spread F

Alternative definitions (0), class: vernacular (0)
Term: spread F

A condition of the F region of the ionosphere caused by patches of ionization that scatter or duct radio signals, characterized on ionograms by a wide range of heights of reflected pulses. In equatorial latitudes spread F is most commonly observed at night and may be negatively correlated with geomagnetic activity.  At high latitudes spread F occurs throughout the daytime and is positively correlated with magnetic activity. The latitude of minimum occurrence of spread F is near 30 degrees magnetic latitude.

Created 2023.04.16
Last Modified 2023.04.16
Contributed by Ryan McGranaghan