Patterns of deoxygenation: sensitivity to natural and anthropogenic drivers.

Oschlies, Andreas , Duteil, Olaf , Getzlaff, Julia, Koeve, Wolfgang , Landolfi, Angela and Schmidtko, Sunke (2017) Patterns of deoxygenation: sensitivity to natural and anthropogenic drivers. Open Access Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 375 (2102). p. 20160325. DOI 10.1098/rsta.2016.0325.

[thumbnail of Oschlies_etalPhilTransA17.pdf] Text
Oschlies_etalPhilTransA17.pdf - Published Version
Restricted to Registered users only

Download (1MB) | Contact
[thumbnail of Oschlies_etalRoySoc_revised.pdf]
Preview
Text
Oschlies_etalRoySoc_revised.pdf - Accepted Version

Download (8MB) | Preview

Supplementary data:

Abstract

Observational estimates and numerical models both indicate a significant overall decline in marine oxygen levels over the past few decades. Spatial patterns of oxygen change, however, differ considerably between observed and modelled estimates. Particularly in the tropical thermocline that hosts open-ocean oxygen minimum zones, observations indicate a general oxygen decline, whereas most of the state-of-the-art models simulate increasing oxygen levels. Possible reasons for the apparent model-data discrepancies are examined. In order to attribute observed historical variations in oxygen levels, we here study mechanisms of changes in oxygen supply and consumption with sensitivity model simulations. Specifically, the role of equatorial jets, of lateral and diapycnal mixing processes, of changes in the wind-driven circulation and atmospheric nutrient supply, and of some poorly constrained biogeochemical processes are investigated. Predominantly wind-driven changes in the low-latitude oceanic ventilation are identified as a possible factor contributing to observed oxygen changes in the low-latitude thermocline during the past decades, while the potential role of biogeochemical processes remains difficult to constrain. We discuss implications for the attribution of observed oxygen changes to anthropogenic impacts and research priorities that may help to improve our mechanistic understanding of oxygen changes and the quality of projections into a changing future.

Document Type: Article
Research affiliation: OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-BM Biogeochemical Modeling
OceanRep > SFB 754
OceanRep > SFB 754 > A2
OceanRep > SFB 754 > B1
OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-PO Physical Oceanography
Kiel University
Refereed: Yes
Open Access Journal?: No
Publisher: The Royal Society
Projects: SFB754
Date Deposited: 15 Aug 2017 08:30
Last Modified: 06 Feb 2020 09:17
URI: https://oceanrep.geomar.de/id/eprint/39111

Actions (login required)

View Item View Item