Chapter 3: Introduction to the Atmosphere

Vocabulary flashcards covering the size, vertical structure, composition, anthropogenic changes, pollution, weather controls, and Coriolis effect from Chapter 3: Introduction to the Atmosphere.

Earth's Atmosphere

An ocean of air held to the surface by gravity that uniformly surrounds Earth, extending outward at least $10{,}000\text{ km}$ ($6{,}000\text{ mi}$) and downward into caves and crevices in rocks and soil, with more than $50\%$ of its total mass located below $6\text{ km}$ ($3.8\text{ mi}$).

Permanent Gases

Atmospheric gases whose proportions remain unvarying, making up over $95\%$ of the total atmosphere; primarily nitrogen (over $78\%$), oxygen (over $20\%$), and argon (nearly $1\%$), having minimal effect on weather and climate.

Variable Gases

Atmospheric gases present in small and varying quantities that have significant effects on weather and climate, primarily including water vapor, carbon dioxide ($CO_2$), and ozone ($O_3$).

Particulates (Aerosols)

Larger nongaseous liquid droplets and solid particles existing in the atmosphere (such as dust, ash, pollen, smoke, and salt spray) derived from natural and human sources that can absorb or reflect radiation and influence weather.

Hygroscopic

A characteristic of certain atmospheric particulates that describes their ability to absorb water.

Troposphere

The lowest thermal layer of the atmosphere in direct contact with Earth's surface, where temperature decreases with increasing altitude and depth varies by season and geographic location.

Stratosphere

The atmospheric thermal layer situated above the troposphere that features layered air, houses the ozone layer, and experiences an increase in temperature with increasing altitude.

Mesosphere

The thermal layer of the atmosphere located above the stratosphere, where temperature decreases with increasing altitude.

Thermosphere

The upper thermal layer of the atmosphere located above the mesosphere, characterized by increasing temperatures with increasing altitude.

Exosphere

The outermost atmospheric layer that gradually transitions into interplanetary space.

Air Pressure

The weight of overlying air, which along with density is highest at sea level and decreases with increasing altitude, with $90\%$ of all atmospheric gas molecules concentrated within $16\text{ km}$ ($10\text{ mi}$) of sea level.

Homosphere

The atmospheric zone of homogeneous composition occupying the lowest $50\text{ miles}$, characterized by a uniform or constant vertical distribution of principal gases.

Heterosphere

The atmospheric zone located above the homosphere where gases are layered vertically according to their atomic weight, with the heaviest gases positioned at the bottom.

Ozone Layer (Ozonosphere)

A concentration of naturally produced ozone ($O_3$) situated between $9\text{ and }30\text{ miles}$ above sea level in the stratosphere that absorbs harmful ultraviolet (UV) radiation.

Ionosphere

A deep layer of highly electrically charged ions situated between $40\text{ and }250\text{ miles}$ above sea level that reflects radio waves back to Earth and serves as the source of auroras.

Anthropogenic

Human-produced atmospheric changes, impurities, or emissions introduced at a rapid pace that impact global climate and life.

Chlorofluorocarbons (CFCs)

Synthetic chemical compounds found in Freon and aerosol sprays that break down in the stratosphere under ultraviolet radiation, releasing chlorine atoms capable of destroying up to $100{,}000$ ozone molecules each.

Polar Vortex

A stratospheric wind pattern over the Antarctic that isolates air and creates conditions where thin polar stratospheric clouds form, accelerating ozone depletion.

Polar Stratospheric Clouds (PSCs)

Thin stratospheric clouds formed of ice crystals within the polar vortex that accelerate ozone destruction through the accumulation of chlorine-based molecules on their surfaces.

Montreal Protocol

An international environmental treaty signed in $1987$ by $189\text{ countries}$ to ban and end the production of chlorofluorocarbons (CFCs)—by $1996$ for industrialized nations and by $2010$ for developing nations.

Primary Pollutants

Contaminants released directly into the atmosphere, predominantly through carbon-based fuel combustion, including carbon monoxide, particulates (smoke and dust), nitrogen compounds, and sulfur compounds.

Secondary Pollutants

Atmospheric contaminants formed when primary pollutants react chemically with other atmospheric components, usually driven by solar ultraviolet (UV) radiation; includes volatile organic compounds (VOCs), nitrogen dioxide, and hydrocarbons.

Photochemical Smog

A secondary atmospheric pollutant mixture composed of left-behind particulate matter and ground-level (tropospheric) ozone.

Weather

The short-term atmospheric conditions occurring at a specific time within a given area, described by measurable elements such as temperature, moisture, pressure, and winds.

Climate

The long-term, aggregate daily weather conditions and patterns of an area, incorporating variations and historical extremes.

Maritime Climate

A coastal climate regime (such as Seattle, WA) characterized by milder temperature variations and typically higher humidity due to the moderating influence of the ocean.

Continental Climate

An interior continental climate regime (such as Fargo, ND) characterized by more extreme seasonal temperature differences and typically lower humidity.

Coriolis Effect

The apparent deflection in the path of free-moving objects over Earth's surface caused by Earth's rotation, deflecting motion to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, with maximum deflection occurring at the poles and zero deflection at the equator.

Upwelling

The oceanographic process where currents transfer colder water from lower, deeper layers of a water body up toward the surface.