Atmosphere of Earth

(See also: Extraterrestrial atmospheres and Extraterrestrial skies) The exosphere (Ancient Greek: ἔξω éxō "outside, external, beyond", Ancient Greek: σφαῖρα sphaĩra "sphere") is a thin, atmosphere-like volume surrounding a planet or natural satellite where molecules are gravitationally bound to that body, but where the density is too low for them to behave as a gas by colliding with each other.

An atmospheric sounding is a measurement of vertical distribution of physical properties of the atmospheric column such as pressure, temperature, wind speed and wind direction (thus deriving wind shear), liquid water content, ozone concentration, pollution, and other properties.

The mesosphere (/ˈmɛsoʊsfɪər/; from Greek mesos "middle" and sphaira "balls") is the layer of the Earth's atmosphere that is directly above the stratosphere and directly below the mesopause.

The mesopause is the temperature minimum at the boundary between the mesosphere and the thermosphere atmospheric regions.

The Intertropical Convergence Zone (ITCZ), known by sailors as the doldrums, is the area encircling the earth near the equator where the northeast and southeast trade winds come together.

The stratosphere (/ˈstrætəˌsfɪər, -toʊ-/) is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere.

Carbon dioxide (CO2) is an important trace gas in Earth's atmosphere currently constituting about 0.

The ionosphere (/aɪˈɒnəˌsfɪər/) is a region of Earth's upper atmosphere, from about 60 km (37 mi) to 1,000 km (620 mi) altitude, and includes the thermosphere and parts of the mesosphere and exosphere.

The High Frequency Active Auroral Research Program (HAARP) was an ionospheric research program jointly funded by the U.

Jet streams are fast flowing, narrow, meandering air currents found in the atmosphere of some planets, including Earth.

The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation.

The troposphere is the lowest portion of Earth's atmosphere, and is also where all weather takes place.

The International Standard Atmosphere (ISA) is an atmospheric model of how the pressure, temperature, density, and viscosity of the Earth's atmosphere change over a wide range of altitudes or elevations.

The Great Oxygenation Event (GOE, also called the Oxygen Catastrophe, Oxygen Crisis, Oxygen Holocaust, Oxygen Revolution, or Great Oxidation) was the biologically induced appearance of dioxygen (O2) in Earth's atmosphere.

The U.S. Standard Atmosphere is an atmospheric model of how the pressure, temperature, density, and viscosity of the Earth's atmosphere change over a wide range of altitudes or elevations.

Ozone (O3) is a constituent of the troposphere (it is also an important constituent of some regions of the stratosphere commonly known as the ozone layer).

The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity.