We are observing PCA phenomena among most interesting events of last days.Well,what is this phenomena?
Polar Cap Absorption Events - Massive Short Wave Communications Blackouts The Trigger: The Arrival of a Solar Proton Event Occasionally the Sun blows clouds of very high velocity protons at the Earth (called a solar proton event ). Solar protons can penetrate into the Earth's magnetosphere near the magnetic poles. Solar protons with energies up to about 10 million electron volts bombard the ionosphere, knocking electrons free during collisions with air particles and increasing the density of the ionosphere at low altitudes (in the D- and E-regions). By the way,add informations: Solar Proton Event Solar proton events produce several major consequences at Earth:High energy protons penetrate the Earth's magnetic field in the polar regions, crash into atmospheric particles and produce ion and electron pairs that temporarily increase the density in the lowest regions of the ionosphere. This causes absorption of short wave radio signals and wide-spread blackout of communications, c...