1. Microstructure of the IMF turbulences at 2.5 AU
- Author
-
Helen Mavromichalaki, Edward J. Smith, X. Moussas, L. Marmatsouri, A. Vassilaki, and J. J. Quenby
- Subjects
Physics ,Atmospheric Science ,Field (physics) ,Scattering ,Aerospace Engineering ,Astronomy and Astrophysics ,Computational physics ,symbols.namesake ,Geophysics ,Classical mechanics ,Space and Planetary Science ,Fourier analysis ,Temporal resolution ,Physics::Space Physics ,symbols ,General Earth and Planetary Sciences ,Matrix analysis ,Magnetohydrodynamic drive ,Interplanetary magnetic field ,Magnetohydrodynamics - Abstract
A detailed analysis of small period (15-900 sec) magnetohydrodynamic (MHD) turbulences of the interplanetary magnetic field (IMF) has been made using Pioneer-11 high time resolution data (0.75 sec) inside a Corotating Interaction Region (CIR) at a heliocentric distance of 2.5 AU in 1973. The methods used are the hodogram analysis, the minimum variance matrix analysis and the cohenrence analysis. The minimum variance analysis gives evidence of linear polarized wave modes. Coherence analysis has shown that the field fluctuations are dominated by the magnetosonic fast modes with periods 15 sec to 15 min. However, it is also shown that some small amplitude Alfven waves are present in the trailing edge of this region with characteristic periods (15-200 sec). The observed wave modes are locally generated and possibly attributed to the scattering of Alfven waves energy into random magnetosonic waves.
- Published
- 1995