Interannual variability of air-sea O2 fluxes and the determination of CO2 sinks using atmospheric O2/N2
Abstract
Motivated by the use of atmospheric O2/N2 to determine CO2 sinks under the assumption of negligible interannual variability in air-sea O2 fluxes, we examine interannual fluctuations of the global air-sea flux of O2 during the period 1980-1998 using a global ocean circulation and biogeochemistry model along with an atmospheric transport model. It is found that both the El Niño/Southern Oscillation (ENSO) cycle and wintertime convection in the North Atlantic are primary drivers of global air-sea oxygen flux interannual variability. Model estimated extremes of O2 flux variability are -70/+100 × 1012 mol/yr (Tmol/yr), where positive fluxes are to the atmosphere. O2/N2 variability could cause an up to +/-1.0 PgC/yr error in estimates of interannual variability in land and ocean CO2 sinks derived from atmospheric O2/N2 observations.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- February 2003
- DOI:
- 10.1029/2002GL016044
- Bibcode:
- 2003GeoRL..30.1101M
- Keywords:
-
- Oceanography: Biological and Chemical: Carbon cycling;
- Global Change: Biogeochemical processes (4805);
- Oceanography: General: Numerical modeling;
- Atmospheric Composition and Structure: Air/sea constituent fluxes (3339;
- 4504);
- Oceanography: General: Climate and interannual variability (3309)