Altitude characteristics of plasma turbulence excited with the Tromso superheater

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/93JA02289· OSTI ID:6720853

Djuth, F T; Elder, J H ^[1]; Stubbe, P; Kohl, H ^[2]; Sulzer, M P ^[3]; Rietveld, M T ^[4]

---

1. Geospace Research Inc., El Segundo, CA (United States)
2. Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany)
3. Arecibo Observatory (Puerto Rico)
4. EISCAT Scientific Association, Ramfjordbotn (Norway)

Langmuir/ion turbulence excited with the upgraded high-power (1.2-GW effective radiated power) HF heating facility at Tromso, Norway, has been recently studied with the European Incoherent Scatter VHF and UHF incoherent scatter radars. In this report the authors focus on the altitudinal development of the turbulence observed at the highest HF power levels available. Quite remarkably, the observed plasma turbulence plunges downward in altitude over timescales of tens of seconds following HF beam turn-on; the bottom altitude is generally reached after [approximately]30 s. This phenomenon has a well-defined HF power threshold. It is most likely caused by changes in the electron density profile brought about by HF heating of the electron gas. If this is the case, then the heat source must be nonlinearly dependent on HF power. Overall, the characteristics of the Tromso turbulence are quite distinctive when compared to similar high-resolution measurements made at Arecibo Observatory, Puerto Rico. After HF transmissions have been made for tens of seconds at Tromso, billowing altitude structures are often seen, in sharp contrast to layers of turbulence observed at Arecibo. 17 refs., 3 figs.

• OSTI ID: 6720853
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 99:A1; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALTITUDE
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
ENERGY-LEVEL TRANSITIONS
EXCITATION
HEATING
HIGH-FREQUENCY HEATING
IONOSPHERE
PLANETARY IONOSPHERES
PLASMA HEATING
PLASMA WAVES
RADIATIONS
RADIOWAVE RADIATION
SHORT WAVE RADIATION
TURBULENCE