We analyze UV observations of an isolated sunspot taken with the Transition Region and Coronal Explorer . We produced "space/time slice images," which reveal periodic, inward-propagating, intensity fluctuations in the inner photospheric penumbra and periodic, outward-propagating, annular intensity fluctuations in the outer penumbra and the area around the sunspot. The average propagation velocity of the inward- and outward-propagating intensity flows is about 0.5 and 1 km s -1 , respectively, and the distance between subsequent crests is about 2500 km. Using observations obtained with the Michelson Doppler Imager, we found propagating magnetic field enhancements that present a spatial and temporal coherence with the UV intensity fluctuations. We have not observed any waves similar or related to the chromospheric 5 minute waves.
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Georgakilas et al. (2002) studied this question.
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