Magnetosphere-Ionosphere Coupling During the Paleomagnetic Polarity Reversal

Abstract:

The geomagnetic field plays an important role in protecting the biosphere and helps maintain the livability of the earth for billions of years. Therefore, it is believed that the weakening of the protective effect caused by the geomagnetic reversal process will have a profound negative impact on the biosphere and may be one of the important factors that cause the extinction. This study simulates the last geomagnetic reversal event (Matuyama-Brunhes event) that occurred about 700,000 years ago by using Space Weather Modeling Framework (SWMF). We used a large amount of paleomagnetic field data to invert the magnetic field change during the whole process of geomagnetic reversal. During the Earth's magnetic field reversal, we discovered that the FACs are completely structureless during the time with apparently non-dipole field (774,500 years ago); moreover, there are also multiple energy transmission channels and some interesting phenomena in the ionosphere, allowing solar wind energy to effectively enter the magnetosphere and affect the Earth's atmosphere. The results of this paper provide important support for the newly proposed "many-to-one" relation of the Earth's extinction.