Accession Number:

ADA058246

Title:

High Frequency Drift Waves with Wavelengths Below the Ion Gyroradius in Equatorial Spread F

Descriptive Note:

Interim rept.

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Report Date:

1978-05-01

Pagination or Media Count:

35.0

Abstract:

Evidence is given for intense VHF and UHF radar backscatter during equatorial Spread F resulting from irregularities of 1 meter and 36 cm, respectively. The linear theory for high frequency drift waves, generated by the drift-cyclotron and lower-hybrid-drift instabilities, is presented. This linear theory is set forth as a possible explanation for the occurrence of these irregularities below the ion gyroradius. The maximum growth for these instabilities occurs for kr sub e approximately 1, where k is the wavenumber perpendicular to the magnetic field and r sub e is the electron gyroradius. For these instabilities, the growth rate results in growth times than a second. For typical equatorial Spread F ionospheric parameters, the lower-hybrid-drift instability is dominant.

Subject Categories:

  • Atmospheric Physics
  • Active and Passive Radar Detection and Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE