Viacheslav Sadykov

NameViacheslav Sadykov
AffiliationGeorgia State University, USA
TitleComparison of physical properties of the solar atmosphere and synthetic SDO/HMI line-of-sight observables from 3D Radiative MHD simulations
AuthorsViacheslav M Sadykov, Irina N Kitiashvili, Alexander G Kosovichev, Alan A Wray
AbstractIn this study, we compare the SDO/HMI line-of-sight observables (magnetic field, velocity, continuum intensity, and line depth) with the related physical properties for several dynamo simulation runs performed using the “StellarBox” 3D Radiative MHD code. The modeling of the Fe I 6173 Å Stokes profiles is performed using the SPINOR radiative transfer code in the LTE approximation. The reproduced SDO/HMI line-of-sight pipeline is applied to the modeled spectra, and the observables are synthesized with high (numerical) and SDO/HMI (instrumental) resolutions. Correlations between the observables and the physical properties at various heights in the atmosphere are studied for a set of view angles (0, 30, 45, 60, 70, and 80 degrees away from the solar disk center). It was found that the SDO/HMI magnetic field and velocity measurements are unambiguously correlated with physical parameters at certain heights of the solar atmosphere. These heights increase from about 100 km above the photosphere for the disk center case to 300-600 km above the photosphere for the 80 degree case. The heights are found to be slightly lower in regions where higher magnetic fields are found. The total photospheric magnetic flux derived from SDO/HMI observables underestimates the high-resolution magnetic flux by a factor of 3 on average. Integrated SDO/HMI continuum intensity observables underestimate the actual integrated continuum intensity by about 5%. The results of our study allow us to better understand and interpret the line-of-sight observations of quiet Sun regions from the SDO/HMI mission.