A comprehensive examination of global atmospheric CO2 teleconnections using wavelet-based multi-resolution analysis

Interannual variability of the atmospheric CO₂ accumulation is at a similar magnitude of decadal average CO₂ accumulation in the atmosphere. Part of observed variability in the atmospheric CO₂ can be interpreted by large-scale climate variability. Teleconnection between the atmospheric CO₂ anomalous tendency and selected large-scale coupled oceanic and atmospheric oscillations (AO, NAO, PDO, IOD, ENSO and SAM) are examined using wavelet-based multi-resolution analysis. The results indicate that all six oscillation indices appear to be associated with monthly CO₂ concentration at most of the 13 examined stations. About 70 % of interannual variability of CO₂ anomalous tendency at Mauna Loa and South Pole can be interpreted by the climatic indices. The temperature effects on the CO₂ anomalous tendency are overall positive. At the monthly scale, they interpret 14 % variability in CO₂ anomalous tendency in 1980–2011. At two high elevation stations (Mauna Loa and South Pole) with large footprints, the teleconnection signal is stronger (interpreting 20 and 25 % variability in monthly CO₂ anomalous tendency, respectively). Including global mean monthly air temperature time series, slightly but significantly in the statistical sense, improves the proportion of monthly CO₂ anomalous tendency being interpreted at most of the examined stations. The signs (positive vs. negative) in the association between monthly CO₂ anomalous tendency and the significant climatic indices appear to reflect physical mechanisms leading to such teleconnections.