components meaning 'air envelope'.

Permanent Composition of the Atmosphere

Atmospheric components whose relative proportions remain constant, consisting mainly of Nitrogen ($78.0\%$), Oxygen ($21.0\%$), Argon ($0.96\%$), and Hydrogen.

Variable Composition of the Atmosphere

Atmospheric constituents such as carbon dioxide, water vapor, and dust whose amounts vary and decrease with altitude.

Troposphere

The surface layer of the atmosphere containing $4/5$ of Earth's air, reaching a height of $17\text{--}18\,\text{km}$ at the Equator and $7\text{--}8\,\text{km}$ at the poles, where temperatures drop to $-60\,^{\circ}\text{C}$ at its upper boundary.

Tropopause

The air layer with constant temperature that separates the troposphere from the stratosphere.

Stratosphere

The layer of the atmosphere reaching an altitude of $55\text{--}60\,\text{km}$, where temperature increases significantly above $25\,\text{km}$ due to the presence of ozone.

Ozone

A gas molecule containing $3$ oxygen atoms ($\text{O}_3$).

Ozone Layer

A region in the stratosphere that absorbs solar ultraviolet rays, protects living organisms from harmful radiation, and is heated directly by solar radiation.

Mesosphere

The layer extending up to $80\,\text{km}$ in altitude, where the temperature steadily decreases to $-80\,^{\circ}\text{C}$ at its upper boundary.

Thermosphere

The atmospheric layer extending up to $800\,\text{km}$ altitude, where temperatures rise up to $2000\,^{\circ}\text{C}$ due to direct absorption of ultraviolet solar rays.

Exosphere

The transitional layer between the atmosphere and outer space containing scattered molecules of certain gases.

Natural Atmospheric Pollution

Contamination of the atmosphere caused by natural events such as volcanic eruptions and sandstorms.

Acid Rain

Precipitation caused by sulfur oxides emitted into the atmosphere by industry and transportation, widespread in temperate latitudes of Europe and North America.

Sulfurous Acid Formation

The chemical reaction occurring when sulfur dioxide combines with water: $\text{SO}_2 + \text{H}_2\text{O} \rightarrow \text{H}_2\text{SO}_3$.