Unexpected storm-time nightside plasmaspheric density enhancement at low L shell
Abstract
We have developed a three-dimensional dynamic electron density (DEN3D) model in the inner magnetosphere using a neural network approach. The DEN3D model can provide spatiotemporal distribution of the electron density at any location and time that spacecraft observations are not available. Given DEN3D's good performance in predicting the structure and dynamic evolution of the plasma density, the salient features of the DEN3D model can be used to gain further insight into the physics. For instance, the DEN3D models can be used to find unusual phenomena that are difficult to detect in observations or simulations. We report, for the first time, an unexpected plasmaspheric density increase at low L shell regions on the nightside during the main phase of a moderate storm during 12-16 October 2004, as opposed to the expected density decrease due to storm-time plasmaspheric erosion. The unexpected density increase is first discovered in the modeled electron density distribution using the DEN3D model, and then validated using in-situ density measurements obtained from the IMAGE satellite. The density increase was likely caused by increased earthward transverse field plasma transport due to enhanced nightside ExB drift, which coincided with enhanced solar wind electric field and substorm activity. This is consistent with the results of physics-based simulation SAMI3 model which show earthward enhanced plasma transport and electron density increase at low L shells during storm main phase.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFMSM14A..07C
- Keywords:
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- 1942 Machine learning;
- INFORMATICS;
- 1986 Statistical methods: Inferential;
- INFORMATICS;
- 2799 General or miscellaneous;
- MAGNETOSPHERIC PHYSICS;
- 7924 Forecasting;
- SPACE WEATHER