scholarly journals A new semiempirical model of Saturn's bow shock based on propagated solar wind parameters

2011 ◽  
Vol 116 (A7) ◽  
pp. n/a-n/a ◽  
Author(s):  
D. R. Went ◽  
G. B. Hospodarsky ◽  
A. Masters ◽  
K. C. Hansen ◽  
M. K. Dougherty
2020 ◽  
Vol 58 (6) ◽  
pp. 478-486
Author(s):  
L. S. Rakhmanova ◽  
M. O. Riazantseva ◽  
G. N. Zastenker ◽  
Yu. I. Yermolaev ◽  
I. G. Lodkina

2013 ◽  
Vol 31 (3) ◽  
pp. 419-437 ◽  
Author(s):  
C. Nabert ◽  
K.-H. Glassmeier ◽  
F. Plaschke

Abstract. We present a new analytical method to derive steady-state magnetohydrodynamic (MHD) solutions of the magnetosheath in different levels of approximation. With this method, we calculate the magnetosheath's density, velocity, and magnetic field distribution as well as its geometry. Thereby, the solution depends on the geomagnetic dipole moment and solar wind conditions only. To simplify the representation, we restrict our model to northward IMF with the solar wind flow along the stagnation streamline. The sheath's geometry, with its boundaries, bow shock and magnetopause, is determined self-consistently. Our model is stationary and time relaxation has not to be considered as in global MHD simulations. Our method uses series expansion to transfer the MHD equations into a new set of ordinary differential equations. The number of equations is related to the level of approximation considered including different physical processes. These equations can be solved numerically; however, an analytical approach for the lowest-order approximation is also presented. This yields explicit expressions, not only for the flow and field variations but also for the magnetosheath thickness, depending on the solar wind parameters. Results are compared to THEMIS data and offer a detailed explanation of, e.g., the pile-up process and the corresponding plasma depletion layer, the bow shock and magnetopause geometry, the magnetosheath thickness, and the flow deceleration.


2021 ◽  
Author(s):  
Liudmila Rakhmanova ◽  
Maria Riazantseva ◽  
Georgy Zastenker ◽  
Yuri Yermolaev

<p>Development of the turbulent cascade inside the magnetosheath is known to be affected by the bow shock. Recently a number of studies showed various scenario of turbulent cascade modification at the bow shock including deviation from Kolmogorov scaling and additional damping of the kinetic-scale compressive fluctuations. Also, properties of probability distribution function may be modified behind the bow shock. However, factors which govern turbulence development in the magnetosheath remain unclear. Present study focuses on experimental analysis of the solar wind parameters which influence turbulence inside the magnetosheath. Analyzed data involves the combination of the solar wind parameters measured in L1 point by WIND spacecraft and Themis, Cluster and Spektr-R measurements behind the bow shock. Parameters of the frequency spectra of ion flux and/or magnetic field magnitude at frequency band from 0.01 to 2-10 Hz are considered such as slopes at magnetohydrodynamic and kinetic scales and the break frequency. Parameters of spectra are considered behind the bow shock of various topology i.e. for different mutual orientation of the interplanetary magnetic field and the local bow shock normal. Also, distance from the analyzed point to the bow shock nose is taken to the account. Obtained results point out that modification of the turbulent cascade at the bow shock is controlled not only by the bow shock topology but also by variability of the upstream solar wind plasma parameters and direction of the interplanetary magnetic field. In particular, Kolmogorov scaling often survives across the bow shock during periods of high-amplitude variations of plasma density and magnetic field magnitude in the solar wind. Also, increasing amplitude of northern interplanetary magnetic field results in steepening of spectra behind the bow shock.  </p>


2021 ◽  
Author(s):  
Gilbert Pi ◽  
Zdeněk Němeček ◽  
Jana Šafránková

<p>Magnetosheath is a major interface region between the solar wind and magnetosphere. The changes of solar wind parameters after the bow shock crossing and the phenomena near the magnetopause are intensively studied. However, spatial profiles of different pressure components across the magnetosheath are not comprehensively studied yet, especially in observations. The highly fluctuating sheath, variations of upstream conditions, and permanent motion of the magnetopause and bow shock complicate observational studies. In the present contribution, we use two different methods to obtain a typical magnetosheath profile under specific upstream conditions. One is the superposed epoch analysis of complete crossing events observed by the THEMIS mission. The second method is relocated the THEMIS observations into a normalized magnetosheath coordinate. By contrast to the result of MHD modeling, we found only a very weak difference between pressure profiles for southward and northward IMF. Our results show that the thermal pressure exhibits a peak near the magnetopause that is more pronounced under southward than under northward IMF. The magnetic pressures have a similar trend for both IMF polarities but the magnetic pressure increases faster toward the magnetopause for northward IMF than it does for southward IMF.</p>


2006 ◽  
Vol 12 (1) ◽  
pp. 80-84
Author(s):  
S.N. Samsonov ◽  
◽  
I.Ya. Plotnikov ◽  
D.Y. Sibeck ◽  
Yu. Watermann ◽  
...  

2011 ◽  
Vol 2 (3) ◽  
pp. 205-210 ◽  
Author(s):  
Igor Savel'evich Fal'kovich ◽  
M. R. Olyak ◽  
Nikolai Nikolaevich Kalinichenko ◽  
I. N. Bubnov

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 390
Author(s):  
Pouya Manshour ◽  
Georgios Balasis ◽  
Giuseppe Consolini ◽  
Constantinos Papadimitriou ◽  
Milan Paluš

An information-theoretic approach for detecting causality and information transfer is used to identify interactions of solar activity and interplanetary medium conditions with the Earth’s magnetosphere–ionosphere systems. A causal information transfer from the solar wind parameters to geomagnetic indices is detected. The vertical component of the interplanetary magnetic field (Bz) influences the auroral electrojet (AE) index with an information transfer delay of 10 min and the geomagnetic disturbances at mid-latitudes measured by the symmetric field in the H component (SYM-H) index with a delay of about 30 min. Using a properly conditioned causality measure, no causal link between AE and SYM-H, or between magnetospheric substorms and magnetic storms can be detected. The observed causal relations can be described as linear time-delayed information transfer.


2012 ◽  
Vol 117 (A5) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. O. Archer ◽  
T. S. Horbury ◽  
J. P. Eastwood
Keyword(s):  

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