- Geomagnetic activity:
- Critical frequency of F-layer decreases in association with geomagnetic storms. This effect depends on seasons and is pronounced in summer season.
- SWF (Dellinger effect):
- X-ray and UV emissions from solar flare ionize day-side D-layer. HF radio wave fades out because of absorption of D-layer.
- High-energy protons:
- Information related to radiation hazards.
- Auroral Electrojet (AE) index
- A measure of global electrojet activity in the auroral zone.