VOACAP Sunspot Numbers

VOACAP Quick Guide: Home


VOACAP SSNs for 2006

Below is the list of (near-)current sunspot numbers to be used with VOACAP. This list is manually updated on a regular basis. Consult the source for the latest numbers.

JAN 23.3  JUL 19.0
FEB 22.4  AUG 18.0
MAR 21.5  SEP 17.0
APR 20.8  OCT 16.0
MAY 20.4  NOV 14.9
JUN 19.8  DEC 14.1
Source: ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/sunspot.predict

Propagation tools to aid short-term prediction

Real-Time Solar Wind

http://www.sec.noaa.gov/SWN/sw_dials.gif, National Oceanic and Atmospheric Administration, Space Environment Center

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 (red) are indications of VHF radio-auroral activity (e.g. on 144 MHz when variations suddenly peak, say, 300 nT).

http://sgodata.sgo.fi/pub_mag/Realtime/magrtday.gif, Sodankylä Geophysical Observatory

Real-Time K-Index

A 3-hourly index of geomagnetic activity expressed in the logarithmic units on a scale from 0 to 9.

http://geo.phys.uit.no/knum/k_tro.gif, Tromsų Geophysical Observatory

X-Ray Flux

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).

Proton Flux

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 white line) in the uppermost graph.