Collisionless Magnetic Reconnection and Waves: Progress Review
Magnetic reconnection is a fundamental process whereby microscopic plasma processes cause macroscopic changes in magnetic field topology, leading to explosive energy release. Waves and turbulence generated during the reconnection process can produce particle diffusion and anomalous resistivity, as w...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2019-11-01
|
| Series: | Frontiers in Astronomy and Space Sciences |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/article/10.3389/fspas.2019.00070/full |
| _version_ | 1818190426478215168 |
|---|---|
| author | Yuri V. Khotyaintsev Daniel B. Graham Cecilia Norgren Andris Vaivads |
| author_facet | Yuri V. Khotyaintsev Daniel B. Graham Cecilia Norgren Andris Vaivads |
| author_sort | Yuri V. Khotyaintsev |
| collection | DOAJ |
| description | Magnetic reconnection is a fundamental process whereby microscopic plasma processes cause macroscopic changes in magnetic field topology, leading to explosive energy release. Waves and turbulence generated during the reconnection process can produce particle diffusion and anomalous resistivity, as well as heat the plasma and accelerate plasma particles, all of which can impact the reconnection process. We review progress on waves related to reconnection achieved using high resolution multi-point in situ observations over the last decade, since early Cluster and THEMIS observations and ending with recent Magnetospheric Multiscale results. In particular, we focus on the waves most frequently observed in relation to reconnection, ranging from low-frequency kinetic Alfvén waves (KAW), to intermediate frequency lower hybrid and whistler-mode waves, electrostatic broadband and solitary waves, as well as the high-frequency upper hybrid, Langmuir, and electron Bernstein waves. Significant progress has been made in understanding localization of the different wave modes in the context of the reconnection picture, better quantification of generation mechanisms and wave-particle interactions, including anomalous resistivity. Examples include: temperature anisotropy driven whistlers in the flux pileup region, anomalous effects due to lower-hybrid waves, upper hybrid wave generation within the electron diffusion region, wave-particle interaction of electrostatic solitary waves. While being clearly identified in observations, some of the wave processes remain challenging for reconnection simulations (electron Bernstein, upper hybrid, Langmuir, whistler), as the instabilities (streaming, loss-cone, shell) which drive these waves require high resolution of distribution functions in phase space, and realistic ratio of Debye to electron inertia scales. We discuss how reconnection configuration, i.e., symmetric vs. asymmetric, guide-field vs. antiparallel, affect wave occurrence, generation, effect on particles, and feedback on the overall reconnection process. Finally, we outline some of the major open questions, such as generation of electromagnetic radiation by reconnection sites and role of waves in triggering/onset of reconnection. |
| first_indexed | 2024-12-11T23:58:32Z |
| format | Article |
| id | doaj.art-5b36bfdd46524bc78bde854a642ca0de |
| institution | Directory Open Access Journal |
| issn | 2296-987X |
| language | English |
| last_indexed | 2024-12-11T23:58:32Z |
| publishDate | 2019-11-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Astronomy and Space Sciences |
| spelling | doaj.art-5b36bfdd46524bc78bde854a642ca0de2022-12-22T00:45:18ZengFrontiers Media S.A.Frontiers in Astronomy and Space Sciences2296-987X2019-11-01610.3389/fspas.2019.00070495698Collisionless Magnetic Reconnection and Waves: Progress ReviewYuri V. Khotyaintsev0Daniel B. Graham1Cecilia Norgren2Andris Vaivads3Swedish Institute of Space Physics, Uppsala, SwedenSwedish Institute of Space Physics, Uppsala, SwedenDepartment of Physics and Technology, University of Bergen, Bergen, NorwayDepartment of Space and Plasma Physics, KTH Royal Institute of Technology, Stockholm, SwedenMagnetic reconnection is a fundamental process whereby microscopic plasma processes cause macroscopic changes in magnetic field topology, leading to explosive energy release. Waves and turbulence generated during the reconnection process can produce particle diffusion and anomalous resistivity, as well as heat the plasma and accelerate plasma particles, all of which can impact the reconnection process. We review progress on waves related to reconnection achieved using high resolution multi-point in situ observations over the last decade, since early Cluster and THEMIS observations and ending with recent Magnetospheric Multiscale results. In particular, we focus on the waves most frequently observed in relation to reconnection, ranging from low-frequency kinetic Alfvén waves (KAW), to intermediate frequency lower hybrid and whistler-mode waves, electrostatic broadband and solitary waves, as well as the high-frequency upper hybrid, Langmuir, and electron Bernstein waves. Significant progress has been made in understanding localization of the different wave modes in the context of the reconnection picture, better quantification of generation mechanisms and wave-particle interactions, including anomalous resistivity. Examples include: temperature anisotropy driven whistlers in the flux pileup region, anomalous effects due to lower-hybrid waves, upper hybrid wave generation within the electron diffusion region, wave-particle interaction of electrostatic solitary waves. While being clearly identified in observations, some of the wave processes remain challenging for reconnection simulations (electron Bernstein, upper hybrid, Langmuir, whistler), as the instabilities (streaming, loss-cone, shell) which drive these waves require high resolution of distribution functions in phase space, and realistic ratio of Debye to electron inertia scales. We discuss how reconnection configuration, i.e., symmetric vs. asymmetric, guide-field vs. antiparallel, affect wave occurrence, generation, effect on particles, and feedback on the overall reconnection process. Finally, we outline some of the major open questions, such as generation of electromagnetic radiation by reconnection sites and role of waves in triggering/onset of reconnection.https://www.frontiersin.org/article/10.3389/fspas.2019.00070/fullmagnetic reconnectionturbulencewavesinstabilitieskinetic plasma processes |
| spellingShingle | Yuri V. Khotyaintsev Daniel B. Graham Cecilia Norgren Andris Vaivads Collisionless Magnetic Reconnection and Waves: Progress Review Frontiers in Astronomy and Space Sciences magnetic reconnection turbulence waves instabilities kinetic plasma processes |
| title | Collisionless Magnetic Reconnection and Waves: Progress Review |
| title_full | Collisionless Magnetic Reconnection and Waves: Progress Review |
| title_fullStr | Collisionless Magnetic Reconnection and Waves: Progress Review |
| title_full_unstemmed | Collisionless Magnetic Reconnection and Waves: Progress Review |
| title_short | Collisionless Magnetic Reconnection and Waves: Progress Review |
| title_sort | collisionless magnetic reconnection and waves progress review |
| topic | magnetic reconnection turbulence waves instabilities kinetic plasma processes |
| url | https://www.frontiersin.org/article/10.3389/fspas.2019.00070/full |
| work_keys_str_mv | AT yurivkhotyaintsev collisionlessmagneticreconnectionandwavesprogressreview AT danielbgraham collisionlessmagneticreconnectionandwavesprogressreview AT cecilianorgren collisionlessmagneticreconnectionandwavesprogressreview AT andrisvaivads collisionlessmagneticreconnectionandwavesprogressreview |