arXiv subjects

Inmaculada F. Albert

Publications and source records attributed to Inmaculada F. Albert.

3 recordsLinked to original sources

arXiv2026

Current Sheets and Magnetic Reconnection statistics by Solar Orbiter at few to tens of Ion Inertial Lengths II: Conditions for Reconnection, and Current Sheet Planarity

We present a statistical study of magnetic reconnection and current sheet (CS) properties at scales from the ion inertial length ($δ_i$), up to 86.4 $δ_i$. We analyze 103 hours of high-cadence (4 samples/s) in-situ Solar Orbiter ion data, collected from July 2020 to September 2022, which correspond mainly to slow and Alfvénic solar wind. We applied an automatic detection algorithm to find CSs of thicknesses near and above the ion inertial length ($δ_i$), and classify them as Alfvénic or reconnecting. The orientation of the CSs is consistent with an isotropic distribution of the discontinuities. The median ratio of reconnection jet velocity to theoretical outflow velocity is 0.71. We find that the diamagnetic drift reconnection suppression mechanism has no impact on the cataloged CSs, due to the symmetry of their upstream conditions. We find that a flow shear in the reconnection direction suppresses magnetic reconnection, and it is consistently greater for Alfvénic than for reconnecting CSs. Flow shear in the guide-field direction is too small to suppress magnetic reconnection in ion scale solar wind CSs.

astro-ph.SR↗

arXiv2026

Current Sheets and Magnetic Reconnection statistics by Solar Orbiter at few to tens of Ion Inertial Lengths I: Energy Dissipation

In this work, we study the turbulent origin of ion-scale Current Sheets (CSs) and the dissipation of energy via magnetic reconnection. We analyze 103 hours of high-cadence (4 samples/s) in-situ ion data from Solar Orbiter, collected between July 2020 and September 2022. We apply an automatic detection algorithm that finds current sheets (CSs) of thickness (length in the normal direction, $λ$) near the ion inertial length ($δ_i$), and classifies them as Alfvénic or reconnecting. We compile a catalog of 974 CSs of thickness in the range of few to 90 ion inertial lengths, of which 53 contain an ion reconnection jet. We estimate that Solar Orbiter spends $\sim 1 \%$ of the dwell time inside a CS of few to 90 $δ_i$ thickness, and 0.06\% inside a reconnecting CS of the same thickness range. By comparing these results with previous studies we estimate that the abundance of CSs and of Reconnecting CSs evolves with heliocentric distance ($r$) as $r^{-0.9}$ and $r^{-1.5}$, respectively. We estimate that magnetic reconnection dissipates $ε_{rec}\sim 30 \hspace{5pt} \text{J} \text{kg}^{-1} \text{s}^{-1},$ in the $\sim 1 - 40$ $δ_i$ scale-range, by assessing the amount of plasma that interacts with a reconnection exhaust. We show how the dissipation of turbulence energy cascade by magnetic reconnection at scales smaller than 90 $δ_i$ is more effective closer to the Sun, and decays as $r^{-3.6}$. The current density of Alfvénic CSs thicker than the ion inertial length presents scale invariance, obeying $J_0/J_A=0.9(λ/2δ_i)^{-0.71}$, suggesting that CSs generated locally from solar wind turbulence.

astro-ph.SR↗

arXiv2026

Decay of space plasma turbulence downstream of bow shocks: MMS magnetosheath unbiased campaign observations

Turbulence properties in the solar wind change with increasing heliospheric distance. Observations from different missions have shown how spectral indices converge towards a $f^{-5/3}$ spectrum in the inertial range as the solar wind reaches one astronomical unit, and how the cascade rate decays as the plasma moves away from the Sun. We evaluate whether these properties display similar trends in a smaller astrophysical system, that of a planetary magnetosheath. Using data from the 2023 Magnetospheric Multiscale (MMS) unbiased magnetosheath campaign, we determine the evolution of the spectral indices and the cascade rate along 15 inbound magnetosheath crossings. WIND observations permitted to monitor the state of the solar wind during the campaign and allowed to study the impact of the upstream plasma conditions on the evolution of the cascade rate downstream the bow shock. Our results show an increase of the cascade rate between two to three orders of magnitude after the plasma crosses the bow shock into the magnetosheath. Once in the magnetosheath, turbulence develops with increasing distance to the bow shock in a way similar to solar wind observations, despite the smaller size of the system. Incompressible Hall-MHD scaling-law estimates of the cascade rate show a clear power-law decay of the cascade rate in the magnetosheath, particularly for the cases with upstream slow wind. This suggests that the way energy is injected into the system plays a role in the decay of turbulence as the plasma moves away from the bow shock.

astro-ph.SR↗