Detection and occurrence rate of ion-scale reconnecting current sheets using Solar Orbiter high cadence data.

Magnetic reconnection is process in which magnetic energy dissipates, turning into kinetic and thermal energy, through the reconfiguration of the magnetic field topology. It has been observed in the solar wind at multiple spatial scales and Sun distances.

The study of magnetic reconnection in large- and medium-scale structures has received closer attention than ion-scale magnetic reconnection, due to the instrumental limitations. Thanks to the Solar Orbiter data, and in particular that from the Proton- Alpha Sensor (PAS) from the Solar Wind Analyser (SWA) instrument, we can now resolve ion velocity distribution functions inside current sheets of thicknesses in the range of a few proton gyroradii. Thus, we are granted the possibility of searching for reconnection signatures at scales near the ion spectral break of the turbulent cascade, and we can investigate its prevalence and its impact in heating and accelerating the solar wind.

In this presentation introduce an algorithm we are developing to automatically identify reconnecting current sheets near the ion spectral break in the solar wind. We find that the uncertainty associated with ion bulk velocity measurements constrains the Alfvén velocities that can be resolved with the available data, resulting in a lower threshold for the detectable reconnecting component of the magnetic field.

We present preliminary results, consisting of a catalog of small-scale current sheets in the solar wind and an assessment of reconnection frequency and prevalence. We show the relative occurrence of reconnecting versus Alfvénic current sheets near ion-scales and discuss the relevance of small-scale magnetic reconnection for energy dissipation in solar wind turbulence.