angeo-20-771-2002.pdf (479.83 kB)
Download fileStrong sunward propagating flow bursts in the night sector during quiet solar wind conditions : SuperDARN and satellite observations
journal contribution
posted on 2016-02-10, 11:34 authored by C. Senior, J. C. Cerisier, F. Rich, Mark Lester, G. K. ParksHigh-time resolution data from the two Iceland SuperDARN HF radars show very strong nightside convection activity during a prolonged period of low geomagnetic activity and northward interplanetary magnetic field (IMF). Flows bursts with velocities ranging from 0.8 to 1.7 km/s are observed to propagate in the sunward direction with phase velocities up to 1.5 km/s. These bursts occur over several hours of MLT in the 20:00–01:00 MLT sector, in the evening-side sunward convection. Data from a simultaneous DMSP pass and POLAR UVI images show a very contracted polar cap and extended regions of auroral particle precipitation from the magnetospheric boundaries. A DMSP pass over the Iceland-West field-of-view while one of these sporadic bursts of enhanced flow is observed, indicates that the flow bursts appear within the plasma sheet and at its outward edge, which excludes Kelvin-Helmholtz instabilities at the magnetopause boundary as the generation mechanism. In the nightside region, the precipitation is more spot-like and the convection organizes itself as clockwise U-shaped structures. We interpret these flow bursts as the convective transport following plasma injection events from the tail into the night-side ionosphere. We show that during this period, where the IMF clock angle is around 70°, the dayside magnetosphere is not completely closed.
History
Citation
Annales Geophysicae, 2002, 20 (6), pp. 771-779 (9)Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and AstronomyVersion
- VoR (Version of Record)
Published in
Annales GeophysicaePublisher
Copernicus Publications on behalf of the European Geosciences Unionissn
0992-7689eissn
1432-0576Acceptance date
2002-02-19Copyright date
2002Available date
2016-02-10Publisher DOI
Publisher version
http://www.ann-geophys.net/20/771/2002/Language
enAdministrator link
Usage metrics
Categories
Keywords
Science & TechnologyPhysical SciencesAstronomy & AstrophysicsGeosciences, MultidisciplinaryMeteorology & Atmospheric SciencesGeologyASTRONOMY & ASTROPHYSICSGEOSCIENCES, MULTIDISCIPLINARYMETEOROLOGY & ATMOSPHERIC SCIENCESionosphereauroral ionosphereionosphere-magnetosphere interactionsparticle precipitationINTERPLANETARY MAGNETIC-FIELDHIGH-LATITUDE CONVECTIONRADAR OBSERVATIONSPLASMA SHEETBULK FLOWSMAGNETOSPHEREIONOSPHERENORTHWARDINTENSIFICATIONSASSOCIATION