Multi-instrument Observations of Bursty Bulk Flows and Their Ionospheric Counterparts

During the first three years of its mission the Cluster constellation has passed through the near-Earth inner central plasma sheet ~300 times. During these times Cluster has been able to identify a large number of ‘bursty bulk flow’ events at a range of local times between 20 and 04 MLT. The aim of the present study is to investigate the statistics of these BBF events using both the Cluster data and various ground based datasets and to order their various ionospheric signatures within a simple physical framework. Presented here are some of the statistics from Cluster, along with selected SuperDARN radar observations of ionospheric plasma flows. The upstream interplanetary magnetic field has been monitored during these events by the ACE spacecraft, with ground magnetometers from a number of northern hemisphere arrays providing measurements of the terrestrial field. A relationship between BBF activity in the tail and conjugate ionospheric activity is further demonstrated by these data, however, other factors such as geomagnetic activity clearly influence this relationship which is the subject of ongoing work.