rlo = R_low_si (i,j,bi,bj)
rlo = R_low (i,j,bi,bj)
OD = -1.0 * rlo - streamice_density_firn/rhow *
OD = -1.0 * rlo - rhoi/rhow *
_RL OD, rhoi, rhow, delta, r, h, hf, i_r, rlo