RT Journal Article
T1 Magnetic fields inferred by Solar Orbiter: A comparison between SO/PHI-HRT and SDO/HMI
A1 Sinjan, Jonas
A1 Calchetti, Daniele
A1 Hirzberger, Johann
A1 Kahil, Fátima
A1 Valori, Gherardo
A1 Solanki, Sami K.
A1 Albert, Kinga
A1 Albelo Jorge, Nestor
A1 Álvarez Herrero, Alberto
A1 Appourchaux, Thierry
A1 Bellot Rubio, Luis Ramón
A1 Blanco Rodríguez, Julián
A1 Feller, A.
A1 Gandorfer, Achim
A1 Germerott, Dietmar
A1 Gizón, Laurent
A1 Gómez Cama, José María
A1 Guerrero, Lucas
A1 Gutiérrez Marques, Pablo
A1 Kolleck, Martin
A1 Korpi Lagg, Andreas
A1 Michalik, Harald
A1 Moreno Vacas, Alejandro Miguel
A1 Orozco Suárez, David
A1 Pérez Grande, Isabel
A1 Sanchis Kilders, Esteban
A1 Balaguer Jiménez, María
A1 Schou, Jesper
A1 Schühle, Udo
A1 Staub, Jan
A1 Strecker, Hanna María
A1 Del Toro Iniesta, José Carlos
A1 Volkmer, Reiner
A1 Woch, Joaquim
AB Context. The High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager on board the Solar Orbiter spacecraft (SO/PHI) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) both infer the photospheric magnetic field from polarised light images. SO/PHI is the first magnetograph to move out of the Sun–Earth line and will provide unprecedented access to the Sun’s poles. This provides excellent opportunities for new research wherein the magnetic field maps from both instruments are used simultaneously.Aims. We aim to compare the magnetic field maps from these two instruments and discuss any possible differences between them.Methods. We used data from both instruments obtained during Solar Orbiter’s inferior conjunction on 7 March 2022. The HRT data were additionally treated for geometric distortion and degraded to the same resolution as HMI. The HMI data were re-projected to correct for the 3° separation between the two observatories.Results. SO/PHI-HRT and HMI produce remarkably similar line-of-sight magnetograms, with a slope coefficient of 0.97, an offset below 1 G, and a Pearson correlation coefficient of 0.97. However, SO/PHI-HRT infers weaker line-of-sight fields for the strongest fields. As for the vector magnetic field, SO/PHI-HRT was compared to both the 720-second and 90-second HMI vector magnetic field: SO/PHI-HRT has a closer alignment with the 90-second HMI vector. In the weak signal regime (< 600 G), SO/PHI-HRT measures stronger and more horizontal fields than HMI, very likely due to the greater noise in the SO/PHI-HRT data. In the strong field regime (≳600 G), HRT infers lower field strengths but with similar inclinations (a slope of 0.92) and azimuths (a slope of 1.02). The slope values are from the comparison with the HMI 90-second vector. Possible reasons for the differences found between SO/PHI-HRT and HMI magnetic field parameters are discussed.
PB EDP Sciencies
SN 0004-6361
YR 2023
FD 2023-04-27
LK https://hdl.handle.net/20.500.14352/72311
UL https://hdl.handle.net/20.500.14352/72311
LA eng
NO BMWi - Bundesministerium für Wirtschaft und Energie (Alemania)
NO AEI/MCIN/10.13039/501100011033
NO Ministerio de ciencia e innovación de España
NO Instituto Astrofísico de Andalucía (España)
NO Agencia Estatal de Investigación (España)
NO Fondo Europeo de Desarrollo Regional (Fondos FEDER)
NO Centre national d'études spatiales (CNES) (Francia)
NO CSIC (Centro Superior de Investigaciones Científicas) (España)
DS Docta Complutense
RD 5 abr 2025