Horizontal to Vertical Displacement of Solar Oscillations

With the availability of helioseismic data from both SDO/HMI and SO/PHI it is now possible to observe the same regions on the Sun from two different directions. This has enabled us to measure the ratio of the horizontal to vertical displacement of solar oscillations. This has revealed that a commonly used approximation for this ratio is substantially incorrect. Here we discuss these measurements and the effect of the ratio on helioseismic inferences.