Publications

2026

• Effect of Solar Wind Turbulence on Temperature-Anisotropy-Driven Modes in Mercury's Magnetosheath
  
  • Ballerini G.
  • Califano F.
  • Henri P.
  • Simon Wedlund C.
  • Preisser L.
  • Pucci F.
  • Sporhykin F.
  • Passot T.
  • Sulem P. L.
  Journal of Geophysical Research: Space Physics, 2026, 131. Planetary magnetosheaths are plasma regions between the solar wind and planetary magnetospheres where temperature anisotropies act as a source of free energy driving plasma instabilities. While these instabilities have been extensively studied at Earth, their properties at Mercury remain poorly investigated. To support the science goals of the ongoing BepiColombo mission, we investigate the development of ion temperature anisotropy throughout Mercury's magnetosheath using the first global hybrid particle-in-cell simulations of the Hermean plasma environment under turbulent solar wind conditions. We employ the 3D hybrid PIC code Menura to model Mercury's magnetosphere for both laminar and turbulent upstream states and classify magnetosheath regions by local bow-shock geometry (quasi-parallel, quasi-perpendicular, and intermediate). The simulations reveal strong spatial variations in plasma stability, with quasi-perpendicular sectors showing enhanced occurrence of mirror-mode and ion-cyclotron unstable plasma. Turbulent solar wind produces a dayside magnetosheath that is, on average, more unstable than in laminar case, while the nightside becomes comparatively more stable. These results demonstrate that upstream solar wind turbulence plays a role in regulating anisotropy-driven instabilities in Mercury's magnetosheath and should be accounted for in the interpretation of in situ BepiColombo observations. (10.1029/2025JA034897)
  DOI : 10.1029/2025JA034897
• Properties of Magnetic Switchbacks in the Near-Sun Solar Wind
  
  • Badman Samuel T.
  • Fargette Naïs
  • Matteini Lorenzo
  • Agapitov Oleksiy V.
  • Akhavan-Tafti Mojtaba
  • Bale Stuart D.
  • Bharati Das Srijan
  • Bizien Nina
  • Bowen Trevor A.
  • Dudok de Wit Thierry
  • Froment Clara
  • Horbury Timothy
  • Huang Jia
  • Jagarlamudi Vamsee Krishna
  • Larosa Andrea
  • Madjarska Maria S.
  • Panasenco Olga
  • Pariat Etienne
  • Raouafi Nour E.
  • Rouillard Alexis P.
  • Ruffolo David
  • Sioulas Nikos
  • Soni Shirsh Lata
  • Sorriso-Valvo Luca
  • Suen Gabriel Ho Hin
  • Velli Marco
  • Verniero Jaye
  Space Science Reviews, Springer Verlag, 2026, 222. Magnetic switchbacks are fluctuations in the solar wind in which the interplanetary magnetic field sharply deflects away from its background direction so as to create folds in magnetic field lines while remaining of roughly constant magnitude. The magnetic field and velocity fluctuations are extremely well correlated in a way corresponding to Alfvénic fluctuations propagating away from the Sun. For a background field which is nearly radial this causes an outwardly propagating jet to form. Switchbacks and their characteristic velocity jets have recently been observed to be nearly ubiquitous by Parker Solar Probe with in situ measurements in the inner heliosphere within 0.3 AU. Their prevalence, substantial energy content, and potentially fundamental role in the dynamics of the outer corona and solar wind motivate the significant research efforts into their understanding. Here we review the in situ measurements of these structures (primarily by Parker Solar Probe). We discuss how they are identified and measured, and present an overview of the primary observational properties of these structures, both in terms of individual switchbacks and their collective arrangement into "patches". We identify both properties for which there is a strong consensus and those that have limited or qualified support and require further investigation. We identify and collate several open questions and recommendations for future studies. (10.1007/s11214-026-01267-w)
  DOI : 10.1007/s11214-026-01267-w
• Weibel-mediated filamentary structures observed in the ICF context
  
  • Ruyer C
  • Bolaños S
  • Laborde P.E. Masson
  • Gremillet L
  • Blanchot N
  • Boutoux G
  • Cayzac W
  • Courtois C
  • Dannhoff S.G
  • Denis V
  • Le Deroff L
  • Li C.K
  • Fuchs J
  • Grisollet A
  • Lantuéjoul I
  • Riquier R
  • Smets R
  • Sutcliffe G.D
  • Vauzour B
  Phys.Plasmas, 2026, 33 (5), pp.052113. In light of novel and past experimental results, we demonstrate how Weibel-mediated filamentary structures can develop in the expanding plasma plume of a laser-irradiated foil. The transverse ballistic cooling that occurs during the quasi-spherical plasma expansion naturally drives an electron pressure anisotropy, resulting in the growth of electron current filaments. This effect competes with electron-ion Coulomb collisions which tend to isotropize the electron distribution function. Based on theoretical and particle-in-cell modeling, we provide estimates of the dominant wavelength and amplitude of the self-generated magnetic fluctuations, which are found to explain experimental data obtained at the OMEGA and Laser Megajoule facilities. (10.1063/5.0321057)
  DOI : 10.1063/5.0321057