Journal articles
Cluster and DMSP observations of SAID electric fields
Abstract : [1] We report on magnetically conjugate Cluster and the Defense Meteorological Satellite Program (DMSP) satellite observations of subauroral ion drifts (SAID) during moderate geomagnetic activity levels on 8 April 2004. To our knowledge, the field-aligned separation of DMSP and Cluster (%28,000 km) is the largest separation ever analyzed with respect to the SAID phenomenon. Nonetheless, we show coherent, subauroral magnetosphere-ionosphere (MI) coupling along an entire field line in the post-dusk sector. The four Cluster satellites crossed SAID electric field channels with meridional magnitude E M of 25 mV/m in situ and latitudinal extent DL % 0.5° in the southern and northern hemispheres near 07:00 and 07:30 UT, respectively. Cluster was near perigee (R % 4 R E) and within 5° (15°) of the magnetic equator for the southern (northern) crossing. The SAID were located near the plasmapause—within the ring current-plasmasphere overlap region. Downward field-aligned current signatures were observed across both SAID crossings. The most magnetically and temporally conjugate SAID field from DMSP F16A at 07:12 UT was practically identical in latitudinal size to that mapped from Cluster. Since the DMSP ion drift meter saturated at 3000 m/s (or $114 mV/m) and the electrostatically mapped value for E M from Cluster exceeded 300 mV/m, a magnitude comparison of E M was not possible. Although the conjugate measurements show similar large-scale SAID features, the differences in substructure highlight the physical and chemical diversity of the conjugate regions.
Cited literature [44 references]
https://hal-insu.archives-ouvertes.fr/insu-01408871
Contributor : Nathalie Rouchon <>
Submitted on : Monday, December 5, 2016 - 2:35:08 PM
Last modification on : Tuesday, June 9, 2020 - 10:14:02 AM
Document(s) archivé(s) le : Monday, March 20, 2017 - 6:15:04 PM
Contributor : Nathalie Rouchon <>
Submitted on : Monday, December 5, 2016 - 2:35:08 PM
Last modification on : Tuesday, June 9, 2020 - 10:14:02 AM
Document(s) archivé(s) le : Monday, March 20, 2017 - 6:15:04 PM
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