Identification

Title

Upper ocean O trends: 1958-2015

Abstract

Historic observations of dissolved oxygen (O-2) in the ocean are analyzed to quantify multidecadal trends and variability from 1958 to 2015. Additional quality control is applied, and the resultant oxygen anomaly field is used to quantify upper ocean O-2 trends at global and hemispheric scales. A widespread negative O-2 trend is beginning to emerge from the envelope of interannual variability. Ocean reanalysis data are used to evaluate relationships with changes in ocean heat content (OHC) and oxygen solubility (O-2,O-sat). Global O-2 decline is evident after the 1980s, accompanied by an increase in global OHC. The global upper ocean O-2 inventory (0-1000m) changed at the rate of -243124TmolO(2) per decade. Further, the O-2 inventory is negatively correlated with the OHC (r=-0.86; 0-1000m) and the regression coefficient of O-2 to OHC is approximately -8.20.66nmolO(2)J(-1), on the same order of magnitude as the simulated O-2-heat relationship typically found in ocean climate models. Variability and trends in the observed upper ocean O-2 concentration are dominated by the apparent oxygen utilization component with relatively small contributions from O-2,O-sat. This indicates that changing ocean circulation, mixing, and/or biochemical processes, rather than the direct thermally induced solubility effects, are the primary drivers for the observed O-2 changes. The spatial patterns of the multidecadal trend include regions of enhanced ocean deoxygenation including the subpolar North Pacific, eastern boundary upwelling systems, and tropical oxygen minimum zones. Further studies are warranted to understand and attribute the global O-2 trends and their regional expressions.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7z03b3f

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2017-05-16T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact