Articles | Volume 34, issue 9
Ann. Geophys., 34, 751–758, 2016
Ann. Geophys., 34, 751–758, 2016

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, Vasyl Belyey, Unni Pia Løvhaug, and Cesar La Hoz Lindis Merete Bjoland et al.
  • Department of Physics and Technology, University of Tromsø – The Arctic University of Norway, Tromsø, Norway

Abstract. Incoherent scatter radar measurements are an important source for studies of ionospheric plasma parameters. In this paper the EISCAT Svalbard radar (ESR) long-term database is used to evaluate the International Reference Ionosphere (IRI) model. The ESR started operations in 1996, and the accumulated database up to 2012 thus covers 16 years, giving an overview of the ionosphere in the polar cap and cusp during more than one solar cycle. Data from ESR can be used to obtain information about primary plasma parameters: electron density, electron and ion temperature, and line-of-sight plasma velocity from an altitude of about 50 and up to 1600 km. Monthly averages of electron density and temperature and ion temperature and composition are also provided by the IRI model from an altitude of 50 to 2000 km. We have compared electron density data obtained from the ESR with the predicted electron density from the IRI-2016 model. Our results show that the IRI model in general fits the ESR data well around the F2 peak height. However, the model seems to underestimate the electron density at lower altitudes, particularly during winter months. During solar minimum the model is also less accurate at higher altitudes. The purpose of this study is to validate the IRI model at polar latitudes.

Short summary
​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.​