INFINA (EX INFIP)   05545
INSTITUTO DE FISICA INTERDISCIPLINARIA Y APLICADA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Response of the magnetosphere to tangential stresses applied at its boundary
Autor/es:
FARRUGIA, C. J.; GRATTON, F. T.; FOULLON, C.; LUND, E. J.; TORBERT, R.; SANDHOLT, P. E.; COWLEY, S. W. H.; MANN, I.; WATERMANN, J.; VILJANEN, A.; YUMOTO, K.
Lugar:
Perugia, Italia
Reunión:
Congreso; XXIV IUGG General Assembly; 2007
Institución organizadora:
IAGA (International Association of Geomagnetism and Aeronomy)
Resumen:
Observations in the interplanetary medium (ACE, WIND), at the duskside magnetopause (Cluster), inside the magnetosphere (FAST, GOES, Geotail) and at ground magnetometers spanning a wide range in local time and latitude are complemented by theory to illustrate various aspects of magnetosphere-ionosphere (M-I) coupling during an event characterized by an impulsive change in interplanetary field and flow parameters. We show the discontinuity to be simultaneously a tangential discontinuity (TD) and a vortex sheet (VS) with the field and flow executing a large rotation from west to east. The field turns subsequently northward. Two types of waves are excited at the magnetopause during and after the TD/VS interaction with it. The attendant magnetopause motions produced large effects on the geomagnetic field, setting up standing Alfvén waves on resonating shells. Compressible calculations confirm the presence of MP surface waves of a Kelvin-Helmholtz origin, in addition to the initial undulatory motions of large amplitude. A two-stage response of the magnetosphere is documented. The continuous ground coverage from magnetometer arrays and the in situ observations permits us to detail the global response of the magnetosphere to the applied tangential stresses.