2011 SuperDARN Workshop       

Magnetopause reconnection rate and cold plasma density: a study using SuperDARN

M. Lester (1), A. Grocott (1,2), S. Imber (3), S.E. Milan (1), M. Denton (4) and J. Borovsky (5)
(1) University of Leicester, Leicester, UK
(2) NIPR, Tokyo, Japan
(3) Goddard Space Flight Centre, Laurel, MD, USA
(4) Lancaster University, Lancaster, UK
(5) Los Alamos National Laboratory, Los Alamos, NM, USA

abstract. It has been suggested that cold plasma associated with cold dense plasma plumes from the plasmasphere can decrease the reconnection rate at the magnetopause as the cold plasma convects towards the magnetopause. This paper reports a study using SuperDARN of the cross polar cap potential and the convection flows in the ionosphere which are generated by the reconnection at the magnetopause and therefore are a direct measure of the reconnection rate. Cold plasma density are taken from LANL measurements and have been used in earlier studies of the impact of cold plasma on the reconnection rates. A super posed epoch analysis of northern hemisphere SuperDARN data has been undertaken during some 350 cold density events. The results indicate that during these events the cross polar cap potential increases in the two hours prior to the event onset time while remaining approximately constant after the onset time. Random selections of events demonstrate that this result is not due to radar data coverage nor due to changes in the solar wind

Sakaguchi KaoriNICT Japan