  The quantum corrections to the conductivity and the thermopower in monolayer
graphene are studied. We use the recursive Green's function method to calculate
numerically the conductivity and the thermopower of graphene. We then analyze
these weak localization corrections by fitting with the analytical theory as
function of the impurity parameters and the gate potential. As a result of the
quantum corrections to the thermopower, we find large magnetothermopower which
is shown to provide a very sensitive measure of the size and strength of the
impurities. We compare these analytical and numerical results with existing
experimental measurements of magnetoconductance of single layer graphene and
find that the average size and strength of the impurities in these samples can
thereby be determined. We suggest favorable parameter ranges for future
measurements of the magnetothermopower.
