The Short Wave Radio Band & Space Weather

Radio Band


Short Wave
Frequencies: 2300-26,100 kHz Wavelengths: 11-130 meters
(1 kHz = 1000 Hz = 1000 wave cycles per second)

Local & international, amateurs, maritime and land mobile, point-to-point communications, industrial, scientific, citizens band, search & rescue, police, taxi drivers

Wave Paths

Effects of Space Storms

Signal is reflected from ionosphere so can achieve long distance communicaton. The signal paths are even longer at night because the ionization layer is at higher altitude. Short wave is often the cheapest and sometimes only means of communication in remote regions. Larger distances can be covered at these frequencies than at frequencies shorter and longer.

Space weather disturbances have major and dramatic consequences for short wave communications:

  • Sudden & large communication disturbances occur on the dayside immediately following solar flares. This is because enhanced D region ionization is produced there by the elevated xrays & UV associated with the flare. The enhanced D region ionization absorbs the short waves. These events are called short wave fadeouts and they last a few minutes to a few hours.
  • Solar protons arriving hours to days after the solar disturbance, penetrate into the polar regions and can cause a complete blackout of HF communications. These events, called Polar Cap Absorption events (PCAs), can last for days depending on the size of the flare.
  • Ionospheric storm also occur in association with solar disturbances. These storms either increase or decrease the ionization layer density depending on location and time. Decreases in the density cause major problems in short wave communications.

For Satellite-to-Ground Communications: Signal quality is affected by irregularities in the ionosphere which produces phase and amplitude variations in the received signal.

The source of this material is Windows to the Universe, at from the National Earth Science Teachers Association (NESTA). The Website was developed in part with the support of UCAR and NCAR, where it resided from 2000 - 2010. © 2010 National Earth Science Teachers Association. Windows to the Universe® is a registered trademark of NESTA. All Rights Reserved. Site policies and disclaimer.