Global carbon cycles: A coupled atmosphere-ocean-sediment model
A simple one-dimensional advective-diffusive ocean model with a polar outcrop is developed and calibrated to fit modern ocean temperature, phosphorus, oxygen, total carbon, and total alkalinity data. The ocean model includes an atmospheric box which predicts atmospheric P[sub CO2] and oxygen concentrations. In addition, a sediment model is designed to reproduce modern sediment profiles of solid organic carbon and calcite, and pore water oxygen, sulfate, carbonate bicarbonate and carbon dioxide. The organic matter sediment model is used to investigate the interplay of sedimentation rate, bioturbation and microbial kinetics on the total rates of organic carbon and phosphorus regeneration and accumulation in marine sediments. This is done for sediments ranging from coastal to deep ocean. The model is sensitive to the organic carbon flux, sedimentation rate, bottom water oxygen concentration, degradation kinetics and bioturbation rate. The type of diagenetic environment and the extent of remineralization is very dependent on these variables which are currently poorly constrained. The carbonate model uses organic carbon, oxygen and sulfate profiles from the organic sediment as input in addition to the total carbon and alkalinity of the overlying water. It predicts the carbonate, bicarbonate and carbon dioxide pore water concentrations and the sedimentary carbonate fraction. The lysocline and carbonate compensation depth are sensitive to the calcite dissolution rate, the organic to inorganic carbon ratio and organic matter degradation. The sediment and ocean models are combined to form an atmosphere-ocean-sediment model which is used to test the hypothesis that decreased polar surface nutrients and carbon is the cause of the 80 ppm reduction in atmospheric P[sub CO2] observed during the last ice age. The coupled model suggests that sediments play an important role in the global carbon budget.
- Research Organization:
- Princeton Univ., NJ (United States)
- OSTI ID:
- 6645133
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
CARBON CYCLE
MATHEMATICAL MODELS
EARTH ATMOSPHERE
BOX MODELS
SEAS
SEDIMENTS
ORGANIC MATTER
PH VALUE
MATTER
SURFACE WATERS
540110*
540310 - Environment
Aquatic- Basic Studies- (1990-)
990200 - Mathematics & Computers