Variability of the Incompressible Energy Cascade Rate in Solar Wind Turbulence Around Mars

TL;DR

This study analyzes how the energy transfer rate in solar wind turbulence varies around Mars over five years, revealing a decrease with distance and minimal impact from proton cyclotron waves.

Contribution

It provides the first statistical analysis of the incompressible energy cascade rate in the Martian solar wind environment using MAVEN data.

Findings

Energy cascade rate decreases with increasing Martian heliocentric distance.

Proton cyclotron waves do not significantly affect the MHD scale energy cascade.

The analysis covers over five years of MAVEN observations.

Abstract

We present a statistical analysis on the variability of the incompressible energy cascade rate in the solar wind around Mars, making use of an exact relation for fully developed turbulence and more than five years of Mars Atmosphere and Volatile EvolutioN (MAVEN) observations. Using magnetic field and plasma data, we compute the energy cascade rate in the magnetohydrodynamics (MHD) scales in the pristine solar wind. From our statistical results, we conclude that the incompressible energy cascade rate decreases as the Martian heliocentric distance increases, for each of the three explored Martian years. Moreover, we show that the presence of proton cyclotron waves, associated with the extended Martian hydrogen exosphere, do not have a significant effect in the nonlinear cascade of energy at the MHD scales.