Large fluctuations of dissolved oxygen in the Indian and Pacific oceans during Dansgaard-Oeschger oscillations caused by variations of North Atlantic Deep Water Subduction: Paleoceanography Public Deposited

http://ir.library.oregonstate.edu/concern/defaults/6q182r428

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • Paleoclimate records from glacial Indian and Pacific oceans sediments document millennial-scale fluctuations of subsurface dissolved oxygen levels and denitrification coherent with North Atlantic temperature oscillations. Yet the mechanism of this teleconnection between the remote ocean basins remains elusive. Here we present model simulations of the oxygen and nitrogen cycles that explain how changes in deepwater subduction in the North Atlantic can cause large and synchronous variations of oxygen minimum zones throughout the Northern Hemisphere of the Indian and Pacific oceans, consistent with the paleoclimate records. Cold periods in the North Atlantic are associated with reduced nutrient delivery to the upper Indo-Pacific oceans, thereby decreasing productivity. Reduced export production diminishes subsurface respiration of organic matter leading to higher oxygen concentrations and less denitrification. This effect of reduced oxygen consumption dominates at low latitudes. At high latitudes in the Southern Ocean and North Pacific, increased mixed layer depths and steepening of isopycnals improve ocean ventilation and oxygen supply to the subsurface. Atmospheric teleconnections through changes in wind-driven ocean circulation modify this basin-scale pattern regionally. These results suggest that changes in the Atlantic Ocean circulation, similar to those projected by climate models to possibly occur in the centuries to come because of anthropogenic climate warming, can have large effects on marine ecosystems and biogeochemical cycles even in remote areas.
Resource Type
Date Available
Date Issued
Citation
  • Schmittner, A., Galbraith, E. D., Hostetler, S. W., Pedersen, T. F. and Zhang, R., 2007, Large fluctuations of dissolved oxygen in the Indian and Pacific oceans during Dansgaard-Oeschger oscillations caused by variations of North Atlantic Deep Water Subduction: Paleoceanogr.,v. 22, PA3207, doi:10.1029/2006PA001384
Keyword
Table of Contents
  • 1. Introduction 2. Present-Day Distribution of Dissolved Oxygen in the Ocean 3. Simulations of Dansgaard-Oeschger Events 4. Ventilation Versus Consumption 5. Influence of Wind-Driven Ocean Circulation Changes 6. Estimating δ15N Changes 7. Discussion and Conclusions
Rights Statement
Funding Statement (additional comments about funding)
Publisher
Replaces
Additional Information
  • description.provenance : Submitted by Sue Kunda (sue.kunda@oregonstate.edu) on 2008-06-13T21:52:12Z No. of bitstreams: 1 2006PA001384.pdf: 1576115 bytes, checksum: ce93857098a6aa4f05c846e256ebe7d7 (MD5)
  • description.provenance : Made available in DSpace on 2008-06-13T22:14:35Z (GMT). No. of bitstreams: 1 2006PA001384.pdf: 1576115 bytes, checksum: ce93857098a6aa4f05c846e256ebe7d7 (MD5) Previous issue date: 2007
  • description.provenance : Approved for entry into archive by Sue Kunda(sue.kunda@oregonstate.edu) on 2008-06-13T22:14:35Z (GMT) No. of bitstreams: 1 2006PA001384.pdf: 1576115 bytes, checksum: ce93857098a6aa4f05c846e256ebe7d7 (MD5)

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items