Recent Updates to the AE9/AP9/SPM Radiation Belt and Space Plasma Specification Model

Johnston, William R.; O’Brien, T. P.; Huston, S. L.; Guild, T. B.; Ginet, G. P.

doi:10.1109/tns.2015.2476470

Cited by 32 publications

(15 citation statements)

References 10 publications

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“…Additionally, the MOBE‐DIC model (Hands et al, ) models the worst case environment for internal charging for 3≤ L ≤8 and energies in the range 0.5 to 3 MeV. Recently, the AE9 model (Ginet et al, ; Johnston et al, , ) has been developed. AE9 is based on more data sets, including more modern ones, than AE8, has better spatial resolution, and includes quantification of the uncertainty due to the dynamic behavior of the radiation belts.…”

Section: Introductionmentioning

confidence: 99%

A 30‐Year Simulation of the Outer Electron Radiation Belt

2018

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As society becomes more reliant on satellite technology, it is becoming increasingly important to understand the radiation environment throughout the Van Allen radiation belts. Historically most satellites have operated in low Earth orbit or geostationary orbit (GEO), but there are now over 100 satellites in medium Earth orbit (MEO). Additionally, satellites using electric orbit raising to reach GEO may spend hundreds of days on orbits that pass through the heart of the radiation belts. There is little long-term data on the high-energy electron flux, responsible for internal charging in satellites, available for MEO. Here we simulate the electron flux between the outer edge of the inner belt and GEO for 30 years. We present a method that converts the >2-MeV flux measured at GEO by the Geostationary Operational Environmental Satellites spacecraft into a differential flux spectrum to provide an outer boundary condition. The resulting simulation is validated using independent measurements made by the Galileo In-Orbit Validation Element-B spacecraft; correlation coefficients are in the range 0.72 to 0.88, and skill scores are between 0.6 and 0.8 for a range of L * and energies. The results show a clear solar cycle variation and filling of the slot region during active conditions and that the worst case spectrum overlaps that derived independently for the limiting extreme event. The simulation provides a resource that can be used by satellite designers to understand the MEO environment, by space insurers to help resolve the cause of anomalies and by satellite operators to plan for the environmental extremes.Plain Language Summary Society is becoming more reliant on satellites for navigation, defense, communications, and Earth observation. Increasing numbers of satellites orbit through the Van Allen radiation belts, where charged particles are trapped in orbit around the Earth by the Earth's magnetic field. These radiation belts are very dynamic; the number of electrons, and their energies, can change dramatically in hours in response to changes in the solar wind flowing from the Sun. Since these electrons can damage satellites, it is important to understand the environment that satellites are likely to encounter. Only limited measurements are available throughout the radiation belts, so we have used a physics-based model to simulate their behavior for 30 years. There is good agreement between our simulation and independent measurements. Our results show significant variations in the radiation belts during the 11-year solar cycle and that the region between the inner and outer radiation belts, where the electron population is normally low, can become filled during active geomagnetic conditions. The simulation provides a resource that can be used by satellite designers to understand the radiation belt environment, by space insurers to help resolve the cause of malfunctions, and by satellite operators to plan for the environmental extremes.

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Section: Introductionmentioning

confidence: 99%

A 30‐Year Simulation of the Outer Electron Radiation Belt

2018

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“…The largest and most significant effort in this area has been the development of a successor to the historic AE-8 model. AE-9 [6] is a complex statistical model based on a large number of data sets. AE-9 can be run in different modes, in terms of how statistical fluctuations due to instrumental uncertainties and space weather, are treated.…”

Section: Introductionmentioning

confidence: 99%

Data Exploitation of New Galileo Environmental Monitoring Units

Sandberg

Aminalragia-Giamini

Provatas

et al. 2019

IEEE Trans. Nucl. Sci.

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“…By considering the realistic electron flux around the inner radiation belt, we can assume that there is no contribution from electrons. According to the AE9/AP9 empirical model (Johnston et al., 2015), the high‐energy proton (>30 MeV) flux at an altitude of 1,000 km is estimated to be 10–100 #/min/cm 2 . The model also shows that the flux of the high‐energy electrons (>5 MeV) is negligible.…”

Section: Proton Measurement By Hisakimentioning

confidence: 99%

Long‐Term Monitoring of Energetic Protons at the Bottom of Earth’s Radiation Belt

et al. 2021

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Since the discovery of the radiation belt in the late 1950s, studies on the production, transportation, and loss processes of high-energy particles have been discussed by many researchers. Recently, many satellites for radiation belt plasma measurement, such as Van Allen Probes, Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX), and Arase have been observing plasmas at various spatial and time scales (Baker et al., 1993; Mauk et al., 2012; Miyoshi et al., 2018). In addition, the theoretical and empirical models based on these observations have been developed. In terms of the dynamics of radiation belt plasmas, the penetration of energetic particles deep into the inner magnetosphere as a transient response to solar energetic proton events has been studied through both observations and models (for example,

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Recent Updates to the AE9/AP9/SPM Radiation Belt and Space Plasma Specification Model

Cited by 32 publications

References 10 publications

A 30‐Year Simulation of the Outer Electron Radiation Belt

A 30‐Year Simulation of the Outer Electron Radiation Belt

Data Exploitation of New Galileo Environmental Monitoring Units

Long‐Term Monitoring of Energetic Protons at the Bottom of Earth’s Radiation Belt

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