EarthRef.org Reference Database (ERR)
Development and Maintenance by the EarthRef.org Database Team

Detailed Reference Information
Hospodarsky et al. 1994
Hospodarsky, G.B., Gurnett, D.A., Kurth, W.S., Kivelson, M.G., Strangeway, R.J. and Bolton, S.J. (1994). Fine structure of Langmuir waves observed upstream of the bow shock at Venus. Journal of Geophysical Research 99: doi: 10.1029/94JA00868. issn: 0148-0227.

Highly structured Langmuir waves, also known as electron plasma oscillations, have been observed in the foreshock of Venus using the plasma wave experiment on the Galileo spacecraft during the gravity assist flyby on February 10, 1990. The Galileo wideband sampling system provides digital electric field waveform measurements at sampling rates up to 201,600 samples per second, much higher than any previous instrument of this type. The main Langmuir wave emission band occurs near the local electron plasma frequency, which was approximately 43 kHz. The Langmuir waves are observed to shift above and below the plasma frequency, sometimes by as much as 20 kHz. The shifts in frequency are closely correlated with the downstream distance from the tangent field line, implying that the shifts are controlled by the electron beam velocity. Considerable fine structure is also evident with timescales as short as 0.15 ms, corresponding to spatial scales of a few tens of Debye lengths. The frequency spectrum often consists of beat-type waveforms, with beat frequencies ranging from 0.2 to 7 kHz, and in a few cases, isolated wave packets. The peak electric field strengths are approximately 1 mV/m. These field strengths are too small for strongly nonlinear processes to be important. The beat-type waveforms are suggestive of a parametric decay process. ¿ American Geophysical Union 1994

BACKGROUND DATA FILES

Abstract

Keywords
Interplanetary Physics, Planetary bow shocks, Interplanetary Physics, Plasma waves and turbulence, Interplanetary Physics, Solar wind plasma, Magnetospheric Physics, Planetary magnetospheres
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
2000 Florida Avenue N.W.
Washington, D.C. 20009-1277
USA
1-202-462-6900
1-202-328-0566
service@agu.org
Click to clear formClick to return to previous pageClick to submit