A Numerical Investigation of the Recurrent High-speed Jets as a Possibility of Solar Wind Origin

TL;DR

This study uses numerical simulations to explore how high-speed jets in the solar atmosphere could significantly contribute to the origin and acceleration of the solar wind, matching observational data.

Contribution

It demonstrates through hydrodynamic modeling that high-speed jets can produce a transonic solar wind with realistic properties without additional energy sources.

Findings

Jets can accelerate plasma to form a solar wind consistent with observations.

Shocks generated by jets heat and propel plasma upward.

Increasing jet speed or temperature results in faster, hotter solar wind.

Abstract

In the solar atmosphere, jets are prevalent and they are significant for the mass and energy transport. Here we conduct numerical simulations to investigate the mass and energy contributions of the recently observed high-speed jets to the solar wind. With a one-dimensional hydrodynamic solar wind model, the time-dependent pulses are imposed at the bottom to simulate the jets. The simulation results show that without other energy source, the injected plasmas are accelerated effectively to be a transonic wind with a substantial mass flux. The rapid acceleration occurs close to the Sun, and the resulting asymptotic speed, number density at 0.3 AU, as well as mass flux normalized to 1 AU are compatible with in situ observations. As a result of the high speed, the imposed pulses generate a train of shocks traveling upward. By tracing the motions of the injected plasma, it is found that these shocks heat and accelerate the injected plasmas successively step by step to push them upward and eventually allow them to escape. The parametric studies show that increasing the speed of the imposed pulses or their temperature gives a considerably faster, and hotter solar wind, while increasing their number density or decreasing their recurring period only bring a denser solar wind. These studies provide a possibility that the ubiquitous high-speed jets are a substantial mass and energy contributions to the solar wind.