Magnetospheric Waves at Geostationary Orbit

An important aspect of space weather is the energy distribution of charged particles trapped in Earth’s magnetic field. These energetic particles, in particular the Van Allen radiation belts, pose hazards to astronauts and spacecraft. Geostationary orbit is a particularly important location for many communications, navigation, and weather forecasting satellites but also includes the outer edge of the Van Allen radiation belts. Radiation levels in these belts are controlled in part by interactions between these trapped charged particles and electromagnetic waves in the magnetosphere. Since 1994, NOAA’s geostationary satellites have measured variations in the magnetic field using magnetometers, at sufficiently high temporal resolution to resolve several classes of these waves. However, the overwhelming majority of the highest resolution measurements have not been accessible for scientific study due to infrastructure limitations. In preparation for the upcoming GOES-R era (first launch expected in 2016), the NOAA National Centers for Environmental Information (NCEI), through a NOAA Big Earth Data Initiative, have begun an effort to modernize the archive of geostationary magnetic measurements from GOES-8 through GOES-15, creating official environmental data records (EDR) appropriate for scientific investigations with content and format equivalent to the GOES-R Magnetometer Coordina te Systems Level 2 product. The newly processed data sets will include a variety of features, such as better calibration parameters, updated quality flagging, vector measurements in relevant coordinate systems, and unified standard formatting, among others. Several collaborative scientific studies will be leveraged to optimize the value of the upcoming public EDRs. In particular, we will present our recent study of quasi-sinusoidal magnetospheric fluctuations potentially indicative  of global mode field line resonances during a 4 month period overlapping the period of operation of the low earth orbit NASA Space Technology 5 (ST-5) mission.  The results presented  include wave properties such as frequency, power/amplitude, duration and local time.