IGPP Seminar Series

Linking the C, N, and Fe Cycles in a Global-Scale Ocean Biogeochemical Model

by Prof. Keith Moore
UCI

Abstract

The Biogeochemical Elemental Cycling (BEC) model simulates the global scale cycling of key elements (C, O, N, P, Si, Fe) and includes an explicit ecosystem model with multiple phytoplankton functional groups whose growth can be limited by available light and/or nutrients (N, P, Si, Fe). In this talk, the model is applied to study two related topics concerned with links between the C, N, and Fe cycles in the oceans. Mineral dust deposition is known to be a key source of dissolved iron to ocean surface waters. The model is used to address the impact of decadal timescale variations in dust inputs on rates of primary production, export production, nitrogen fixation, and air-sea CO2 flux. Strong negative feedbacks in the marine nitrogen cycle involving both nitrogen fixation and denitrification have been suggested to maintain the ocean fixed N inventory at relatively constant levels. The strength of these feedbacks in response to strong perturbations to N fixation and denitrification are examined in the context of the BEC model. Mineral dust deposition appears to play a role in governing the strength of the N inventory stabilizing feedbacks.
Tuesday, 23 January 2007
3853 Slichter Hall
Refreshments at 3:45 PM
Lecture at 4:00 PM