2026-05-27T16:46:57Zhttp://doidb.wdc-terra.org/oaip/oai

oai:doidb.wdc-terra.org:65792019-03-23T09:56:41ZDOIDBDOIDB.GFZ

false4DOIDB.GFZ 10.5880/GFZ.2.3.2018.007 Ritter, Patricia Patricia Ritter 0000-0002-0926-1771 GFZ German Research Centre for Geosciences, Potsdam, Germany Hall current densities derived from CHAMP scalar magnetic field data during six magnetic storms 2003 and 2005 GFZ Data Services 2018 CHAllenging Minisatellite Payload CHAMP Satellite geomagnetic field ionospheric current system Hall current magnetic storm Ritter, Patricia Patricia Ritter 0000-0002-0926-1771 GFZ German Research Centre for Geosciences, Potsdam, Germany en 10.5194/angeo-36-1361-2018 10.5047/eps.2010.07.006 10.1029/96GL02896 10.5636/jgg.47.191 10.5194/angeo-22-417-2004 891815 Bytes 2 Files application/octet-stream application/pdf 1.0 CC BY 4.0 This dataset comprises profiles of Hall ionospheric current densities derived from scalar magnetic field data measured from the CHAMP satellite during six magnetic storms. The Hall currents are intense electric currents that flow horizontally above the earth’s surface in the polar region and perpendicular to the geomagnetic field. They peak at approximately ± 80° of geomagnetic latitude. Together with the field-aligned currents they form part of the ionospheric current system. During enhanced geomagnetic activity the Hall current peak locations are shifted equatorward. The CHAllenging Minisatellite Payload (CHAMP) spacecraft circled the Earth during the years 2000 – 2010 on a near-polar orbit (inclination 87.3°), each orbit taking 93 minutes at an altitude of initially 455 km. Within 4 months CHAMP covered all local times. The data records used for determining the Hall currents are scalar magnetic field measurements obtained with the Overhauser magnetometer on the satellite boom, with a sample frequency of 1 Hz and a resolution of 0.1 nT. In order to isolate the magnetic effects of ionospheric currents in the satellite observations, the contributions from all other sources were removed from the scalar field readings. The main, crustal and external magnetic fields were subtracted using the POMME 6 model (Maus et al, 2010, http://www.geomag.us/models/pomme6.html). The Hall current densities were obtained by fitting a line current model to the observed magnetic field residuals. The model consists of a series of 160 horizontal infinite current lines centered at the orbit position closest to the geographic pole, at an altitude of 110 km and separated by 1° in latitude. The magnetic field of the line currents are related to the current strength according to the Biot–Savart law. Assuming a static current, the strength of each current line is derived from an inversion of the observed field residuals applying a least squares fitting approach. This method of Hall current estimation from scalar magnetometer records measured at satellites was proposed initially by Olsen (1996). The reliability of the approach was demonstrated and validated in a statistical study where Hall current density estimates from CHAMP were directly compared with independent determinations from ground observations of the IMAGE magnetometer array (Ritter et al., 2004). Bundesministerium für Wirtschaft und Technologie http://doi.org/10.13039/501100002765 50EE0944