New GOES High-Res Magnetic Measurements: Spectral Properties and Studies of Field Line Conjunctions
Abstract
We present on our efforts to create a new 20+ year archive of science-quality, high-cadence geostationary measurements of the magnetic field from eight NOAA spacecraft, GOES-8 through GOES-15 and on scientific findings afforded by the new data set. The era of NOAA operational, high-resolution observations of the geomagnetic field started with GOES-8 in 1995 and continues to this day with GOES-13-16 (on-orbit). Uses of these geomagnetic observations are diverse. They provide an early warning of impending space weather, they are the core geostationary data set used for the construction of empirical models of the geomagnetic field and their spectral properties are used to develop estimates of electromagnetic wave power in bands important for magnetospheric plasma processes. Many science grade improvements are being made across the GOES archive to unify the format and content from GOES-8 through the new GOES-R series. A majority of the 2 Hz GOES-8 through GOES-12 magnetic observations have never before been publicly accessible due to processing constraints. Now, a NOAA Big Earth Data Initiative project is underway to process these measurements starting from original telemetry records. Overall the new archive will include the highest temporal cadence, recomputed means, comprehensive documentation, the best calibration parameters, updated quality flagging, vector measurements in geophysically relevant coordinates (EPN, GSM, VDH), full ephemeris information, a unified standard format and public access. We have also developed spectral characterization tools for estimating power in standard bands, and detecting quasi-sinusoidal waves related to field-line resonances. We will present our initial findings in the context of past research, including in situ statistical properties and case studies where the oscillations along the same field line were observed simultaneously by GOES near the equator in the magnetosphere, the ST-5 satellites at low altitudes, and ground magnetometer stations. We find that the wave amplitude of poloidal oscillations is amplified at low altitudes but attenuated on the ground, confirming the theoretical predictions of wave propagation from the magnetosphere to the ground.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMGP31C1319R
- Keywords:
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- 1515 Geomagnetic induction;
- GEOMAGNETISM AND PALEOMAGNETISMDE: 2799 General or miscellaneous;
- MAGNETOSPHERIC PHYSICSDE: 4313 Extreme events;
- NATURAL HAZARDSDE: 7904 Geomagnetically induced currents;
- SPACE WEATHER