3:30 PM - 3:45 PM
[AAS12-07] Temporal variations of the atmospheric CO2 concentration and d13C at Ny-Ålesund, Svalbard
Keywords:atmospheric CO2, carbon isotope ratio, O2/N2 ratio
The CO2 concentrations show a clear seasonal cycle with peak-to-peak amplitude of about 17 ppmv, which reaches the maxima in late April to early May and the minima in late August, superimposed on a secular increase with an average rate of 2.0 ppmv/yr for the period of 1996–2013. On the other hand, the d13C decreases secularly at an average rate of –0.018 ‰/yr, and varies seasonally in opposite phase with the CO2 concentration. We have also maintained atmospheric d(O2/N2) measurements at Ny-Ålesund since 2001 (Ishidoya et al., 2012). Using the atmospheric d(O2/N2) and CO2 concentration records, the terrestrial and oceanic CO2 sinks are estimated to be 1.7 ± 0.8 GtC/yr and 2.2 ± 0.7 GtC/yr, respectively, for the 13-year period (2001–2013). Using these values of CO2 sinks and the d13C record, the average isofulx for the period of 2001–2013 is estimated to be 99 ± 28 Gt ‰/yr.
Ishidoya et al. (2012) Oceanic and terrestrial biospheric CO2 uptake estimated from atmospheric potential oxygen observed at Ny-Ålesund, Svalbard and Syowa, Antarctica. Tellus B, 64, 18924, http://dx.doi.org/10.3402/tellusb.v64i0.18924.
Morimoto et al. (2001) Temporal variations of atmospheric CO2 concentration and carbon isotope ratio in Ny-Alesund, Svalbard, Mem. Natl Inst. Polar Res., Spec. Issue, 54, 71–79.