2011 SuperDARN Workshop       

Symmetry and asymmetry of interhemispheric dayside ionospheric convection seen by the SuperDARN Kerguelen and Hankasalmi radars

A. Marchaudon (1), J.-C. Cerisier (2), R.C. Fear (3), S.E. Milan (3), M. Lester (3)
(1) Laboratoire de Physique et Chimie de l?Environnement et de l?Espace, CNRS et Universit??d?Orl??ns, Orl??ns, France
(2) Laboratoire de Physique des Plasmas, Ecole Polytechnique, CNRS et Universit??Pierre et Marie Curie-Paris 6, Saint-Maur-des-Foss??, France
(3) Radio and Space Plasma Physics Group, Department of Physics and Astronomy, Leicester University, Leicester, UK.

abstract. We have identified excellent conjugated observations in the cusp regions by Hankasalmi (Northern Hemisphere) and Kerguelen (Southern Hemisphere) SuperDARN radars. First, we have investigated the location of the boundary between low and high spectral width in both hemispheres, studied their relative positions with respect to interplanetary conditions, focusing on periods where the boundaries behave differently in both hemispheres, and finally, we have compared the location between the northern spectral width boundary and the open-closed magnetic field boundary obtained from particles precipitation measured by low-altitude spacecraft. Second, we have identified conjugated pulsed ionospheric flows characteristics of sporadic magnetopause reconnection events (Flux Transfer Events, FTE). These observations were perfectly conjugated, suggesting a unique subsolar magnetopause reconnection line. However, the number, the velocity, and the shape of these ionospheric structures are very different in both hemispheres. We have investigated the causes for these different properties, with respect to season and interplanetary conditions.

Sakaguchi KaoriNICT Japan