Abstract: | Consider the advection–diffusion equation: u1 + aux1 ? vδu = 0 in ?n × ?+ with initial data u0; the Support of u0 is contained in ?(x1 < 0) and a: ?n → ? is positive. In order to approximate the full space solution by the solution of a problem in ? × ?+, we propose the artificial boundary condition: u1 + aux1 = 0 on ∑. We study this by means of a transmission problem: the error is an O(v2) for small values of the viscosity v. |