Skip to main content

Home / Astronomy (thesaurus)

Astronomy (thesaurus)

... > upper atmosphere > ionosphere > topside ionosphere > ionospheric F region > ionospheric F1 layer

... > upper atmosphere > ionosphere > topside ionosphere > ionospheric F region > ionospheric F1 layer

Preferred term

ionospheric F1 layer

The F1 layer is the lower sector of the F layer and exists from about 150 to 220 km (100 to 140 miles) above the surface of the Earth and only during daylight hours. It is composed of a mixture of molecular ions O₂⁺ and NO⁺, and atomic ions O⁺. Above the F1 region, atomic oxygen becomes the dominant constituent because lighter particles tend to occupy higher altitudes above the turbopause (at ~100 km, 60 miles). This atomic oxygen provides the O⁺ atomic ions that make up the F2 layer. The F1 layer has approximately 5 × 10⁵ e/cm³(free electrons per cubic centimeter) at noontime and minimum sunspot activity, and increases to roughly 2 × 10⁶ e/cm³during maximum sunspot activity. The density falls off to below 10⁴ e/cm³at night. (Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/wiki/F_region)

ionospheric F region

F 1 layer
F1 layer
F 1 region
F1 region

couche F1 de l'ionosphère

French

URI

http://data.loterre.fr/ark:/67375/MDL-Z50VZZQ4-L

Download this concept:

RDF/XML TURTLE JSON-LD