Effect of the solar wind and IMF parameters on the formation of long-period irregular pulsation burst regimes

Magnetohydrodynamic (MHD) oscillatory processes in different plasma systems, such as the corona of the Sun and the Earth's magnetosphere show interesting similarities and differences, which so far received little attention and remain underexploited. The successful commissioning within the past ten years of SDO, Hinode, STEREO and THEMIS spacecraft, in combination with matured analysis of data from earlier spacecraft (Wind, SOHO, ACE, Cluster, TRACE and RHESSI) makes it very timely to survey the breadth of observations giving evidence for MHD oscillatory processes in solar and space plasmas, and state-of-the-art theoretical modelling. The paper reviews several important topics, such as Alfvénic resonances and mode conversion; MHD waveguides, such as the magnetotail, coronal loops, coronal streamers; mechanisms for periodicities produced in energy releases during substorms and solar flares, possibility of Alfvénic resonators along open field lines; possible drivers of MHD waves; diagnostics of plasmas with MHD waves; interaction of MHD waves with partly-ionised boundaries (ionosphere and chromosphere). The review is mainly oriented to specialists in magnetospheric physics and solar physics, but not familiar with specifics of the adjacent research fields.

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“…Kurazhkovskaya and Klain 2012). The Miles-Phillips instability is also a shear flow instability that is thought to grow waves at any flow speed.…”

Section: Shear Flow Instabilitiesmentioning

confidence: 99%

Magnetohydrodynamic Oscillations in the Solar Corona and Earth’s Magnetosphere: Towards Consolidated Understanding

Nakariakov

Пилипенко

Heilig³

et al. 2016

Space Sci Rev

185

128

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“…Beside KHI, another shear flow instability -similar to the hydrodynamic Miles-Phillips instability -may develop at the magnetopause, and even under lower SW velocity than the KHI. The Miles-Phillips instability is caused by nonlinear ponderomotive wave generation, and its development is determined by the flow velocity profile and flow turbulence (Kurazhkovskaya and Klain, 2012;Potapov, 2013). These notions are based on the well-established statistical fact of strong growth of Pc5 intensity with the increase of the SW velocity (Engebretson et al, 1998;Mathie and Mann, 2001;Pahud et al, 2009).…”

Section: Introduction: Mechanisms Of Pc5 Wave Excitationmentioning

confidence: 99%

Global Pc5 pulsations during strong magnetic storms: excitation mechanisms and equatorward expansion

et al. 2014

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Abstract. The dynamics of global Pc5 waves during the magnetic storms on 29-31 October 2003 are considered using data from the trans-American and trans-Scandinavian networks of magnetometers in the morning and post-noon magnetic local time (MLT) sectors. We study the latitudinal distribution of Pc5 wave spectral characteristics to determine how deep into the magnetosphere these Pc5 waves can extend at different flanks of the magnetosphere. The wave energy transmission mechanisms are different during 29-30 October and 31 October wave events. Further, we examine whether the self-excited Kelvin-Helmholtz instability is sufficient as an excitation mechanism for the global Pc5 waves. We suggest that on 31 October a magnetospheric magnetohydrodynamic (MHD) waveguide was excited, and the rigid regime of its excitation was triggered by enhancements of the solar wind density. The described features of Pc5 wave activity during recovery phase of strong magnetic storm are to be taken into account during the modeling of the relativistic electron energization by ultra-low-frequency (ULF) waves.Keywords. Magnetospheric physics (MHD waves and instabilities; storms and substorms) -space plasma physics (kinetic and MHD theory)

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“…Under the conditions of a moderately disturbed mag netosphere, ipcl burst regime generation is similar to wind instability in hydrodynamics (the Miles-Phillips mechanism) (Kurazhkovskaya and Klain, 2012). The development of Miles-Phillips instability is charac terized by the same regularities as the conditions for the generation of ipcl burst regimes: turbulence, the velocity threshold value, and magnetic pressure fluc tuations.…”

Section: Discussionmentioning

confidence: 86%

“…At the same time, the effect of the IMF Bz component and its combina tion with the solar wind velocity (VBz) on the psd of pulsations in two frequency bands is almost absent. Our studies (Kurazhkovskaya and Klain, 2012) indi cated that the solar wind velocity and plasma magnetic pressure control the amplitude annual variation and the dynamics of the fractal dimension of ipcl burst series upon moderate geomagnetic activity. The begin ning of the ipcl burst regime generation depends on the threshold values of the solar wind velocity (V ~ 320 km/s) and dynamic pressure (P ~ 1 nPa).…”

Section: Introductionmentioning

confidence: 73%

“…The relation of some characteristics of long period irregular pulsations to the solar wind and IMF parameters was studied in (Bolshakova et al, 1974;Bolshakova and Troitskaya, 1982;Vennerstrom, 1999;Kurazhkovskaya and Klain, 2012). Thus, Bolshakova et al (1974) showed experimentally that the ipcl amplitude is linearly related to the solar wind velocity and the value of the negative IMF Bz compo nent.…”

Section: Introductionmentioning

confidence: 99%

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Long-period irregular pulsations under the conditions of a quiet magnetosphere

2016

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Simultaneous observations of high latitude long period irregular pulsations at frequencies of 2.0-6.0 mHz (ipcl) and magnetic field disturbances in the solar wind plasma at low geomagnetic activity (Kp ~ 0) have been studied. The 1 s data on the magnetic field registration at Godhavn (GDH) high latitude observa tory and the 1 min data on the solar wind plasma and IMF parameters for 2011-2013 were used in an anal ysis. Ipcl (irregular pulsations continuous, long), which were observed against a background of the IMF Bz reorientation from northward to southward, have been analyzed. In this case other solar wind plasma and IMF parameters, such as velocity V, density n, solar wind dynamic pressure P = ρV 2 (ρ is plasma density), and strength magnitude B, were relatively stable. The effect of the IMF Bz variation rate on the ipcl spectral composition and intensity has been studied. It was established that the ipcl spectral density reaches its maxi mum (~10-20 min) after IMF Bz sign reversal in a predominant number of cases. It was detected that the ipcl average frequency (f) is linearly related to the IMF Bz variation rate (ΔBz/Δt). It was shown that the depen dence of f on ΔBz/Δt is controlled by the α = arctan(By/Bx) angle value responsible for the MHD disconti nuity type at the front boundary of magnetosphere. The results made it possible to assume that the formation of the observed ipcl spectrum, which is related to the IMF Bz reorientation, is caused by solar wind plasma turbulence, which promotes the development of current sheet instability and surface wave amplification at the magnetopause.

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Effect of the solar wind and IMF parameters on the formation of long-period irregular pulsation burst regimes

Cited by 6 publications

References 16 publications

Magnetohydrodynamic Oscillations in the Solar Corona and Earth’s Magnetosphere: Towards Consolidated Understanding

Magnetohydrodynamic Oscillations in the Solar Corona and Earth’s Magnetosphere: Towards Consolidated Understanding

Global Pc5 pulsations during strong magnetic storms: excitation mechanisms and equatorward expansion

Long-period irregular pulsations under the conditions of a quiet magnetosphere

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