Dissolved Oxygen in the Oceans: An Examination of the Late Ordovician and the Near Future Using an Earth System Climate Model
Year: 2017
Type: article
Abstract: One of the largest ecosystem controls in the oceans is the presence of dissolved oxygen.As oxygen levels fall, both micro-and macroorganisms face shrinking habitats and potential mortality.There have been several periods in Earth history where oxygen levels have fallen to anoxic (dissolved O2 concentration < 10 μmol L -1 ) or hypoxic (< 60 μmol L -1 ) levels in certain ocean basins or within inland seas and some of these events could potentially be linked to mass extinction events.Several hypotheses exist regarding the depletion of oxygen, the spread of hypoxia-anoxia, and why the low oxygen events occur at certain points in the geologic record, including rapid climate warming, enhanced nutrient inputs, and modifications to the surface biological pump.Unfortunately, there is little agreement on which of these potential hypotheses caused individual events and what might impact the oxygenation of our oceans in the future.This dissertation will test hypotheses related to deep ocean oxygen using the University of Victoria Earth System Climate Model.The first set of experiments feature Late Ordovician winds and paleogeography and test the impacts of atmospheric CO2 and O2, ocean bottom topography, and nutrient loadings on deep ocean oxygen concentrations.The second set of experiments is also within the Late Ordovician, but tests the impacts of remineralization rates, detrital sinking velocities, and ocean surface albedo on ocean oxygenation.The final set of experiments tests the impacts of a warming Chapters 2, 3, and 4 of this dissertation: Alvaro Montenegro (also my advisor), Michael J.Melchin (committee member) and Michael Eby.Their helpful suggestions transformed each of these three chapters into publishable papers, which will hopefully be in press soon.
Author: Daniel F. D'Amico
Institution: The Ohio State University
Language: English
Subfield: Paleontology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: green
Funder: Ohio State University
OpenAlex ID: W2889729953