( Rth Syenss Ahlsoh Kahld Jeeohsyenss )

prefix geo Uhv Geoscience Uhv Gaia Earth Science Sizomes Uhv Syzohmz Uhv Omneeonizm.

IPA(key): /xe.o/


From Ancient Greek γῆ (gê, “earth”) (combining form γεω- (geō-)).



Structure of the Atmosphere

Earth's atmosphere Lower 4 layers of the atmosphere in 3 dimensions as seen diagonally from above the exobase. Layers drawn to scale, objects within the layers are not to scale. Aurorae shown here at the bottom of the thermosphere can actually form at any altitude in this atmospheric layer.

Principal layers

In general, air pressure and density decrease with altitude in the atmosphere. However, temperature has a more complicated profile with altitude, and may remain relatively constant or even increase with altitude in some regions (see the temperature section, below). Because the general pattern of the temperature/altitude profile is constant and measurable by means of instrumented balloon soundings, the temperature behavior provides a useful metric to distinguish atmospheric layers. In this way, Earth's atmosphere can be divided (called atmospheric stratification) into five main layers. Excluding the exosphere, the atmosphere has four primary layers, which are the troposphere, stratosphere, mesosphere, and thermosphere.[10] From highest to lowest, the five main layers are:

Exosphere: 700 to 10,000 km (440 to 6,200 miles)
Thermosphere: 80 to 700 km (50 to 440 miles)[11]
Mesosphere: 50 to 80 km (31 to 50 miles)
Stratosphere: 12 to 50 km (7 to 31 miles)
Troposphere: 0 to 12 km (0 to 7 miles)[12]
Main article: Exosphere
The exosphere is the outermost layer of Earth's atmosphere (i.e. the upper limit of the atmosphere). It extends from the exobase, which is located at the top of the thermosphere at an altitude of about 700 km above sea level, to about 10,000 km (6,200 mi; 33,000,000 ft) where it merges into the solar wind.

This layer is mainly composed of extremely low densities of hydrogen, helium and several heavier molecules including nitrogen, oxygen and carbon dioxide closer to the exobase. The atoms and molecules are so far apart that they can travel hundreds of kilometers without colliding with one another. Thus, the exosphere no longer behaves like a gas, and the particles constantly escape into space. These free-moving particles follow ballistic trajectories and may migrate in and out of the magnetosphere or the solar wind.

The exosphere is located too far above Earth for any meteorological phenomena to be possible. However, the aurora borealis and aurora australis sometimes occur in the lower part of the exosphere, where they overlap into the thermosphere. The exosphere contains most of the satellites orbiting Earth.

Main article: Thermosphere
The thermosphere is the second-highest layer of Earth's atmosphere. It extends from the mesopause (which separates it from the mesosphere) at an altitude of about 80 km (50 mi; 260,000 ft) up to the thermopause at an altitude range of 500–1000 km (310–620 mi; 1,600,000–3,300,000 ft). The height of the thermopause varies considerably due to changes in solar activity.[11] Because the thermopause lies at the lower boundary of the exosphere, it is also referred to as the exobase. The lower part of the thermosphere, from 80 to 550 kilometres (50 to 342 mi) above Earth's surface, contains the ionosphere.

The temperature of the thermosphere gradually increases with height. Unlike the stratosphere beneath it, wherein a temperature inversion is due to the absorption of radiation by ozone, the inversion in the thermosphere occurs due to the extremely low density of its molecules. The temperature of this layer can rise as high as 1500 °C (2700 °F), though the gas molecules are so far apart that its temperature in the usual sense is not very meaningful. The air is so rarefied that an individual molecule (of oxygen, for example) travels an average of 1 kilometre (0.62 mi; 3300 ft) between collisions with other molecules.[13] Although the thermosphere has a high proportion of molecules with high energy, it would not feel hot to a human in direct contact, because its density is too low to conduct a significant amount of energy to or from the skin.

This layer is completely cloudless and free of water vapor. However, non-hydrometeorological phenomena such as the aurora borealis and aurora australis are occasionally seen in the thermosphere. The International Space Station orbits in this layer, between 350 and 420 km (220 and 260 mi).

Main article: Mesosphere
The mesosphere is the third highest layer of Earth's atmosphere, occupying the region above the stratosphere and below the thermosphere. It extends from the stratopause at an altitude of about 50 km (31 mi; 160,000 ft) to the mesopause at 80–85 km (50–53 mi; 260,000–280,000 ft) above sea level.

Temperatures drop with increasing altitude to the mesopause that marks the top of this middle layer of the atmosphere. It is the coldest place on Earth and has an average temperature around −85 °C (−120 °F; 190 K).[14][15]

Just below the mesopause, the air is so cold that even the very scarce water vapor at this altitude can be sublimated into polar-mesospheric noctilucent clouds. These are the highest clouds in the atmosphere and may be visible to the naked eye if sunlight reflects off them about an hour or two after sunset or a similar length of time before sunrise. They are most readily visible when the Sun is around 4 to 16 degrees below the horizon. Lightning-induced discharges known as transient luminous events (TLEs) occasionally form in the mesosphere above tropospheric thunderclouds. The mesosphere is also the layer where most meteors burn up upon atmospheric entrance. It is too high above Earth to be accessible to jet-powered aircraft and balloons, and too low to permit orbital spacecraft. The mesosphere is mainly accessed by sounding rockets and rocket-powered aircraft.

Main article: Stratosphere
The stratosphere is the second-lowest layer of Earth's atmosphere. It lies above the troposphere and is separated from it by the tropopause. This layer extends from the top of the troposphere at roughly 12 km (7.5 mi; 39,000 ft) above Earth's surface to the stratopause at an altitude of about 50 to 55 km (31 to 34 mi; 164,000 to 180,000 ft).

The atmospheric pressure at the top of the stratosphere is roughly 1/1000 the pressure at sea level. It contains the ozone layer, which is the part of Earth's atmosphere that contains relatively high concentrations of that gas. The stratosphere defines a layer in which temperatures rise with increasing altitude. This rise in temperature is caused by the absorption of ultraviolet radiation (UV) radiation from the Sun by the ozone layer, which restricts turbulence and mixing. Although the temperature may be −60 °C (−76 °F; 210 K) at the tropopause, the top of the stratosphere is much warmer, and may be near 0 °C.[16]

The stratospheric temperature profile creates very stable atmospheric conditions, so the stratosphere lacks the weather-producing air turbulence that is so prevalent in the troposphere. Consequently, the stratosphere is almost completely free of clouds and other forms of weather. However, polar stratospheric or nacreous clouds are occasionally seen in the lower part of this layer of the atmosphere where the air is coldest. The stratosphere is the highest layer that can be accessed by jet-powered aircraft.

Main article: Troposphere
The troposphere is the lowest layer of Earth's atmosphere. It extends from Earth's surface to an average height of about 12 km, although this altitude actually varies from about 9 km (30,000 ft) at the poles to 17 km (56,000 ft) at the equator,[12] with some variation due to weather. The troposphere is bounded above by the tropopause, a boundary marked in most places by a temperature inversion (i.e. a layer of relatively warm air above a colder one), and in others by a zone which is isothermal with height.[17][18]

Although variations do occur, the temperature usually declines with increasing altitude in the troposphere because the troposphere is mostly heated through energy transfer from the surface. Thus, the lowest part of the troposphere (i.e. Earth's surface) is typically the warmest section of the troposphere. This promotes vertical mixing (hence the origin of its name in the Greek word τρόπος, tropos, meaning "turn"). The troposphere contains roughly 80% of the mass of Earth's atmosphere.[19] The troposphere is denser than all its overlying atmospheric layers because a larger atmospheric weight sits on top of the troposphere and causes it to be most severely compressed. Fifty percent of the total mass of the atmosphere is located in the lower 5.6 km (18,000 ft) of the troposphere.

Nearly all atmospheric water vapor or moisture is found in the troposphere, so it is the layer where most of Earth's weather takes place. It has basically all the weather-associated cloud genus types generated by active wind circulation, although very tall cumulonimbus thunder clouds can penetrate the tropopause from below and rise into the lower part of the stratosphere. Most conventional aviation activity takes place in the troposphere, and it is the only layer that can be accessed by propeller-driven aircraft.

Space Shuttle Endeavour orbiting in the thermosphere. Because of the angle of the photo, it appears to straddle the stratosphere and mesosphere that actually lie more than 250 km below. The orange layer is the troposphere, which gives way to the whitish stratosphere and then the blue mesosphere.

Other layers

Within the five principal layers that are largely determined by temperature, several secondary layers may be distinguished by other properties:

The ozone layer is contained within the stratosphere. In this layer ozone concentrations are about 2 to 8 parts per million, which is much higher than in the lower atmosphere but still very small compared to the main components of the atmosphere. It is mainly located in the lower portion of the stratosphere from about 15–35 km (9.3–21.7 mi; 49,000–115,000 ft), though the thickness varies seasonally and geographically. About 90% of the ozone in Earth's atmosphere is contained in the stratosphere.
The ionosphere is a region of the atmosphere that is ionized by solar radiation. It is responsible for auroras. During daytime hours, it stretches from 50 to 1,000 km (31 to 621 mi; 160,000 to 3,280,000 ft) and includes the mesosphere, thermosphere, and parts of the exosphere. However, ionization in the mesosphere largely ceases during the night, so auroras are normally seen only in the thermosphere and lower exosphere. The ionosphere forms the inner edge of the magnetosphere. It has practical importance because it influences, for example, radio propagation on Earth.
The homosphere and heterosphere are defined by whether the atmospheric gases are well mixed. The surface-based homosphere includes the troposphere, stratosphere, mesosphere, and the lowest part of the thermosphere, where the chemical composition of the atmosphere does not depend on molecular weight because the gases are mixed by turbulence.[21] This relatively homogeneous layer ends at the turbopause found at about 100 km (62 mi; 330,000 ft), the very edge of space itself as accepted by the FAI, which places it about 20 km (12 mi; 66,000 ft) above the mesopause.
Above this altitude lies the heterosphere, which includes the exosphere and most of the thermosphere. Here, the chemical composition varies with altitude. This is because the distance that particles can move without colliding with one another is large compared with the size of motions that cause mixing. This allows the gases to stratify by molecular weight, with the heavier ones, such as oxygen and nitrogen, present only near the bottom of the heterosphere. The upper part of the heterosphere is composed almost completely of hydrogen, the lightest element.
The planetary boundary layer is the part of the troposphere that is closest to Earth's surface and is directly affected by it, mainly through turbulent diffusion. During the day the planetary boundary layer usually is well-mixed, whereas at night it becomes stably stratified with weak or intermittent mixing. The depth of the planetary boundary layer ranges from as little as about 100 metres (330 ft) on clear, calm nights to 3,000 m (9,800 ft) or more during the afternoon in dry regions.

See also:

Thiss Iz Thuh LasT Lyn Uhv TeksT In Thuh Paeej Naeemd " Rth ".

United Nations International Geoscience Programme

InTernaTional in FuhnehTik Inglish iz InTrnashuhnuL

(Received Pronunciation) IPA(key): /ˌɪntəˈnæʃ(ə)n(ə)l/, [ˌɪntəˈnæʃ(ə)n(ə)ɫ]
(General American) IPA(key): /ˌɪntɚˈnæʃ(ə)n(ə)l/, [ˌɪntɚˈnæʃ(ə)n(ə)ɫ], [ˌɪɾ̃ɚˈnæʃ(ə)n(ə)ɫ]

inter- +‎ national. Reportedly coined in modern English by Jeremy Bentham.

Prefix inter uv international law uv Lahz uv Omneeoh


  • IPA(key): [ˈintɛr]

From Latin inter- (“between, amid”), a form of prepositional inter (“between”).

National in Funetik Inglish iz Nashuhnal.

IPA(key): /ˈnæʃ(ə)nəl/

From Middle French national; see nation.

Legal Dictionary national adjective affecting the nation as a whole, common, country-wide, domestic, established by the federal government, federal, general, government, governmental, public, publicly owned, sovereign

Thus InTrnashuhnuL Meenz BeeTween nations.

Geoscience in Funetik Inglish iz jeohsyuhns.

From Prefix Geo- +‎ science.

Geosciences in FohnehTik Eeng-glish Speech Sownd Synz iz Jeeohsyensez.

prefix geo Uhv Geoscience Uhv Gaia Earth Science Sizomes Uhv Syzohmz Uhv Omneeonizm.

IPA(key): /xe.o/


From Ancient Greek γῆ (gê, “earth”) (combining form γεω- (geō-)).

Rth Syensez

THuh Nekst Tekst Wuhz Fruhm:

UNESCO » Natural Sciences » Environment » Earth Sciences

Earth Sciences
International Geoscience and Geoparks Programme
International Geoscience Programme
UNESCO Global Geoparks
Geo-Hazards Risk Reduction
Section on Earth Sciences and Geo-Hazards Risk Reduction (EGR)

Responsible for providing the [[secretariat]]] service for the International Geoscience and Geoparks Programme (IGGP). The IGGP comprises the International Geoscience Programme (IGCP), which for over 45 years has brought geoscientists together from all regions of the world to study the Earth and geological processes under themes which have increasing societal relevance, and the UNESCO Global Geoparks, which promote sites of international geological value and are the basis of local sustainable development.

IGGP functions to serve as a knowledge hub of UNESCO to facilitate international scientific cooperation in the geosciences and sustainable use of natural resources, in particular mineral resources, and to advance new initiatives related to geo-diversity and geo-heritage.

The section has also the role to be an in-house interdisciplinary task force for a coherent UNESCO response based on sound science to natural hazards and disaster risk reduction, including capacity for early warning and early recovery response in UN Member States.

The increasing losses from disasters caused by natural hazards, including earthquakes, floods, landslides, volcanoes, windstorms, drought and desertification, represent a major challenge to UNESCO’s Member States, in particular developing ones.

Building a culture of resilient communities requires active and knowledgeable citizens and informed decision-makers.

Through a multidisciplinary and intersectoral approach, the Earth Sciences and Geo-Hazards Risk Reduction Section builds capacities and fosters partnerships so that Earth sciences and technology can serve to mitigate the effects of the threats and reduce vulnerability increase scientific knowledge and improve living conditions and well-being of communities in general.

Thuh NeksT TeksT Wuhz Fruhm:

International Geoscience Programme

Better understanding the Earth is essential for the diversity of life and future of human society.

The Earth sciences hold key answers to the challenges we must overcome to preserve our environment and develop sustainably.

For over forty years, UNESCO has worked with the International Union for Geological Sciences (IUGS) to mobilize global cooperation in the Earth sciences through the International Geoscience Programme (IGCP). This Programme has provided a platform for scientists from across the world to push the frontiers of knowledge forward through concrete projects.

In the early years, the Programme enhanced scientific exchange through the correlation of geological strata and research data, focusing on basic geoscientific research and on making connections between events throughout the Earth's history.

The Programme supports work on five themes:

Earth Resources: Sustaining our Society
Global Change: Evidence from the geological record
Geohazards: Mitigating the risks
Hydrogeology: Geoscience of the water cycle
Geodynamic: Control our environment

The Programme has always built bridges between disciplines and between scientists, including young ones, with aims of stimulating cutting-edge research and sharing scientific knowledge for the benefit of all.

UNESCO is the only United Nations organization with a mandate to support research and capacity in geology and geophysics, and the International Geoscience Programme is our flagship.


See also:

  • Projects of the International Geoscience Programme

See also: