Aggregation in the Marine Environment

This is the authors' abstract. We don't add key points for this paper.

The spatial distribution of chemical elements in the ocean is controlled by particles (including organisms); aggregation controls the particle properties. Coagulation is an important mechanism for controlling the size of marine particles and thereby their transport properties. Coagulation theory has provided a framework for the calculation of aggregation rates and size distributions. The use of fractal scaling to relate aggregate length to mass has been an important development that still needs to be fully incorporated into mathematical expressions for particle collision rates. In addition, disaggregation has emerged as an important process that is poorly described mathematically. Observations of particle spectra in the ocean are in general agreement with those expected for coagulation processes but tend to be for too small a size range to include the effects of particle disaggregation. Analysis of material caught in sediment traps suggests that aggregates are the dominant form of material falling through the ocean. An important aspect of the marine system is the presence of multiple particle sources that can confound fractal scaling based on single source particles. Coupled coagulation and chemical reaction models have become important tools in the interpretation of Th distributions. Further development of coagulation theory to describe marine systems promises to push the limits of our understanding of coagulation processes and their implications.