Electron Fluxes at Geostationary Orbit From GOES MAGED Data

• Published in: Space Weather Vol. 15; no. 12; p. 1602
• Main Authors: Sillanpaa, Ilkka, Ganushkina, N Yu, Dubyagin, S, Rodriguez, J V
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 01.12.2017
• Subjects: Charged particles; Charging; Earth orbits; Electron density; Electron flux; Electrons; Empirical analysis; Empirical models; Geosynchronous orbits; Interplanetary magnetic field; Magnetic fields; Magnetospheres; Mathematical models; Meteorological satellites; Satellites; Solar magnetic field; Solar wind; Solar wind velocity; Spacecraft; Statistical analysis; Wind speed
• ISSN: 1539-4964; 1542-7390
• DOI: 10.1002/2017SW001698

Electron behavior in energies below 200 keV at geostationary orbit has significance for satellite operations due to charging effects on spacecraft. Five years of keV energy electron measurements by the geostationary GOES-13 satellite's MAGnetospheric Electron Detector (MAGED) instrument has been analyzed. A method for determining flight direction integrated fluxes is presented. The electron fluxes at the geostationary orbit are shown to have significant dependence on solar wind speed and interplanetary magnetic field (IMF) BZ: increased solar wind speed correlates with higher electron fluxes with all magnetic local times while negative IMF BZ increases electron fluxes in the 0 to 12 magnetic local time sector. A predictive empirical model for electron fluxes in the geostationary orbit for energies 40, 75, and 150 keV was constructed and is presented here. The empirical model is dependent on three parameters: magnetic local time, solar wind speed, and IMF BZ. Plain Language Summary Low-energy electrons in near-Earth space can be hazardous to satellites due to charging effects they may cause. Five years of low-energy electron data from the geostationary orbit of Earth by GOES-13 satellite was analyzed. The statistical analysis showed that low-energy electron fluxes were elevated by increased solar wind velocity for any position on the geostationary orbit. In addition, when the magnetic field carried by the solar wind was southward, the electron fluxes were elevated in about half the orbit, while on the other half the fluxes were not affected. A predictive model of low-energy electrons at geostationary orbit was built based on this data. A new empirical model was constructed to predict electron fluxes in energies between 30 and 200 keV at the different positions at the geostationary orbit. The model uses solar wind speed and magnetic field values to calculate the predicted electron fluxes. Key Points An empirical, predictive model function is presented for electron fluxes for energies of 40, 75, and 150 keV at geostationary orbit Higher solar wind speed in general results in electron flux enhancements in energies 30-200 keV at geostationary orbit Negative IMF BZ at midnight to noon results in electron flux enhancements in energies 30-200 keV at geostationary orbit