Anomalous Propagation

  • In the presence of a strong, inversion near the ground, the radar beam may be refracted
  • Recall from Physical Met that electromagnetic and sound waves may be refracted in the atmosphere due to density variations (Snells Law)
  • If a strong low-level inversion exists, the radar beam may be refracted such that it strikes the ground some distance from the radar.
  • The resultant echo is from the ground (ground clutter) and is called anomalous propagation
  • Here is an example
  • What time of the day would you more likely expect to see anomalous propagation?
  • Test your knowledge - where is the AP in this image?