F - regionF区
F-regionF层
f 2 regionf层
F-region currentF层电流
f-region in ionosphere电离层f层
e-f-regione层f层
chart f region赤道F区
Ionospheric F region电离层F区
f region magnetic noon phenomena磁中午现象
N（名词） the highest region of the ionosphere, extending from a height of about 150 kilometres to about 1000 kilometres. It contains the highest proportion of free electrons and is the most useful region for long-range radio transmission F电离层 (Also called Appleton layer) → see also ionosphere