中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
A NONLOCAL CONVECTION MODEL OF THE SOLAR CONVECTION ZONE

文献类型:期刊论文

作者XIONG, DR; CHEN, QL
刊名ASTRONOMY & ASTROPHYSICS
出版日期1992-02-01
卷号254期号:1-2页码:362-370
关键词CONVECTION OVERSHOOTING SUN, ATMOSPHERE SUN, INTERIOR
ISSN号0004-6361
英文摘要The models of the solar convection zone with various convective parameters c1 and c2 have been constructed based on Xiong's nonlocal convection theory (Xiong 1979, 1981). The departure form radiative equilibrium is taken into account by means of the generalized Eddington approximation (Xiong 1989a). The nonlocal convection model has a large temperature gradient in the surface superadiabatic convection zone and a rather shallow convectively instable zone in comparison with the local convection model with the same c1. The departures from radiative equilibrium are negligible except at the most upper layer of the convection zone, where the maximum relative departure \1 - aT4/E(r)\ is about 3%. A comparison of the model based on the Eddington approximation with the one based on the radiative diffusion approximation shows that they are very close.to each other. The theoretical rms turbulent velocity component and the rms relative temperature fluctuation at the photosphere are about 1.4 km s-1 and 0.04 respectively, and decrease exponentially with In P upwards. The e-folding length is about 1.4 square-root c1 c2 times the pressure scale height. Passing through the boundary of the convectively unstable zone the turbulent velocity-temperature correlation changes its sign. The turbulent kinetic energy is less than about 1.5% of the total energy flux, and has no significant direct influence on the structure of the convection zone. The turbulent pressure gradient can achieve few tenths in the upper layer of the convection zone and its influence on the structure of the convection zone cannot be neglected. A comparison of the theoretical eigenfrequencies of the adiabatic p-mode oscillations and the surface lithium depletion with the observed ones shows that the model with c1 = 0.75 and c2 = 0.25 seems to be optimal. The theoretical eigenfrequencies of the modes of degree l < 60 are systematically smaller than the observed ones and the overshooting seems slightly deeper in views of the surface lithium depletion. A reasonable explanation may be that there is an about 10(4) G magnetic field in the lower convection zone. The magnetic fields will brake extensive overshooting and block the convective heat transport, which will increase the temperature gradient in the lower convection zone.
WOS标题词Science & Technology ; Physical Sciences
学科主题天文和天体物理
类目[WOS]Astronomy & Astrophysics
研究领域[WOS]Astronomy & Astrophysics
关键词[WOS]RADIATION-HYDRODYNAMIC EQUATIONS ; STELLAR ENVELOPES ; HEIGHT DEPENDENCE ; OSCILLATIONS ; STATE ; FREQUENCIES ; ATMOSPHERE ; STARS ; PHOTOSPHERE ; VELOCITIES
收录类别SCI
语种英语
WOS记录号WOS:A1992HC81700053
公开日期2015-04-20
源URL[http://libir.pmo.ac.cn/handle/332002/11241]  
专题紫金山天文台_院士文集_熊大闰
推荐引用方式
GB/T 7714
XIONG, DR,CHEN, QL. A NONLOCAL CONVECTION MODEL OF THE SOLAR CONVECTION ZONE[J]. ASTRONOMY & ASTROPHYSICS,1992,254(1-2):362-370.
APA XIONG, DR,&CHEN, QL.(1992).A NONLOCAL CONVECTION MODEL OF THE SOLAR CONVECTION ZONE.ASTRONOMY & ASTROPHYSICS,254(1-2),362-370.
MLA XIONG, DR,et al."A NONLOCAL CONVECTION MODEL OF THE SOLAR CONVECTION ZONE".ASTRONOMY & ASTROPHYSICS 254.1-2(1992):362-370.

入库方式: OAI收割

来源:紫金山天文台

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