Rapidly sinking marine snow aggregates play an important role in the vertical transport of carbon in the ocean. During their descent, particulate organic carbon is gradually turned over by microbial respiration and solubilization, while solutes are constantly released into the water. This steady-state scenario is interrupted when the aggregate passes through density discontinuities (pycnoclines), resulting in a retention period before resuming their decent. The accumulated excess solutes mediated by the absence of advection will then release dynamically into ambient water. In an attempt to quantify this dynamic process, we present numerical simulations of the flow adjacent to and solute release from porous spheres in a hydrodynamic regime representative of marine snow. We focus on the interdependence of internal diffusion-dominated transport and advective flow around an aggregate. The aggregate has been assumed to have a constant size, excess density, and permeability. We propose a new relationship for the dynamic release of solutes from sinking, porous aggregates in terms of the average Sherwood number, Sh ¼ 1 + 8Pe ), as a function of the Peclét number, Pe, where Pe ¼ aw s D -1 , a is the radius of the sphere, w s is the settling velocity, and D is the diffusion coefficient. An additional degradation rate constant, which was considered, did not change this finding significantly. From this relationship, release times and export depths-that is, the distances within which 99% of the excess solute is released into the ambient water-can be readily obtained as a function of aggregate size and excess density.