A Long-Term Decrease of the Mid-Size Segmentation Lengths Observed in the HeII 30.4 nm Solar EUV Emission

Leonid Didkovsky, Seth Wieman, Elena Korogodina

Power spectra of segmentation-cell length (a dominant length scale of EUV emission in the transition region) from full-disk HeII extreme ultraviolet (EUV) images observed by the Ex…