In situ observations of large amplitude Alfvén waves heating and accelerating the solar wind

Abstract

After leaving the Sun's corona, the solar wind continues to accelerate and cools, but more slowly than expected for a freely expanding adiabatic gas. We use in situ measurements from the Parker Solar Probe and Solar Orbiter spacecrafts to investigate a stream of solar wind as it traverses the inner heliosphere. The observations show heating and acceleration of the the plasma between the outer edge of the corona and near the orbit of Venus, in connection to the presence of large amplitude Alfvén waves. Alfvén waves are perturbations in the interplanetary magnetic field that transport energy. Our calculations show the damping and mechanical work performed by the Alfvén waves is sufficient to power the heating and acceleration of the fast solar wind in the inner heliosphere.

This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science on August 30 2024, DOI: 10.1126/science.adk6953

References in corpus (7)

• The Solar Orbiter mission -- Science overview
• Observation of inertial energy cascade in interplanetary space plasma
• Magnetic connectivity of the ecliptic plane within 0.5 AU : PFSS modeling of the first PSP encounter
• Electrons in the Young Solar Wind: First Results from the Parker Solar Probe
• Evolution of switchbacks in the inner Heliosphere
• The Radial Evolution of the Solar Wind as Organized by Electron Distribution Parameters
• Prediction and Verification of Parker Solar Probe Solar Wind Sources at 13.3 R${}_{\odot }$