Air-water CO₂ fluxes were up-scaled to take into account the latitudinal and ecosystem diversity of the coastal ocean, based on an exhaustive literature survey. Marginal seas at high and temperate latitudes act as sinks of CO₂ from the atmosphere, in contrast to subtropical and tropical marginal seas that act as sources of CO₂ to the atmosphere. Overall, marginal seas act as a strong sink of CO₂ of about -0.45 Pg C yr^-1. This sink could be almost fully compensated by the emission of CO₂ from the ensemble of near-shore coastal ecosystems of about 0.40 Pg C yr^-1.

Numerical models of the carbon cycle are becoming increasingly sophisticated. One result of this is that these models now require fossil-fuel carbon-dioxide emissions data with sub-annual (e.g., seasonal) time resolution. They also require finer spatial resolution than national averages (i.e., than one point per nation). Finer spatial resolution is especially needed for countries as large in area as the United States of America (U.S.A.). Here we present a summary of monthly data for the entire nation, and annual data for each state in the U.S.A.

We present 16 months of semi-continuous Ar/N₂ data measured at the Scripps Pier in La Jolla, CA. The concentration of atmospheric Ar/N₂ depends on air-sea heat flux. As the ocean takes up heat, both argon and nitrogen are degassed to the atmosphere; as the ocean cools, they are taken up. This record is the beginning of a long-term monitoring program that will parallel the O₂/N₂ and CO₂ measurement programs at Scripps and may help resolve the oceanic contribution to atmospheric CO₂ variability.

We present here a test of convection uncertainty within a single model framework driven by the same meteorological fields. Our primary goal is to explore to what extent do convection schemes impact atmospheric CO₂ distribution, by testing three referred cloud convection schemes ranging from a very simple to a relatively complex form [Table 1]. Our second goal is to examine the sensitivity of atmospheric CO₂ to its regional emission/sink uncertainty [Fig. 1] constrained by IPCC 2001 at a “fixed” convection scheme to clarify the pros and cons of the convection schemes.

A detailed comparison of global atmospheric CH₄ retrievals from the space-borne spectrometer SCIAMACHY onboard the European environmental satellite ENVISAT is presented with the atmospheric transport models TM4 and TM5.

Measurements of atmospheric O₂/N₂ ratios and CO₂ concentrations can be combined to form the tracer Atmospheric Potential Oxygen (APO), reflecting primarily ocean biogeochemistry and atmospheric circulation. Building on the work of Stephens et al. [1998], we present a new set of APO observations including shipboard collections from the equatorial Pacific. Our data show a smaller interhemispheric gradient than observed in past studies and a substantial APO maximum around the equator. Following a modeling approach developed by Gruber et al. [2001], we compare these observations with APO fields generated by a set of oceanic and atmospheric models. Overall, our model results agree well with observations, but small differences suggest that modeled north-south transport may be too vigorous, air-sea fluxes may be too coarsely resolved in some regions, and seasonal trapping of surface fluxes may be excessive in some model locations.

The CROZEX cruises (November 2004 to January 2005) had the objective to test whether natural iron fertilisation from the Crozet plateau promotes algal blooms. Results from the cruises show that algal blooms created an oceanic CO₂ sink downstream of the Crozet plateau. Vertical advection of water into the mixed layer occurred close to two islands on the plateau. Data from 18 cruises between 1991 and 2002 are used to quantify the seasonal variability of surface pCO₂ and CO₂ air-sea exchange in the region.

Transport-based inversions of atmospheric CO₂ concentration measurements have been used by several groups [e.g., Bousquet, et al., 2000; Rödenbeck, et al., 2003; Baker, et al., 2005] to estimate monthly regional CO₂ fluxes from the 1980s to the present. When compared at the scale of broad latitude bands, the inter-annual variability (IAV) of these results is broadly consistent. This agreement breaks down, however, when the fluxes are partitioned regionally inside these latitude bands, or even into global land/ocean totals. We show here that this disagreement can largely be explained by random estimation errors and transport model errors affecting the estimates.