Space Climate and Space Weather over the past 400 years: 1. The Power input to the Magnetosphere

TL;DR

This study reconstructs 400 years of solar wind and heliospheric magnetic field data to quantify the long-term power input into Earth's magnetosphere, advancing space weather climatology.

Contribution

It introduces a novel reconstruction method combining historic observations and models to estimate long-term solar wind parameters and magnetospheric power input.

Findings

Annual mean power input varies over 400 years.

Distribution of daily power input follows a stable lognormal pattern.

Provides a foundation for physics-based long-term space weather climatology.

Abstract

Using information on geomagnetic activity, sunspot numbers and cosmogenic isotopes, supported by historic eclipse images and in conjunction with models, it has been possible to reconstruct annual means of solar wind speed and number density and heliospheric magnetic field (HMF) intensity since 1611, when telescopic observations of sunspots began. These models are developed and tuned using data recorded by near-Earth interplanetary spacecraft and by solar magnetograms over the past 53 years. In this paper, we use these reconstructions to quantify power input into the magnetosphere over the past 400 years. For each year, both the annual mean power input is computed and its distribution in daily means. This is possible because the distribution of daily values divided by the annual mean is shown to maintain the same lognormal form with a constant variance. This study is another important step towards the development of a physics-based, long-term climatology of space weather conditions.