|
|
 |
|
|
Ann. Geophys., 23, 2335-2345, 2005
www.ann-geophys.net/23/2335/2005/
© European Geosciences Union 2005
Electron density and plasma waves in mid-latitude sporadic-E layer observed during the SEEK-2 campaign
M. Wakabayashi1, T. Ono1, H. Mori2, and P. A. Bernhardt3
1Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan
2National Institute of Information and Communications Technology, Tokyo, Japan
3Naval Research Laboratory, Washington, DC, USA
Abstract. The SEEK-2 campaign was carried out over Kyushu Island in Japan on 3 August
2002, by using the two sounding rockets of S310-31 and S310-32. This campaign was
planned to elucidate generation mechanisms of Quasi-Periodic Echoes (QPEs)
associated with mid-latitude sporadic-E (Es) layers. Electron number
densities were successfully measured in the Es layers by using the
impedance probe on board two rockets. The plasma waves in the VLF and ELF ranges
were also observed on board the S310-32 rocket. Results of electron density
measurement showed that there were one or two major peaks in the Es layers
along the rockets' trajectories near the altitude of about 10km. There
were some smaller peaks associated with the main Es layers in the altitude
range from 90 to 120 km. These density peaks were distributed in a very large
extent during the SEEK-2 campaign. The Es layer structure is also
measured by using the Fixed Bias Probe (FBP), which has a high spatial
resolution of several meters (the impedance probe has an altitude resolution of
about 400 m). The comparison with the total electron content (TEC) measured
by the Dual Band Beacon revealed that the Es layer was also modulated in
the horizontal direction with the scale size of 30–40 km. It was shown that
the QP echoes observed by the ground-based coherent radar come from the
major density peak of the Es layer. The plasma wave instrument detected
the enhancement of VLF and ELF plasma waves associated with the operation of
the TMA release, and also with the passage of the Es layers.
Keywords. Ionosphere (Ionospheric irregularities; Midlatitude
ionosphere; Plasma temeperature and density)
Full Article in PDF (2447 KB) |
|
|
