Atmospheric potential oxygen: New observations and their implications for some atmospheric and oceanic models

摘要: [1] Measurements of atmospheric O2/N2 ratios and CO2 concentrations can be combined into a tracer known as potential oxygen (APO ≈ + CO2) that is conservative with respect to terrestrial biological activity. Consequently, APO reflects primarily ocean biogeochemistry circulation. Building on the work Stephens et al. (1998), we present set observations for years 1996–2003 unprecedented spatial coverage. Combining data from Princeton Scripps air sampling programs, includes new collected ships in low-latitude Pacific. The show smaller interhemispheric gradient than was observed past studies, different structure within hemispheres. These differences appear due real changes field over time. also significant maximum near equator. Following approach Gruber (2001), compare these predictions generated O2 flux fields forward models transport. Our model differ those earlier modeling reflecting choice transport (TM3 this study). generally good agreement observations, matching size gradient, approximate amplitude extent equatorial maximum, phasing seasonal cycle at most stations. Room improvement remains. appears coincidental; last decade, true has evolved value consistent our time-independent model. In addition, somewhat more pronounced This may overly vigorous transport, or insufficient resolution air-sea fluxes used effort. Finally, cycles predicted by evidence an excessive rectifier Aleutian Islands problems elsewhere.