SA23C-2355
Magnetic field fluctuations observed by the Swarm constellation in the nighttime mid-latitude topside ionosphere
Tuesday, 15 December 2015
Poster Hall (Moscone South)
Jaeheung Park1, Hermann Luhr2, Guram Kervalishvili2, Jan Rauberg3, Ingo Michaelis2, Claudia Stolle4 and Young-Sil Kwak1, (1)KASI Korea Astronomy and Space Science Institute, Daejeon, South Korea, (2)Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany, (3)GFZ German Research Centre for Geosciences, Potsdam, Germany, (4)Deutsches GeoForschungsZentrum GFZ, Potsdam, Germany
Abstract:
Using single-satellite observations on Low-Earth-Orbits (LEO), some previous studies suggested that electric and magnetic field fluctuations observed in the nighttime mid-latitude ionosphere originate from medium-scale traveling ionospheric disturbances (MSTIDs). With the inherently 1-dimensional sampling, however, those studies could not confirm whether (1) the electric and magnetic field fluctuations are spatial structures rather than temporal variations, and (2) horizontal shapes of the field fluctuation regions generally have mirror symmetry with respect to the magnetic equator, just as MSTIDs do. In this presentation we analyze magnetic field data sampled by three identical Swarm satellites. The results support the idea of a close connection between mid-latitude magnetic fluctuations (MMFs) and MSTIDs in the nighttime sector. Combined with the relationship between MMFs and MSTIDs, the MMF climatology can be used for extending that of MSTIDs, which has been poorly investigated over oceans. In addition, we have conducted a scale size analysis and found that coherence lengths of MMFs are typically shorter than 150 km. We also discuss the possibility that the MMF regions are aligned with the background magnetic field.
