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arXiv · 2610.38861

Mg II Signatures of Frequency Dependent Wave Propagation in Magnetic Elements

Deborah Baker·David M. Long·Marco Stangalini·Michele Berretti·Andy S. H. To·Stephanie L. Yardley·Paola Testa
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Abstract

Waves in solar magnetic elements provide a pathway for transporting and dissipating energy in the chromosphere, yet the relationship between photospheric oscillations and chromospheric spectral structure remains incompletely understood. We investigate whether distinct chromospheric Mg II spectral states are linked to different populations of photospheric kink mode oscillations, with particular focus on the role of high frequency (~5mHz) waves. Magnetic elements are tracked in SDO/HMI magnetograms to derive horizontal velocity power spectra, while corresponding Mg II h + k profiles from IRIS are classified using k-means clustering into morphology-based (SHAPE) and intensity-based (ABS) groups. Both classifications exhibit systematic differences in oscillatory behavior. The SHAPE clusters isolate spectral morphologies associated with enhanced high-frequency power, including cases where oscillations in the 4-6 mHz band exceed those in the photospheric p-mode band. In contrast, the ABS clusters show a monotonic increase in the relative contribution of high-frequency oscillations with increasing emission strength and magnetic flux. These results indicate that high-frequency oscillations are both selectively enhanced in specific chromospheric states and systematically strengthened in stronger magnetic environments. This suggests that magnetic structuring plays a key role in regulating both the transmission and the conversion of kink mode wave energy into observable chromospheric signatures.

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Deborah Baker, David M. Long, Marco Stangalini, Michele Berretti, Andy S. H. To, Stephanie L. Yardley, Paola Testa. 2026-10-28. Mg II Signatures of Frequency Dependent Wave Propagation in Magnetic Elements. https://arxiv.org/abs/2610.38861

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