Cavitons and spontaneous hot flow anomalies in a hybrid-Vlasov global magnetospheric simulation

Authors

Xochitl Blanco-Cano, Universidad Nacional Autonoma de Mexico
Markus Battarbee, University of Helsinki
Lucile Turc, University of Helsinki
Andrew P. Dimmock, Swedish Institute of Space Physics & Aalto University
Emilia K.J. Kilpua, University of Helsinki
Sanni Hoilijoki, University of Colorado
Urs Ganse, University of Helsinki
David G. Sibeck, NASA Goddard Space Flight Center
Paul A. Cassak, West Virginia University
Robert C. Fear, University of Southampton
Riku Jarvinen, Aalto University & Finnish Meteorological Institute
Liisa Juusola, Finnish Meteorological Institute & University of Helsinki
Yann Pfau-Kempf, University of Helsinki
Rami Vainio, University of Turku
Minna Palmroth, University of Helsinki & Finnish Meteorological Institute

Author ORCID Identifier

https://orcid.org/0000-0001-7171-0673

https://orcid.org/0000-0001-7055-551X

https://orcid.org/0000-0002-7576-3251

https://orcid.org/0000-0003-1589-6711

N/A

https://orcid.org/0000-0001-5709-2346

https://orcid.org/0000-0003-0872-1761

N/A

https://orcid.org/0000-0002-5938-1050

N/A

https://orcid.org/0000-0002-4246-2954

N/A

https://orcid.org/0000-0001-5793-7070

N/A

https://orcid.org/0000-0003-4857-1227

Document Type

Article

Publication Date

2018

College/Unit

Eberly College of Arts and Sciences

Department/Program/Center

Physics and Astronomy

Abstract

Abstract. In this paper we present the first identification of foreshock cavitons and the formation of spontaneous hot flow anomalies (SHFAs) with the Vlasiator global magne- tospheric hybrid-Vlasov simulation code. In agreement with previous studies we show that cavitons evolve into SHFAs. In the presented run, this occurs very near the bow shock. We report on SHFAs surviving the shock crossing into the down- stream region and show that the interaction of SHFAs with the bow shock can lead to the formation of a magnetosheath cavity, previously identified in observations and simulations. We report on the first identification of long-term local weak- ening and erosion of the bow shock, associated with a re- gion of increased foreshock SHFA and caviton formation, and repeated shock crossings by them. We show that SHFAs are linked to an increase in suprathermal particle pitch-angle spreads. The realistic length scales in our simulation allow us to present a statistical study of global caviton and SHFA size distributions, and their comparable size distributions support the theory that SHFAs are formed from cavitons. Virtual spacecraft observations are shown to be in good agreement with observational studies.

Digital Commons Citation

Blanco-Cano, Xochitl; Battarbee, Markus; Turc, Lucile; Dimmock, Andrew P.; Kilpua, Emilia K.J.; Hoilijoki, Sanni; Ganse, Urs; Sibeck, David G.; Cassak, Paul A.; Fear, Robert C.; Jarvinen, Riku; Juusola, Liisa; Pfau-Kempf, Yann; Vainio, Rami; and Palmroth, Minna, "Cavitons and spontaneous hot flow anomalies in a hybrid-Vlasov global magnetospheric simulation" (2018). Faculty & Staff Scholarship. 1393.
https://researchrepository.wvu.edu/faculty_publications/1393

Source Citation

Blanco-Cano, X., Battarbee, M., Turc, L., Dimmock, A. P., Kilpua, E. K. J., Hoilijoki, S., Ganse, U., Sibeck, D. G., Cassak, P. A., Fear, R. C., Jarvinen, R., Juusola, L., Pfau-Kempf, Y., Vainio, R., & Palmroth, M. (2018). Cavitons and spontaneous hot flow anomalies in a hybrid-Vlasov global magnetospheric simulation. Annales Geophysicae, 36(4), 1081–1097. https://doi.org/10.5194/angeo-36-1081-2018

Comments

Ann. Geophys., 36, 1081–1097, 2018 https://doi.org/10.5194/angeo-36-1081-2018 © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License.