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Title: Turbulence transport modeling of the temporal outer heliosphere

Abstract

The solar wind can be regarded as a turbulent magnetofluid, evolving in an expanding solar wind and subject to turbulent driving by a variety of in situ sources. Furthermore, the solar wind and the drivers of turbulence are highly time-dependent and change with solar cycle. Turbulence transport models describing low-frequency magnetic and velocity fluctuations in the solar wind have so far neglected solar cycle effects. Here we consider the effects of solar cycle variability on a turbulence transport model developed by Zank et al. This model is appropriate for the solar wind beyond about 1 AU, and extensions have described the steady-state dependence of the magnetic energy density fluctuations, correlation length, and solar wind temperature throughout the outer heliosphere. We find that the temporal solar wind introduces a periodic variability, particularly beyond ∼10 AU, in the magnetic energy density fluctuations, correlation length, and solar wind temperature. The variability is insufficient to account for the full observed variability in these quantities, but we find that the time-dependent solutions trace the steady-state solutions quite well, suggesting that the steady-state models are reasonable first approximations.

Authors:
; ;  [1];  [2]
  1. Department of Space Science, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)
  2. Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899 (United States)
Publication Date:
OSTI Identifier:
22364986
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 793; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; ENERGY DENSITY; FLUCTUATIONS; HELIOSPHERE; MAGNETOHYDRODYNAMICS; PERIODICITY; SOLAR CYCLE; SOLAR WIND; STEADY-STATE CONDITIONS; TIME DEPENDENCE; TRANSPORT THEORY; TURBULENCE; VELOCITY

Citation Formats

Adhikari, L., Zank, G. P., Hu, Q., and Dosch, A., E-mail: la0004@uah.edu. Turbulence transport modeling of the temporal outer heliosphere. United States: N. p., 2014. Web. doi:10.1088/0004-637X/793/1/52.
Adhikari, L., Zank, G. P., Hu, Q., & Dosch, A., E-mail: la0004@uah.edu. Turbulence transport modeling of the temporal outer heliosphere. United States. doi:10.1088/0004-637X/793/1/52.
Adhikari, L., Zank, G. P., Hu, Q., and Dosch, A., E-mail: la0004@uah.edu. Sat . "Turbulence transport modeling of the temporal outer heliosphere". United States. doi:10.1088/0004-637X/793/1/52.
@article{osti_22364986,
title = {Turbulence transport modeling of the temporal outer heliosphere},
author = {Adhikari, L. and Zank, G. P. and Hu, Q. and Dosch, A., E-mail: la0004@uah.edu},
abstractNote = {The solar wind can be regarded as a turbulent magnetofluid, evolving in an expanding solar wind and subject to turbulent driving by a variety of in situ sources. Furthermore, the solar wind and the drivers of turbulence are highly time-dependent and change with solar cycle. Turbulence transport models describing low-frequency magnetic and velocity fluctuations in the solar wind have so far neglected solar cycle effects. Here we consider the effects of solar cycle variability on a turbulence transport model developed by Zank et al. This model is appropriate for the solar wind beyond about 1 AU, and extensions have described the steady-state dependence of the magnetic energy density fluctuations, correlation length, and solar wind temperature throughout the outer heliosphere. We find that the temporal solar wind introduces a periodic variability, particularly beyond ∼10 AU, in the magnetic energy density fluctuations, correlation length, and solar wind temperature. The variability is insufficient to account for the full observed variability in these quantities, but we find that the time-dependent solutions trace the steady-state solutions quite well, suggesting that the steady-state models are reasonable first approximations.},
doi = {10.1088/0004-637X/793/1/52},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 793,
place = {United States},
year = {2014},
month = {9}
}