标题： 时间-距离helioseismic测量对振荡幅度空间变化的敏感性 I. 观测与数值模型 显示英文标题

标题： Sensitivity of time-distance helioseismic measurements to spatial variation of oscillation amplitudes I. Observations and a numerical model

摘要： 众所周知，太阳黑子区域观测到的太阳振荡振幅比太阳平静区域的要低。 我们表明，这种局部振幅降低与时间距离helioseismic分析中的相速滤波程序相结合，可能是导致太阳黑子周围声波测量的传播时间异常出现5%-40%系统误差的一个来源。 消除这些传播时间伪影对于正确推断太阳黑子的次表层结构非常重要。 我们提出了一种经验修正程序，并以一个小黑子为例展示了其使用方法。 本研究利用了MDI/SOHO的数据。 显示英文摘要

摘要： It is well known that the observed amplitude of solar oscillations is lower in sunspots than in quiet regions of the Sun. We show that this local reduction in oscillation amplitudes combined with the phase-speed filtering procedure in time-distance helioseismic analyses could be a source of systematic errors in the range of 5 - 40% in the measured travel-time anomalies of acoustic waves around sunspots. Removing these travel time artifacts is important for correctly inferring the subsurface structure of sunspots. We suggest an empirical correction procedure and illustrate its usage for a small sunspot. This work utilizes data from MDI/SOHO.