Journal article
Examining the Radial Evolution of a Corotating Interaction Region Observed at STEREO-A and MAVEN
The Astrophysical journal, Vol.992(1), 34
10/10/2025
DOI: 10.3847/1538-4357/adfd55
Abstract
Corotating interaction regions (CIRs) are long-lasting solar wind structures that persist over multiple solar rotations. These structures accelerate particles throughout the heliosphere and can impart significant energy onto planetary ionospheres and magnetospheres. Understanding how CIRs and their associated energetic particles evolve radially with heliocentric distance is of great interest and can give insight into acceleration mechanisms that occur within these structures. CIR solar wind and particle properties have been examined at numerous heliocentric distances but have been largely unexplored at Mars. We examine the properties of a CIR observed over two Carrington rotations by the Solar Terrestrial Relations Observatory (STEREO)-A at 1 au and the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft at 1.5 au. This CIR was observed during near-radial alignment of the spacecraft, allowing for the exclusion of significant longitudinal variations in the CIR’s properties. We find that during both rotations, the scaled solar wind density and interplanetary magnetic field are slightly higher at MAVEN than measurements at STEREO-A, and the CIR compression occurs over similar periods at both spacecraft during each event. Suprathermal particle enhancements are observed at both spacecraft during both passes of the CIR. Variations in the particle spectra between observations indicate suprathermal particle acceleration at both spacecraft, with higher-energy populations observed at 1.5 au compared to 1 au. Spectral anisotropies observed at MAVEN also indicate a combination of local and nonlocal particle acceleration, further demonstrating that the acceleration mechanisms associated with CIRs are complex and evolve with heliocentric distance.
Details
- Title: Subtitle
- Examining the Radial Evolution of a Corotating Interaction Region Observed at STEREO-A and MAVEN
- Creators
- Sarah A. HendersonRachael J. Filwett - Montana State UniversityChristina O. Lee - Space Sciences LaboratoryRebecca Jolitz - Space Sciences LaboratoryRobert C. Allen - Southwest Research InstituteMaher A. Dayeh - Southwest Research InstituteAli Rahmati - Space Sciences LaboratoryDavin Larson - Space Sciences LaboratoryJasper S. Halekas - University of Iowa , Iowa City, IA, USAJacob R. Gruesbeck - Goddard Space Flight CenterAntoinette Galvin - University of New HampshireHanying Wei - University of California, Los AngelesBernd Heber - Christian-Albrechts-Universität zu Kiel
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.992(1), 34
- DOI
- 10.3847/1538-4357/adfd55
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Publisher
- IOP Publishing
- Grant note
- National Science Foundation (NSF)https://doi.org/10.13039/100000001: 3672337588 IMPACT Investigation - NASA Heliophysics Division through the STEREO Project Office at NASA GSFC: 80NSSC21K1512 NASA Mars Exploration ProgramNASA: 80NSSC24K0908, 80NSSC21K1325, 80NSSC21K0119
We would like to thank the National Science Foundation for making this work possible through Award Number 3672337588. We also acknowledge support from the IMPACT Investigation funded by the NASA Heliophysics Division through the STEREO Project Office at NASA GSFC (grant No. 80NSSC21K1512), as well as the MAVEN project funded through the NASA Mars Exploration Program. We would also like to thank NASA for its support through LWS awards 80NSSC24K0908, 80NSSC21K1325, and 80NSSC21K0119. Lastly, we want to thank the developers of SolarMACH (J. Gieseler et al. 2023) for making their code publicly available, which was adapted to generate the spacecraft geometry portion of Figures 3 and 5.
- Language
- English
- Date published
- 10/10/2025
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984969243702771
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