Estimation of the solar wind extreme events

TL;DR

This paper applies extreme value theory to 20 years of solar wind data to estimate rare extreme events and their potential impact on the magnetosphere, revealing an upper boundary in the magnitudes studied.

Contribution

It introduces a novel application of extreme value theory to solar wind data for estimating rare extreme events and their magnitudes over a 20-year period.

Findings

Estimated 1-in-40 and 1-in-80 year extreme values for solar wind parameters.

Verification of estimated extremes with historical recorded events.

Identification of an upper boundary in the magnitudes of extreme solar wind events.

Abstract

This research provides an analysis of extreme events in the solar wind and in the magnetosphere due to disturbances of the solar wind. Extreme value theory has been applied to a 20 year data set from the Advanced Composition Explorer (ACE) spacecraft for the period 1998-2017. The solar proton speed, solar proton temperature, solar proton density and magnetic field have been analyzed to characterize extreme events in the solar wind. The solar wind electric field, vB$_{z}$ has been analyzed to characterize the impact from extreme disturbances in the solar wind to the magnetosphere. These extreme values were estimated for one-in-40 and one-in-80 years events, which represent two and four times the range of the original data set. The estimated values were verified by comparison with measured values of extreme events recorded in previous years. Finally, our research also suggests the presence of an upper boundary in the magnitudes under study.