... ULF range, broadband, bursty geomagnetic pulsations occurring in the Pi 1 and Pi 2 frequency ranges (2 mHz - 1 Hz; sometimes frequencies above 1 Hz are also seen) are called PiB pulsations (Heacock, 1967). ... Arnoldy, R. L., J. L. Posch, M. J. Engebretson, H. Fukunishi, and H. J. Singer, Pi1 magnetic pulsations in space and at high latitudes on the ground, J. Geophys. ... Grant, I. F. and G. B. Burns, Observations and modeling of correlated Pi B magnetic and auroral luminosity pulsations, J....