Comparison of ULF Waves - Pc5 range - in the solar wind and on 
the ground during high speed solar wind streams

We show a clear correlation between the power in ULF waves 
(Pc5 range) inside and outside Earth's magnetosphere during high speed 
streams in 1995. We find that the peak power in high speed streams is in 
the 0-10 mHz range, particularly below 2 mHz, where the Pc5 range is 
defined as 1-10 mHz. We trace the waves beginning 200~$R_E$ upstream 
using Wind data to waves just upstream from Earth's bow shock and in the 
magnetosheath using Geotail data to waves on the ground at the 
Kilpisjarvi ground station. We compare the total power in the Pc5 
frequency from the upstream waves to the total power from Pc5 pulsations 
at the Kilpisjarvi ground station. We find that the pattern of increases 
and decreases in ULF wave power at Pc5 frequencies correlates in all 
regions; between the solar wind and the ground the correlation 
coefficient is 0.61. The total power in the solar wind is about a factor 
of 10 less than that on the ground, but the total power increases in the 
magnetosheath to values comparable to the ground. This suggests that 
solar wind waves may provide a source of wave power for the 
magnetosphere; the solar wind waves may be acting as seed perturbations 
to drive boundary displacements that are amplified by the Kelvin-Helmholtz 
instability. We discuss features of the waves in all regions and suggest 
possible transmission scenarios.