SOLARNET Conference: The Many Scales of the Magnetic Sun

Data-driven model of temporal evolution of the solar Mg II h & k profiles over the solar cycle

11 May 2023, 12:05

15m

Haus H, Telegrafenberg

Oral presentation 4) Variations of magnetic fields with the solar cycle – synoptic observations and Theory Variations of magnetic fields with the solar cycle – synoptic observations and Theory

Speaker

Dr Julius Koza (Astronomical Institute, Slovak Academy of Sciences)

Description

The solar radiation in the cores of the Mg II h & k spectral lines strongly correlates with solar magnetic activity and global variations of magnetic fields with the solar cycle. This work provides a data-driven model of temporal evolution of the solar full-disk Mg II h & k profiles over the solar cycle. Based on selected 76 IRIS near-UV full-Sun mosaics covering almost the full solar cycle 24, we find the parameters of double-Gaussian fits of the disk-averaged Mg II h & k profiles and a model of their temporal evolution parameterized by the Bremen composite Mg II index. The Markov Chain Monte Carlo algorithm implemented in the IDL toolkit SoBAT is used in modeling and predicting temporal evolution of the Mg II h & k peak-to-center intensity ratio and the Bremen Mg II index. The relevant full-disk Mg II h & k calibrated profiles with uncertainties and spectral irradiances are provided as an online machine-readable table. To facilitate utilization of the model corresponding routines, written in IDL, are made publicly available at GitHub.