Seasonal and interannual variations in atmospheric oxygen and implications for the global carbon cycle

  title={Seasonal and interannual variations in atmospheric oxygen and implications for the global carbon cycle},
  author={Ralph F. Keeling and Steve Shertz},
Measurements of changes in atmospheric molecular oxygen using a new interferometric technique show that the O2 content of air varies seasonally in both the Northern and Southern Hemispheres and is decreasing from year to year. The seasonal variations provide a new basis for estimating global rates of biological organic carbon production in the ocean, and the interannual decrease constrains estimates of the rate of anthropogenic CO2 uptake by the oceans. 

Trends in marine dissolved oxygen: Implications for ocean circulation changes and the carbon budget

Recent measurements and model studies have consistently identified a decreasing trend in the concentration of dissolved O2 in the ocean over the last several decades. This trend has important

Revision of the global carbon budget due to changing air‐sea oxygen fluxes

Carbon budgets inferred from measurements of the atmospheric oxygen to nitrogen ratio (O2/N2) are revised considering sea‐to‐air fluxes of O2 and N2 in response to global warming and volcanic

The ocean as part of the global carbon cycle

  • D. Wolf-Gladrow
  • Environmental Science
    Environmental science and pollution research international
  • 1994
Although the ocean may take up much of the carbon released by the increased burning of fossil fuels, this capacity is limited because of the chemical buffering and a mismatch in time scales (oceanic mixing is much slower than anthropogenic perturbations).

Variations in terrestrial oxygen sources under climate change

The terrestrial ecosystem is an important source of atmospheric oxygen, and its changes are closely related to variations in atmospheric oxygen level. However, few studies have focused on the

Measurements and models of the atmospheric Ar/N2 ratio

The Ar/N2 ratio of air measured at 6 globally distributed sites shows annual cycles with amplitudes of 12 to 37 parts in 106. Summertime maxima reflect the atmospheric Ar enrichment driven by

What atmospheric oxygen measurements can tell us about the global carbon cycle

This paper explores the role that measurements of changes in atmospheric oxygen, detected through changes in the O2/N2 ratio of air, can play in improving our understanding of the global carbon

Effects of plankton dynamics on seasonal carbon fluxes in an ocean general circulation model

We discuss the effect of embedding a simple plankton model in the Hamburg model of the oceanic carbon cycle (HAMOCC3) [Maier-Reimer, 1993]. The plankton model consists of five components:

Atmospheric gas concentrations over the past century measured in air from firn at the South Pole

The extraction and analysis of air from the snowpack (firn) at the South Pole provides atmospheric concentration histories of biogenic greenhouse gases since the beginning of the present century

Air‐sea flux of oxygen estimated from bulk data: Implications For the marine and atmospheric oxygen cycles

We estimate the annual net air‐sea fluxes of oxygen for 13 regions on the basis of a steady state inverse modeling technique that is independent of air‐sea gas exchange parameterizations. The

Variability in atmospheric O2 and CO2 concentrations in the southern Pacific Ocean and their comparison with model estimates

[1] We examine ship-based observations of atmospheric O2 and CO2 in the southern Pacific Ocean made during two voyages: in February 2003 and in April 2004. We found, for the Austral late summer to



Seasonal oxygen cycles and biological new production in surface waters of the subarctic Pacific Ocean

Seasonal cycles of oxygen, temperature and salinity at Ocean Weather Station P in the subarctic Pacific Ocean reveal a regular 4–6% supersaturation of oxygen in the surface waters during the summers

Observational Contrains on the Global Atmospheric Co2 Budget

The observed differences between the partial pressure of CO2 in the surface waters of the Northern Hemisphere and the atmosphere are too small for the oceans to be the major sink of fossil fuel CO2, and a large amount of the CO2 is apparently absorbed on the continents by terrestrial ecosystems.

Seasonal variability of carbon dioxide, nutrients and oxygen in the northern North Atlantic surface water: observations and a model*

The seasonal variation of various surface water properties has been monitored at a station located at about 120 miles south of the Iceland-Greenland sill during the two-year period, March 1983

Latitudinal distribution of the sources and sinks of atmospheric carbon dioxide derived from surface observations and an atmospheric transport model

Determination of the present global budget of atmospheric carbon dioxide (CO2) from the small and persistent concentration gradients that exist in the atmosphere is discussed. The CO2 concentration

Tracers in the Sea

A book about chemical processes occurring in the ocean with emphasis on the cycles of carbon and other nutrients. In addition to a treatment of the present distribution of those constituents,

Atmospheric Oxygen in 1967 to 1970

Observations of atmospheric oxygen in clean air between 50�N and 60�S, mainly over the oceans, yield an almost constant value of 20.946 percent by volume in dry air. Since 1910 changes with time over

Particulate organic matter flux and planktonic new production in the deep ocean

Primary production in the oceans results from allochthonous nutrient inputs to the euphotic zone (new production) and from nutrient recycling in the surface waters (regenerated production). Global

Measuring correlations between atmospheric oxygen and carbon dioxide mole fractions: A preliminary study in urban air

On 25 and 26 October 1986 the air in Cambridge, Massachusetts was monitored for O2 and CO2 mole fraction. O2 concentrations were detected from changes in the relative refractivity of dried air

Downward transport and fate of organic matter in the ocean: Simulations with a general circulation model

A phosphorus-based model of nutrient cycling has been developed and used in conjunction with a general circulation model to evaluate the roles of the dissolved and sinking particulate phases in the


The use of 15N-labeled compounds to obtain specific uptake rates for the various nitrogen sources available to the phytoplankton makes it possible to separate the fractions of primary productivity