Study of the relation between turbulent activity in the quasi-parallel foreshock and the ULF band pulsations of the geomagnetic field

Details Study of the relation between turbulent activity in the quasi-parallel foreshock and the ULF band pulsations of the geomagnetic field Study of the relation between turbulent activity in the quasi-parallel foreshock and the ULF band pulsations of the geomagnetic field

Dec 2010

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010agufmsh41b1791k&link_type=abstract

American Geophysical Union, Fall Meeting 2010, abstract #SH41B-1791

Physics

Geophysics

[2159] Interplanetary Physics / Plasma Waves And Turbulence, [2784] Magnetospheric Physics / Solar Wind/Magnetosphere Interactions, [4490] Nonlinear Geophysics / Turbulence

Scientific paper

The aim of the paper is to investigate the relation between the plasma turbulence upstream to the quasi-parallel bow shock (BS), and the ULF band pulsation activity of the geomagnetic field. In the study the FGM magnetic records of the Cluster mission and the pulsation records of ground observatories are used. We show that the level of turbulent dynamics in the different regions of the foreshock can be adequately monitored by the investigation of the change of the intermittent properties of in-situ magnetic time-series. The level of intermittency is measured in space and time by computing the probability density functions (PDF) and the fourth statistical moment of the temporal differences of the time-series, i.e. their flatness. However, in the analyses, it must be taken into account that the dynamics of the foreshock region is governed not only by turbulent fluctuations but also by wave activities occurring in certain frequencies. It was previously shown by synthetic data that the wave phenomena can strongly complicate the interpretation of the results of the study of turbulence, since in certain time scales or scale ranges they can e.g. distort the power-law behavior of the turbulent spectra and influence the shapes of the PDF-s and structure functions of the magnetic records. For this reason, in this study we introduce a wavelet filtering to discriminate between wave and turbulent components of the analyzed time records. Using the FGM magnetic records of several solar wind crossings of the Cluster mission, map of the average distribution of the level of turbulent fluctuations is presented in the quasi-parallel foreshock region in terms of the distance from the bow shock and the angle of incidence of the interplanetary magnetic field line (IMF) to the bow shock normal. The relation between the level of turbulent dynamics and some solar wind parameters (SW speed and SW Alfvén Mach number) is also investigated. The variation of the physical parameters in the foreshock has direct or indirect impact on the geomagnetic variation recorded in the ULF range. For this reason, the relation between the nonlinear physical processes observed in the space and the turbulent or wave activities inherent in the geomagnetic records is also studied using the Pc3-Pc4 frequency pulsation records of the MM100 pulsation network and the observatories of the US Geological Survey.

Affiliated with

Also associated with

No associations

Rating

Study of the relation between turbulent activity in the quasi-parallel foreshock and the ULF band pulsations of the geomagnetic field does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Study of the relation between turbulent activity in the quasi-parallel foreshock and the ULF band pulsations of the geomagnetic field, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Study of the relation between turbulent activity in the quasi-parallel foreshock and the ULF band pulsations of the geomagnetic field will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1510285