scholarly journals Self-similar scaling of kinetic energy density in the inertial range of solar wind turbulence

2007 ◽  
Vol 112 (A11) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. J. Podesta
Keyword(s):  
Solar Wind ◽  
Energy Density ◽  
Kinetic Energy ◽  
Inertial Range ◽  
Kinetic Energy Density ◽  
Solar Wind Turbulence ◽  
Wind Turbulence ◽  
Self Similar

Statistical Research of the Intermittency and Cascade of Solar Wind Turbulence Based on Analysis of PSP Measurements

2020 ◽  
Author(s):  
Ying Wang ◽  
Jiansen He ◽  
Die Duan ◽  
Xingyu Zhu
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Break Point ◽  
Inertial Range ◽  
Scaling Exponent ◽  
The Sun ◽  
Peak Point ◽  
Solar Wind Turbulence ◽  
Wind Turbulence ◽  
Inner Heliosphere

<p>By analyzing the turbulent magnetic field data from PSP, we find that: the solar wind turbulence in the inner heliosphere close to the Sun has formed the transition from multifractal intermittency at MHD scales to monofractal intermittency at kinetic scales. The order-dependent scaling exponent of the multi-order structure function shows a concave profile indicating the multifractal property at MHD scales, while its counterpart at kinetic scales shows a linear trend suggesting the monofractal property. We also find that, the closer to the sun, the more obvious the concave profile of the scaling exponent in the inertial range, which indicates that the multifractal characteristic of the magnetic field turbulence intermittency is also more evident when getting closer to the Sun.</p><p>Based on the Castaing description of the probability distribution function(PDF) of the disturbance difference, the key parameters(μ & λ^2) of the Castaing function are estimated as a function of scale. We find that: (1) when close to the sun (R~0.17 AU), the break point of μ is about 0.2 second, and the peak point of λ^2 is about 0.6 second, the two of which are about three times different in scale; (2) when far from the sun (R~0.8 AU), the break point of μ is about 1 second and the peak point of λ^2 is about 3 seconds, the two of which are also about three times different in scale. We also point out that the profiles (including the break/peak position) of both the parameters (μ & λ^2) along with the scale together determine the profile (including the spectral breaks) of the power spectrum.</p><p>Following the PP98 model function of incompressible MHD turbulent cascade rate (εZ), we first compared the cascade rate εZ with εB=<δB^3>/τ at the distance close to the sun, we find that the two trends over scales are in good agreement with one another. We therefore suggest that, to some extent (e.g. in the inertial region), εB=<δB^3>/τ can be used as a proxy of the cascade rate εZ. For the first time, by statistical analysis, we obtained that εB satisfies the following relation with the scale and the heliocentric distance: εB=((τ/τ0)^α)((r/r0)^β). In the inertial range, α changes from about -0.5 to about 0.5 as r increases from 0.17 AU to 0.81 AU, and β is about 6.4; in the kenetic range, when r increases from 0.17 AU to 0.25 AU, α keeps at about 2, and β is about 12.8. The εB(τ,r) expression given in this work, is believed to help understanding the transport and cascade processes of solar wind turbulence in the inner heliosphere. </p><p>Corresponding author:<br>Jiansen HE, [email protected]</p><p>Acknowledgements:<br>We would like to thank the PSP team for providing the data of PSP to the public.</p>

scholarly journals Dependence of 3D Self-correlation Level Contours on the Scales in the Inertial Range of Solar Wind Turbulence

2019 ◽  
Vol 883 (1) ◽  
pp. L9 ◽  
Author(s):  
Honghong Wu ◽  
Chuanyi Tu ◽  
Xin Wang ◽  
Jiansen He ◽  
Linghua Wang
Keyword(s):  
Solar Wind ◽  
Inertial Range ◽  
Solar Wind Turbulence ◽  
Wind Turbulence ◽  
Correlation Level

scholarly journals Solar Wind Turbulence from 1 to 45 au. II. Analysis of Inertial-range Fluctuations Using Voyager and ACE Observations

2020 ◽  
Vol 900 (2) ◽  
pp. 92 ◽  
Author(s):  
Zackary B. Pine ◽  
Charles W. Smith ◽  
Sophia J. Hollick ◽  
Matthew R. Argall ◽  
Bernard J. Vasquez ◽  
...  
Keyword(s):  
Solar Wind ◽  
Inertial Range ◽  
Solar Wind Turbulence ◽  
Wind Turbulence

scholarly journals Solar Wind Turbulence from 1 to 45 au. III. Anisotropy of Magnetic Fluctuations in the Inertial Range Using Voyager and ACE Observations

2020 ◽  
Vol 900 (2) ◽  
pp. 93 ◽  
Author(s):  
Zackary B. Pine ◽  
Charles W. Smith ◽  
Sophia J. Hollick ◽  
Matthew R. Argall ◽  
Bernard J. Vasquez ◽  
...  
Keyword(s):  
Solar Wind ◽  
Inertial Range ◽  
Magnetic Fluctuations ◽  
Solar Wind Turbulence ◽  
Wind Turbulence

scholarly journals The Evolution and Role of Solar Wind Turbulence in the Inner Heliosphere

2020 ◽  
Author(s):  
Christopher Chen ◽  
Keyword(s):  
Solar Wind ◽  
Kinetic Energy ◽  
Large Scale ◽  
Energy Levels ◽  
Turbulence Energy ◽  
Energy Fraction ◽  
Solar Wind Turbulence ◽  
Rate Of Increase ◽  
Wind Turbulence ◽  
Order Of Magnitude

<p>The first two orbits of the Parker Solar Probe (PSP) spacecraft have enabled the first in situ measurements of the solar wind down to a heliocentric distance of 0.17 au (or 36 Rs). Here, we present an analysis of this data to study solar wind turbulence at 0.17 au and its evolution out to 1 au. While many features remain similar, key differences at 0.17 au include: increased turbulence energy levels by more than an order of magnitude, a magnetic field spectral index of -3/2 matching that of the velocity and both Elsasser fields, a lower magnetic compressibility consistent with a smaller slow-mode kinetic energy fraction, and a much smaller outer scale that has had time for substantial nonlinear processing. There is also an overall increase in the dominance of outward-propagating Alfvenic fluctuations compared to inward-propagating ones, and the radial variation of the inward component is consistent with its generation by reflection from the large-scale gradient in Alfven speed. The energy flux in this turbulence at 0.17 au was found to be ~10% of that in the bulk solar wind kinetic energy, becoming ~40% when extrapolated to the Alfven point, and both the fraction and rate of increase of this flux towards the Sun is consistent with turbulence-driven models in which the solar wind is powered by this flux.</p>

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