A Model for Coronal Inflows and In/Out Pairs

TL;DR

This paper introduces a 3D MHD model that simulates coronal inflows and in/out pairs observed in the solar corona, providing insights into their formation, structure, and role in solar wind variability.

Contribution

The study presents a novel 3D MHD simulation that reproduces coronal inflows and in/out pairs, linking observational phenomena with magnetic reconnection processes.

Findings

Narrow density depletion lanes form high in the corona and move inward.

Simulation inflow velocities and structures match observational data.

Magnetic field analysis explains the formation of in/out pairs.

Abstract

This report presents a three-dimensional (3D) numerical magnetohydrodynamics (MHD) model of the white-light coronagraph observational phenomena known as coronal inflows and in/out pairs. Coronal inflows in the LASCO/C2 field of view (approximately 2-6 Rs) were thought to arise from the dynamic and intermittent release of solar wind plasma associated with the helmet streamer belt as the counterpart to outward-propagating streamer blobs, formed by magnetic reconnection. This interpretation was essentially confirmed with the subsequent identification of in/out pairs and the multispacecraft observations of their 3D structure. The MHD simulation results show relatively narrow lanes of density depletion form high in the corona and propagate inwards with sinuous motion which has been characterized as `tadpole-like' in coronagraph imagery. The height--time evolution and velocity profiles of the simulation inflows and in/out pairs are compared to their corresponding observations and a detailed analysis of the underlying magnetic field structure associated with the synthetic white-light and mass density evolution is presented. Understanding the physical origin of this structured component of the slow solar wind's intrinsic variability could make a significant contribution to solar wind modeling and the interpretation of remote and in-situ observations from Parker Solar Probe and Solar Orbiter.