Ionospheric and geomagnetic response to the total solar eclipse on 21 August 2017

Solar eclipses provide an excellent opportunity to study the effects of a sudden localized change in photoionization flux in the Earth's ionosphere and its consequent repercussion in the Geomagnetic field. We have focused on a subset of the data available from the North American 2017 eclipse in order to study VTEC measurements from GNSS data and geomagnetic field estimations from INTERMAG-NET observatories near the eclipse path. Our simultaneous analysis of both datasets allowed us to quantify the ionosphere and magnetic field reaction to the eclipse event with which allowed us to compare how differently these take place in time. We found that studying the behaviour of VTEC differences with respect to reference values provides better insight of the actual eclipse effect and were able to characterize the dependence of parameters such as time delay of maximum depletion and recovery phase. We were also able to test models that link the ionospheric variations in a quantitative manner. Total electron content depletion measured from GNSS were fed into an approximation of Ashour-Chapman model at the locations of geomagnetic observatories and its predictions match the behaviour of magnetic field components in time and magnitude strikingly accurately. (C) 2021 COSPAR. Published by Elsevier B.V. All rights reserved.

Automated summary

Researchers studied VTEC measurements and geomagnetic field estimations during the 2017 North American eclipse, finding significant differences in the responses of the ionosphere and magnetic field to the eclipse event. They discovered that analyzing VTEC differences with respect to reference values provides better insight into the actual eclipse effect, and were able to characterize parameters such as time delay of maximum depletion and recovery phase. Additionally, they were able to test models quantitatively linking ionospheric variations, showing a striking accurate match between total electron content depletion measurements from GNSS and the behavior of magnetic field components over time.