234Th as a tracer of particle flux and POC export in the northern North Sea during a coccolithophore bloom

A multidisciplinary cruise to the northern North Sea was undertaken during June 1999 to carry out a Lagrangian study of an Emiliania huxleyi bloom. During this experiment, the naturally occurring radionuclide, 234Th, was measured in the water column to estimate particle fluxes and resulting residence times. Simple steady state modelling of changes in 234Th activity suggests an increase in scavenging efficiency over an 8day period. The steady …