CG: n
CT: It is also necessary to introduce elements of neutral atmospheric and magnetospheric physics since the ionosphere is very much affected by processes that originate in these two regions. The ionosphere coexists with the upper portion of the neutral atmosphere and receives considerable energy and momentum from the lower atmosphere as well as from the magnetosphere.
S: GBSS – http://shorturl.at/iptE6 (p.3) (last access: 20 January 2021)
N: 1. Region of the outer atmosphere, 1926, from “ion” (1834, introduced by English physicist and chemist Michael Faraday -suggested by the Rev. William Whewell, English polymath-, coined from Greek ion, neuter present participle of ienai “go,” from PIE root *ei- “to go”; so called because ions move toward the electrode of opposite charge) and “sphere” (mid-15c., Latinized spelling of Middle English spere (c. 1300) “cosmos; space, conceived as a hollow globe about the world,” from Anglo-French espiere, Old French espere (13c., Modern French sphère), from Latin sphaera “globe, ball, celestial sphere” -Medieval Latin spera–, from Greek sphaira “globe, ball, playing ball, terrestrial globe,” a word of unknown origin). Coined by Scottish radar pioneer Robert A. Watson-Watt (1892-1973). So called because it contains many ions.
2. A layer of the earth’s atmosphere between about 80 and 1 000 kilometres above the surface of the earth that reflects radio waves around the earth.
3. High-energy X-rays and ultraviolet (UV) “light” from the Sun are constantly colliding with gas molecules and atoms in Earth’s upper atmosphere. Some of these collisions knock electrons free from the atoms and molecules, creating electrically charged ions (atoms or molecules with missing electrons) and free electrons. These electrically charged ions and electrons move and behave differently than normal, electrically neutral atoms and molecules. Regions with higher concentrations of ions and free electrons occur at several different altitudes and are known, as a group, as the ionosphere.
4. There are three main regions of the ionosphere, called the D layer, the E layer, and the F layer. These regions do not have sharp boundaries, and the altitudes at which they occur vary during the course of a day and from season to season. The D region is the lowest, starting about 60 or 70 km (37 or 43 miles) above the ground and extending upward to about 90 km (56 miles). Next higher is the E region, starting at about 90 or 100 km (56 or 62 miles) up and extending to 120 or 150 km (75 or 93 miles). The uppermost part of the ionosphere, the F region, starts about 150 km (93 miles) and extends far upward, sometimes as high as 500 km (311 miles) above the surface of our home planet.
5. The height, fraction of ionized particles, and even the existence of the different regions of the ionosphere varies over time. The ionosphere is very different in the daytime versus night. During the day, X-rays an UV light from the Sun continuously provides the energy that knocks electrons free from atoms and molecules, producing a continuous supply of ions and free electrons. At the same time, some of the ions and electrons collide and re-combine to form normal, electrically neutral atoms and molecules. During the day, more ions are created than are destroyed, so the number of ions in the three regions increases. At night, the recombination process takes over in the absence of sunlight, and the number of ions drops. Over the course of most nights, the D region disappears entirely and the E region weakens as the number of ions in that layer plummets. Each morning, as solar X-rays and UV light return, the D and E regions are repopulated with ions. The highest altitude F region sticks around throughout the night, but generally splits into an upper F2 layer and a lower F1 layer during the day.
6. In the ionosphere, charged particles are affected by the magnetic fields of both Earth and the sun. This is where auroras happen. Those are the bright, beautiful bands of light that you sometimes see near Earth’s poles. They’re caused by high-energy particles from the sun interacting with the atoms in this layer of our atmosphere.
7. ionosphere: term standardized by ISO.
S: 1. OED – https://www.etymonline.com/search?q=ionosphere&ref=searchbar_searchhint; https://www.etymonline.com/search?q=ion; https://www.etymonline.com/search?q=sphere (last access: 23 January 2021). 2. OD – https://www.oxfordlearnersdictionaries.com/definition/english/the-ionosphere?q=ionosphere (last access: 20 January 2021). 3 to 5. UCAR – https://scied.ucar.edu/ionosphere (last access: 20 January 2021). 6. NASA – https://spaceplace.nasa.gov/ionosphere/en/ (last access: 20 January 2021). 7. TERMIUM PLUS – https://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&srchtxt=ionosphere&codom2nd_wet=1#resultrecs (last access: 23 January 2021).
OV: ionesphere
S: TERMIUM PLUS – https://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&srchtxt=ionosphere&codom2nd_wet=1#resultrecs (last access: 23 January 2021)
SYN: Earth’s ionosphere
S: TERMIUM PLUS – https://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&srchtxt=ionosphere&codom2nd_wet=1#resultrecs (last access: 23 January 2021)
CR: biosphere, carbon dioxide, carbon monoxide, ecology, environment, mesopause, mesosphere, nitrogen dioxide, nitrogen oxide, nitrous oxide, ozone layer, stratosphere, stratospheric ozone, tropospheric ozone.
