Category Archives: Helioseismology
66. A Poynting-Robertson-Like Drag at the Sun’s Surface
A new analysis using about 4 years of HMI 5-min solar p-mode limb oscillations as a rotation “tracer” finds a large velocity gradient at the top of the photosphere. It is suggested that the net effect of the photospheric angular momentum loss is similar to Poynting-Robertson “photon braking” on, for example, Sun-orbiting dust.
64. Slow Appearance of Sunspots Challenges Theory
62. Tracing p-Mode Waves from the Photosphere to the Corona in Active Regions
Through analyzing a suite of space- and ground-based observations, the authors report that above sunspots, helioseismic waves of different frequencies are able to channel up through the chromosphere and transition region into corona. General pictures of how the waves make into corona are also shown.