Modeling the Dynamic Global Distribution of the Ring Current Oxygen Ions
Using Artificial Neural Network Technique
Abstract
The ring current is an important component of the Earth’s near-space
environment, as its variations are the direct driver of geomagnetic
storms that can disrupt power grids, satellite communications, and
navigation systems, thereby impacting a wide range of technological and
human activities. Oxygen ions (O+) are one of the major components of
the ring current and play a significant role in both the enhancement and
depletion of the ring current during geomagnetic storms. Although a
standard statistical study can provide average global distributions of
ring current ions, it can’t offer insight into the short-term dynamic
variations of the global distribution. Therefore, we employed the
Artificial Neural Network (ANN) technique to construct a global ring
current O+ ion model based on the Van Allen Probes observations. Through
optimization of the combination of input geomagnetic indices and their
respective time history lengths, the model can well reproduce the
spatiotemporal variation of the oxygen ion flux distributions and
demonstrates remarkable accuracy and minimal errors. Additionally, the
model effectively reconstructs the temporal variation of ring current O+
ions for an out-of-sample dataset. Furthermore, the model provides a
comprehensive and dynamic representation of global ring current O+ ion
distribution. It accurately captures the dynamics of O+ ions during a
geomagnetic storm with the oxygen ion fluxes enhancement and decay, and
reveals distinct characteristics for different energy levels, such as
injection from the plasma sheet, outflow from the ionosphere, and
magnetic local time asymmetry.