Limitations of the Ca ii 8542 Å Line for the Determination of Magnetic Field Oscillations

Chromospheric umbral oscillations produce periodic brightenings in the core of some spectral lines, known as flashes. They are also accompanied by fluctuations velocity, temperature, and, according to several recent works, magnetic field. In this study, we aim ascertain accuracy field determined from inversions Ca II 8542 \AA\ line. We have developed numerical simulations wave propagation a sunspot umbra. Synthetic Stokes profiles emerging simulated atmosphere were computed and then inverted using NICOLE code. The atmospheres inferred been compared with original parameters simulations. Our results show that chromospheric velocity temperature match simulation. contrast, vertical obtained exhibits an oscillatory pattern $\sim$300 G peak-to-peak amplitude which is absent assessed error performing numerous slightly different configurations same profiles. find when approximately at rest, inversion tends favor solutions underestimate strength. On contrary, during flashes, values most concentrated stronger fields than those analysis provides quantification errors associated line suggests caution interpretation fluctuations.