Solar wind turbulence effects on the magnetosphere: information theoretic approach
Abstract
The effects of the solar wind turbulence on the magnetospheric activity are investigated with information theory. Because external fluctuations can drive waves in the magnetosphere that can affect transport processes, it is important to understand the effect of these fluctuations on the magnetospheric response. Previously, a study found that the inclusion of solar wind fluctuations as an input parameter improved the prediction of Dst. For this study we consider solar wind turbulence proxied by the perturbed upstream solar wind magnetic field amplitude normalized by the ambient magnetic field magnitude (δ B/B). Previous studies have found that δ B/B is weakly correlated with many magnetospheric parameters, such as Dst, AE, and AL. On the other hand, the solar wind velocity (Vsw) is relatively strongly correlated with these parameters. However, δ B/B is correlated with Vsw and hence, some of the correlations of δ B/B with the magnetospheric parameters may be attributed to the correlation of Vsw with these parameters. Using conditional mutual information, we calculate how much information is transferred from δ B/B to the magnetospheric parameters after the effects of Vsw are removed. Additionally, δ B/B is also correlated with solar wind ion temperature (Tp), ambient magnetic field magnitude, density (nsw), and Mach number. The effects of these solar wind parameters are also removed. The magnetospheric parameters are ranked based on the amount of information transferred from δ B/B, rank-ordered from the most to the least information transferred: Dst, Kp, PCI, MBI, E(1) [Borovsky and Denton, 2014], Sgr-d (ground-based ULF index) [Borovsky and Denton, 2014] , Sgeo-d (geosynchronous-based ULF index), AE, and AL.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMSH33D3676W
- Keywords:
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- 2494 Instruments and techniques;
- IONOSPHEREDE: 2704 Auroral phenomena;
- MAGNETOSPHERIC PHYSICSDE: 7899 General or miscellaneous;
- SPACE PLASMA PHYSICSDE: 7924 Forecasting;
- SPACE WEATHER