Ｆ層えふそう

noun

F layer; F region

Technical term in atmospheric physics for the highest region of the ionosphere, important for radio wave propagation.

• Ｆ層そうは電でん離り層そうの最もっとも高たかい部ぶ分ぶんで、夜や間かんでも電でん波ぱを反はん射しゃする。

  The F layer is the highest part of the ionosphere and reflects radio waves even at night.