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Dissipation in turbulent plasma due to reconnection in thin current sheets
David Sundkvist1, Alessandro Retinò, Andris Vaivads
1Space Sciences Laboratory, University of California, Berkeley, California, USA. sundkvist@ssl.berkeley.edu
Physical Review Letters
|August 7, 2007
Summary
Thin current sheets, abundant in space plasma turbulence, show microphysical signs of magnetic reconnection. These structures are key to understanding energy dissipation in turbulent plasmas.
Area of Science:
- Space plasma physics
- Astrophysics
- Plasma turbulence
Background:
- Space plasma is characterized by complex turbulent dynamics.
- Understanding energy dissipation mechanisms in plasma is crucial.
- Current sheets are theorized to play a role in plasma dissipation.
Purpose of the Study:
- To investigate the existence and properties of thin current sheets in space plasma turbulence.
- To determine if these current sheets exhibit signatures of magnetic reconnection.
- To assess the role of reconnecting current sheets in energy dissipation.
Main Methods:
- In situ measurements within space plasma.
- Analysis of plasma turbulence and current sheet structures.
- Identification of microphysical signatures of magnetic reconnection.
Main Results:
- Thin current sheets, at the ion inertial length scale, are abundant in strong, intermittent plasma turbulence.
- Many observed current sheets display microphysical signatures indicative of magnetic reconnection.
- The spatial scale of intermittency aligns with the observed current sheet structures.
- Dissipation rates in reconnecting current sheets are comparable to or exceed collisionless damping rates.
Conclusions:
- Reconnecting current sheets are a significant dissipation mechanism in turbulent space plasmas.
- These findings have broad implications for understanding small-scale energy dissipation across various turbulent plasma environments.
- The ion inertial length scale is a critical scale for these microphysical processes.
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