HR: 16:33h
AN: SH44A-03 INVITED [Abstracts]
TI: Review of Solar Wind Heating: Observations and Theory
AU: * Smith, C W
EM: Charles.Smith@unh.edu
AF: Space Science Center, Morse Hall,
University of New Hampshire, Durham, NH 03824
United States
AB:
Observations from Helios, Pioneer 11, and the Voyager 1/2 spacecraft provide clear evidence for heating of the solar wind
protons. Several sources of energy to drive the heating are now recognized, from residual waves originating in the low solar
corona that may be at least partially responsible for heating the inner heliosphere, to wind shear and shocks that provide
energy to heat the solar wind inside 10 to 20 AU, to waves generated by newborn interstellar pickup ions that heat the outer
heliosphere. These processes imply the need for a theory to convert energy associated with large-scale structures into the
small-scale fluctuations that can interact with the protons via familiar plasma processes. We will briefly review such a
theory and test it against the observations. We will examine several formalisms for computing an inferred turbulent heating
rate from magnetic field measurements and compare their predictions with observations. We will also review past and recent
attempts to identify the plasma processes responsible for converting magnetic energy into heat. This involves studying the
so-called dissipation range and resolving its properties in comparison with the more familiar inertial range of
interplanetary magnetic fluctuations. While this will not lead to a final decision on what plasma processes heat the solar
wind, it will provide a list of diagnostics and observations that constrain the discussion.
DE: 2134 Interplanetary magnetic fields
DE: 2149 MHD waves and turbulence
DE: 2152 Pickup ions
DE: 2164 Solar wind plasma
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting