Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Ionospheric convection signatures of tail fast flows during substorms and Poleward Boundary Intensifications (PBI)
Ist Teil von
Geophysical research letters, 2011-04, Vol.38 (8), p.np-n/a
Ort / Verlag
Washington, DC: Blackwell Publishing Ltd
Erscheinungsjahr
2011
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
Tail fast flows have been associated both with the onset of substorms and with auroral Poleward Boundary Intensifications (PBIs) that extend equatorward as streamers. We study here a series of bursts of fast tail flow that occurred on 5 March 2008 when four of the THEMIS probes were aligned in the tail from mid‐tail to inner magnetosphere and were in good conjunction with the Sondrestrom Incoherent Scatter Radar. The series of burst are identified as two separate events. We find that the first event is associated with a small substorm onset, and the second with a PBI and then possibly another onset. The ionospheric flow signatures of the substorm and the PBI are distinctly different: the substorm onset is characterized by flow enhancement in the polar cap several minutes before onset and by sudden ionospheric flow reduction at onset, while the PBI is accompanied by a flow enhancement directed primarily equatorward and intruding from the polar cap into the plasma sheet.
Key Points
Distinct tail and ionospheric flow signatures for substorm onsets and PBIs
Enhanced flow in polar cap min before onset
During PBI upward FAC at separatrix, equatorward flow from open to closed field