Abstract : Coagulation describes the process in which two particles collide to form one larger particle, typically with a greater settling speed. By multiple collisions and joining, small particles can form particles with a range of particle sizes and settling speeds and increase particle loss by settling. The theory is simple in principle but the complexities of applying it to real systems has inspired work in such areas as fractal theory. Because particles are such an important aspect of our world, the theory of coagulation has been widely used to describe rainfall resulting from cloud formation, pollutant removal in water treatment systems, and, more recently, particle removal from the surface of the ocean. The theory has also been expanded to describe the interactions between pairs of marine organisms. By enhancing the sedimentation and removal of planktonic algae from the surface mixed layer, coagulation can represent a form of algae mortality that is not grazer controlled. The lectures on coagulation will emphasise the formulation of the theory and its applicability to the marine environment, with an introduction to issues associated with the measurement of particle size distributions, the use of fractal scaling to describe particle properties, and the incorporation into biological models. There will also be an introduction to the application of the theory to describe interactions between organisms.

Lecture 1 (45 min) : An introduction to coagulation theory. Deriving the equations.

Lecture 2 (45 min): Solving the equations numerically: the sectional approach. Introduction to fractal scaling. Disaggregation.

Lecture 3 (45 min): Coagulation in the marine environment.

- marine snow

- maximum particle concentrations and their predictions.

- coagulation in marine food web models.

- coagulation and iron fertilization expts.

- coagulation and Th distributions

- issues arising: how to parameterize stickiness, organic compounds, TEP, multiple particle sources, simplifying for large scale models

Lecture 4 (45 min): Use of coagulation mechanisms to describe interactions between planktonic organisms.