Abstract
Emerging coronal loops were studied with extreme ultraviolet observations performed by SOHO/EIT on 5 and 6 August 1997 for NOAA 8069. Physical parameters (size and twist) were determined by a new stereoscopic method. The flux tubes were measured twisted when first observed by EIT. After emerging, they de-twisted as they expanded, which corresponds to a minimization of the energy. Different scenarios which take into account the conservation of the magnetic helicity are discussed in relation with structure and temperature variations.
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Portier-Fozzani, F., Aschwanden, M., Démoulin, P. et al. Measurement of coronal magnetic twists during loop emergence of NOAA 8069. Sol Phys 203, 289–308 (2001). https://doi.org/10.1023/A:1013329626327
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DOI: https://doi.org/10.1023/A:1013329626327