Computing the reconnection rate at the Earth's magnetopause using two spacecraft observations

Abstract

A new multispacecraft technique is introduced which, under some restrictive assumptions and conditions, provides a snapshot of the reconnection inflow velocity into the magnetosphere and an estimate of the distance from the spacecraft to the reconnection site. The two quantities are not obtained independent of one another and additional, independent information is needed to separate them. This new technique is applied to Cluster spacecraft observations at the Earth's magnetopause. Additional Cluster observations and observations from the IMAGE spacecraft are used as independent information to provide an estimate of the distance from the spacecraft to the reconnection site for the event. From this distance estimate and the new multispacecraft technique, it is concluded that component reconnection was probably occurring at the magnetopause and that the local inflow velocity was significantly less than 0.1 V_A.