Observations of Dispersionless Modulation in the GCR Intensity in Association with Changes in the Suprathermal Electron Heat Flux

Focusing upon the GCR intensity within a three-day interval during an unusually active period in the solar wind from 19 August 2006 to 21 August 2006 reveals many intensity variations in the GCR on a variety of timescales and amplitudes. These intensity variations are greater than the 3ó error in all the datasets used from Wind, ACE, Polar and INTEGRAL. The fine structures in the GCR intensities along with the Forbush decrease are propagated outward from ACE to the Earth with very little change. The solar wind speed stays relatively constant during these periods indicating that parcels of solar wind are transporting the GCR population outward in the heliosphere. This solar wind convection of GCR fine structure is observed for both increases and decreases in GCR intensity and the fine-structure increases and decreases are bracketed by solar wind magnetic field discontinuities associated with ICME magnetosheath regions, clearly seen as discontinuous rotations of the field components at ACE and at Wind. Interestingly, the electron heat flux shows different flux tube connectivity also associated with the different regions of the ICME and magnetosheath. Gosling et al., [2004] first discussed the idea that solar energetic particle intensities commonly undergo dispersionless modulation in direct association with discontinuous changes in the solar wind electron strahl. The observations show that the intensity levels in the GCR flux may undergo a similar partitioning, possibly due to the different magnetic field regions having differing magnetic topologies. This new observation of GCR intensity being modulated by the local magnetic field topology will be compared to previous studies of GCR intensity anti-correlation with the interplanetary magnetic field strength [Burlaga et al., 1993; Burlaga and Ness, 1998] and discussed in more detail. Such comparisons will lead to further understanding of the underlying physics of energetic particle transport though the interplanetary medium.