| 释义 |
DictionarySeeF regionF1 layer
F1 layerThe lower layer of the ionosphere, it has the best concentrations of ions—about 106/cm3. Its height is around 100 miles (160 km). Its height varies in summers and winters as well as during the days and nights. It affects daytime radio wave propagation and reflects waves from 1.5 to above 30 MHz. See F layer. |