A5038651438- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Planetary Science and Exploration
- Earthquake Detection and Analysis
- Radiation Therapy and Dosimetry
- Gamma-ray bursts and supernovae
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Radiation Effects in Electronics
- Radiation Detection and Scintillator Technologies
- Space Satellite Systems and Control
- Geophysics and Gravity Measurements
- Atmospheric Ozone and Climate
- Seismic Waves and Analysis
- Geological and Geochemical Analysis
- Geochemistry and Geologic Mapping
- earthquake and tectonic studies
- Geology and Paleoclimatology Research
- Dark Matter and Cosmic Phenomena
- GNSS positioning and interference
- Particle Dynamics in Fluid Flows
- Plasma Diagnostics and Applications
- Space Exploration and Technology
Université de Toulouse
2018-2024
Office National d'Études et de Recherches Aérospatiales
2014-2024
Institut Superieur de l'Aeronautique et de l'Espace (ISAE-SUPAERO)
2013-2017
Centre National d'Études Spatiales
2005-2007
Gyroresonant wave particle interactions with whistler mode chorus play a fundamental role in the dynamics of Earth's radiation belts and inner magnetosphere, affecting both acceleration loss belt electrons. Knowledge variability power as function spatial location geomagnetic activity, required for computation pitch angle energy diffusion rates, is thus critical input global models. Here we present model lower band (0.1 f ce < 0.5 ) upper (0.5 chorus, where local electron gyrofrequency,...
Abstract In this study, we present a method that combines Long Short‐Term Memory (LSTM) recurrent neural network with Gaussian process (GP) model to provide up 6‐hr‐ahead probabilistic forecasts of the Dst geomagnetic index. The proposed approach brings together sequence modeling capabilities error bars and confidence bounds provided by GP. Our is trained using hourly OMNI Global Positioning System (GPS) databases, both which are publicly available. We first develop LSTM get single‐point...
Abstract We present a global model of plasmaspheric hiss, using data from eight satellites, extending the coverage and improving statistics existing models. use geomagnetic activity dependent templates to separate hiss chorus. In region 22–14 magnetic local time (MLT) boundary between chorus moves lower values with increasing activity. The average wave intensity is largest on dayside increases midnight through dawn dusk. Plasmaspheric most intense spatially extended in 200 500 Hz frequency...
Global models of the Van Allen radiation belts usually include resonant wave‐particle interactions as a diffusion process, but there is large uncertainty over rates. Here we present new matrix for whistler mode chorus waves that can be used in such models. Data from seven satellites are to construct 3536 power spectra upper and lower band 1.5≤ L ∗ ≤10 MLT, magnetic latitude 0°≤| λ m |≤60° five levels K p . Five density also constructed data. Gaussian functions fitted capture typically 90%...
Département Environnement Spatial, Office National d'Etudes et de Recherches Aérospatiales (ONERA) has been developing a model for the geostationary electron environment since 2003. Until now, this was called Particle ONERA‐LANL Environment (POLE), and it is valid from 30 keV up to 5.2 MeV. POLE based on full complement of Los Alamos Laboratory satellites, covers period 1976–2005, takes into account solar cycle variation. Over 1976 present, four different detectors were flown: charged...
The origin of plasmaspheric hiss, the electromagnetic emission responsible for gap between inner and outer radiation belts, has been debated over four decades. Recently, a new theory proposed that chorus, which is excited in equatorial region outside plasmapause, can propagate to low altitudes on dayside evolve into hiss. Here we combine data from six satellites show chorus extends along Earth's magnetic field high latitudes prenoon sector, and, region, there clear order 1–2 Earth radii hiss...
Abstract A new global physical model of the electron radiation belts Jupiter inside orbit Europa is presented. It an update Office National d'Etudes et de Recherches Aérospatiales Salammbô proposed by Sicard and Bourdarie ( ) that now integrates a contribution wave‐particle interaction above Io. In addition, revisited more realistic boundary condition near implemented. The validated against in situ flux measurements obtained Pioneer 10, 11, Voyager 1 missions. role discussed investigating...
Abstract Severe and extreme surface charging on geosynchronous spacecraft is examined through the analysis of 16 years data from particles detectors on‐board Los Alamos National Laboratory spacecraft. Analysis shows that high frame potentials are correlated with 10 to 50 keV electron fluxes, especially when these fluxes exceed 1 × 8 cm −2 s −1 sr . Four criteria have been used select severe environments: 1) large flux electrons energies above keV, 2) below 200 3) low 4) long periods time a...
Context. Observing Jupiter's synchrotron emission from the Earth remains today sole method to scrutinize distribution and dynamical behavior of ultra energetic electrons magnetically trapped around planet (because in-situ particle data are limited in inner magnetosphere). Aims. We perform first resolved low-frequency imaging with LOFAR at 127 MHz. The radiation comes low energy (~1-30 MeV) which map a broad region magnetosphere. Methods (see article for complete abstract) Results. images...
Specification models for radiation belts are essential the design of resistant, long-lasting spacecraft. Using available in-situ measurements allows these to virtually describe average space environment. However, their dependence on observations may make them suffer from data gaps which lead poor assessment degradation risks. To counter this problem, one can have access continuous descriptions belt dynamics long time periods through climate reanalysis. This operation consists in assimilation...
As part of the ESA Testbed for Radiation and Plasma Planetary Environments (TRAPPED) project, we present first empirical-based specification model Saturn&#8217;s plasma environment based on analysis all publicly available moment datasets derived using multiple techniques from Cassini observations made by Spectrometer (CAPS) Radio Wave Science (RPWS) instrument covering entire 13-year mission.We investigate variability spatio-temporal dynamics moments with respect to various magnetic...
Energetic electrons in Earth&#8217;s radiation belts emit cyclo-synchrotron as they are deflected by the planet&#8217;s magnetic field. These emissions provide valuable insights into spatial and energy distributions of trapped their dynamic behavior over time. However, because this occurs at frequencies below 10 MHz, it is blocked ionosphere, making direct observation from Earth impossible. Current situ satellite measurements offer critical data but limited temporal coverage, leaving...
Missions are being studied to the systems of outer planets, including extended observation periods by local orbiters or possible landers, that require careful evaluation radiation and plasma environment for design both platform science payload. Radiation impact potentially includes total cumulative doses, single event effects from short term enhancements internal charging risk whilst environments present risks surface charging.Under ESA Project TRAPPED (Testbed Plasma Planetary...
Whistler mode chorus is an important magnetospheric emission, playing a dual role in the acceleration and loss of relativistic electrons Earth's outer radiation belt. Chorus typically generated equatorial region frequency range 0.1–0.8 f ce , where local electron gyrofrequency. However, as waves propagate to higher latitudes, significant wave power can occur at frequencies below 0.1 . Since this largely omitted current belt models, we construct global model low‐frequency chorus, LHR <...
Abstract A physical model of the Jovian trapped protons with kinetic energies higher than 1 MeV inward orbit icy moon Europa is presented. The model, named Salammbô, takes into account radial diffusion process, absorption effect moons, and Coulomb collisions charge exchanges cold plasma neutral populations inner magnetosphere. Preliminary modeling wave‐particle interaction electromagnetic ion cyclotron waves near Io also performed. Salammbô validated against in situ proton measurements...
Abstract. GREEN (Global Radiation Earth ENvironment) is a new model (in beta version) providing fluxes at any location between L∗= 1 and 8, all along the magnetic field lines, for local times energy keV 10 MeV electrons 800 protons. This composed of global models (AE8 AP8, SPM low energies) (SLOT model, OZONE IGE-2006 electrons, OPAL IGP protons). not just collection various models; it calculates electron proton from most relevant existing given location. Moreover, some can be updated or...
This document presents a new Jovian Specification Environment model (JOSE), developed at ONERA based on Galileo data and validated with all relevant measured by spacecraft having flown or orbited Jupiter, in order to obtain an easy-to-use engineering for Jupiter's environment. has been protons electrons from several tens of keV hundreds MeV.
High-energy charged particles in the van Allen radiation belts and solar energetic particle events can damage satellites on orbit leading to malfunctions loss of satellite service. Here we describe some recent results from SPACECAST project modelling forecasting belts, events. We system that uses physical models include wave-particle interactions forecast electron up 3 h ahead. show forecasts were able reproduce >2 MeV flux at GOES 13 during moderate storm 7–8 October 2012, period following...
Abstract Relativistic electrons dynamics is still challenging to predict during the main phase of a storm. In particular, three dimensions radiation belt models, for which temporal resolution limited, fail in predicting their behavior, especially when dropouts occur. this paper we present new model magnetopause shadowing losses be incorporated into ONERA Salammbô code order improve accuracy. We show that above few hundred keVs, first contribution outer electron dropout events. Global...
Abstract The 400 worst‐case severe environments for surface charging detected at Los Alamos National Laboratory satellites during the years of 1990–2005 as binned by definitions four criteria developed Matéo‐Vélez et al. (2018, https://doi.org/10.1002/2017sw001689 ) and solar wind Interplanetary Magnetic Field (IMF) parameters geomagnetic activity indices are analyzed. conducted analysis shows that only Auroral Electrojet/Auroral Lower index determines highest risk to happen. presence a...
Abstract In this paper, we present a new method to compute rapidly, wave particle interaction induced pitch angle and momentum diffusion coefficients. Those terms are normally obtained by the numerical solving of equations based on quasi‐linear theory. However, bulk resolution leads high computational cost, preventing integration plasma density VLF waves nowcasts forecasts. Therefore, in context SAFESPACE project (H2020), implemented code called FARWEST (FAst Radiation with Waves ESTimator),...
Radiation belts cause irreversible damages to on‐board instrument materials. Studies about radiation can provide precious information for future interplanetary missions. Pioneer 11, Voyager 2 and nowadays Cassini missions give the characteristics of Saturn's inner magnetosphere: famous rings, various moons, neutral particles ejected from Enceladus waves. Thanks its experience with Earth's Jupiter's belt studies, ONERA is now able develop an electron model environment, i.e., a new version...
The existence of high-energy ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> > 1 MeV) electrons in the inner zone is always a debatable issue. This paper aims at answering this question using both simulation-based and data-based measurement evidences. First, NOAA measurements, particular proton channel contaminated by 1.2 MeV electrons, slot filling was studied over solar cycles. Then, found profiles were compared with CRRES SAMPEX...
Abstract Jupiter is surrounded by intense and energetic radiation belts, yet most of the available in‐situ data, in volume quality, were taken outward Europa's orbit, where conditions are not as extreme. Here, we study measurements ions tens keV to MeV at <10 radii ( R J ) distance Jupiter, therefore inward orbit Europa. Ion intensities drop around 6 , near Io's orbit. Previous missions reported on belts hundreds located between 2 4 . Measurements lower energies conclusive because high...
The three‐dimensional model, Salammbô‐3D, which was initially developed to model the Earth's radiation belts, has been adapted Jupiter's environment. As a first step, this validated between L = 1 and 6 (L: MacIlwain parameter), just inside Io's obit. In order extend our (3‐D) code up 9.5, Europa's orbit, more realistic magnetic field than dipole used before introduced in Salammbô. Two models are available: of Connerney [1981] one Khurana [1997] . Both them composed two parts: An internal...