Details

Autor(en) / Beteiligte

• Gong, Fan
• Yu, Yiqun
• Cao, Jinbin
• Wei, Yong
• Gao, Jiawei
• Li, Hui
• Zhang, Binzheng
• Ridley, Aaron

Titel

Simulating the Solar Wind‐Magnetosphere Interaction During the Matuyama‐Brunhes Paleomagnetic Reversal

Ist Teil von

• Geophysical research letters, 2022-02, Vol.49 (3), p.n/a

Ort / Verlag

Washington: John Wiley & Sons, Inc

Erscheinungsjahr

2022

Quelle

Wiley Online Library

Beschreibungen/Notizen

• During a paleomagnetic reversal, Earth's geomagnetic field is about 10% of today's magnitude and its topology is far more complex than dipolar. Revealing the solar wind energy transmission during the reversal is of importance for understanding the historic space environment. Using a global magnetohydrodynamic model implemented with a data‐reconstructed time‐dependent paleomagnetic field, this study simulates the solar wind‐magnetosphere interactions during the last Matuyama‐Brunhes reversal that occurred about 780,000 years ago. As the magnetosphere shrinks in the midst of the reversal, the stand‐off distance of the subsolar magnetopause approaches as close as 3 Re. Moreover, multiple magnetic reconnection sites emerge due to the irregular geomagnetic configuration, opening up many channels on the magnetopause surface for the solar wind to directly access. The power transmission efficiency through the magnetopause increases to 18%. Plain Language Summary Earth's dynamo at the core produces the intrinsic geomagnetic field that helps prevent solar wind from directly impacting the atmosphere. We present simulation results on the evolution of the space environment during the Matuyama‐Brunhes event that occurred about 780,000 years ago and show that the protection was weakened in two ways: The reduction of the size of the magnetosphere and the increase of power input efficiency. The stand‐off distance of the subsolar magnetopause during the polarity reversal approaches as close as 3 Re. Due to the irregular magnetic field configuration, multiple channels for solar wind energy appear on the magnetosphere, increasing the power transmission efficiency through the magnetopause up to 18%. This implies that many satellites may become more vulnerable to solar storms if a new reversal is underway. Key Points We simulate the solar wind‐magnetosphere interactions during the Matuyama‐Brunhes reversal event with the space weather modeling framework During the reversal, the magnetosphere shrinks, and the transmission efficiency of solar wind power increases up to 18% Multiple magnetic reconnection sites open up channels of solar wind power transmission globally