- Conference date: 25-30 Jun 1995
- Location: Dana Point, California (USA)
Observations of solar Lyman α have been interpreted as indicating that the solar wind mass flux density is lower at polar latitudes than at equatorial latitudes. This led Lallement et al.  to make a parametric study of solar wind acceleration, along the lines of the earlier Munro-Jackson study , in which they concluded that uncertainties in the polar mass flux were large enough to be consistent with two extreme opposites: (1) a substantial energy supply beyond classical thermal conduction is required, or (2) classical thermal conduction is adequate to drive the flow. This ambiguity has been clarified by Ulysses observations of the polar outflow [Phillips et al., 1995]. The polar mass flux density lies near or somewhat above the middle of the range studies by Lallement et al. , which indicates that extended heating is likely to be going on out to at least solar radii. Independent, purely energetic arguments can be made to estimate the required coronal source (electron) temperature that would be required to account for the observed energy flux density. An electron temperature of well above would be required for the classical conduction flux density to be comparable to the total energy flux density; such a high temperature is unlikely in a coronal hole. These arguments strongly suggest that some extended heating or momentum transfer mechanism is required to drive the solar wind from the polar coronal hole.
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