Direct observations of cross-scale wave-particle energy transfer in space plasmasShow others and affiliations
2025 (English)In: Science Advances, E-ISSN 2375-2548, Vol. 11, no 6, article id eadr8227Article in journal (Refereed) Published
Abstract [en]
The collisionless plasmas in space and astrophysical environments are intrinsically multiscale in nature, behaving as conducting fluids at macroscales and kinetically at microscales comparable to ion and/or electron gyroradii. A fundamental question in understanding the plasma dynamics is how energy is transported and dissipated across scales. Here, we present spacecraft measurements in the terrestrial foreshock, a region upstream of the bow shock where the solar wind population coexists with the reflected ions. In this region, the fluid-scale, ultralow-frequency waves resonate with the reflected ions to modify the velocity distributions, which in turn cause the growth of the ion-scale, magnetosonic-whistler waves. The latter waves then resonate with the electrons, and the accelerated electrons contribute to the excitation of electron-scale, high-frequency whistler waves. These observations demonstrate that the chain of wave-particle resonances is an efficient mechanism for cross-scale energy transfer, which could redistribute the kinetic energy and accelerate the particles upstream of the shocks.
Place, publisher, year, edition, pages
American Association for the Advancement of Science (AAAS), 2025. Vol. 11, no 6, article id eadr8227
National Category
Fusion, Plasma and Space Physics Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:uu:diva-551610DOI: 10.1126/sciadv.adr8227ISI: 001416079000006PubMedID: 39919183Scopus ID: 2-s2.0-85218218036OAI: oai:DiVA.org:uu-551610DiVA, id: diva2:1941093
2025-02-272025-02-272025-02-27Bibliographically approved