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.

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.

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.

The results of an optimisation of inter-annual methane sources and sinks calculated by inversion of atmospheric observations are presented and analysed for the 1984-2003 period. We focus our presentation on sources trend and inter-annual variability. Comparisons with bottom-up estimates are presented for biomass burning and wetlands emissions (only in the poster).

Seven CARIOCA lagrangian buoys drifted in the Subantarctic Zone, SAZ, of the Indian and Pacific Ocean between 2001 and 2005. Measurements indicate that pCO₂ in sea water is undersaturated with respect to the atmospheric value and consequently the subantartic zone of the Southern Ocean acts as a sink for atmospheric CO₂ during all seasons. Large observed pCO₂ variability is associated with mixing close to the subantarctic front, with biological activity and local warming. These variabilities are higher than the seasonal cycle in the studied areas.

We present a 30+ year record of continuous atmospheric CO₂ concentrations and a 5 year record of continuous O₂ concentrations from Baring Head, New Zealand. When compared to South Pole data, the CO₂ concentrations indicate a persistent, but variable net carbon sink in the Southern Ocean since the late 1970s. The amplitude of the seasonal cycle of O₂ concentrations (expressed as “APO”, Atmospheric Potential Oxygen) shows large inter-annual variability, suggesting high variability in annual air-sea O₂ fluxes, and thus also potentially suggesting high variability in year to year marine productivity in the Southern Ocean.

We analysed the temporal variations of the CO₂ system in the Southern Ocean south of Tasmania and compared the seasonality of the carbon dioxide fugacity (fCO₂) and the air-sea CO₂ flux during spring and summer for two different years: 1996/97 and 2002/03. In summer, the CO₂ flux presents large and contrasting interannual changes in the Permanent Open Ocean Zone (POOZ, 53-61°S): the oceanic CO₂ sink varies from about –0.3 mmol.m^-2.d^-1 in 1997 to –20.6 mmol.m^-2.d^-1 in 2003. This strong sink in February 2003 was related to an increased phytoplankton biomass in this high-nutrient, low-chlorophyll (HNLC) region.

We consider the ability of an inverse model framework and observations from the Cooperative Air Sampling Network to resolve fluxes at various scales over a 20-year period. During this time the observational network underwent a significant expansion. We calculate the resolution kernel to determine which continental/ocean basin scale fluxes may be resolved, and which spatial aggregations of fluxes are well resolved. In addition, the resolution kernel is used to obtain insights into how source regions are constrained by individual measurement sites.

Spatial and temporal characteristics of land and ocean sources and sinks of carbon remain elusive. Better understanding of the anthropogenic influences on these carbon cycle dynamics is a common goal. This experiment is one of the efforts to reach a middle ground of flux estimates for regions larger than experimental plots and flux tower footprints, but smaller than continents and ocean basins. This work tests the hypothesis that including well-calibrated continuous North American continental CO₂ measurements in the observation data used in a global inversion will provide a constraint that improves inversion estimates of the source and sink regions within North America. These continuous data are collected at tall towers and flux towers. The experiment follows the TransCom 3 synthesis inversion framework, using the NASA Goddard Space Flight Center Parameterized Chemistry and Transport Model (PCTM) with Goddard Earth Observing System, version 4 (GEOS-4) meteorological data. Seasonal fluxes are estimated for a recent year for sub-regions within North America and at continent and basin scale globally. Methods of preparing the continental continuous CO₂ measurements for the inversion will be tested. Initial inversion results will be presented along with recommendations for applicability to other global regions and use of the method to evaluate additional sites for the measurement network.