Predictions for Near Sun Turbulent Spectra from Synthetic Time Series

Abstract:

The unprecedented observations of the near Sun environment
that will soon be afforded by the launch of Solar Probe Plus
and Solar Orbiter will help discern the underlying nature
of the acceleration of the solar wind and the heating of the
corona.
Preliminary theoretical predictions for the signatures of
the possible mechanisms driving these phenomena are necessary
to interpret measurements from these missions.
In this work, we construct such predictions
for the turbulent magnetic and velocity spectra
using synthetic time series constructed from
a spectrum of linear eigenmodes, a technique previously
validated for studying the solar wind near 1 AU.
This technique has been extended to include mechanisms
unique to the near Sun environment, including the
violation of the Taylor Hypothesis, the rapidly varying
transverse and radial velocities, and the inbalanced
flux of Alfvenic fluctuations, all of which will make
interpretations of in situ observations more difficult.
The synthetic time series spectra are also compared
to results from nonlinear turbulence simulations relevant to
the near Sun environment as a means of validating and establishing
the limitations of the synthetic time series approach.