  We present evidence for finite magnetic helicity density in the heliosphere
and numerical models thereof, and relate it to the magnetic field properties of
the dynamo in the solar convection zone. We use simulations and solar wind data
to compute magnetic helicity either directly from the simulations, or
indirectly using time series of the skew-symmetric components of the magnetic
correlation tensor. We find that the solar dynamo produces negative magnetic
helicity at small scales and positive at large scales. However, in the
heliosphere these properties are reversed and the magnetic helicity is now
positive at small scales and negative at large scales. We explain this by the
fact that a negative diffusive magnetic helicity flux corresponds to a positive
gradient of magnetic helicity, which leads to a change of sign from negative to
positive values at some radius in the northern hemisphere.
