Estimation of Turbulent Proton and Electron Heating Rates via Landau Damping Constrained by Parker Solar Probe Observations
Abstract
The heating of ions and electrons due to turbulent dissipation plays a crucial role in the thermodynamics of the solar wind and other plasma environments. Using magnetic field and thermal plasma observations from the first two perihelia of the Parker Solar Probe, we model the relative heating rates as a function of the radial distance, magnetic spectra, and plasma conditions, enabling us to better characterize the thermodynamics of the inner heliosphere. We employ the Howes et al. steadystate cascade model, which considers the behavior of turbulent, lowfrequency, wavevectoranisotropic, critically balanced Alfvénic fluctuations that dissipate via Landau damping to determine protontoelectron heating rates Q _{ p }/Q _{ e }. We distinguish ion cyclotron frequency circularly polarized waves from lowfrequency turbulence and constrain the cascade model using spectra constructed from the latter. We find that the model accurately describes the observed energy spectrum from over 39.4% of the intervals from Encounters 1 and 2, indicating the possibility for Landau damping to heat the young solar wind. The ability of the model to describe the observed turbulent spectra increases with the ratio of thermaltomagnetic pressure, β _{ p }, indicating that the model contains the necessary physics at higher β _{ p }. We estimate high magnitudes for the Kolmogorov constant which is inversely proportional to the nonlinear energy cascade rate. We verify the expected strong dependency of Q _{ p }/Q _{ e } on β _{ p } and the consistency of the critical balance assumption.
 Publication:

The Astrophysical Journal
 Pub Date:
 April 2023
 DOI:
 10.3847/15384357/acb542
 arXiv:
 arXiv:2301.09713
 Bibcode:
 2023ApJ...946...85S
 Keywords:

 Solar wind;
 Interplanetary turbulence;
 Space plasmas;
 Wavelet analysis;
 1534;
 830;
 1544;
 1918;
 Astrophysics  Solar and Stellar Astrophysics;
 Physics  Plasma Physics;
 Physics  Space Physics
 EPrint:
 doi:10.3847/15384357/acb542