The State of the Solar Wind, Magnetosphere, and Ionosphere During the Maunder Minimum

TL;DR

This study reconstructs the solar wind, magnetosphere, and ionosphere conditions during the Maunder Minimum, revealing significantly weaker solar wind and altered space environment compared to the modern era.

Contribution

It develops a novel MHD modeling approach to infer Maunder Minimum space conditions and assesses their impact on Earth's magnetosphere and ionosphere.

Findings

Solar wind density and magnetic field were an order of magnitude lower.

Magnetopause and shock distances were twice as large.

Ionospheric electron density was substantially lower.

Abstract

Both direct observations and reconstructions from various datasets, suggest that conditions were radically different during the Maunder Minimum (MM) than during the space era. Using an MHD model, we develop a set of feasible solutions to infer the properties of the solar wind during this interval. Additionally, we use these results to drive a global magnetospheric model. Finally, using the 2008/2009 solar minimum as an upper limit for MM conditions, we use results from the International Reference Ionosphere (ILI) model to speculate on the state of the ionosphere. The results describe interplanetary, magnetospheric, and ionospheric conditions that were substantially different than today. For example: (1) the solar wind density and magnetic field strength were an order of magnitude lower; (2) the Earth's magnetopause and shock standoff distances were a factor of two larger; and (3) the maximum electron density in the ionosphere was substantially lower.