The interior of the Sun is filled acoustic waves with periods of about 5 min. These waves, called “p modes,” are understood to be excited by convection in a thin layer beneath the Sun's surface. The p modes cause seismic ripples, which we call “the solar oscillations.” Helioseismic observatories use Doppler observations to map these oscillations, both spatially and temporally. The p modes propagate freely throughout the solar interior, reverberating between the near and far hemispheres. They also interact strongly with active regions at the surfaces of both hemispheres, carrying the signatures of said interactions with them. Computational analysis of the solar oscillations mapped in the Sun's near hemisphere, applying basic principles of wave optics to model the implied p modes propagating through the solar interior, gives us seismic maps of large active regions in the Sun's far hemisphere. These seismic maps are useful for space weather forecasting. For the past decade, NASA's twin STEREO spacecraft have given us full coverage of the Sun's far hemisphere in electromagnetic (EUV) radiation from the far side of Earth's orbit about the Sun. We are now approaching a decade during which the STEREO spacecraft will lose their farside vantage. There will occur significant periods from thence during which electromagnetic coverage of the Sun's far hemisphere will be incomplete or nil. Solar seismology will make it possible to continue our monitor of large active regions in the Sun's far hemisphere for the needs of space weather forecasters during these otherwise blind periods.

中文翻译：

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太阳远半球的地震成像及其在空间天气预报中的应用。

太阳的内部充满了大约5分钟的声波。这些被称为“ p模式”的波被理解为在太阳表面下的薄层中通过对流被激发。该p模式引起地震的涟漪，我们称之为“太阳振荡。” 日震观测台使用多普勒观测在空间和时间上绘制这些振荡。该p模态在整个太阳内部自由传播，在近半球和远半球之间回荡。它们还与两个半球表面的活性区域强烈相互作用，并带有与它们相互作用的特征。计算太阳近半球中映射的太阳振荡的计算分析，应用波光学的基本原理对隐含的p进行建模在太阳内部传播的各种模式，为我们提供了太阳远半球中大型活动区域的地震图。这些地震图对于空间天气预报很有用。在过去的十年中，NASA的双STEREO航天器从地球绕太阳轨道的另一端向我们提供了电磁（EUV）辐射对太阳远半球的全面覆盖。现在，我们正接近十年，在此期间，STEREO航天器将失去其遥远的优势。从那时起，将发生相当长的一段时间，在此期间，太阳的远半球的电磁覆盖范围将不完整或为零。太阳地震学将使我们有可能继续监测太阳远半球的大型活动区域，以满足在这些否则为盲目的时期内空间天气预报员的需求。