标题： 太阳次表层分层随11年活动周期的变化 显示英文标题

标题： Changes in the subsurface stratification of the Sun with the 11-year activity cycle

摘要： 我们报告了从日震学数据推断出的太阳内部分层结构的变化情况。利用 SOHO/MDI（太阳和日球观测台/迈克尔逊多普勒成像仪）过去9年的数据，特别是f模频率的时间变化，通过应用日震学反演方法，我们计算出了太阳次表层各层次半径的变化。我们发现“日震学”半径的变化与太阳活动呈反相位关系，分层结构最显著的变化出现在接近表面约0.995$R_{\odot}$的位置。此外，太阳较深层（0.975$R_{\odot}$到0.99$R_{\odot}$之间）的半径变化与11年周期同步。 显示英文摘要

摘要： We report on the changes of the Sun's subsurface stratification inferred from helioseismology data. Using SOHO/MDI (SOlar and Heliospheric Observatory/Michelson Doppler Imager) data for the last 9 years and, more precisely, the temporal variation of f-mode frequencies, we have computed the variation of the radius of subsurface layers of the Sun by applying helioseismic inversions. We have found a variability of the ``helioseismic'' radius in antiphase with the solar activity, with the strongest variations of the stratification being just below the surface around 0.995$R_{\odot}$. Besides, the radius of the deeper layers of the Sun, between 0.975$R_{\odot}$ and 0.99$R_{\odot}$ changes in phase with the 11-year cycle.