A Survey of Electron Cyclotron Waves in the Magnetosphere and the Diffuse Auroral Electron Precipitation
Abstract
Narrowband electrostatic wave emissions at frequencies above the local electron cyclotron frequency are known variously as electron cyclotron harmonic (ECH) waves or 'n+1/2' waves since they tend to occur at odd half- multiples of the electron cyclotron frequency. Natural ECH emissions in the outer magnetosphere are often cited as the electron scattering mechanism which results in the diffuse auroral precipitation. A survey is presented of the characteristics of these waves using data from both the SCATHA and AMPTE-IRM plasma wave instruments. The emissions were observed most often in the 0300-0600 LT sector at L = approx. 4-8 and magnetic latitudes in the range + or - 10 deg. In this region, emissions exceeding 35 microVolt/m were detected only 25% of the time and those exceeding 12 microVolt/m were detected 60% of the time. In agreement with Belmont et al., we consider these amounts grossly insufficient to account for the diffuse auroral electron precipitation by quasilinear pitch angle diffusion. (edc)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 09, 1990
- Accession Number
- ADA220705
Entities
People
- Harry C. Koons
- James Roeder
Organizations
- The Aerospace Corporation