Transport of cross helicity and radial evolution of Alfvénicity in the solar wind

Matthaeus, W. H.; Minnie, J.; Breech, B.; Parhi, S.; Bieber, J. W.; Oughton, Sean

doi:10.1029/2004gl019645

Cited by 86 publications

(99 citation statements)

References 25 publications

(58 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[27] Energy injection due to coupling of the fluctuations with pickup ions, _ E PI , is approximated as in earlier works [e.g., Williams and Zank, 1994;Williams et al, 1995;Zank et al, 1996;Matthaeus et al, 1999Matthaeus et al, , 2004Smith et al, 2001Smith et al, , 2006Isenberg et al, 2003;Isenberg, 2005;Breech et al, 2005Breech et al, , 2008, although as discussed below, the impact on the length scales is modeled in a much-improved fashion. Recall that only a small fraction of the ostensibly available pickup ion energy is actually transferred to the wave-like component [Isenberg et al, 2003;Isenberg, 2005].…”

Section: Transport Modelmentioning

confidence: 99%

“…; they approach zero or unity in appropriate limits for the cross helicities. See Matthaeus et al [2004] for discussion of these attenuation factors in the context of a single-component transport model.…”

Section: Incompressible Two-component Turbulence Modelmentioning

confidence: 99%

“…Generalizations that support shear driving at other length scales are straightforward to obtain [e.g., Matthaeus et al, 2004;Breech et al, 2005].…”

Section: Transport Modelmentioning

confidence: 99%

“…Subsequent observational studies indicated that at magnetohydrodynamic (MHD) scales there are at least two distinct types of fluctuation and that the wave-like energy may be a minor component Bieber et al, 1996;Milano et al, 2004;Dasso et al, 2005;Horbury et al, 2005Horbury et al, , 2008Podesta, 2009;Osman and Horbury, 2009;Narita et al, 2010]. This encouraged development of more complete transport theories for the energy-containing range quantities [e.g., Tu and Marsch, 1993;Matthaeus et al, 1994Matthaeus et al, , 1996Matthaeus et al, , 1999Matthaeus et al, , 2004Zank et al, 1996;Smith et al, 2001Smith et al, , 2006Isenberg et al, 2003Isenberg et al, , 2010aIsenberg, 2005;Breech et al, 2005Breech et al, , 2008Yokoi and Hamba, 2007;Usmanov and Goldstein, 2010;Ng et al, 2010], in which turbulence properties are built in, contrasting with WKB theory, in which the waves are noninteracting at leading order. The agreement between observations made from 0.3 to 80 AU and numerical solutions to these models has also improved, with reasonable accord achieved for the radial evolution of the energy, cross helicity (H c ), and correlation length of the fluctuations and also for the proton temperature.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Transport of solar wind fluctuations: A two-component model

et al. 2011

Self Cite

View full text Add to dashboard Cite

[1] We present a new model for the transport of solar wind fluctuations which treats them as two interacting incompressible components: quasi-two-dimensional turbulence and a wave-like piece. Quantities solved for include the energy, cross helicity, and characteristic transverse length scale of each component, plus the proton temperature. The development of the model is outlined and numerical solutions are compared with spacecraft observations. Compared to previous single-component models, this new model incorporates a more physically realistic treatment of fluctuations induced by pickup ions and yields improved agreement with observed values of the correlation length, while maintaining good observational accord with the energy, cross helicity, and temperature.

show abstract

Section: Transport Modelmentioning

confidence: 99%

Section: Incompressible Two-component Turbulence Modelmentioning

confidence: 99%

“…Generalizations that support shear driving at other length scales are straightforward to obtain [e.g., Matthaeus et al, 2004;Breech et al, 2005].…”

Section: Transport Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Transport of solar wind fluctuations: A two-component model

et al. 2011

Self Cite

View full text Add to dashboard Cite

show abstract

“…Of course, this problem can also be addressed using the more standard wave techniques [e.g., Lou, 1995;Orlando et al, 1997;Oughton and Matthaeus, 1995]. Other approaches have considered parametric instabilities of Alfvén waves [del Zanna et al, 2001[del Zanna et al, , 2003Malara et al, 2001;Vasquez, 1995] and MHD turbulence [e.g., Breech et al, 2005;Matthaeus et al, 1998Matthaeus et al, , 2004.…”

Section: Introductionmentioning

confidence: 99%

Reflection of Alfvén waves in the corona and solar wind: An impulse function approach

Hollweg

Isenberg

2007

J. Geophys. Res.

View full text Add to dashboard Cite

[1] We consider the reflection of Alfvén waves in the corona and solar wind, using variables f and g which follow sunward and antisunward characteristics, respectively. We show that the basic equations for f and g have the same structure as the Klein-Gordon equation. Unlike previous studies which used a harmonic analysis, we emphasize the impulse response of the system. This is equivalent to finding the Green's function, but it may have direct application to situations where Alfvén waves are launched impulsively. We provide an approximate analysis which can be used to understand most features that appear in detailed numerical solutions. The analysis reveals the origin of a previous result that f and g each has both sunward and antisunward propagating phase in a harmonic analysis, even though f (g) follows only the sunward (antisunward) characteristic. We numerically study the propagation of an antisunward moving impulse in the corona and solar wind. We find that the sunward moving ''wake'' tends to become more important at greater distances beyond the Alfvén critical point, possibly providing a natural explanation of the observation that outward propagating waves become less dominant at greater distances from the Sun. There is an extended region behind the initial impulse in which magnetic energy dominates kinetic energy; it is not clear, however, whether our result can explain the observed dominance of magnetic energy throughout many decades of frequency in the observed power spectrum. We also find that the outgoing wake has a tendency to ''ring,'' with periods of the order of 15-30 min. The ringing is associated mainly with propagation through a structured Alfvén speed profile rather that with the cutoff in the Klein-Gordon equation. These oscillation periods seem too short to explain why Alfvén waves in the solar wind have most power at periods of hours, but other Alfvén speed profiles could yield longer periods. We also investigate whether the same approach can be used for acoustic-gravity waves propagating along magnetic flux tubes in the solar atmosphere.

show abstract

Turbulence Studied via Elsässer Variables

Bruno

Carbone

2016

Turbulence in the Solar Wind

View full text Add to dashboard Cite

Transport of cross helicity and radial evolution of Alfvénicity in the solar wind

Cited by 86 publications

References 25 publications

Transport of solar wind fluctuations: A two-component model

Transport of solar wind fluctuations: A two-component model

Reflection of Alfvén waves in the corona and solar wind: An impulse function approach

Turbulence Studied via Elsässer Variables

Contact Info

Product

Resources

About