Atmospheric-radiation boundary conditions for high-frequency waves in time-distance helioseismology

نویسندگان
چکیده

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Surface Magnetism Effects in Time-Distance Helioseismology

Recent observations of helioseismic holography revealed that magnetic fields that are inclined relative to the line-of-sight direction could cause systematic variations in measured acoustic phase shifts (hereafter, “inclined magnetic field effect”), and that the presence of surface magnetic field may shift the phases and impair the coherence of acoustic waves (known as “showerglass effect”), th...

متن کامل

Radiation boundary conditions for time-dependent waves based on complete plane wave expansions

We develop complete plane wave expansions for time-dependent waves in a halfspace and use them to construct arbitrary-order local radiation boundary conditions for the scalar wave equation and equivalent first order systems. We demonstrate that, unlike other local methods, boundary conditions based on complete plane wave expansions provide nearly uniform accuracy over long time intervals. This ...

متن کامل

Analytical models for Cross-correlation signal in Time-Distance Helioseismology

In time-distance helioseismology, the time signals (Doppler shifts) at two points on the solar surface, separated by a fixed angular distance are crosscorrelated, and this leads to a wave packet signal. Accurately measuring the travel times of these wave packets is crucial for inferring the sub-surface properties in the Sun. The observed signal is quite noisy, and to improve the signal-tonoise ...

متن کامل

Internal gravity waves, boundary integral equations and radiation conditions

Three-dimensional time-harmonic internal gravity waves are generated by oscillating a bounded object (or by scattering from a fixed object) in a stratified fluid. Energy is found in conical wave beams: the problem is to calculate the wave fields for an object of arbitrary shape. An integral formula for the pressure is derived, using a reciprocal theorem and a Green’s function. The boundary inte...

متن کامل

High-order non-reflecting boundary conditions for dispersive waves

Problems of linear time-dependent dispersive waves in an unbounded domain are considered. The infinite domain is truncated via an artificial boundary B, and a high-order non-reflecting boundary condition (NRBC) is imposed on B. Then the problem is solved by a finite difference (FD) scheme in the finite domain bounded by B. The sequence of NRBCs proposed by Higdon is used. However, in contrast t...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Astronomy & Astrophysics

سال: 2017

ISSN: 0004-6361,1432-0746

DOI: 10.1051/0004-6361/201731283