Solar Wind and PUI Proton Heating Rates and Turbulence Effects on Energetic Particles in the Heliosphere
7 affiliations
- 1University of Alabama in Huntsville
- 2Princeton University
- 3Johns Hopkins Applied Physics Laboratory
- 4Boston University
- 5Massachusetts Institute of Technology
- 6Southwest Research Institute
- 7Center for Space Research and Technology
Abstract
We present a method for estimating the heating rate of solar wind (SW) and pickup ion (PUI) protons from their respective energy equations. Here, we estimate the heating rate for SW protons along the New Horizons (NH), Voyager 2 (V2), and Pioneer 10 (P10) trajectories using plasma measurements, rather than the magnetic field measurements. We also compute the heating rate for PUI protons for the first time along the NH direction. We find that the SW proton heating rate in the V2 direction is higher than that along the NH direction between ∼26 and ∼52 au. Along the P10 direction, the proton heating rate exceeds that of V2 between 20 and 38 au, but is less beyond 38 au. The heating rate differs along the spacecraft trajectories in the upwind and downwind directions. The PUI proton heating rate is found to be more than 2 orders of magnitude larger than that of SW protons between ∼26 and ∼52 au. The SW/PUI heating rate correlates with SW speed and SW/PUI temperature. We present a comparison between the injection rate of turbulence energy in the energy-containing range and the intensity profile of energetic particles in the ∼50–110 keV range as a function of distance along the NH and V2 directions. It suggests that turbulence may play an important role in the modulation of energetic particles throughout the heliosphere.
Related
- Equipartition between Alfvénic turbulence and energetic ions as the origin of the -5 common spectrum in the heliosphere
- Velocity Dispersion of Solar Energetic Particles in the Turbulent Heliosphere
- Proton Heating Rates in the Inner Heliosphere: Helios Observations
- Kinetic wave activity and proton heating in 3D hybrid simulations of decaying balanced and imbalanced Alfvénic turbulence
- Solar-wind proton heating and its effect on the temperature anisotropy evolution between 0.05 and 1 au
BibTeX
@article{adhikari2026solar,
title = {{Solar Wind and PUI Proton Heating Rates and Turbulence Effects on Energetic Particles in the Heliosphere}},
author = {Laxman Adhikari and Bishwas L. Shrestha and Gary P. Zank and Vladimir Florinski and Ashutosh Giri and Sagar Ghimire and Bingbing Wang and Romina Nikoukar and Matthew E. Hill and Jakobus Le Roux and David J. McComas and Merav Opher and John Richardson and Bartholomeus Van Der Holst and Lingling Zhao and Parisa Mostafavi and Justyna M. Sokół and Konstantinos Dialynas and Heather Elliott},
journal = {The Astrophysical Journal},
year = {2026},
month = nov,
doi = {10.3847/1538-4357/aeacc4},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/aeacc4},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Solar Wind and PUI Proton Heating Rates and Turbulence Effects on Energetic Particles in the Heliosphere
AU - Laxman Adhikari
AU - Bishwas L. Shrestha
AU - Gary P. Zank
AU - Vladimir Florinski
AU - Ashutosh Giri
AU - Sagar Ghimire
AU - Bingbing Wang
AU - Romina Nikoukar
AU - Matthew E. Hill
AU - Jakobus Le Roux
AU - David J. McComas
AU - Merav Opher
AU - John Richardson
AU - Bartholomeus Van Der Holst
AU - Lingling Zhao
AU - Parisa Mostafavi
AU - Justyna M. Sokół
AU - Konstantinos Dialynas
AU - Heather Elliott
PY - 2026
DA - 2026/11/06
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/aeacc4
UR - https://iopscience.iop.org/article/10.3847/1538-4357/aeacc4
AB - We present a method for estimating the heating rate of solar wind (SW) and pickup ion (PUI) protons from their respective energy equations. Here, we estimate the heating rate for SW protons along the New Horizons (NH), Voyager 2 (V2), and Pioneer 10 (P10) trajectories using plasma measurements, rather than the magnetic field measurements. We also compute the heating rate for PUI protons for the first time along the NH direction. We find that the SW proton heating rate in the V2 direction is higher than that along the NH direction between ∼26 and ∼52 au. Along the P10 direction, the proton heating rate exceeds that of V2 between 20 and 38 au, but is less beyond 38 au. The heating rate differs along the spacecraft trajectories in the upwind and downwind directions. The PUI proton heating rate is found to be more than 2 orders of magnitude larger than that of SW protons between ∼26 and ∼52 au. The SW/PUI heating rate correlates with SW speed and SW/PUI temperature. We present a comparison between the injection rate of turbulence energy in the energy-containing range and the intensity profile of energetic particles in the ∼50–110 keV range as a function of distance along the NH and V2 directions. It suggests that turbulence may play an important role in the modulation of energetic particles throughout the heliosphere.
SN - 1538-4357
SN - 0004-637X
ER -