Vortex Flows in the Solar Atmosphere: Automated Identification and Statistical Analysis
| Autor: | David B. Jess, Ioannis Giagkiozis, Viktor Fedun, Eamon Scullion, Gary Verth |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Physics
atmosphere [Sun] Photosphere 010504 meteorology & atmospheric sciences Turbulence photosphere [Sun] F300 oscillations [Sun] Flux Astronomy and Astrophysics F500 01 natural sciences Magnetic flux Vortex Magnetic field Computational physics Physics::Fluid Dynamics Eddy Space and Planetary Science 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics 010303 astronomy & astrophysics Intensity (heat transfer) 0105 earth and related environmental sciences |
| Zdroj: | Giagkiozis, I, Fedun, V, Scullion, E, Jess, D B & Verth, G 2018, ' Vortex Flows in the Solar Atmosphere: Automated Identification and Statistical Analysis ', The Astrophysical Journal, vol. 869, 169 . https://doi.org/10.3847/1538-4357/aaf797 |
| ISSN: | 0004-637X |
| DOI: | 10.3847/1538-4357/aaf797 |
| Popis: | Vortices on the photosphere are fundamentally important as these coherent flows have the potential to form coherent magnetic field structures in the solar atmosphere, e.g. twisted magnetic flux tubes. These flows have traditionally been identified by tracking magnetic bright points using primarily visual inspection. This approach has the shortcoming that it introduces bias into the statistical analyses. In this work we fully automate the process of vortex identification using an established method from hydrodynamics for the study of eddies in turbulent flows. For the first time, we apply this to detect inter-granular photospheric intensity vortices. Using this approach, we find that the expected lifetime of intensity vortices is much shorter (17s) compared with previously observed magnetic bright point swirls. We suggest that at any time there are 1:4x106 such small-scale intensity vortices covering about 2:8% of the total surface of the solar photosphere. Lastly, we propose that if this increased number of vortices is reflected in proportion to the number of magnetic tornadoes, this would imply that more than 17% of the area of the lower corona has more than adequate energy flux to satisfy quiet Sun heating requirements within that area. Lastly, assuming a causal relation between intensity vortices and magnetic tornadoes, we find based on a Monte Carlo simulation that every ~ 1.5 minute at least 60% of the lower corona will be swept by tornadoes, implying that intensity vortices may offer an answer to the quiet Sun heating problem. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|