A Global MHD Simulation of ULF Waves Activity in the inner Magnetosphere Resulting from CIR followed by ALFVENIC Fluctuations
Abstract
The interaction between the disturbed solar wind and the geomagnetic field gives rise to different physical processes that can significantly affect technological systems as well as human life. Here we investigate the role of a complex solar structure, a corotating interaction region (CIR) followed by magnetic field Alfvénic fluctuations in the generation of disturbances in the inner magnetosphere. These disturbances are observed in terms of the power spectral density (PSD) of the ultra low frequency waves (ULF) in the nightside, equatorial region. Several studies show the correlation between CIRs followed by Alfvénic fluctuations and the generation of ULF waves in the internal magnetosphere. However, until now it is not straightforward to decisively say which solar wind parameters or which combinations thereof are most effective in causing disturbances in the inner magnetosphere, or how each part of the complex interplanetary structure influences the most the temporal evolution of the magnetosphere. Using global MHD simulations we try to address some of these questions. Firstly, we use the magnetic field and plasma parameters of a real, complex CIR+Alfvénic fluctuations event as input to the SWMF/BATS-R-US code and then calculate from the model outputs the PSD of ULF waves in the aforementioned region. Then, we separate the complex event into its constituent parts by building synthetic magnetic field and plasma profiles based on the physical parameters that characterize each of these parts. The MHD code is then fed with each new synthetic profile to provide ULF PSDs that are compared with those from the simulation with real solar wind inputs. This numerical experiment will help us to understand which solar wind parameters contribute the most for the ULF waves activity in the nightside magnetosphere. We expect to provide important information for future forecasting studies of ULF wave activity in the Earth's magnetosphere whenever the geospace is under the influence of recurrent events as the one analyzed here.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMSM43D3592A
- Keywords:
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- 2716 Energetic particles: precipitating;
- MAGNETOSPHERIC PHYSICSDE: 2720 Energetic particles: trapped;
- MAGNETOSPHERIC PHYSICSDE: 2774 Radiation belts;
- MAGNETOSPHERIC PHYSICSDE: 7867 Wave/particle interactions;
- SPACE PLASMA PHYSICS