Perturbations of the northern hemisphere freshwater ux have become a standard experiment to test a climate model's sensitivity to climate change, both for past and future climate scenarios. There are two different processes that determine the strength of the freshwater forcing: The hydrological cycle, which does not change the volume of the ocean, and melting (or accumulation) of inland ice and snow, which causes a net volume ux into (or out of) the ocean. We use a 4-box model of the Atlantic Ocean to test for differences in the oceanic response to either of these processes.