A parametric study of solar wind properties and composition using fluid and kinetic solar wind models

Abstract

The physical processes in the solar corona that shape the solar wind remain an active research topic. Modeling efforts have shown that energy and plasma exchanges near the transition region plays a crucial role in modulating solar wind properties. Although these regions cannot be measured in situ, plasma parameters can be inferred from coronal spectroscopy and ionization states of heavy ions, which remain unchanged as they escape the corona. We introduce a new solar wind model extending from the chromosphere to the inner heliosphere, capturing thermodynamic coupling across atmospheric layers. By including neutral and charged particle interactions, we model the transport and ionisation processes of the gas through the transition region, the corona and into the solar wind. Instead of explicitly modeling coronal heating, we link its spatial distribution to large-scale magnetic field properties. Our results confirm that energy deposition strongly affects wind properties through key mechanisms involving chromospheric evaporation, thermal expansion, and magnetic flux expansion. For sources near active regions, the model predicts significant solar wind acceleration, with plasma outflows comparable to those inferred from coronal spectroscopy. For winds from large coronal holes, the model reproduces the observed anticorrelation between charge state and wind speed. However, the predicted charge state ratios are overall lower than observed. Inclusion of a population of energetic electrons enhances both heavy ion charge states and solar wind acceleration, improving agreement with observations.

21 pages, 10 figures, to be published in ApJ

References in corpus (11)

• The Solar Orbiter mission -- Science overview
• Self-consistent Coronal Heating and Solar Wind Acceleration from Anisotropic Magnetohydrodynamic Turbulence
• CHIANTI -- an atomic database for emission lines -- Paper XVI: Version 10, further extensions
• In situ observations of large amplitude Alfvén waves heating and accelerating the solar wind
• The temporal and spatial scales of density structures released in the slow solar wind during solar activity maximum
• Tearing instability and periodic density perturbations in the slow solar wind
• Suprathermal Electrons in the Solar Corona: Can Nonlocal Transport Explain Heliospheric Charge States?
• The Origin of Non-Maxwellian Solar Wind Electron Velocity Distribution Function: Connection to Nanoflares in the Solar Corona
• A Steady-State Picture of Solar Wind Acceleration and Charge State Composition Derived from a Global Wave-Driven MHD Model
• Flux ropes and dynamics of the heliospheric current sheet
• Observations of Slow Solar Wind from Equatorial Coronal Holes