Primeau Group Research:

We are interested in the ocean's role in the climate of the Earth. The ocean plays a determining role in the variability of the climate system on inter-annual to millennial timescales. We use global observations and a hierarchy of ocean models together with advanced computational and mathematical techniques to study the ocean. Our current research is directed in three broad areas: (1) the surface-to-surface transport and ventilation of ocean water masses (2) inter-annual to decadal variability of the ocean's wind-driven circulation (3) global ocean biogeochemical cycles.

Surface-to-surface transport and ventilation: Recent work has focused on developing new ways of characterizing the ventilation rate of the ocean. Our continuing efforts in this area are focused on determining the interior transport pathways of heat, fresh water and other biogeochemical tracers. We are also using global datasets and inverse methods to obtain improved estimates of the ocean's ventilation rate. Among other things, constraining the ocean's ventilation rate will allow us to better estimate and predict the current and future rates of anthropogenic carbon dioxide uptake by the ocean.

Low-frequency variability of the wind-driven circulation: We are applying dynamical systems theory to a hierarchy of numerical ocean models to shed light on the nonlinear dynamics of western boundary currents and their seaward extensions. Our goal is to develop a dynamical understanding of the causes for the observed inter-annual to decadal variability in the Gulf Stream and Kuroshio current systems. Low-frequency variability in the regions of large air-sea fluxes of heat and fresh water that flank these currents have the potential of modulating weather on inter-annual to decadal timescales.

Global ocean biogeochemistry: We are developing fast implicit solvers for global ocean-biogeochemistry models and using them together with global observations to constrain uncertain biogeochemical parameters and to test hypotheses concerning the impact of changes in the surface patterns of nutrient utilization and in the remineralization rates of particulate organic material.