Comparison of the Coronal Magnetic Fields Estimated by Kink Oscillations and Extrapolation

Abstract

A series of events featuring decaying Transverse Coronal Loop Oscillations is examined utilizing high-resolution observations from the Atmospheric Imaging Assembly on board Solar Dynamic Observatory and Extreme Ultraviolet Imager from Solar Terrestrial Relations Observatory twin spacecrafts, A (ahead) and B (behind). We used two distinct methods, coronal seismology and extrapolations, independently to assess the coronal magnetic field values within oscillating loops. For the coronal seismology, we performed stereoscopic tracing of coronal loops to obtain an accurate measurement of their lengths. Subsequently, we estimated the oscillation parameters such as amplitude, period, phase, and damping time. Using the periods of oscillations and loop lengths, we calculated average magnetic field values within the oscillating coronal loops, ranging from 12 to 146 G. On the other hand, we performed non-linear extrapolations to match field lines with the coronal loops, resulting magnetic field values between 54 and 187 G. Our findings indicate that extrapolated field lines exhibited slightly higher values than those obtained through coronal seismology, though both methods provided reasonable estimates of the magnetic field strengths in the analyzed coronal loops.