scholarly journals Comparative Analysis of the Various Generalized Ohm's Law Terms in Magnetosheath Turbulence as Observed by Magnetospheric Multiscale

Author(s):  
J. E. Stawarz ◽  
L. Matteini ◽  
T. N. Parashar ◽  
L. Franci ◽  
J. P. Eastwood ◽  
...  
2021 ◽  
Author(s):  
Julia Stawarz ◽  
Lorenzo Matteini ◽  
Tulasi Parashar ◽  
Luca Franci ◽  
Jonathan Eastwood ◽  
...  

<p><span>Electric fields (<strong>E</strong>) play a fundamental role in facilitating the exchange of energy between the electromagnetic fields and the changed particles within a plasma. </span>Decomposing <strong>E</strong> into the contributions from the different terms in generalized Ohm's law, therefore, provides key insight into both the nonlinear and dissipative dynamics across the full range of scales within a plasma. Using the unique, high‐resolution, multi‐spacecraft measurements of three intervals in Earth's magnetosheath from the Magnetospheric Multiscale mission, the influence of the magnetohydrodynamic, Hall, electron pressure, and electron inertia terms from Ohm's law, as well as the impact of a finite electron mass, on the turbulent electric field<strong> </strong>spectrum are examined observationally for the first time. The magnetohydrodynamic, Hall, and electron pressure terms are the dominant contributions to <strong>E</strong> over the accessible length scales, which extend to scales smaller than the electron gyroradius at the greatest extent, with the Hall and electron pressure terms dominating at sub‐ion scales. The strength of the non‐ideal electron pressure contribution is stronger than expected from linear kinetic Alfvén waves and a partial anti‐alignment with the Hall electric field is present, linked to the relative importance of electron diamagnetic currents within the turbulence. The relative contributions of linear and nonlinear electric fields scale with the turbulent fluctuation amplitude, with nonlinear contributions playing the dominant role in shaping <strong>E</strong> for the intervals examined in this study. Overall, the sum of the Ohm's law terms and measured <strong>E</strong> agree to within ∼ 20% across the observable scales. The results both confirm a number of general expectations about the behavior of <strong>E</strong> within turbulent plasmas, as well as highlight additional features that may help to disentangle the complex dynamics of turbulent plasmas and should be explored further theoretically.</p>


Author(s):  
Julia E. Stawarz ◽  
Lorenzo Matteini ◽  
Tulasi N. Parashar ◽  
Luca Franci ◽  
Jonathan P. Eastwood ◽  
...  

2016 ◽  
Vol 72 (7) ◽  
Author(s):  
Alexander Alexandrovich Antonov
Keyword(s):  

1975 ◽  
Vol 57 (S1) ◽  
pp. S38-S38
Author(s):  
W. M. Mills ◽  
J. D. Gilliom
Keyword(s):  

2021 ◽  
Author(s):  
Jinyun Tang ◽  
Jinyun Tang ◽  
William Riley ◽  
Gianna L Maschmann ◽  
Eoin L Brodie
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document