Accession Number:

ADP006502

Title:

Enhanced Fading Rates Produced During Ionospheric Modification,

Descriptive Note:

Corporate Author:

LEICESTER UNIV (UNITED KINGDOM)

Personal Author(s):

Report Date:

1990-10-01

Pagination or Media Count:

7.0

Abstract:

When very high power radiowaves are reflected from the ionosphere, modifications in the physical characteristics of the ambient plasma are produced. These include the production of field aligned plasma striations with scale sizes across the geomagnetic field lines ranging from a few metres to a few kilometres. The presence of these striations produces anomalous absorption of both the heater wave itself and of other HF signals propagating through the modified region. During experiments at Tromso, Norway, with the heating facility constructed by the Max Planck Institut fur Aeronomy, Lindau, West Germany, marked changes in the fading rate of HF signals reflected from the heated volume have been noted. These rapid fluctuations in signal amplitudes are thought to be produced by medium scale striations generated during the heating process. An estimate of scale size of these striations is made from the experimental data.

Subject Categories:

  • Atmospheric Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE