Satellite Magnetic Fields Data Analysis: Magnetospheric/Ionospheric Currents and Waves

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This proposal is a request for the continuation of NSF support for analysis of magnetic field observations acquired by APL-developed satellite experiments. The proposed research will make substantial contributions to NSF initiatives such as GEM, CEDAR, and Space Weather. Satellite magnetic field data from Freja and Viking, HILAT, DMSP-F7, TRIAD, AMPTE/CCE, MAGSAT, and UARS will be used in studies of large and small scale current systems and magnetic wave phenomena associated with the magnetospheric boundaries and current source regions. The intent is also to disseminate data and information by way of scientific journal publications, presentations, and collaborative efforts with individual scientists and agency programs. The proposal includes the Freja data processing and analysis effort. The following areas will be investigated: (1) Multiple data sets will be used to characterize the distribution and source regions of the large scale currents and their variation with the phase of geomagnetic storms, including theoretical investigation of the current disruption process. (2) Identify and analyze simultaneous observations of large scale currents to thoroughly characterize the local time and altitude structure of the current systems. (3) Conduct pilot studies of Poynting flux using the Freja electric and magnetic field data, concentrating on small and intermediate scales. (4) Investigate the detailed correlation of magnetic fluctuations with field aligned currents and particle precipitation regions to put the use of AC Fluctuations on a firm scientific footing. (5) Refine empirical models of the auroral oval shape and size to allow a more reliable extrapolation of the auroral position in local time. This will involve inter-comparison of real-time predicted auroral dynamics with Geomagnetic Induced Currents to quantitatively test the model and forecasting system. (6) The usefulness of the Freja data and its importance to other programs motivates the developme nt of an efficient means of rapidly disseminating these data to the scientific community. (7) Continue studies of wave phenomena. Freja data cover a previously unexplored frequency range, and the availability of simultaneous electric field and high time resolution 3-D particle measurements assures that study of these phenomena will yield important results concerning the dynamics of the Birkeland current flow regions. Also pursued, will be the fluctuations inherent to the magnetopause current layer paying particular attention to the correlation of these fluctuations with theoretical predictions of current layer turbulence.