DR. PANIVENI UDAYASHANKAR

The speaker employs fractal analysis to study the complexity of the supergranulation structure using SOHO Dopplergrams, obtained during the solar minimum phase. The data consists of 200 visually selected supergranular cells, for which she finds a broad, slightly asymmetric dispersion in the size distribution with the most probable size around 31.9 Mm. From the area-perimeter relation, she has obtained a fractal dimension ‘D’ of about 1.25. This is consistent with that for isobars, and suggests a possible turbulent origin of supergranulation. Also, she has analysed 57 active region supergranular cells using Intensitygrams, obtained at the Kodaikanal Solar Observatory during the solar maximum phase. From the area-perimeter relation, she has obtained a fractal dimension of about 1.19. By relating this to the variances of kinetic energy, temperature and pressure, it is concluded that the supergranular network is close to being isobaric and that it has a possible turbulent origin.