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This panel gives solar information which can affect radio communications conditions for VHF and HF frequencies. The panel along with many others is provided by Paul L. Hermann, N0NBH and is available on

Here is what is available on the Solar panel:

SFI (Solar Flux Index)
Measures the 2800MHz radiation generated by the sun. It's measured every day at 1200 PST and usually varies between 60-300.

SN (Sunspot Number)
Measures the size, number and grouping of the sunspots. This number can vary from 0-250. The higher the SN, the higher the level of UV and x-ray radiation which in turn generates the D, E, and F layers. As ionospheric ionization increases so does the Maximum Usable Frequency (MUF). Thus, the higher the SFI and SN together, the more improved HF propagation conditions are.

SW (Solar Wind): 0-2000
Typically near 375 but when if it goes higher than 500 it can lead to poorer HF conditions.

X-ray Intensity (XRY)
Measures the intensity of high frequency x-rays hitting the earth. These x-rays pass through the F layer of the ionosphere and are primarily responsible for ionization levels in the D layer and to a lesser extent the E layer. But if the x-rays are too strong a complete DX communications blackout on the daylight side of the earth can occur lasting several hours.

This value is a measure of solar radiation strength at 30.4 nanometers and is responsible for about half the ionization of the F layer. The value of 304A correlates with the SFI so an increase in 304A generally means improved F layer propagation.

Interplanetary Magnetic Field (BZ)
Indicates the strength and orientation of the interplanetary magnetic field. It normally varies between +50 and -50. A negative value can cause an increase in any related ionospheric and geomagnetic disturbances.

Solar Wind (SW)
This is the speed in kilometers per second of the charged particles passing the earth. It varies between 0-2000 but is typically around 375. If the SW rises above 500 it can disturb the Earth's magnetic field which in turn can lead to reduced ionization and poor HF conditions.

Proton Flux (PF)
Measures the density of protons in the Earth's magnetic field. These protons strike the Earth's magnetic field and follow the field lines to the Earth's poles. The normal PF is around 10 but as the PF rises the protons can funnel toward the Earth's poles and can increase the ionosphere's density in the polar regions. At PF levels of 10,000 the signal paths that go over the poles will begin experiencing degraded conditions. Levels above 100,000 are considered an Extreme Solar Radiation Storm and can lead to complete communications blackouts except for paths that do not go over the poles.

Electron Flux (EF)
Measure of Electrons within the Earth's magnetic field.

MUF US Boulder
Maximum Usable Frequency (HF) as measured at Boulder, Colorado at the time indicated (UTC)

Earth-Moon-Earth Degradation (EME Deg)
This is the amount of attenuation in dB along the Earth-Moon-Earth radio path. EME degradation is defined as Very Poor (>5.5 dB), Poor (>4 dB), Fair (>2.5 dB), Good (>1.5 dB) and Excellent (<= 1.5 dB) Information taken from "Solar Panels - A Propagation Resource" by Steve Sant Andrea, AG1YK, QST Magazine, February 2014, Pages 78-79.