A Stealth CME Bracketed between Slow and Fast Wind Producing Unexpected Geo-effectiveness
arXiv:1805.03128 · doi:10.3847/1538-4357/aac381
Abstract
We investigate how a weak coronal mass ejection (CME) launched on 2016 October 8 without obvious signatures in the low corona produced a relatively intense geomagnetic storm. Remote sensing observations from SDO, STEREO and SOHO and in situ measurements from WIND are employed to track the CME from the Sun to the Earth. Using a graduated cylindrical shell (GCS) model, we estimate the propagation direction and the morphology of the CME near the Sun. CME kinematics are determined from the wide-angle imaging observations of STEREO A and are used to predict the CME arrival time and speed at the Earth. We compare ENLIL MHD simulation results with in situ measurements to illustrate the background solar wind where the CME was propagating. We also apply a Grad--Shafranov technique to reconstruct the flux rope structure from in situ measurements in order to understand the geo-effectiveness associated with the CME magnetic field structure. Key results are obtained concerning how a weak CME can generate a relatively intense geomagnetic storm: (1) there were coronal holes at low latitudes, which could produce high speed streams (HSSs) to interact with the CME in interplanetary space; (2) the CME was bracketed between a slow wind ahead and a HSS behind, which enhanced the southward magnetic field inside the CME and gave rise to the unexpected geomagnetic storm.
arXiv comment8 figures; accepted by ApJ
References in corpus (13)
- Observations of an extreme storm in interplanetary space caused by successive coronal mass ejections
- No Trace Left Behind: Stereo Observation of a Coronal Mass Ejection without Low Coronal Signatures
- Geometric Triangulation of Imaging Observations to Track Coronal Mass Ejections Continuously Out to 1 AU
- The Deflection of the Two Interacting Coronal Mass Ejections of 2010 May 23-24 as Revealed by Combined In situ Measurements and Heliospheric Imaging
- Deriving the radial distances of wide coronal mass ejections from elongation measurements in the heliosphere - Application to CME-CME interaction
- Reconstructing CMEs with Coordinated Imaging and In Situ Observations: Global Structure, Kinematics, and Implications for Space Weather Forecasting
- On Sun-to-Earth Propagation of Coronal Mass Ejections
- Interactions between Coronal Mass Ejections Viewed in Coordinated Imaging and In Situ Observations
- Observational Characteristics of CMEs without Low Coronal Signatures
- On Sun-to-Earth Propagation of Coronal Mass Ejections: 2. Slow Events and Comparison with Others
- Multi-spacecraft Observations of the Coronal and Interplanetary Evolution of a Solar Eruption Associated with Two Active Regions
- Propagation and Interaction Properties of Successive Coronal Mass Ejections in Relation to a Complex Type II Radio Burst
- Propagation Characteristics of Two Coronal Mass Ejections From the Sun Far into Interplanetary Space
Cited by in corpus (11)
- CME -- HSS interaction and characteristics tracked from Sun to Earth
- Characteristics of a Gradual Filament Eruption and Subsequent CME Propagation in Relation to a Strong Geomagnetic Storm
- Radial Evolution of the April 2020 Stealth Coronal Mass Ejection between 0.8 and 1 AU -- A Comparison of Forbush Decreases at Solar Orbiter and Earth
- Investigating Remote-sensing Techniques to Reveal Stealth Coronal Mass Ejections
- On the Relationship Between Transit Time of ICMEs and Strength of the Initiated Geomagnetic Storms
- Interaction of coronal mass ejections and the solar wind. A force analysis
- Recurrent Solar Energetic Particle Flux Enhancements Observed near Earth and Mars
- Understanding the Origins of Problem Geomagnetic Storms Associated With "Stealth" Coronal Mass Ejections
- Interplanetary magnetic flux rope observed at ground level by HAWC
- Earth-affecting Solar Transients: A Review of Progresses in Solar Cycle 24
- Prompt identification of solar wind stream interaction regions from Survey Burst 1 Mode observations of the Radio and Plasma Wave experiment on Solar Orbiter