Heliospheric physics and space weather

An average main-sequence star, the Sun is at a long and uneventful stage of its evolution. However, it experiences periodic changes and unpredictable bursts of activity known as solar activity. The response of the space environment to the constantly changing Sun is known as “space weather”. Solar activity can trigger sporadic bursts of energetic particles that cause damage to satellites and are a hazard for spacecraft systems and a constraint on our ambitions for human activities in space. Primary radiation sources of this environment are energetic protons and electrons during solar energetic particle (SEP) events, with energies up to a few 100 MeV. They are difficult to predict due to uncertainties over the basic physical processes, and the need to access reliable data in real time. [+]

These energetic particles generally result from the acceleration of the ambient plasma as magnetohydrodynamic shocks propagate through the solar corona and the solar wind, as reflected in their composition. Most of the shocks are driven by solar coronal mass ejections (CMEs). Some of these CMEs are accompanied by a solar flare (often visible as impulsive events in H-alpha light and X-rays). In such cases the composition may reflect the large heating or ionization of the local impulsive acceleration in the solar corona. Our lack of knowledge in this field sets stringent limits to the validity and reliability of any application.

ICCUB Contribution

ICCUB’s lines of research of in solar physics mainly deal with SEP events triggered by solar activity and interplanetary disturbances, i.e. energetic protons (~150 keV to 0.5 GeV) and near relativistic electrons (~20 keV up to 0.5 MeV). Solar flares and coronal mass ejections, which are the main agents of SEP-acceleration, together with proxies of solar activity (radioemission, H-alpha, X-ray, etc.), and the solar wind plasma and the interplanetary magnetic field, are also topics of research at ICCUB, as are background components of the SEP scenario. [+]

Similarly, the ICCUB researchers are working on data analysis and the study of SEP events, individual cases and multispacecraft events (ACE, Wind, Ulysses, SOHO, ISEE-3, Helios, Goes, IMPs, Phobos, STEREO and other spacecraft and satellites), multi-instrument observations and interdisciplinary analysis of relevant solar events, from Sun to Earth magnetosphere. They are also modeling gradual proton events, and giving scientific support to the participation of technological groups of the UB in ESA’s Solar Orbiter project: Polarimetric and Helioseismic Imager (PHI) and LET-EPD (Energetic Particle Detector) instruments.

Lines of Research

• Solar energetic particle events, interplanetary shocks and related solar activity.
• Modeling gradual proton events: magneto hydrodynamics (MHD) shock simulation plus particle transport simulation.
• Modeling near-relativistic electron events: inversion methods.
• Space weather: Engineering models for solar energetic particle events.

Members