| Volumes Volume 3 Contents of Current Session |
www.adv-radio-sci.net/3/427/2005/
© Author(s) 2005. This work is licensed
under a Creative Commons License.
Long-term Measurements of Nighttime LF Radio Wave Reflection Heights over Central Europe
1Institute for Meteorology, University of Leipzig, Stephanstr. 3, 04103 Leipzig, Germany
2Institute for Geophysics and Geology, University of Leipzig, Collm Observatory, 04779 Wermsdorf, Germany
Abstract. The nighttime ionospheric absolute reflection height of low-frequency (LF) radio waves at oblique incidence has been measured continuously since late 1982 using 1.8kHz sideband phase comparisons between the sky wave and the ground wave of a commercial 177kHz LF transmitter. The dataset allows the analysis of long-term trends and other regular variations of the reflection height. Beside the clear signal of the 11-year solar cycle a quasi-biennial oscillation is visible in LF reflection heights, which is correlated to the equatorial stratospheric wind field. A long-term decreasing reflection height trend is found, confirming results from other measurements and theoretical estimations. The results can be interpreted as a long-term decrease of the height levels of fixed electron density in the lower E region, reflecting a long-term cooling trend of the middle atmosphere.
Full Article in PDF (PDF, 109 KB)
Citation: Jacobi, C. and Kürschner, D.: Long-term Measurements of Nighttime LF Radio Wave Reflection Heights over Central Europe, Adv. Radio Sci., 3, 427-430, 2005. Bibtex EndNote Reference Manager
