SM41G-2563
Monitoring of the mass density profile along the 0° geomagnetic longitude during magnetic storms with the use of ground magnetometers.
Thursday, 17 December 2015
Poster Hall (Moscone South)
Natalia Romanova, University of Santiago Chile, Santiago, Chile, Marina V Stepanova, University of Santiago Chile, Physics Department, Santiago, Chile, Olga V. Kozyreva, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences, Moscow, Russia and Viacheslav Pilipenko, Space Research Institute RAS, Moscow, Russia
Abstract:
Ground magnetometers offer a very cheap and robust means of globally monitoring the magnetospheric mass density, by determining the ULF field line resonant frequency. ULF waves are almost always present in near-Earth environment and are generated by the solar wind interaction with the terrestrial magnetosphere. These waves from the magnetopause propagate through the magnetosphere. When they encounter a field line that resonates at the same frequency, coupling to the Alfven field line oscillations occurs and the resonance can be detected on the ground at that particular latitude. There are different methods for determining resonant frequencies from ground ULF waves. the density profiles along the 0° geomagnetic longitude were obtained using both the gradient and the amplitude-phase methods for the analysis of the magnetic field data from the magnetometer arrays: SAMBA (South American Meridional B-field Array), MAGDAS and American Antarctic bases (Palmer, WAIS-D). We compared the density profiles during quiet magnetic conditions and during strong magnetic storms (recovery phase). It is shown that in the recovery phase of strong magnetic storms (Dst <-150 nT) profile of the equatorial mass density varies greatly in comparison with the density distribution in quiet days.
