An evaluation of space weather conditions for FORMOSAT-3 satellite anomalies

Abstract

The variable electromagnetic environment in geospace plays a crucial role in influencing the occurrence probability of satellite anomalies. FORMOSAT-3 (FS3) is a Low-Earth-Orbit (LEO) mission, which consists of six identical microsatellites that orbit in the altitude of 700–800 km and with an inclination of 72°. The dependences of the FS3 satellite anomalies on space weather conditions have not been investigated in the past. With an exception of a small number of extremely high geomagnetic events, we find that the occurrence rate of the FS3 anomalies is negatively correlated with the level of geomagnetic activity. Moreover, the relationship between numbers of anomalies and sunspots is also anti-correlated. A superposed epoch analysis demonstrates that the intensity of galactic cosmic rays (GCR) is relatively high at the times of the anomalies. All these results infer that the FS3 anomalies predominantly occurred under the conditions associated with low solar activity. The possible main cause for the FS3 anomalies is high-energy trapped protons or GCR. In summary, this paper presents a statistical result that a satellite can be prone to suffer an anomaly under low solar or geomagnetic activity.

Electron Precipitation Observed by ELFIN Using Proton Precipitation as a Proxy for Electromagnetic Ion Cyclotron (EMIC) Waves

“…Flux variations in the radiation belt environment and the atmospheric impact of particle precipitation are essential for predicting and mitigating space weather. Charged particles in the radiation belts can potentially damage satellite electronics or instrumentation leading to anomalies or failures (Baker et al., 2018; Choi et al., 2011; Lotoaniu et al., 2015; Love et al., 2000; Shen et al., 2021), whereas precipitating electrons enhance ionospheric conductance and indirectly facilitate ozone reduction (Khazanov et al., 2018, 2021; Meraner & Schmidt, 2018; Randall et al., 2007; Yu et al., 2018). Therefore, it is crucial to quantify the effects of EMIC waves and characterize the resulting electron precipitation.…”