Study of Alpha Particle Properties Across Rarefaction Regions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F21%3A10440085" target="_blank" >RIV/00216208:11320/21:10440085 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.mff.cuni.cz/veda/konference/wds/proc/pdf21/WDS21_04_f2_Durovcova.pdf" target="_blank" >https://www.mff.cuni.cz/veda/konference/wds/proc/pdf21/WDS21_04_f2_Durovcova.pdf</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Study of Alpha Particle Properties Across Rarefaction Regions

Popis výsledku v původním jazyce

CRRs are characterized by a monotonic decrease of the solar wind speed and are associated with the regions of a small longitudinal extent on the Sun. Differences between properties of protons and alpha particles (the two most abundant ionic components of the solar wind) are often used to identify the source regions of solar wind streams. However, stream interactions can change alpha-proton relations. In our study, we use near-Earth measurements and focus on the behavior of alpha particles in CRRs. We observed large variations of the alpha particle relative abundance nα/np in these regions which are usually not connected with the solar wind speed and alpha-proton relative drift changes. We perform a superposed epoch analysis of the collected CRRs with a motivation to determine the global profile of alpha particle parameters across CRRs. We find that CRRs exhibit a continuous transition of the alpha particle characteristics from fast to slow streams. For a large part of the CRR, nα/np corresponds to values usually observed in the fast solar wind. We suggest that either a majority of the wind streams in the CRR originate from a coronal hole, or that an additional process altering the alpha parameters occurs in the CRR.

Název v anglickém jazyce

Study of Alpha Particle Properties Across Rarefaction Regions

Popis výsledku anglicky

CRRs are characterized by a monotonic decrease of the solar wind speed and are associated with the regions of a small longitudinal extent on the Sun. Differences between properties of protons and alpha particles (the two most abundant ionic components of the solar wind) are often used to identify the source regions of solar wind streams. However, stream interactions can change alpha-proton relations. In our study, we use near-Earth measurements and focus on the behavior of alpha particles in CRRs. We observed large variations of the alpha particle relative abundance nα/np in these regions which are usually not connected with the solar wind speed and alpha-proton relative drift changes. We perform a superposed epoch analysis of the collected CRRs with a motivation to determine the global profile of alpha particle parameters across CRRs. We find that CRRs exhibit a continuous transition of the alpha particle characteristics from fast to slow streams. For a large part of the CRR, nα/np corresponds to values usually observed in the fast solar wind. We suggest that either a majority of the wind streams in the CRR originate from a coronal hole, or that an additional process altering the alpha parameters occurs in the CRR.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

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Návaznosti

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

WDS&apos;21 Proceedings of Contributed Papers — Physics

ISBN

978-80-7378-455-3

ISSN

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e-ISSN

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Počet stran výsledku

7

Strana od-do

27-33

Název nakladatele

Matfyzpress

Místo vydání

Praha

Místo konání akce

Praha/ZOOM

Datum konání akce

15. 6. 2021

Typ akce podle státní příslušnosti

EUR - Evropská akce

Kód UT WoS článku

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