The Role of Biological Production in Pleistocene Atmospheric Carbon Dioxide Variations and the Nitrogen Isotope Dynamics of the Southern Ocean.

This dissertation contributes to the search for a cause of glacial/interglacial variations in atmospheric carbon dioxide. The hypotheses addressed involve changes in low and high-latitude biological export production. A modelling exercise demonstrates that the paleoceanographic record of calcite pre...

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Bibliographic Details
Main Author: Sigman, Daniel M.
Other Authors: WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
Format: Text
Language:English
Published: 1997
Subjects:
Atmospheric Physics
Isotopes
*NITROGEN
*ISOTOPES
*CARBON DIOXIDE
*ATMOSPHERIC CHEMISTRY
EQUATORIAL REGIONS
PRODUCTION
BIOLOGY
MODELS
DYNAMICS
SATURATION
CALCITE
HYPOTHESES
OCEANS
PRESERVATION
SOUTH(DIRECTION)
LATITUDE
Southern Ocean
Online Access:http://www.dtic.mil/docs/citations/ADA342811
http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA342811
Description
Summary:This dissertation contributes to the search for a cause of glacial/interglacial variations in atmospheric carbon dioxide. The hypotheses addressed involve changes in low and high-latitude biological export production. A modelling exercise demonstrates that the paleoceanographic record of calcite preservation places constraints on hypothesized changes in low latitude biological production. The model results indicate that large, production-driven changes in the depth of the calcite saturation horizon during the last ice age would have caused a similar deepening of the calcite lysocline, even when the effect of sediment respiration-driven dissolution is considered. Such a large glacial lysocline deepening is not evident on an ocean-average basis. The results indicate very few mechanisms by which low latitude production could have driven Pleisotocene carbon dioxide variations, generally arguing against a low latitude cause for these variations.

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