Modelling the formation and evolution of solar wind microstreams:from coronal plumes to propagating Alfvénic velocity spikes.

Our research delves into solar wind's mesoscale features known as microstreams—periods of heightened speed and temperature lasting hours. Initially observed in Helios and Ulysses data, they're now prevalent in the 'young' solar wind by Parker Solar Probe and Solar Orbiter. Recent findings unveil microstreams' carriage of abundant Alfvénic perturbations—velocity spikes and magnetic switchbacks.

Employing a high-resolution 2.5 MHD model, we scrutinize the genesis of microstreams from emerging bipoles interacting with the ambient corona. Our simulations reveal the tearing-mode instability, forming plasmoids released into the solar wind. Our domain spans the lower corona to 20 Rs, enabling observation of plasmoid formation and their evolution into Alfvénic spikes (Gannouni et al. 2023). The magnetic emergence rate modulates microstream characteristics.

Additionally, 3D MHD simulations explore intermittent interchange reconnection in a 24x24x30Mm domain with a flux emergence rate of 1.38G/s. Reconnection spawns plasma jets and twisted magnetic field bundles, releasing hot plasma into the solar wind, inducing propagating waves and twists along magnetic field lines.