A novel approach to identify resonant MHD wave modes in solar pores and sunspot umbrae: <i>B</i> − <i>ω</i> analysis

The umbral regions of sunspots and pores in the solar photosphere are generally dominated by $3$~mHz oscillations, which due to $p$-modes penetrating magnetic region. In these locations, wave power is also significantly reduced with respect quiet Sun. However, here we study a pore where oscillations umbra not only comparable, or even larger than that Sun, but main dominant frequency as expected, instead $5$~mHz. By combining Doppler velocities spectropolarimetry analysing relationship between field strength frequency, resultant $B-\omega$ diagram reveals distinct ridges remarkably clear signatures resonant MHD confined within umbra. addition velocity demonstrate modes accompanied predicted from theory. novel technique analysis, proposed this Letter, opens an exciting new avenue for identifying both sunspots.