Helioseismic and Magnetic Imager Multi-height Dopplergrams
arXiv:1401.3182
Abstract
We study Doppler velocity measurements at multiple heights in the solar atmosphere using a set of six filtergrams obtained by the Helioseismic magnetic Imager on board the Solar Dynamics Observatory. There are clear and significant phase differences between core and wing Dopplergrams in the frequency range above the photospheric acoustic cutoff frequency, which indicates that these are really "multi-height" datasets.
4 pages, 3 figures, in the proceedings "Progress in Physics of the Sun and Stars: A New Era in Helio- and Asteroseismology" (ASP Conference Series)