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- Ludwig, Hans-Günter, et al.
(författare)
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3D Hydrodynamical Modelling of the Solar Chromosphere
- 2003
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Ingår i: International Astronomical Union Symposium. - 158381163X ; 219, s. 40-40
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Konferensbidrag (refereegranskat)abstract
- We report on 3D radiation-hydrodynamics modelling of the non-magneticsolar atmosphere with emphasis on the problem of the acoustic heating ofthe chromosphere. Our models include the generation of acoustic waves inthe uppermost layers of the solar convection zone their propagationthrough the photospheric layers and their ultimate transformation intoshock fronts which are dissipated in the chromospheric layers. In thechromosphere we find a bimodal temperature distribution consisting of acool non-shocked and hot shocked gas component. The hot gas is locatedin small-scale filamentary structures associated with propagating shockfronts which evolve rapidly in time. The detailed spatial and temporalinformation provided by the models can be exploited to predictobservational diagnostics hitherto unavailable. We present syntheticimages of features in the millimetre and sub-millimetre radio continuumpotentially observable by the Atacama Large Millimetre Array (ALMA).
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| 2. |
- Wedemeyer, Sven, et al.
(författare)
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Acoustic Energy Generated by Convection: 3-D Numerical Simulations for the Sun
- 2001
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Ingår i: Astronomische Gesellschaft Abstract Series, Vol. 18. Abstracts of Contributed Talks and Posters presented at the Annual Scientific Meeting of the Astronomische Gesellschaft at the Joint European and National Meeting JENAM 2001 of the European Astronomical. ; 18
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Konferensbidrag (refereegranskat)abstract
- Dissipation of acoustic waves may be an efficient heating mechanism forthe lower and middle chromosphere of the quiet Sun. The basic idea isthat turbulent motions at the top of the solar convection zone generateacoustic waves which propagate upwards and dissipate in the lower andmiddle chromosphere, transporting energy into the higher layers. Butstill the question remains if this amount of energy is sufficient toexplain the observed temperature increase without invoking magneticfields. With a new version of the COBOLD radiation hydrodynamics code weare able to compute 3-D models extending all the way from the upperconvection zone to the middle chromosphere. First 3-D simulations reveala complex, inhomogenous and highly dynamical structure of the lower andmiddle chromosphere which evolves on rather short timescales. On smallspatial dimensions very cool regions are present next to a "network" ofhotter matter. The code is being developed further to provide a moredetailed analysis and comparison with observations.
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