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Extreme relativistic electron fluxes at geosynchronous orbit: Analysis of GOES E > 2 MeV electrons
Relativistic electrons are a major and well-established cause of radiation damage to satellites. In this paper we apply extreme value analysis to 20 years of operational satellite data from the NOAA Geostationary Operational Environmental Satellites (GOES) to determine the 1-in-10 and 1-in-100 year relativistic electron flux. For the first time we apply a dead time correction to the data and sort the data by satellite location.
We find that the 1-in-10 and 1-in-100 year flux of E > 2 MeV electrons at geosynchronous orbit are 1.8 x 105 cm-2s-1sr-1 and 7.7 x 105 cm-2s-1sr-1, factors of 3 and 7 higher than previous estimates based on earlier satellite measurements. These new results, which are being used to help assess the effects of extreme events on satellites in the EU FP7 project SPACESTORM, have already been used by one satellite operator in the evaluation of satellite tenders.
We find that the largest flux of relativistic electrons observed during the 20 year period, on 29th July 2004, was a 1-in-50 year event. During the disturbed period associated with this event the Double Star TC1 and TC2 satellites experienced over 30 anomalies and Galaxy 10R lost its secondary xenon ion propulsion system, used to maintain its on-orbit position, resulting in an insurance payout of US $75.3 million.
Space weather is a critical natural hazard risk. It was added to the UK National Risk Register of Civil Emergencies in 2012 and is a priority for the European Space Agency’s Space Situational Awareness program.
Link to the full paper in the NERC Open Research Archive
Authors
Meredith, N. P., R. B. Horne, J. D. Isles, and J. V. Rodriguez (2015)
Publication
Space Weather, 13, 170–184. doi: 10.1002/2014SW001143
