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Reanalysis of relativistic radiation belt electron phase space density using multisatellite observations: Sensitivity to empirical magnetic field models

Ni B., Y. Shprits, R. Thorne, R. Friedel, T. Nagai, (2009), Reanalysis of relativistic radiation belt electron phase space density using multisatellite observations: Sensitivity to empirical magnetic field models, J. of Geophys. Res. [Space Physics], 114, doi:10.1029/2009JA014438

Abstract

Using empirical external magnetic field models (T89, T96, T01s, and T04s) and simultaneous observations from four satellites (CRRES, Akebono, and two GEO satellites) during a 7-day period from 1 to 7 August 1991, we performed a combined reanalysis of radiation belt electron phase space density (PSD). While precise L* locations of the satellites are sensitive to the adopted magnetic field model, comparisons between the reconstructed radial profiles of electron PSD, obtained using Kalman filtering, indicate that the combined reanalyses are relatively insensitive to the choice of the magnetic field model during geomagnetically quiet or moderate activity times or for the long-term reanalysis studies. The reanalysis results using the four external magnetic field models show similarities in the locations of peaks in radial profiles of PSD and the radial extent of the dropouts. The largest difference between assimilated PSD using different Tsyganenko models occurs mostly during geomagnetically active periods when the Dst index is low or at higher L* shells near the boundary. Presented results also suggest that the errors of assimilated PSD based on multiple satellite measurements can become smaller than errors of PSD reconstructed from individual satellites.

Authors (sorted by name)

Friedel Nagai Ni Shprits Thorne

Journal / Conference

Journal Of Geophysical Research (Space Physics)

Acknowledgments

We would like to thank the developers of the NSSDC OMNIWeb database for using the solar wind data and Howard Singer for providing the CRRES magnetic field data. We are grateful to D. Boscher and S. Bourdarie, who provided the ONERA‐DESP codes. We are also indebted to Dmitri Kondrashov, Michael Ghil, Yue Chen, Viacheslav Merkin, and Hee‐jeong Kim for helpful discussions and insightful comments. This work was supported by the Lab Research Fee grant 09‐LR‐04‐116720‐SHPY.

Grants

09‐LR‐04116720

Bibtex

@article{doi:10.1029/2009JA014438,
author = {Ni, Binbin and Shprits, Yuri and Thorne, Richard and Friedel, Reiner and Nagai, Tsugunobu},
title = {Reanalysis of relativistic radiation belt electron phase space density using multisatellite observations: Sensitivity to empirical magnetic field models},
journal = {Journal of Geophysical Research: Space Physics},
year = {2009},
volume = {114},
number = {A12},
pages = {},
keywords = {radiation belt electron phase space density, data assimilation technique, external magnetic field model},
doi = {10.1029/2009JA014438},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2009JA014438},
eprint = {https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2009JA014438},
abstract = {Using empirical external magnetic field models (T89, T96, T01s, and T04s) and simultaneous observations from four satellites (CRRES, Akebono, and two GEO satellites) during a 7-day period from 1 to 7 August 1991, we performed a combined reanalysis of radiation belt electron phase space density (PSD). While precise L* locations of the satellites are sensitive to the adopted magnetic field model, comparisons between the reconstructed radial profiles of electron PSD, obtained using Kalman filtering, indicate that the combined reanalyses are relatively insensitive to the choice of the magnetic field model during geomagnetically quiet or moderate activity times or for the long-term reanalysis studies. The reanalysis results using the four external magnetic field models show similarities in the locations of peaks in radial profiles of PSD and the radial extent of the dropouts. The largest difference between assimilated PSD using different Tsyganenko models occurs mostly during geomagnetically active periods when the Dst index is low or at higher L* shells near the boundary. Presented results also suggest that the errors of assimilated PSD based on multiple satellite measurements can become smaller than errors of PSD reconstructed from individual satellites.}
}