Nom de l'entreprise / du laboratoire: Laboratoire de physique et chimie de l’environnement et de l’Espace (LPC2E) - CNRS, Orléans

Context : In the solar corona, long-period intensity pulsations (on timescales of several hours) are a very common phenomenon. These pulsations, i.e. quasi-periodic intensity variations, are detected in extreme ultraviolet (EUV) channels that are primarily sensitive to coronal plasma at temperatures of several million degrees. They are strongly associated with coronal loops (magnetically closed structures) and constitute a manifestation of coronal heating processes. Indeed, they are caused by cycles of evaporation and condensation occurring within coronal loops, a phenomenon resulting from quasi-steady heating concentrated at low altitudes in the solar atmosphere. This process is referred to as thermal non-equilibrium (TNE). TNE may also be responsible for the formation of coronal rain, consisting of cool, dense plasma condensations that form in the corona and fall back toward the solar surface.

Several recent studies have highlighted the possibility that these events may occur in magnetically open structures connected to interplanetary space, or in initially closed structures that open as a result of magnetic reconnection. While these processes may contribute to plasma release into the solar wind, their numerical reproduction often leads to the emergence of non-physical particle velocities.

At LPC2E, we are conducting a project called CROSSWIND (funded by the French National Research Agency) that is dedicated to studying these types of events and tracking their potential consequences in the solar wind.

Subject : The work proposed in this project will consist of using the 1D plasma simulation code HYDRAD (HYDrodynamics and RADiation; e.g. Bradshaw & Mason 2003), which models plasma behavior in the solar corona along a magnetic field line. The primary objective will be to investigate the possibility of the development of thermal non-equilibrium (TNE) cycles in magnetically open field lines, and to determine the physical conditions that favor their occurrence. The second part of the project will focus on analyzing the origin of the anomalous velocities obtained in certain simulations, identifying the parameters that lead to such non-physical behavior, and assessing the reliability of the TNE cycles generated in these configurations.

This work will contribute to a better understanding of the physical and numerical limitations of simulations used within the community, and to evaluating the relevance of the proposed scenarios for supplying the solar wind. The student will develop analysis tools in Python and/or C++ in order to process the outputs of the HYDRAD code that she/he will generate during the project.

Nature of the work requested : Modeling – Data processing – Programming

Requirements : Ability to code in Python or C++, and basic knowledge of hydrodynamics

Level : Master 1 in physics or equivalent