INTERNATIONAL JOURNAL OF GEOMAGNETISM AND AERONOMY VOL. 7, GI3005, doi:10.1029/2007GI000169, 2008

Comparison and validation studies related to the modeling ionospheric convection and the European incoherent scatter observations in the polar cap

Arctic and Antarctic Research Institute, St. Petersburg, Russia

A. Kozlovsky, and T. Turunen

Sodankyla Geophysical Observatory, Sodankyla, Finland

Abstract

[1]  We use the ionospheric velocity measurements obtained by the European incoherent scatter (EISCAT) Svalbard radar (ESR) for comparison with the electric field distribution predicted by the new ionospheric convection model based on realistic maps of field-aligned currents. The comparative analysis of model output and observations is based on the data contained both the north-south and east-west components of the ionospheric electric field. Such a comparison provides an independent check of the model. It is shown that the model represents accurately the large-scale features of statistical electric field inferred from the ion velocity measured by the ESR. From observations and modeling we quantitatively determine the dependence of the ionospheric electric field strength on the IMF conditions and how this varies with magnetic local time. For specification of the relationship we derive average convection patterns for sorting by the magnitude and direction of the IMF. The dependence is clearly seen by contrasting the results for two magnitudes of the IMF strength ( B _T=1 and 5 nT), for two opposite directions of the IMF  B_z component, and for B_y+, B_y-. The magnitude of the IMF has the main impact on the average flows under southward IMF conditions. The sign of IMF  B_y is the most important factor influenced the convection system under the IMF northward. For B_y- \ the northward component is negative during a major part of the day indicating counterclockwise plasma flow around the pole. For B_y+, the situation is opposite, the electric field is directed poleward and the plasma rotate clockwise. These are confirmed nicely by the ESR observations.

Received 24 May 2007; accepted 14 February 2008; published 8 March 2008.

Keywords: EISCAT observation, ionospheric convection model, polar cap, field-aligned currents.

Index Terms: 2409 Ionosphere: Current systems; 2411 Ionosphere: Electric fields; 2475 Ionosphere: Polar cap ionosphere; 6969 Radio Science: Remote sensing.

Citation: Lukianova, R., A. Kozlovsky, and T. Turunen (2008), Comparison and validation studies related to the modeling ionospheric convection and the European incoherent scatter observations in the polar cap, Int. J. Geomagn. Aeron., 7, GI3005, doi:10.1029/2007GI000169.