Magnetospheric response to solar wind driving

Interaction of solar events propagating throughout the interplanetary space with the magnetic field of the Earth may result in disruption of the magnetosphere. Disruption of the magnetic field is followed by the formation of the time-varying electric field and thus electric current is induced in Earth-bound structures such as transmission networks, pipelines or railways. In that case, it is necessary to be able to predict a future state of the magnetosphere and magnetic field of the Earth. The most straightforward way would use geomagnetic indices. Several studies are investigating the relationship of the response of the magnetosphere to changes in the solar wind with motivation to give a more accurate prediction of geomagnetic indices during geomagnetic storms. To forecast these indices, different approaches have been attempted--from simple correlation studies to neural networks.

We study the effects of interplanetary shocks observed at L1 on the Earth's magnetosphere with a database of tens of shocks between 2009 and 2019. Driving the magnetosphere is described as integral of reconnection electric field for each shock. The response of the geomagnetic field is described with the SYM-H index. We created an algorithm in Python for prediction of the magnetosphere state based on the correlation of solar wind driving and magnetospheric response and found that typical time-lags range between tens of minutes to maximum 2 hours. The results are documented by a large statistical study.