Academic Journal
Interface region imaging spectrograph (IRIS) observations of the fractal dimension in the solar atmosphere
| العنوان: | Interface region imaging spectrograph (IRIS) observations of the fractal dimension in the solar atmosphere |
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| المؤلفون: | Markus J. Aschwanden, Nived Vilangot Nhalil |
| المصدر: | Frontiers in Astronomy and Space Sciences, Vol 9 (2022) |
| بيانات النشر: | Frontiers Media S.A., 2022. |
| سنة النشر: | 2022 |
| المجموعة: | LCC:Astronomy LCC:Geophysics. Cosmic physics |
| مصطلحات موضوعية: | methods, statistical -fractal dimension -sun, transition region -solar granulation -solar photosphere, fractal dimension, statistical, Astronomy, QB1-991, Geophysics. Cosmic physics, QC801-809 |
| الوصف: | We focus here on impulsive phenomena and Quiet-Sun features in the solar transition region, observed with the Interface Region Imaging Spectrograph (IRIS) at 1,400 Å (at formation temperatures of Te ≈ 104–106 K). Summarizing additional literature values we find the following fractal dimensions (in increasing order): DA = 1.23 ± 0.09 for photospheric granulation, DA =1.40 ± 0.09 for chromospheric (network) patterns, DA = 1.54 ± 0.04 for plages in the transition region, DA = 1.56 ± 0.08 for extreme ultra-violet (EUV) nanoflares, DA = 1.59 ± 0.20 for active regions in photospheric magnetograms, and DA = 1.76 ± 0.14 for large solar flares. We interpret low values of the fractal dimension (1.0 ≲ DA ≲ 1.5) in terms of sparse curvi-linear flow patterns, while high values of the fractal dimension (1.5 ≲ DA ≲ 2.0) indicate quasi-space-filling transport processes, such as chromospheric evaporation in flares. Phenomena in the solar transition region appear to be consistent with self-organized criticality (SOC) models, based on their fractality and their size distributions of fractal areas A and (radiative) energies E, which show power law slopes of αAobs=2.51±0.21 (with αAtheo=2.33 predicted), and αEobs=2.03±0.18 (with αEtheo=1.80 predicted). This agreement suggests that brightenings detected with IRIS at 1,400 Å reveal the same nonlinear SOC statistics as their coronal counterparts in EUV. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 2296-987X |
| Relation: | https://www.frontiersin.org/articles/10.3389/fspas.2022.999319/full; https://doaj.org/toc/2296-987X |
| DOI: | 10.3389/fspas.2022.999319 |
| URL الوصول: | https://doaj.org/article/3d4545b4ed9442c683a0e2b4b495ff70 |
| رقم الانضمام: | edsdoj.3d4545b4ed9442c683a0e2b4b495ff70 |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 2296987X |
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| DOI: | 10.3389/fspas.2022.999319 |