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We report observations by the Voyager 1 and 2 spacecraft of low-frequency magnetic waves excited by newborn interstellar pickup ions H + and He + during 1978-1979 when the spacecraft were in the range from 2 to 6.3 au. The waves have the expected association with the cyclotron frequency of the source ions, are left-hand polarized in the spacecraft frame, and have minimum variance directions that are quasi-parallel to the local mean magnetic field. There is one exception to this in that one wave event that is excited by pickup H + is right-hand polarized in the spacecraft frame, but similar exceptions have been reported by Cannon et al. and remain unexplained. We apply the theory of Lee & Ip that predicts the energy spectrum of the waves and then compare growth rates with turbulent cascade rates under the assumption that turbulence acts to destroy the enhanced wave activity and transport the associated energy to smaller scales where dissipation heats the background plasma. As with Cannon et al., we find that the ability to observe the waves depends on the ambient turbulence being weak when compared with growth rates, thereby allowing sustained wave growth. This analysis implies that the coupled processes of pitch-angle scattering and wave generation are continuously associated with newly ionized pickup ions, despite the fact that the waves themselves may not be directly observable. When waves are not observed, but wave excitation can be argued to be present, the wave energy is simply absorbed by the turbulence at a rate that prevents significant accumulation. In this way, the kinetic process of wave excitation by scattering of newborn ions continues to heat the plasma without producing observable wave energy. These findings support theoretical models that invoke efficient scattering of new pickup ions, leading to turbulent driving in the outer solar wind and in the IBEX ribbon beyond the heliopause.

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1] Interplanetary shocks propagating into the magnetosphere can have significant space weather consequences. However, for many purposes it is the ejecta behind the shock that is the greater threat. The ejecta can be fast moving, impart significant momentum upon the magnetopause, and may contain a flux rope with strong southward magnetic fields. When transient solar wind activity strikes the magnetosphere, it can lead to enhanced magnetospheric currents and elevated radiation levels in the near-Earth environment. It is therefore desirable to use the observed shocks ahead of ejecta to predict any aspects of the approaching ejecta that can be predicted. We have examined 39 shocks observed by the Advanced Composition Explorer spacecraft in the years 1998 to 2003. Within the selection are shocks that were chosen because they appear to propagate significantly more slowly than the speed of the ejecta behind it. While appearing at first to be a contradiction, we show that the shocks are propagating across the radial direction and at significant angles to the velocity of the ejecta. These slow-moving shocks are actually precursors of fast-moving and potentially significant ejecta. Reversing the analysis, we are able to predict the peak speed of the ejecta well in advance of their observation, up to or in excess of 10 h following the shock crossing, when slow-moving shocks are seen, and we have incorporated this feature into our real-time shock analysis. (2012), Advance warning of highspeed ejecta based on real-time shock analyses: When fast-moving ejecta appear to be overtaking slow-moving shocks, Space Weather, 10, S12002,