Magnetoseismological determination of magnetic field and plasma density height variation in a solar spicule

The variation of magnetic field strength and plasma density along a solar spicule is determined by the use of magnetoseismology. From Solar Optical Telescope observations of a kink wave propagating along a spicule, by estimating the spatial change in phase speed and velocity amplitude, a novel approach is demonstrated to determine the chromospheric height variation of both magnetic field and plasma density. Furthermore, the magnetoseismological estimate of the plasma density gradient is combined with electron density estimates from spectroscopy to determine the changing degree of ionization of hydrogen along a spicule.