Glossary: O

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  1. a change in the color of the ocean surface as a result of sediment, organic matter, or phytoplankton, all of which can change how the ocean surface reflects and absorbs sunlight. In a natural-color (photo-like) image from space, the clear waters of...
  2. United Nations Office for the Coordination of Humanitarian Affairs
  3. In calculating the transfer of radiant energy, the mass of an absorbing or emitting material lying in a vertical column of unit cross-sectional area and extending between two specified levels. Also, the degree to which a cloud prevents light from...
  4. The path described by a heavenly body in its periodic revolution. Earth satellite orbits with inclinations near 0 degree are called equatorial orbits because the satellite stays nearly over the equator. Orbits with inclinations near 90 degrees are...
  5. An imaginary gigantic flat plate containing an Earth satellite's orbit. The orbital plane passes through the center of the Earth. Source: NASA (http://earthobservatory.nasa.gov/Glossary)
  6. An almost colorless, gaseous form of oxygen with an odor similar to weak chlorine. A relatively unstable compound of three atoms of oxygen, ozone constitutes--on the average--less than one part per million (ppm) of the gases in the atmosphere (peak...
  7. A large area of intense stratospheric ozone depletion over the Antarctic continent that typically occurs annually between late August and early October, and generally ends in mid-November. This severe ozone thinning has increased conspicuously since...
  8. The layer of ozone that begins approximately 15 km above Earth and thins to an almost negligible amount at about 50 km, shields the Earth from harmful ultraviolet radiation from the sun. The highest natural concentration of ozone (approximately 10...