TY - JOUR N1 - This version is the author accepted manuscript. For information on re-use, please refer to the publisher's terms and conditions. VL - 385 SP - 962 PB - American Association for the Advancement of Science (AAAS) A1 - Rivera, Yeimy J A1 - Badman, Samuel T A1 - Stevens, Michael L A1 - Verniero, Jaye L A1 - Stawarz, Julia E A1 - Shi, Chen A1 - Raines, Jim M A1 - Paulson, Kristoff W A1 - Owen, Christopher J A1 - Niembro, Tatiana A1 - Louarn, Philippe A1 - Livi, Stefano A A1 - Lepri, Susan T A1 - Kasper, Justin C A1 - Horbury, Timothy S A1 - Halekas, Jasper S A1 - Dewey, Ryan M A1 - De Marco, Rossana A1 - Bale, Stuart D JF - Science TI - In situ observations of large-amplitude Alfvén waves heating and accelerating the solar wind Y1 - 2024/08/30/ AV - public N2 - 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. Alfvén waves are perturbations of the interplanetary magnetic field that transport energy. We use in situ measurements from the Parker Solar Probe and Solar Orbiter spacecraft to investigate a stream of solar wind as it traverses the inner heliosphere. The observations show heating and acceleration of the plasma between the outer edge of the corona and near the orbit of Venus, along with the presence of large-amplitude Alfvén waves. We calculate that the damping and mechanical work performed by the Alfvén waves are sufficient to power the heating and acceleration of the fast solar wind in the inner heliosphere. IS - 6712 UR - http://dx.doi.org/10.1126/science.adk6953 EP - 966 ID - discovery10197343 ER -