Description du projet
De nouveaux modèles informatiques pourraient faire la lumière sur les explosions solaires dans la chromosphère
Le Soleil est bien connu pour son activité magnétique, notamment les éruptions périodiques qui se produisent à sa surface lorsque les lignes de champ magnétique s’entremêlent, se croisent ou se réorganisent à proximité des taches solaires. Les éruptions projettent des flux de particules chargées dans l’espace. Si elles sont orientées vers la Terre, ces particules peuvent perturber les satellites ou provoquer des aurores polaires colorées. Le projet CHLARE, financé par l’UE, entend améliorer notre compréhension des éruptions solaires et des événements solaires correspondants dans la chromosphère, une zone peu étudiée. Ce projet améliorera le code d’inversion existant, servant à interpréter la physique des éruptions solaires dans la région spectrale contenant le triplet de raies d’émission de l’He I autour de 1083 nm, et le mettra gratuitement à disposition. Ces travaux seront complétés par des simulations hydrodynamiques, et les résultats du projet constitueront une base précieuse pour l’analyse des éruptions solaires et de la météorologie spatiale.
Objectif
This research project aims to study the variations of the solar magnetic field in flares, the most energetic events in our solar system. Flares accelerate charged particles into space, which may adversely affect satellites and Earth’s technology. Despite their clear importance for today’s technology, the timing and positioning when flares occur are so far unpredictable. Changes in the solar magnetic field topology are known to be the causes for flares, but their physics is not understood in detail. Past studies have shown prominent changes of the magnetic field in the photosphere during flares. But higher in the atmosphere, in the chromosphere, studies are scarce because ground-based telescopes with special instrumentation and capabilities are needed. No space mission has been or is being planned with capabilities for those chromospheric magnetic measurements. The most suitable spectral range to study the upper chromosphere is the He I 1083.0 nm triplet and the project has access to two unique data sets of high-energetic flares in this spectral region. Since there are no diagnostic tools for this prominent spectral triplet in flares, the first goal is to upgrade an existing tool (spectral-line inversion code) to include flare physics. The code will be made freely available for the benefit of the scientific community, so that it can be used to analyze future flare observations in this wavelength range. The second aim is to use the upgraded tool to infer for the first time the evolution of the magnetic field vector in the two abovementioned data sets. The results will provide thresholds for the shear/ twist of the field lines that lead to the analyzed flares. Hydrodynamic simulations and satellite data will complement the results to simulate the atmospheric response to the flare and compute the energy budget of the magnetic changes compared to other flare processes. The results will have a deep impact on flare models, future predictors, and space weather.
Champ scientifique
Programme(s)
Régime de financement
MSCA-IF-EF-ST - Standard EFCoordinateur
38205 San Cristobal De La Laguna
Espagne