Journal cover Journal topic
Annales Geophysicae An open-access journal of the European Geosciences Union
Ann. Geophys., 31, 1103-1108, 2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
Regular paper
21 Jun 2013
Observations of HF-induced instability in the auroral E region
N. M. Schlatter1, N. Ivchenko1, B. Gustavsson2, T. Leyser3, and M. Rietveld4 1School of Electrical Engineering, Royal Institute of Technology, Teknikringen 31, 10044 Stockholm, Sweden
2EISCAT Scientific Association, Rymdcampus 1, 98192 Kiruna, Sweden
3Swedish Institute for Space Physics, Uppsala Division, Box 537, 751 21 Uppsala, Sweden
4EISCAT Scientific Association, Ramfjordmoen, 9027 Ramfjordbotn, Norway
Abstract. Enhancements were observed in backscattered radar power during an ionospheric heating experiment from two distinct altitude regions in the auroral E region above Tromsø. For the experiment the EISCAT Tromsø heater was operated with O mode and X mode alternated at 4.04 MHz, close to the 3rd electron gyroharmonic. Ion-line data recorded with the EISCAT UHF radar reveal different temporal evolutions as well as different ion-line characteristics for the enhancements from the two altitude regions. The upper layer is dominated by a strong central feature, whereas the lower layer has three peaks corresponding to the central feature and the two ion lines. The altitude region of the two closely spaced (altitude separation ~ 5 km) but distinct enhancements is close to the critical altitude for the heater wave.

Citation: Schlatter, N. M., Ivchenko, N., Gustavsson, B., Leyser, T., and Rietveld, M.: Observations of HF-induced instability in the auroral E region, Ann. Geophys., 31, 1103-1108,, 2013.
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