Significant Amplification of Turbulent Energy Dissipation through the Shock Transition at Mars

TL;DR

This study uses MAVEN data to show that shock transitions at Mars significantly amplify turbulence energy dissipation, especially downstream of oblique and quasi-perpendicular shocks, revealing shock obliquity's role in turbulence enhancement.

Contribution

It provides the first observational evidence of shock-induced turbulence amplification at Mars and quantifies how shock obliquity influences energy cascade rates.

Findings

Turbulence energy cascade rate increases by three orders of magnitude at the shock transition.

Downstream of oblique and quasi-perpendicular shocks, dissipation rates are higher than in quasi-parallel shocks.

Shock obliquity directly correlates with turbulence amplification in planetary magnetosheaths.

Abstract

Turbulence is fundamental to energy transfer across scales in space and astrophysical plasmas. Bow shock interactions have long been hypothesized to significantly modify turbulence in planetary environments, yet the quantification of such effects and their parametric dependencies remain largely unaddressed. Using in situ long-term high-time resolution measurements from NASA's MAVEN mission, we report the first observational characterization of the evolution and parametric dependence of the turbulence energy cascade rate $\varepsilon_C$ at magnetohydrodynamic (MHD) scales. Key findings reveal an averaged three-order-of-magnitude enhancement in $\varepsilon_C$ when transitioning from the solar wind to the magnetosheath. Notably, downstream measurements of oblique and quasi-perpendicular shocks exhibit higher energy dissipation rates than those of quasi-parallel configurations. These results provide the first direct evidence linking shock obliquity to turbulence amplification, offering key insights into shock-mediated turbulence in similar but inaccessible systems.