Science Source

Upper Ocean O2 trends: 1958‐2015

Analyzes historic observations of dissolved oxygen (O2) in the ocean to quantify multi-decadal trends and variability from 1958 to 2015
Uses ocean reanalysis data to evaluate relationships with changes in ocean heat content (OHC) and oxygen solubility
Finds that global O2 decline is evident after the 1980s, accompanied by an increase in global OHC
Finds that the global upper ocean O2 inventory (0-1,000m) changed at the rate of -243±124TmolO2 per decade
Results show that O2 inventory is negatively correlated with the OHC
Findings indicate that changing ocean circulation, mixing and/or biochemical processes, rather than the direct thermally-induced solubility effects, are the primary drivers for observed O2 changes