Statistical analysis of comet disconnection events using STEREO HI and a data-assimilative solar wind model

Watson, S., Scott, C. ORCID: https://orcid.org/0000-0001-6411-5649, Owens, M. ORCID: https://orcid.org/0000-0003-2061-2453, Barnard, L. ORCID: https://orcid.org/0000-0001-9876-4612 and Lang, M. (2025) Statistical analysis of comet disconnection events using STEREO HI and a data-assimilative solar wind model. The Astrophysical Journal, 982 (2). 66. ISSN 1538-4357 doi: 10.3847/1538-4357/adb978

Abstract/Summary

Comets tails can reveal information about the local solar wind conditions. They can exhibit various signatures of interactions with the solar wind including bending, developing kinks and sometimes a undergoing tail disconnections. In this study, we investigate comet tail disconnection events observed in the STEREO HI data during the period of 2007 to 2023. Using the Heliospheric Upwind eXtrapolation model with a time-dependency (HUXt) solar wind model alongside novel solar wind data assimilation (DA) techniques, each disconnection event was investigated to determine its cause. The resulting statistical analysis led to three main conclusions; 1) For every Heliospheric Current Sheet (HCS) crossing predicted by HUXt that occurs when the comet is within the region of influence of DA, a tail disconnection follows, 2) For HCS crossings that occur outside the region where DA can be applied, 54.5% are followed by a tail disconnection, 3) There is an approximately linear relationship between the speed of the solar wind at the HCS crossing and the time delay to the onset of a disconnection given by the equation V_rel (km s^-1) = (2.23 +/- 0.35)Delta_t (hours) + (400 +/- 10) (km s^-1).

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/121577
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Astronomical Society
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