Relationships are examined between interplanetary parameters and local daytime geomagnetic energy (at Pittsburg, New Hampshire; L~3.5) in three period bands. Ground-based magnetometer data, for 336 hours during July and August 1975, are studied when good interplanetary data coverage was available from instruments on the Imp J spacecraft. Multiple linear regression analyses show that the most important interplanetary parameter controlling ground hourly magnetic energy (in the period range 60--240 s) is the solar wind speed. Multiple linear regression analyses further show that hourly magnetic energy in the 30- to 60-s period range is controlled by the solar wind speed and the interplanetary magnetic field direction. The velocity dependence supports the idea of wave production at the magnetopause via the Kelvin-Helmholtz instability. These waves are later observed as magnetic pulsations (30-240 s) on the ground. The interplanetary magnetic field direction dependence supports the idea that waves produced at or near the earth's bow shock are later observed on the ground as magnetic pulsations in the shortest period band (30-60 s).