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 - A Self-consistent Explanation for a Plasma Flow Vortex Associated with the Brightening of an Auroral Arc.
AU - Kosch, Mike J.
AU - Scourfield, M. W. J.
AU - Nielsen, E.
N1 - Copyright (1998) American Geophysical Union.
PY - 1998/12
Y1 - 1998/12
N2 - Simultaneous observations have been made of an auroral arc by an all-sky TV imager and of plasma flows near the arc by the Scandinavian Twin Auroral Radar Experiment. After the Harang Discontinuity, during a quiet geomagnetic interval (Kp = 1 +), the arc undergoes a sudden brightening during an eastward surge. This is accompanied by a vortex in the plasma drift velocities, poleward of the arc, of spatial extent 180 × 140 km. Westward drifts at higher latitudes merge with eastward drifts at lower latitudes near the arc. No radar backscatter was recorded equatorward of the arc. The plasma flow vortex is shown to correspond with an ionospheric region of diverging horizontal electric fields, which is equivalent to a downward field-aligned current. This region may correspond to black auroras. Spatial location of the closure current region associated with an arc by ground-based observations is a novel result.
AB - Simultaneous observations have been made of an auroral arc by an all-sky TV imager and of plasma flows near the arc by the Scandinavian Twin Auroral Radar Experiment. After the Harang Discontinuity, during a quiet geomagnetic interval (Kp = 1 +), the arc undergoes a sudden brightening during an eastward surge. This is accompanied by a vortex in the plasma drift velocities, poleward of the arc, of spatial extent 180 × 140 km. Westward drifts at higher latitudes merge with eastward drifts at lower latitudes near the arc. No radar backscatter was recorded equatorward of the arc. The plasma flow vortex is shown to correspond with an ionospheric region of diverging horizontal electric fields, which is equivalent to a downward field-aligned current. This region may correspond to black auroras. Spatial location of the closure current region associated with an arc by ground-based observations is a novel result.
KW - DCS-publications-id
KW - art-99
KW - DCS-publications-personnel-id
KW - 7
U2 - 10.1029/98JA02480
DO - 10.1029/98JA02480
M3 - Journal article
VL - 103
SP - 29383
EP - 29391
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
SN - 0148-0227
IS - A12
ER -