Monitor za spremljanje nenadnih ionosferskih motenj

Nenadne ionosferske motnje (SID) so izjemno močne gostote ionizacije v D sloju Zemljine ionosfere, ki jih povzročajo izbruhi na Soncu. Ko se izbruh na Soncu zgodi, sunek močnega ultravijoličnega in rentgenskega sevanja zadane dnevno stran Zemlje. Visokoenergijsko sevanje absorbirajo delci v atmosferi, ki preko procesa foto ionizacije postanejo vzbujeni. Najnižjim slojem obsevane ionosfere (D in E sloj) se gostota elektronov nemudoma poveča. Ionosferske motnje ojačajo širjenje valov zelo nizkih frekvenc (VLF). S SID monitorjem, ki se nahaja na astronomskem geofizikalnem observatoriju Golovec v Ljubljani, lahko detektiramo izbruhe na Soncu tako, da spremljamo moč radijskega signala oddaljenega VLF oddajnika, v odvisnosti od časa. Izmerjena motnja (SID) pove, ali je zares prišlo do Sončevega izbruha.

Sudden ionospheric disturbances monitor

A sudden ionospheric disturbance (SID) is an abnormally high ionization density in the D layer of the Earth’s ionosphere caused by a Solar flare. When a Solar flare occurs on the Sun a blast of intense ultraviolet and X-ray radiation hits the dayside of the Earth. This high energy radiation is absorbed by atmospheric particles, raising them to excited states and knocking electrons free in the process of photoionization. The low-altitude ionospheric layers (D and E layer) immediately increase in electron density over the entire dayside. The ionospheric disturbance enhances very low frequency (VLF) radio propagation. With an instrument called the SID monitor, located at Astronomical Geophysical Observatory on the Golovec hill in Ljubljana, we can detect Solar flares by monitoring the signal strength of distant VLF transmitters over the course of time. The recorded SIDs indicate whether Solar flares have taken place.