We report on the temperature and magnetic field dependence of the c-ax
is thermopower in high-quality Bi2Sr2CaCu2O8+delta single crystals. In
contrast to the in-plane thermopower the temperature dependence of th
e c-axis thermopower is nonmonotonic below T-c and we show that this i
s the result of a significant contribution of Josephson vortices. The
magnetic field dependence of the thermopower supports the proposed exp
lanation. [S0163-1829(98)01625-7].