Tracking the Rapid Opening and Closing of Polar Coronal Holes through IBEX ENA Observations

Autor:	Bishwas L. Shrestha, David McComas, Eric Zirnstein
Rok vydání:	2023
Předmět:	Space and Planetary Science Astronomy and Astrophysics
Zdroj:	The Astrophysical Journal. 943:34
ISSN:	1538-4357 0004-637X
DOI:	10.3847/1538-4357/aca891
Popis:	Fast solar wind (SW) flows outward from polar coronal holes (PCHs). The latitudinal extent of the fast SW varies during different phases of the solar cycle. The fast SW in the inner heliosheath produces a flatter proton spectrum than the slow SW that can be observed through energetic neutral atoms (ENAs) by the Interstellar Boundary Explorer (IBEX). In this study, we investigate the evolution of PCHs as reflected in the high-time resolution ENA flux measurements from IBEX-Hi, where the PCHs are identified by ENA spectral indices closing of PCHs in 2012 and that in 2017 is related to a rapid opening of PCHs in late 2014. These results also agree qualitatively with the evolution of the ENA spectral index from simulations using a simple time-dependent heliospheric flow model.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::cf0dfa23745699211882c96e54f834cc https://doi.org/10.3847/1538-4357/aca891 Zobrazit plný text záznamu