Bibcode
Shchukina, N. G.; Khomenko, E. V.; Kostyk, R. I.
Bibliographical reference
Astronomy Reports, vol. 50, Issue 7, p.588-600
Advertised on:
7
2006
Journal
Citations
11
Refereed citations
11
Description
Spectral observations of the 639.361-nm FeI line at the center of the
quiet solar disk with high spatial (0.4″) and temporal (10 s)
resolution are used to investigate the behavior of local 5-min
oscillations over granules and intergranular lanes. The power of the
5-min oscillations in the upper photosphere (at heights of H ≈ 490
km) is higher the faster the convective motions in the lower photosphere
(H ≈ 10 km). This suggests that turbulent convection is responsible
for the excitation of local solar oscillations. A statistical analysis
of the oscillations shows that, on average, both the intensity and
velocity of the oscillation amplitudes are greater over intergranular
lanes. This difference in amplitudes is present throughout the studied
heights in the photosphere (H = 0-490 km). The period at which the power
spectrum of velocity oscillations reaches its maximum is longer over
intergranules than over granules. Simulations of the propagation of
acoustic-gravity waves in an atmosphere taking into account the
convection pattern give a satisfactory explanation for the above
observed effects. It is concluded that the atmospheric modulation of the
5-min oscillations is an additional or alternative mechanism responsible
for differences between these oscillations over granules and
intergranules.