First observations of a geomagnetic superstorm with a sub-L1 monitor
First observations of a geomagnetic superstorm with a sub-L1 monitor
Forecasting the geomagnetic effects of solar coronal mass ejections (CMEs) is currently an unsolved problem. CMEs, responsible for the largest values of the north-south component of the interplanetary magnetic field, are the key driver of intense and extreme geomagnetic activity. Observations of southward interplanetary magnetic fields are currently only accessible directly through in situ measurements by spacecraft in the solar wind. On 10-12 May 2024, the strongest geomagnetic storm since 2003 took place, caused by five interacting CMEs. We clarify the relationship between the CMEs, their solar source regions, and the resulting signatures at the Sun-Earth L1 point observed by the ACE spacecraft at 1.00 AU. The STEREO-A spacecraft was situated at 0.956 AU and 12.6{\deg} west of Earth during the event, serving as a fortuitous sub-L1 monitor providing interplanetary magnetic field measurements of the solar wind. We demonstrate an extension of the prediction lead time, as the shock was observed 2.57 hours earlier at STEREO-A than at L1, consistent with the measured shock speed at L1, 710 km/s, and the radial distance of 0.04 AU. By deriving the geomagnetic indices based on the STEREO-A beacon data, we show that the strength of the geomagnetic storm would have been decently forecasted, with the modeled minimum SYM-H=-478.5 nT, underestimating the observed minimum by only 8%. Our study sets an unprecedented benchmark for future mission design using upstream monitoring for space weather prediction.
Emma E. Davies、Christian M?stl、Astrid Veronig、Justin Le Lou?dec、Tanja Amerstorfer、Ute V. Amerstorfer、Eva Weiler、Maike Bauer、Noé Lugaz、Veronika Haberle、Hannah T. Rüdisser、Satabdwa Majumdar、Martin Reiss
Institute of Physics, University of Graz, Graz, AustriaAustrian Space Weather Office, GeoSphere Austria, Graz, AustriaInstitute of Physics, University of Graz, Graz, AustriaAustrian Space Weather Office, GeoSphere Austria, Graz, AustriaAustrian Space Weather Office, GeoSphere Austria, Graz, AustriaAustrian Space Weather Office, GeoSphere Austria, Graz, AustriaAustrian Space Weather Office, GeoSphere Austria, Graz, AustriaAustrian Space Weather Office, GeoSphere Austria, Graz, AustriaSpace Science Center and Department of Physics and Astronomy, University of New Hampshire, Durham, NH, USAConrad Observatory, GeoSphere Austria, Vienna, AustriaAustrian Space Weather Office, GeoSphere Austria, Graz, AustriaAustrian Space Weather Office, GeoSphere Austria, Graz, AustriaCommunity Coordinated Modeling Center, NASA Goddard Space Flight Center, Greenbelt, MD, USA
天文学地球物理学
Emma E. Davies,Christian M?stl,Astrid Veronig,Justin Le Lou?dec,Tanja Amerstorfer,Ute V. Amerstorfer,Eva Weiler,Maike Bauer,Noé Lugaz,Veronika Haberle,Hannah T. Rüdisser,Satabdwa Majumdar,Martin Reiss.First observations of a geomagnetic superstorm with a sub-L1 monitor[EB/OL].(2024-11-19)[2025-04-26].https://arxiv.org/abs/2411.12490.点此复制
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