Abstract. Using improved, self-consistent analysis techniques, we determine the average solar wind charge state and elemental composition of nearly 40 ion species of He, C, N, O, Ne, Mg, Si, S, and Fe observed with the Solar Wind Ion Composition Spectrometer on Ulysses. We compare results obtained during selected time periods, including both slow solar wind and fast streams, concentrating on the quasi-stationary flows away from recurrent or intermittent disturbances such as corotating interaction regions or coronal mass ejections. In the fast streams the charge state distributions are consistent with a single freezing-in temperature for each element, whereas in the slow wind these distributions appear to be composed of contributions from a range of temperatures. The elemental composition shows the well-known first ionization potential (FIP) bias of the solar wind composition with respect to the photosphere. However, it appears that our average enrichment factor of low-FIP elements in the slow wind, not quite a factor of 3, is smaller than that in previous compilations. In fast streams the FIP bias is found to be yet smaller but still significantly above 1, clearly indicating that the FIP fractionation effect is also active beneath coronal holes from where the fast wind originates. This imposes basic requirements upon FIP fractionation models, which should reproduce the stronger and more variable low-FIP bias in the slow wind and a weaker (and perhaps conceptually different) low-FIP bias in fast streams. Taken together, these results firmly establish the fundamental difference between the two quasi-stationary solar wind types.

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Abstract. Magnetic holes are sudden changes in the magnetic field intensity IBI from typical interplanetary values (-10 nT) to less than 1 nT in a matter of seconds. The intensity then recovers within seconds or up to -30 min later. These IBI dropouts can be seen daily. Less often observed, but even more dramatic, are magnetic field depletions that last for up to several hours. We use selected periods of magnetic flux dropouts observed with various sensors of the Advanced Composition Explorer (ACE), which has a unique combination of magnetic field, plasma, and composition experiments, to establish the origin of these peculiar objects. We conclude that these microscale magnetic holes very likely develop in the heliosphere and are not of direct solar origin. We also suggest a possible formation mechanism associated with magnetic reconnection close to the Sun.

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Abstract. Elemental, isotopic and charge state abundances provide valuable information about the source and acceleration mechanism of Coronal Mass Ejections (CMEs). Even though the kinetic properties of the plasma might be subject to changes because of dynamic effects occurring during the expansion of the CME, the composition of the solar wind remains unchanged after it leaves the low corona. Data from the Solar Wind Ion Composition Spectrometer (SWICS) on ACE are used to study the elemental and charge state composition of He, O, C, N, and Fe as well as the isotopic ratio of He during the very large CME of May 2-3, 1998. We find in this CME anomalously large enrichment of 3He++/nHe ++, He/O and Fe/O. During the 28 hour long cloud portion of the CME unusually cold material (4He + and very low charge state heavy ions) was observed together with hot (high charge state ions) and normal solar wind plasma.