Climate change is expected to modify ecological responses in the ocean, with the potential for important effects on the ecosystem services provided to humankind. As part of the effort towards detection of long‐term trends, a network of ocean observatories and time series stations provide high quality data for a number of key parameters, such as oxygen concentration. The temporal and spatial...
O2 inventories in the ocean and the atmosphere are linked. As the ocean warms, it loses O2 to the atmosphere. The amount of O2 lost by the ocean could be quantified with the complementary change observed in the atmosphere, using precise atmospheric O2 measurements spanning nearly three decades. This method is not limited by data sparseness, as fast mixing in the atmosphere efficiently...
The Eastern Tropical Pacific (ETP) hosts two of the world’s three Oxygen Deficient Zones (ODZs), large bodies of suboxic water that are subject to high rates of water column denitrification (WCD). In the mean, these two ODZs are responsible for 15 to 40% of all fixed N loss in the ocean, but knowledge is limited on how this loss varies in time. Here, we use hindcast simulations with both a...
Historic observations of dissolved oxygen O$_2$ in the ocean are analyzed to quantify multidecadal trends and variability from 1958 to 2015. The global gridded oxygen anomaly dataset for the upper 1000 m on $1{\times}1$ degree grid is produced in Hokkaido University based on ocean observations collected in the World Ocean Database 2013 with additional quality control. The resultant oxygen...
Open ocean oxygen deficient zones (ODZ’s) host unique subsurface biogeochemical processes that have global impacts including fixed nitrogen loss and the cycling of N2O. They have been predicted to expand geographically in response to global warming though contrary perspectives are available. In addition, biogeochemical activity is highly variable in time and space as associated with coastal...
Ocean deoxygenation in the past decades is commonly considered as a consequence of global warming. Because of large internal variability in the climate system, it is generally hard to robustly conclude the cause of deoxygenation from limited observations. Here, we explore the potential role of the internal variability in shaping the decadal deoxygenation using the MPI-ESM’s Large Ensemble...
Quantifying ocean variability requires baseline observations of known quality on relevant spatial and temporal scales. The World Ocean Database (WOD) is the largest digital collection of freely accessible, uniformly formatted, and quality controlled historical and modern in situ ocean profile data. These data are the basis for developing the World Ocean Atlas (WOA) series. We compared the data...
Volcanic eruptions are expected to have a major influence on ocean physics and biogeochemistry. The magnitude, spatial patterns, and mechanisms of volcanic impacts on the oceans, however, remain poorly understood due to the confounding effects of internal variability and limited observations. Here, the oceanic response to recent major tropical eruptions is evaluated in the Large Ensemble...
The current generation of climate models leaves us with a conundrum. On the one hand, the models project a decline of the export of organic matter from the surface ocean and a decline in biological oxygen consumption in the ocean interior, which should be consistent with an increase of the ocean’s oxygen content. On the other hand, they project an increase in apparent oxygen utilization (AOU),...