kth.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Segmentation of Coronal Features to Understand the Solar EUV and UV Irradiance Variability III. Inclusion and Analysis of Bright Points
European Space Res & Technol Ctr ESTEC, NL-2200 AG Noordwijk, Netherlands.;Delft Univ Technol, Kluyverweg 1, NL-2629 HS Delft, Netherlands..
Iceye Oy, Maarintie 6, Espoo 02150, Finland.;Julias Maximilians Univ Wurzburg, Inst Informat, D-97074 Wurzburg, Germany..
European Space Res & Technol Ctr ESTEC, NL-2200 AG Noordwijk, Netherlands..
Indian Inst Astrophys, Bangalore 560034, Karnataka, India.;Nagoya Univ, Inst Space Earth Environm Res, Nagoya, Aichi, Japan..
Show others and affiliations
2021 (English)In: Solar Physics, ISSN 0038-0938, E-ISSN 1573-093X, Vol. 296, no 9, article id 138Article in journal (Refereed) Published
Abstract [en]

The study of solar irradiance variability is of great importance in heliophysics, Earth's climate, and space weather applications. These studies require careful identifying, tracking and monitoring of features in the solar photosphere, chromosphere, and corona. Do coronal bright points contribute to the solar irradiance or its variability as input to the Earth atmosphere? We studied the variability of solar irradiance for a period of 10 years (May 2010 - June 2020) using the Large Yield Radiometer (LYRA), the Sun Watcher using APS and image Processing (SWAP) on board PROBA2, and the Atmospheric Imaging Assembly (AIA), and applied a linear model between the segmented features identified in the EUV images and the solar irradiance measured by LYRA. Based on EUV images from AIA, a spatial possibilistic clustering algorithm (SPoCA) is applied to identify coronal holes (CHs), and a morphological feature detection algorithm is applied to identify active regions (ARs), coronal bright points (BPs), and the quiet Sun (QS). The resulting segmentation maps were then applied on SWAP images, images of all AIA wavelengths, and parameters such as the intensity, fractional area, and contribution of ARs/CHs/BPs/QS features were computed and compared with LYRA irradiance measurements as a proxy for ultraviolet irradiation incident to the Earth atmosphere. We modeled the relation between the solar disk features (ARs, CHs, BPs, and QS) applied to EUV images against the solar irradiance as measured by LYRA and the F10.7 radio flux. A straightforward linear model was used and corresponding coefficients computed using a Bayesian method, indicating a strong influence of active regions to the EUV irradiance as measured at Earth's atmosphere. It is concluded that the long- and short-term fluctuations of the active regions drive the EUV signal as measured at Earth's atmosphere. A significant contribution from the bright points to the LYRA irradiance could not be found.

Place, publisher, year, edition, pages
Springer Nature , 2021. Vol. 296, no 9, article id 138
Keywords [en]
Sun, UV radiation, activity, corona, atmosphere, bright points, Solar terrestrial relations
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:kth:diva-303075DOI: 10.1007/s11207-021-01863-9ISI: 000696529200001Scopus ID: 2-s2.0-85115063803OAI: oai:DiVA.org:kth-303075DiVA, id: diva2:1600549
Note

QC 20211005

Available from: 2021-10-05 Created: 2021-10-05 Last updated: 2022-06-25Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records

Giono, Gabriel

Search in DiVA

By author/editor
Giono, Gabriel
By organisation
Space and Plasma Physics
In the same journal
Solar Physics
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 25 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf