Plasma transport processes at the high latitude magnetosphere observed by cluster

Cluster four spacecraft data is used to study the spatial-temporal characteristics in/near the high and mid-altitude cusp under northward IMF. In our previous work a transition layer equatorward of the cusp was observed, which is suggested to be the entry layer during northward IMF. From event study and a further survey tailward of the Cusp, some transport processes of sheath-like ions in the magnetosphere are studied. Possible (dual) lobe reconnection model in the northward IMF condition are applied to explain these observations.