Average solar active region: I. Intensities, velocities, and the photospheric magnetic field

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F25%3A00638178" target="_blank" >RIV/67985815:_____/25:00638178 - isvavai.cz</a>

Result on the web

<a href="https://hdl.handle.net/11104/0368921" target="_blank" >https://hdl.handle.net/11104/0368921</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202554440" target="_blank" >10.1051/0004-6361/202554440</a>

Result language

angličtina

Original language name

Average solar active region: I. Intensities, velocities, and the photospheric magnetic field

Original language description

Aims. Solar active regions (ARs) are key manifestations of the Sun's magnetic activity, displaying diverse spatial and temporal characteristics. Their formation and evolution play a crucial role in understanding the solar dynamo and space weather. While individual ARs exhibit significant variability, ensemble averaging o_ers a method to extract their typical properties and evolution. Methods. This study aims to construct an average bipolar AR using ensemble averaging of observational data. By normalizing ARs in space and time, we seek to identify general trends in the evolution of magnetic flux, velocity fields, and atmospheric emissions, providing insights into the underlying physical mechanisms governing AR development. Results. We analysed a sample of bipolar ARs observed by the Helioseismic and Magnetic Imager and Atmospheric Imaging Assembly aboard the Solar Dynamics Observatory. The ARs were selected based on strict criteria, ensuring clear polarity separation and emergence within 60_ of the solar central meridian. Normalisation procedures were applied to align ARs spatially and temporally before computing an ensemble average of various observables, including line-of-sight magnetograms, Dopplergrams, and multi-wavelength intensity maps. Conclusions. The average AR exhibits a well-defined evolutionary pattern, with flux emergence followed by peak activity and subsequent decay. The leading polarity retains coherence longer than the trailing one, consistent with previous studies. Surface flow maps revealed a diverging outflow near the emergence site before the emerged AR is clearly visible in magnetograms. Atmospheric emission variations indicate enhanced heating above the AR in later phases, possibly due to persistent reconnection events. The ensemble averaging approach highlights systematic features of AR evolution that are often obscured by individual-case variability.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GF23-07633K" target="_blank" >GF23-07633K: Unveiling the principles of solar magneto-convection</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

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

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

700

Issue of the periodical within the volume

Aug.

Country of publishing house

FR - FRANCE

Number of pages

22

Pages from-to

A40

UT code for WoS article

001544326900005

EID of the result in the Scopus database

2-s2.0-105012626511