Here we restrict our investigation to SST, sea ice, and wind speeds. Pressure plays a modest role in the air–sea flux and the differences among the reanalysis products is relatively small. Wind stresses are critical drivers of the circulation patterns and vertical processes, but they operate in complex ways and much of their influence is reflected in the

SST. Beginning with the high latitudes, the Antarctic basin exhibits a very large range of estimated fluxes from the different reanalysis products (Fig. 5), with NCEP2 producing a much lower sink than the other reanalyses. The NCEP2 selleck kinase inhibitor reanalysis coincidentally has the highest SST (>1 °C higher than the lowest from ECMWF), and the highest wind speeds (1.4 m s−1 higher than the lowest, represented by NCEP1), as seen in Fig. 6. The higher temperature from NCEP2 coupled with stronger winds is consistent with stronger outgassing of CO2 in the Antarctic, which would produce a reduced basin scale sink, as observed here. In buy Entinostat the northern high latitudes, MERRA forcing produces the weakest sinks, which correspond with relatively low wind speeds (Fig. 9). MERRA

winds are >1 m s−1 lower than the highest winds in both the North Pacific and North Atlantic. These low winds in MERRA are consistent with reduced exchange of pCO2 with the atmosphere and result in reduced sinks of atmospheric carbon. The relatively from high SST of MERRA may also play a role in weakening the North Atlantic fluxes. Similarly, we note that the strongest sinks in the North Atlantic are produced by NCEP2 and NCEP1. NCEP2 has the strongest winds, while NCEP1 has the lowest SST’s.

The tropical basins produce the largest range in air–sea carbon fluxes among the 4 reanalysis products (Fig. 5 and Fig. 6). The most notable divergences are NCEP2 (strongest source) and MERRA (weakest source) in the Equatorial Pacific. NCEP2 SST and wind speeds are both the largest of the reanalyses (Fig. 10). NCEP2 SST is >1 °C higher than the lowest (ECMWF, although NCEP1 and MERRA are consistent to within 0.03 °C), and NCEP2 wind speed is 0.9 m s−1 higher than the lowest, represented by NCEP1. These high SST’s and wind speeds can be associated with stronger outgassing as observed in the fluxes. The converse is true as well: NCEP1’s and MERRA’s weaker winds produce lower fluxes, despite high pCO2 than the data (Fig. 7). A similar series of observations occur in the Equatorial Atlantic, with NCEP2’s stronger representation of a source to the atmosphere (Fig. 5) is associated with the highest SST and wind speed (Fig. 10).