| Term: | Polar cap absorption |
| Definition: |
Effect on radio waves in high latitudes, caused by a sudden increase in the electron concentration in the D layer of the ionosphere. The effect is produced by the influx of high energy solar protons; it begins a few hours after a solar flare is observed and may in exceptional cases persist for a few days. WMOMeteoterm
GCW |
| Term: | Polar cap absorption |
| Definition: | Effect on radio waves in high latitudes, caused by a sudden increase in the electron concentration in the D layer of the ionosphere. The effect is produced by the influx of high energy solar protons; it begins a few hours after a solar flare is observed and may in exceptional cases persist for a few days. |