Staples, FA;
Rae, IJ;
Forsyth, C;
Smith, ARA;
Murphy, KR;
Raymer, KM;
Plaschke, F;
... Imber, SM; + view all
(2020)
Do Statistical Models Capture the Dynamics of the Magnetopause During Sudden Magnetospheric Compressions?
Journal of Geophysical Research: Space Physics
, 125
(4)
, Article e2019JA027289. 10.1029/2019ja027289.
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Abstract
Under periods of strong solar wind driving, the magnetopause can become compressed, playing a significant role in draining electrons from the outer radiation belt. Also termed “magnetopause shadowing,” this loss process has traditionally been attributed to a combination of magnetospheric compression and outward radial diffusion of electrons. However, the drift paths of relativistic electrons and the location of the magnetopause are usually calculated from statistical models and, as such, may not represent the time‐varying nature of this highly dynamic process. In this study, we construct a database ∼20,000 spacecraft crossings of the dayside magnetopause to quantify the accuracy of the commonly used Shue et al. (1998, https://doi.org/10.1029/98JA01103) model. We find that, for the majority of events (74%), the magnetopause model can be used to estimate magnetopause location to within ±1 RE. However, if the magnetopause is compressed below 8 RE, the observed magnetopause is greater than 1 RE inside of the model location on average. The observed magnetopause is also significantly displaced from the model location during storm sudden commencements, when measurements are on average 6% closer to the radiation belts, with a maximum of 42%. We find that the magnetopause is rarely close enough to the outer radiation belt to cause direct magnetopause shadowing, and hence rapid outward radial transport of electrons is also required. We conclude that statistical magnetopause parameterizations may not be appropriate during dynamic compressions. We suggest that statistical models should only be used during quiescent solar wind conditions and supplemented by magnetopause observations wherever possible.
| Type: | Article |
|---|---|
| Title: | Do Statistical Models Capture the Dynamics of the Magnetopause During Sudden Magnetospheric Compressions? |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1029/2019ja027289 |
| Publisher version: | https://doi.org/10.1029/2019ja027289 |
| Language: | English |
| Additional information: | ©2020. The Authors. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10094798 |
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