Outer Electron Belt Specification Model

Abstract

Data assimilation techniques have already been developed and have shown to provide "the best" estimate of the state of the electron radiation belts. Data assimilation proceeds in analysis cycles-in each analysis cycle, observations of the current (and possibly past) state of a system are combined with the results from a mathematical model (the forecast) to produce an analysis, which is considered as the best estimate of the current state of the system. In this paper, such an analysis has been performed from January 1990 to December 2006 and has produced full electron radiation belt state every 20 min. Then, based on this 17 year run, a new outer electron belt specification model is developed: we perform a data synthesis to deduce a yearly average electron belt state over a full solar cycle. Lastly, this new specification model for the Earth's radiation belt is compared to existing specification models.

AE9, AP9 and SPM: New Models for Specifying the Trapped Energetic Particle and Space Plasma Environment

“…However, the latter problem is likely beyond the capabilities of the current empirically based statistical algorithms given the required spatial and temporal data coverage. A more promising approach is to build a "sample solar cycle (or cycles)" that attempts to reconstruct past particle flux distributions using data, physics-based models, data-assimilation and other statistical techniques (O'Brien and Guild 2010; Bourdarie et al 2009). Such a reanalysis could provide an environment with variations on time scales limited only by the fidelity of the physics-based models.…”

“…Progress has been made on some fronts by developing models using data acquired onboard the CRRES (Meffert and Gussenhoven 1994;Brautigam and Bell 1995), NOAA/TIROS (Huston et al 1996;Huston 2002), LANL-GEO (Boscher et al 2003;, SAMPEX (Heynderickx et al 1999) and Polar (Roeder et al 2005) satellites. Data assimilative techniques that ingest a variety of data sets to drive physics-based models have also been developed (Bourdarie et al 2009;Reeves et al 2012). Whereas the NASA models span the entire inner magnetosphere over a very wide range of energies, these more recent models face various limitations, either in energy range, spatial range (e.g., exclusively at geosynchronous orbit (GEO), medium-Earth orbit (MEO) or low-Earth orbit (LEO)), temporal range (limited to a small portion of the solar cycle), or possibly all three.…”

Near-Earth Space Radiation Models

“…The Salammbo team has used the results of their solar-cycle length reanalysis to generate a global model of the electron belts [32]. So far, even though the underlying reanalysis evolves the state on timescales shorter than individual storms, only an average specification model has been developed, with separate yearly averages to capture intra-solar-cycle variability.…”

“…1 shows results of four models for the electron fluence at a GPS orbit. We include AE8 Min/Max [11], the GNSS model [24], a reanalysis [32] and AE9 [33], for a 10 year mission. AE8 Min and Max do not really represent error bars, since one is usually advised to add them together in some combination based on how much time the mission is expected to experience solar minimum and solar maximum conditions.…”

Radiation Belt Activity Indices and Solar Proton Event Alarm on the CRATERRE project web site

“…It offers access to near real time measurements and historical data, by providing an easy and friendly to use interface, to analyse and visualize measurements, locate in flight anomaly with in situ environment from various sources. After several years, the CRATERRE project has led to significant advances in radiation belts detection and comprehension with in-situ measurement analysis aboard the French Spacecraft JASON-2 [5], physical modeling improvement with for example electron radiation belt data assimilation [6] and specification models development with new models of electron fluxes such as OZONE in the outer zone electron belt [7], model at MEO orbit (MEO V2 [8]), at geostationary orbit (IGE 2006 [9]) and in the slot region [10].…”