Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Transient plasma injections in the dayside magnetosphere: One-to-one correlated observations by cluster and by SuperDARN
AU - Marchaudon, A.
AU - Cerisier, J. C.
AU - Bosqued, J. M.
AU - Dunlop, M. W.
AU - Wild, J. A.
AU - Décréau, P. M. E.
AU - Foerster, M.
AU - Fontaine, D.
AU - Laakso, H.
PY - 2004
Y1 - 2004
N2 - Conjunctions in the cusp between the four Cluster spacecraft and SuperDARN ground-based radars offer unique opportunities to compare the signatures of transient plasma injections simultaneously in the high-altitude dayside magnetosphere and in the ionosphere. We report here on such observations on 17 March 2001, when the IMF initially northward and duskward, turns southward and dawnward for a short period. The changes in the convection direction at Cluster are well correlated with the interplanetary magnetic field (IMF) By variations. Moreover, the changes in the ionosphere follow those in the magnetosphere, with a 2-3 min delay. When mapped into the ionosphere, the convection velocity at Cluster is about 1.5 times larger than measured by SuperDARN.In the high-altitude cusp, field and particle observations by Cluster display the characteristic signatures of plasma injections into the magnetosphere suggestive of Flux Transfer Events (FTEs). Simultaneous impulsive and localized convection plasma flows are observed in the ionospheric cusp by the HF radars. A clear one-to-one correlation is observed for three successive injections, with a 2–3 min delay between the magnetospheric and ionospheric observations. For each event, the drift velocity of reconnected flux tubes (phase velocity) has been compared in the magnetosphere and in the ionosphere. The drift velocity measured at Cluster is of the order of 400–600 m/s when mapped into the ionosphere, in qualitative agreement with SuperDARN observations. Finally, the reconnected flux tubes are elongated in the north-south direction, with an east-west dimension of 30–60 km in the ionosphere from mapped Cluster observations, which is consistent with SuperDARN observations, although slightly smaller.
AB - Conjunctions in the cusp between the four Cluster spacecraft and SuperDARN ground-based radars offer unique opportunities to compare the signatures of transient plasma injections simultaneously in the high-altitude dayside magnetosphere and in the ionosphere. We report here on such observations on 17 March 2001, when the IMF initially northward and duskward, turns southward and dawnward for a short period. The changes in the convection direction at Cluster are well correlated with the interplanetary magnetic field (IMF) By variations. Moreover, the changes in the ionosphere follow those in the magnetosphere, with a 2-3 min delay. When mapped into the ionosphere, the convection velocity at Cluster is about 1.5 times larger than measured by SuperDARN.In the high-altitude cusp, field and particle observations by Cluster display the characteristic signatures of plasma injections into the magnetosphere suggestive of Flux Transfer Events (FTEs). Simultaneous impulsive and localized convection plasma flows are observed in the ionospheric cusp by the HF radars. A clear one-to-one correlation is observed for three successive injections, with a 2–3 min delay between the magnetospheric and ionospheric observations. For each event, the drift velocity of reconnected flux tubes (phase velocity) has been compared in the magnetosphere and in the ionosphere. The drift velocity measured at Cluster is of the order of 400–600 m/s when mapped into the ionosphere, in qualitative agreement with SuperDARN observations. Finally, the reconnected flux tubes are elongated in the north-south direction, with an east-west dimension of 30–60 km in the ionosphere from mapped Cluster observations, which is consistent with SuperDARN observations, although slightly smaller.
KW - Cluster
KW - SuperDARN DCS-publications-id
KW - art-675
KW - DCS-publications-credits
KW - iono
KW - DCS-publications-personnel-id
KW - 104
U2 - 10.5194/angeo-22-141-2004
DO - 10.5194/angeo-22-141-2004
M3 - Journal article
VL - 22
SP - 141
EP - 158
JO - Annales Geophysicae
JF - Annales Geophysicae
SN - 0992-7689
IS - 1
ER -