Observation of Turbulent Magnetohydrodynamic Cascade in the Jovian Magnetosheath

TL;DR

This study estimates the energy cascade rate in Jupiter's magnetosheath using in-situ spacecraft data, revealing a significantly lower cascade rate compared to Earth's magnetosheath, and highlights the presence of compressible turbulence.

Contribution

First estimation of the energy cascade rate in Jupiter's magnetosheath using in-situ data and recent models, revealing unique turbulence characteristics.

Findings

Energy cascade rate in Jupiter's MS is at least 100 times smaller than Earth's.

High levels of compressible density fluctuations are observed.

A constant energy flux exists in the MHD inertial range.

Abstract

We present the first estimation of the energy cascade rate in Jupiter's magnetosheath (MS). We use in-situ observations from the Jovian Auroral Distributions Experiment (JADE) and the magnetometer investigation (MAG) instruments onboard the Juno spacecraft, in concert with two recent compressible models to investigate the cascade rate in the magnetohydrodynamic (MHD) scales. While a high level of compressible density fluctuations is observed in the Jovian MS, a constant energy flux exists in the MHD inertial range. The compressible isothermal and polytropic energy cascade rates increase in the MHD range when density fluctuations are present. We find that the energy cascade rate in Jupiter's magnetosheath is at least two orders of magnitude (100 times) smaller than the corresponding typical value in the Earth's magnetosheath.