Global solar wind variations over the last four centuries

Owens, M. J. ORCID: https://orcid.org/0000-0003-2061-2453, Lockwood, M. ORCID: https://orcid.org/0000-0002-7397-2172 and Riley, P. (2017) Global solar wind variations over the last four centuries. Scientific Reports, 7. 41548. ISSN 2045-2322 doi: 10.1038/srep41548

Abstract/Summary

The most recent “grand minimum” of solar activity, the Maunder minimum (MM, 1650–1710), is of great interest both for understanding the solar dynamo and providing insight into possible future heliospheric conditions. Here, we use nearly 30 years of output from a data-constrained magnetohydrodynamic model of the solar corona to calibrate heliospheric reconstructions based solely on sunspot observations. Using these empirical relations, we produce the first quantitative estimate of global solar wind variations over the last 400 years. Relative to the modern era, the MM shows a factor 2 reduction in near-Earth heliospheric magnetic field strength and solar wind speed, and up to a factor 4 increase in solar wind Mach number. Thus solar wind energy input into the Earth’s magnetosphere was reduced, resulting in a more Jupiter-like system, in agreement with the dearth of auroral reports from the time. The global heliosphere was both smaller and more symmetric under MM conditions, which has implications for the interpretation of cosmogenic radionuclide data and resulting total solar irradiance estimates during grand minima.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/68606
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Nature Publishing Group
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