Limitations of Hall MHD as a model for turbulence in weakly collisional plasmas
The limitations of Hall MHD as a model for turbulence in weakly collisional plasmas are explored using quantitative comparisons to Vlasov-Maxwell kinetic theory over a wide range of parameter space. The validity of Hall MHD in the cold ion limit is shown, but spurious undamped wave modes exist in Ha...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2009-03-01
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| Series: | Nonlinear Processes in Geophysics |
| Online Access: | http://www.nonlin-processes-geophys.net/16/219/2009/npg-16-219-2009.pdf |
| _version_ | 1819199662316322816 |
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| author | G. G. Howes |
| author_facet | G. G. Howes |
| author_sort | G. G. Howes |
| collection | DOAJ |
| description | The limitations of Hall MHD as a model for turbulence in weakly collisional plasmas are explored using quantitative comparisons to Vlasov-Maxwell kinetic theory over a wide range of parameter space. The validity of Hall MHD in the cold ion limit is shown, but spurious undamped wave modes exist in Hall MHD when the ion temperature is finite. It is argued that turbulence in the dissipation range of the solar wind must be one, or a mixture, of three electromagnetic wave modes: the parallel whistler, oblique whistler, or kinetic Alfvén waves. These modes are generally well described by Hall MHD. Determining the applicability of linear kinetic damping rates in turbulent plasmas requires a suite of fluid and kinetic nonlinear numerical simulations. Contrasting fluid and kinetic simulations will also shed light on whether the presence of spurious wave modes alters the nonlinear couplings inherent in turbulence and will illuminate the turbulent dynamics and energy transfer in the regime of the characteristic ion kinetic scales. |
| first_indexed | 2024-12-23T03:19:54Z |
| format | Article |
| id | doaj.art-5329bfbc8a694f86b1331d932d4ec6de |
| institution | Directory Open Access Journal |
| issn | 1023-5809 1607-7946 |
| language | English |
| last_indexed | 2024-12-23T03:19:54Z |
| publishDate | 2009-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Nonlinear Processes in Geophysics |
| spelling | doaj.art-5329bfbc8a694f86b1331d932d4ec6de2022-12-21T18:02:02ZengCopernicus PublicationsNonlinear Processes in Geophysics1023-58091607-79462009-03-01162219232Limitations of Hall MHD as a model for turbulence in weakly collisional plasmasG. G. HowesThe limitations of Hall MHD as a model for turbulence in weakly collisional plasmas are explored using quantitative comparisons to Vlasov-Maxwell kinetic theory over a wide range of parameter space. The validity of Hall MHD in the cold ion limit is shown, but spurious undamped wave modes exist in Hall MHD when the ion temperature is finite. It is argued that turbulence in the dissipation range of the solar wind must be one, or a mixture, of three electromagnetic wave modes: the parallel whistler, oblique whistler, or kinetic Alfvén waves. These modes are generally well described by Hall MHD. Determining the applicability of linear kinetic damping rates in turbulent plasmas requires a suite of fluid and kinetic nonlinear numerical simulations. Contrasting fluid and kinetic simulations will also shed light on whether the presence of spurious wave modes alters the nonlinear couplings inherent in turbulence and will illuminate the turbulent dynamics and energy transfer in the regime of the characteristic ion kinetic scales.http://www.nonlin-processes-geophys.net/16/219/2009/npg-16-219-2009.pdf |
| spellingShingle | G. G. Howes Limitations of Hall MHD as a model for turbulence in weakly collisional plasmas Nonlinear Processes in Geophysics |
| title | Limitations of Hall MHD as a model for turbulence in weakly collisional plasmas |
| title_full | Limitations of Hall MHD as a model for turbulence in weakly collisional plasmas |
| title_fullStr | Limitations of Hall MHD as a model for turbulence in weakly collisional plasmas |
| title_full_unstemmed | Limitations of Hall MHD as a model for turbulence in weakly collisional plasmas |
| title_short | Limitations of Hall MHD as a model for turbulence in weakly collisional plasmas |
| title_sort | limitations of hall mhd as a model for turbulence in weakly collisional plasmas |
| url | http://www.nonlin-processes-geophys.net/16/219/2009/npg-16-219-2009.pdf |
| work_keys_str_mv | AT gghowes limitationsofhallmhdasamodelforturbulenceinweaklycollisionalplasmas |