  An update of Owens et al. (2008) shows that the relationship between the
coronal mass ejection (CME) rate and the heliospheric magnetic field strength
predicts a field floor of less than 4 nT at 1 AU. This implies that the record
low values measured during this solar minimum do not necessarily contradict the
idea that open flux is conserved. The results are consistent with the
hypothesis that CMEs add flux to the heliosphere and interchange reconnection
between open flux and closed CME loops subtracts flux. An existing model
embracing this hypothesis, however, overestimates flux during the current
minimum, even though the CME rate has been low. The discrepancy calls for
reasonable changes in model assumptions.
