Stationary concentration profiles resulting from the two-dimensional diffusion of material away from a continuous source in an advective flow field on the infinite plane are considered. The advection field contains a straining component, in addition to a spatially uniform part. The inhomogeneous advection-diffusion equation describing the spreading away from the source can be transformed to a noncentrally forced Schrodinger equation with a two-dimensional harmonic oscillator potential. The exact solution of this equation is given in terms of a definite integral, being an incomplete integral representation of thezeroth order modified Bessel function of the second kind (to which it reduces in appropriate circumstances). The field dependence is present not only in the kernel function, but also in one of the limits of integration. The near-field limit leads to concentration profiles in which curvature effects of the straining flow field may be neglected in comparison to the uniformly advecting part. Taking th...