Compressional Pc5 pulsations in space and Ps6 pulsations on the ground are common features observed in the morning sector. Here we use a conjunction study of Equator-S, Geotail, and ground stations in Canada to show that Ps6 pulsations can be the ground counterpart of compressional Pc5 pulsations observed by satellites. Because strong Ps6 pulsations are associated with optical omega-band signatures, we also suggest that the omega-band counterparts in space might be compressional pulsations on the Pc5 scale. We also discuss the magnetic field configuration that makes all these observations consistent. ¿ 2001 American Geophysical Union