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F layer
F layern.1. The highest region of the ionosphere, extending at night from about 190 to 400 kilometers (120 to 250 miles) and during the day from about 145 to 400 kilometers (90 to 250 miles) above the earth. Also called F region.2. Either of two layers, designated F1 and F2, into which this region is divided during the day, extending respectively from about 145 to 240 kilometers (90 to 150 miles) and from about 190 to 400 kilometers (120 to 250 miles) above the earth.F layer
n. the highest radio-reflective region of the ionosphere, at an altitude of ab. 80 mi. (130 km). [1925–30] Thesaurus| Noun | 1.F layer - the highest region of the ionosphere (from 90 to 600 miles up) which contains the highest concentration of free electrons and is most useful for long-range radio transmissionAppleton layer, F regionionosphere - the outer region of the Earth's atmosphere; contains a high concentration of free electrons |
F layer
F layer[′ef ‚lā·ər] (geophysics) An ionized layer in the F region of the ionosphere which consists of the F1 and F2 layers in the day hemisphere, and the F2 layer alone in the night hemisphere; it is capable of reflecting radio waves to earth at frequencies up to about 50 megahertz. F layer An ionized layer of atmosphere located approximately 90 to 240 miles (150-400 km) above the earth. This layer plays an important role in radio communications and reflects electromagnetic emissions from 1.5 to above 30 MHz. The height of the F layer varies, depending on the seasons and whether it is day or night. It is divided into two layers: F1 and F2. The F2 layer is always present and has a higher electron density than the F1 layer. F1 is the lower of the two and has a higher level of ionization.F layer
Related to F layer: E layer, D layerSynonyms for F layernoun the highest region of the ionosphere (from 90 to 600 miles up) which contains the highest concentration of free electrons and is most useful for long-range radio transmissionSynonymsRelated Words |