This paper presents particle flux measurements (protons and electrons) obtained with the ICARE-NG detector on the JASON-2 orbit (1336 km alt., 66 incl.) for the period June 2008-Aug. 2010. At this altitude, the South Atlantic Anomaly is greatly broadened as compared to lower altitudes. Proton flux measurements are made in the range 27.5-290 MeV and electron flux in the range 1.6-3.6 MeV. A great care was taken to assess the influence of the satellite on the particle measurements. Comparison of measurements with the results of the AP8 MIN model are given for protons, taken into account environment anisotropy.

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Abstract. GREEN (Global Radiation Earth ENvironment) is a new model (in beta version) providing fluxes at any location between L∗= 1 and L∗= 8, all along the magnetic field lines, for all local times and for any energy between 1 keV and 10 MeV for electrons and between 1 keV and 800 MeV for protons. This model is composed of global models (AE8 and AP8, and SPM for low energies) and local models (SLOT model, OZONE and IGE-2006 for electrons, and OPAL and IGP for protons). GREEN is not just a collection of various models; it calculates the electron and proton fluxes from the most relevant existing model for a given energy and location. Moreover, some existing models can be updated or corrected in GREEN. For examples, a new version of the SLOT model is presented here and has been integrated in GREEN. Moreover, a new model of proton flux in geostationary orbit (IGP) developed a few years ago is also detailed here and integrated in GREEN. Finally a correction of the AE8 model at high energy for L∗ < 2.5 has also been implemented. The inputs of the GREEN model are the coordinates of the points and the date (year, month, day, UTC) along an orbit, the particle species (electron or proton) and the energies. Then GREEN provides fluxes all along the given orbit, depending on the solar cycle and other magnetic parameters such as L∗, Bmirror and Beq.

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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.

Over the last decade, efforts have been made in the radiation belt community to develop data assimilation tools in order to improve the accuracy of radiation belts models. In this paper we present a new method to correctly take into account the outer boundary conditions at L* = 8 in such an enhanced model of the radiation belts. To do that we based our work on the Time History of Events and Macroscale Interactions during Substorms/Solid State Telescope data set. Statistics are developed to define a consistent electron distribution at L* = 8 (in both equatorial pitch angle and energy), and a variance‐covariance matrix is estimated in order to more realistically drive the Monte Carlo sampling required by the Ensemble Kalman Filter (EnKF). Data processing is first described as well as caveats avoided, and then the use of these information in a machinery such as the EnKF is described. It is shown that the way the Monte Carlo simulations are performed is of great importance to realistically reproduced outer boundary distribution needed by the physic‐based Salammbô model. Finally, EnKF simulations are performed and compared during September 2011 in order to analyze the improvements gained using this new method of defining outer boundary conditions. In particular, we highlight in this study that such a method provides great improvement in the reconstruction of the dynamics observed at geosynchronous orbit, both during quiet and active magnetic conditions.

A new specification model of low energy electrons fluxes, included in GREEN model, has been developed at ONERA. This model is based on several data sets, from low altitudes with NOAA-POES measurements to higher altitudes with POLAR, THEMIS and LANL measurements. It provides mean electron fluxes versus L, B/B eq , MLT and energy (for energies between 0.19 keV and few 10s of keV). In this paper, the model is compared to AE9/SPM model and Van Allen Probe measurements.Index Terms-plasma, specification model. I. INTRODUCTIONHE space environment is composed of charged particles: electrons and ions (mainly protons). These particles induce effects on materials used in space systems like the well-known ones of high energy particles (> 30 keV) on electronic devices. But high-energy particles are not the only population to consider. Indeed lower-energy particles (< 30 keV) can create significant damages on surface materials used in space systems (thermal coatings, cover glass …). Those effects are cumulative such as the relevant radiation environment specification is the total fluence of low-energy particles over the entire mission. Currently, the model available to evaluate this low-energy population is part of AE9/AP9 models and is called SPM [1][2].