Articles | Volume 34, issue 9
Regular paper 13 Sep 2016
Regular paper | 13 Sep 2016
An evaluation of International Reference Ionosphere electron density in the polar cap and cusp using EISCAT Svalbard radar measurements
Lindis Merete Bjoland et al.
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N. M. Schlatter, V. Belyey, B. Gustavsson, N. Ivchenko, D. Whiter, H. Dahlgren, S. Tuttle, and T. Grydeland
Ann. Geophys., 33, 837–844,Short summary
The high-latitude ionosphere is a dynamic region where particle precipitation leads to various phenomena including wave instability and turbulence. Anomalous echoes related to aurora are observed in ground-based radar observations of the ionosphere. These echoes indicate enhanced ion acoustic fluctuations. In this article, we show that the origin of the echo is located in or close to the region of particle precipitation and that the echo region itself is limited to hundreds of meters.
O. Havnes, H. Pinedo, C. La Hoz, A. Senior, T. W. Hartquist, M. T. Rietveld, and M. J. Kosch
Ann. Geophys., 33, 737–747,Short summary
Noctilucent clouds were observed by two radars at different wavelengths. Artificial electron heating was applied. As predicted by modelling, there is a general difference between the observations by the two radars. However, for some heater cycles we observed an exceptionally strong, rapid and similar increase in backscatter for both radars when the heater was on. Models predict a considerable difference in reaction. Our observation indicate that the charging models may not be complete.
The international reference ionosphere (IRI) model is a widely used model of the ionosphere. We compared this model with 16 years of radar measurements of electron density from Svalbard at altitudes between 200 and 500 km. Our results show that the model is biased towards an underestimation of the electron density in the high-latitude ionosphere and that this underestimation is most severe at nighttime. The model performs best at altitudes around the peak height of the electron density.
The international reference ionosphere (IRI) model is a widely used model of the ionosphere....