Kim K., Y. Shprits, (2017), Dependence of the amplitude of magnetosonic waves on the solar wind and AE index using Van Allen Probes, J. Geophys. Res. [Space Physics], 122, 6022-6034, doi:10.1002/2017JA024094

Abstract

Abstract We present the dependence of the magnetosonic wave amplitudes both outside and inside the plasmapause on the solar wind and AE index using Van Allen Probe-A spacecraft during the time period of 1 October 2012 to 31 December 2015, based on a correlation and regression analysis. Solar wind parameters considered are the southward interplanetary magnetic field (IMF BS), solar wind number density (NSW), and bulk speed (VSW). We find that the wave amplitudes outside (inside) the plasmapause are well correlated with the preceding AE, IMF BS, and NSW with time delays, each corresponding to 2–3 h (3–4 h), 4–5 h (3–4 h), and 2–3 h (8–9 h), while the correlation with VSW is ambiguous both inside and outside the plasmapause. As measured by the correlation coefficient, the IMF BS is the most influential solar wind parameter that affects the dayside wave amplitudes both outside and inside the plasmapause, while NSW contributes to enhancing the duskside waves outside the plasmapause. The AE effect on wave amplitudes is comparable to that of IMF BS. More interestingly, regression with time histories of the solar wind parameters and the AE index preceding the wave measurements outside the plasmapause shows significant dependence on the IMF BS, NSW, and AE: the region of peak coefficients is changed with time delay for IMF BS and AE, while isolated peaks around duskside remain gradually decrease with time for NSW. In addition, the regression with magnetosonic waves inside the plasmapause shows high coefficients around prenoon sector with preceding IMF BS and VSW.

Authors (sorted by name)

Kim Shprits

Journal / Conference

Journal Of Geophysical Research (Space Physics)

Acknowledgments

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF‐2016R1D1A1B03935148). Y.Y.S. would like to acknowledge funding from the European Union's Horizon 2020 research and innovation program under grant agreement 637302 and Helmholtz Associate ion Rutting Initiative. We thank the GSFC/SPDF OMNIWeb for the provision of the solar wind parameters and geomagnetic activity indices used in this report. The EMFISIS data used for this paper are available from http://emfisis.physics.uiowa.edu/Flight/. We graciously thank the EMFISIS Principal Investigator, Craig Kletzing, and the EMFISIS team.

Grants

637302

Bibtex

@article{doi:10.1002/2017JA024094,
author = {Kim, Kyung-Chan and Shprits, Yuri},
title = {Dependence of the amplitude of magnetosonic waves on the solar wind and AE index using Van Allen Probes},
journal = {Journal of Geophysical Research: Space Physics},
volume = {122},
year = {2017},
number = {6},
pages = {6022-6034},
keywords = {magnetosonic equatorial noise, solar wind dependence, Van Allen Probes},
doi = {10.1002/2017JA024094},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017JA024094},
eprint = {https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2017JA024094},
abstract = {Abstract We present the dependence of the magnetosonic wave amplitudes both outside and inside the plasmapause on the solar wind and AE index using Van Allen Probe-A spacecraft during the time period of 1 October 2012 to 31 December 2015, based on a correlation and regression analysis. Solar wind parameters considered are the southward interplanetary magnetic field (IMF BS), solar wind number density (NSW), and bulk speed (VSW). We find that the wave amplitudes outside (inside) the plasmapause are well correlated with the preceding AE, IMF BS, and NSW with time delays, each corresponding to 2–3 h (3–4 h), 4–5 h (3–4 h), and 2–3 h (8–9 h), while the correlation with VSW is ambiguous both inside and outside the plasmapause. As measured by the correlation coefficient, the IMF BS is the most influential solar wind parameter that affects the dayside wave amplitudes both outside and inside the plasmapause, while NSW contributes to enhancing the duskside waves outside the plasmapause. The AE effect on wave amplitudes is comparable to that of IMF BS. More interestingly, regression with time histories of the solar wind parameters and the AE index preceding the wave measurements outside the plasmapause shows significant dependence on the IMF BS, NSW, and AE: the region of peak coefficients is changed with time delay for IMF BS and AE, while isolated peaks around duskside remain gradually decrease with time for NSW. In addition, the regression with magnetosonic waves inside the plasmapause shows high coefficients around prenoon sector with preceding IMF BS and VSW.}
}