Glossary: G

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  1. Global Climate Observing System
  2. GEO
    Group on Earth Observation
  3. A branch of applied mathematics concerned with measuring the shape of the Earth and describing variations in the Earth's gravity field. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  4. The study of the Earth's motions, including rotation, tectonics, ocean tides, and structure (i.e., core, mantle). Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  5. A system for archiving, retrieving, and manipulating data that has been stored and indexed according to the geographic coordinates of its elements. The system generally can utilize a variety of data types, such as imagery, maps. table, etc. Source:...
  6. The study of present-day landforms, including their classification, description, nature, origin, development, and relationships to underlying structures. Also the history of geologic changes as recorded by these surface features. The term is...
  7. Relating to the study of the physical characteristics and properties of the solid earth, its air and waters, and its relationship to space phenomena. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  8. The physical elements of the Earth's surface crust, and interior. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  9. Describes an orbit in which a satellite is always in the same position (appears stationary) with respect to the rotating Earth. The satellite travels around the Earth in the same direction, at an altitude of approximately 35,790 km (22,240 statute...
  10. Synchronous with respect to the rotation of the Earth. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  11. A multi-year surplus accumulation of snowfall in excess of snowmelt on land and resulting in a mass of ice at least 0.1 km2 in area that shows some evidence of movement in response to gravity. A glacier may terminate on land or in water. Glacier ice...
  12. The long-term fluctuations in temperature, precipitation, wind, and all other aspects of the Earth's climate. External processes, such as solar-irradiance variations, variations of the Earth's orbital parameters (eccentricity, precession, and...
  13. All of the activities required to specify a global variable, such as ozone. These activities range from data acquisition to the generation of a data-analysis product, and include estimates of the uncertainties in that product. A global measurement...
  14. Space-based radio positioning systems that provide 240-hour, three dimensional position, velocity and time information, in any weather conditions, to suitable equipped users anywhere on the surface of the Earth, as well as airborne and space users.
  15. A system consisting of 25 satellites in 6 orbital planes at 20,000 km altitude with 12 hr periods, used to provide highly precise position, velocity and time information to users anywhere on Earth or in its neighborhood at any time. Source: NASA (...
  16. An increase in the near surface temperature of the Earth. Global warming has occurred in the distant past as the result of natural influences, but the term is most often used to refer to the warming predicted to occur as a result of increased...
  17. The warming of an atmosphere by its absorbing and reemitting infrared radiation while allowing shortwave radiation to pass on through. Certain gaseous components of the atmosphere, called greenhouse gases, transmit the visible portion of solar...
  18. A gaseous component of the atmosphere contributing to the greenhouse effect. Greenhouse gases are transparent to certain wavelengths of the sun's radiant energy, allowing them to penetrate deep into the atmosphere or all the way into the Earth's...
  19. The inclination of a satellite, together with its orbital altitude and the period of its orbit, creates a track defined by an imaginary line connecting the satellite and the Earth's center. The intersection on the line with the Earth's surface is...