Solar Observations using the EAARO Very Low Frequency Detector
The VLF Detector will be used to observe solar activity indirectly using radio waves reflected off the ionosphere in order to sense for sudden disturbances.
The Sun is a magnetically active star. It supports a strong, changing magnetic field that varies year-to-year and reverses direction about every eleven years around solar maximum. The Sun's magnetic field leads to many effects that are collectively called solar activity, including sunspots on the surface of the Sun, solar flares, and variations in solar wind that carry material through the Solar System. Effects of solar activity on Earth include auroras at moderate to high latitudes, and the disruption of radio communications and electric power. Solar activity is thought to have played a large role in the formation and evolution of the Solar System. Solar activity changes the structure of Earth's outer atmosphere.
The ionosphere is an ionized layer in the atmosphere roughly 50-600 km above the Earth‟s surface. Its ionization is caused by incoming UV and X-ray radiation from the sun. The degree of ionization increases with the amount of solar radiation received, and therefore tends to depend on the latitude, the season, and the time of day. Ionization is also dramatically affected by exceptional events such as solar flares and coronal mass ejections.
Sudden changes in the degree of ionization can be detected by monitoring the signal strength of a radio transmission that is being carried through the ionosphere, thus indicating the occurrence of solar events.
We will use the VLF (Very Low Frequency) Radio Spectrum to observe the reflected radio signal from a high power transmitter which will produces a diurnal trace that can be interpreted to reveal solar events such as storms, flares, and coronal mass ejections.
The EAARO VLF Detector will observe signals in the VLF Band on a 24 hour cycle and log the signal strength against time.