Intense Geomagnetic Storms during Solar Cycles 23-25

TL;DR

This paper analyzes intense geomagnetic storms during solar cycles 23-25, emphasizing the importance of understanding storm evolution through solar source and solar wind parameters, with a focus on recent events like the April 2023 storm.

Contribution

It highlights the need to catalog geomagnetic storms to better understand their main phase evolution based on solar and solar wind data.

Findings

CME storms can reach Dst -500 nT or lower.

CIR storms are confined to Dst values above -150 nT.

Recent storm analysis motivates comprehensive event cataloging.

Abstract

Intense geomagnetic storms are characterized by a minimum value of the Dst index at or below -100 nT. It is well known that these storms are caused by the southward magnetic fields in coronal mass ejections (CMEs) and corotating interaction regions (CIRs). While CIR storms are confined to Dst values at or above -150 nT, CME storms can reach Dst -500 nT or lower. In this report, we illustrate the need to understand the storm evolution based on solar source and solar wind parameters using a recent storm (2023 April 24) by way of providing the motivation to catalog such events for a better understanding of the main phase time structure of geomagnetic storms