On the evaluation of solar wind's heating rates by Arnaud Zaslavsky. on Monday 21 November
Solar wind heating rates have often been calculated by fitting plasma and
magnetic field data with a set of model functions. In this letter, we show that
the rates obtained by such an approach strongly depend on the rather arbitrary
choice one makes for these model functions. An alternative approach, consisting
in monitoring the radial evolution of the adiabatic invariants, based on
locally and consistently measured plasma and magnetic field parameters, is free
from such a flaw. We apply this technique to a recently released Helios proton
dataset, and confirm the existence of a clear perpendicular heating of solar
wind's protons. On the other hand, no significant change in the parallel
adiabatic invariant is visible in the data. We conclude that to date, and in
the distance range of 0.3 to 1 AU, no clear observation of a deviation of solar
wind's protons from parallel adiabaticity has ever been made.
arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.09650v1
