VOACAP Quick Guide: Home
Space Weather on 25 October 2021, 20:20 UTCSN 0 | SFI 70 | Kp 2 | Ap 4 | Kt 3 | At 7 | Bz 4.2 | Dst 12 | XRY 1.00 | Pf 0.5 | SW 325
Sunspot Numbers for VOACAP
The SSN source of (near-)current sunspot numbers to be used with VOACAP:
SIDC (Belgium), http://www.sidc.be/silso/prediml
A 3-hourly index of geomagnetic activity expressed in the logarithmic units on a scale from 0 to 9.
http://flux.phys.uit.no/Kindice/k_tro2a.gif, Tromso Geophysical Observatory
Magnetogram: State of Earth's Magnetic Field
Variations in Earth's magnetic field are measured by magnetometers. Any strong and sudden variations (up or down) in the X component (uppermost graph) are indications of VHF radio-auroral activity (e.g. on 144 MHz when variations suddenly peak, say, 300 nT).
http://www.sgo.fi/Data/RealTime/Kuvat/magrtday.png, Sodankylä Geophysical Observatory
Real-Time Solar Wind
http://services.swpc.noaa.gov/images/ace-mag-swepam-3-day.gif, National Oceanic and Atmospheric Administration, Space Environment Center
Class M and X flares affect the sunlit area of the Earth, causing increased D-region absorption. Strong flares are source of Shortwave Fadeouts (SWF) and Sudden Ionospheric Disturbances (SID). Look for the 1-8 Angstrom graph (red).
High-energy protons are guided into the polar cap by Earth's magnetic field. Strong proton bursts are source of Polar Cap Absorption (PCA), i.e. high D-region absorption on paths passing through the polar areas. A proton event is in progress if the red curve crosses the threshold (dotted line) in the uppermost graph.