Abstract:
We show that for long-baseline experiments using a Mt water Cerenkov detector atmospheric neutrino data provide a powerful method to resolve parameter degeneracies. In particular, the combination of long-baseline and atmospheric data increases significantly the sensitivity to the neutrino mass hierarchy and the octant of $\theta_{23}$. Furthermore, we discuss the possibility to use $\mu$-like atmospheric neutrino data from a big magnetized iron calorimeter to determine the neutrino mass hierarchy.