Seasonal sources and sinks of atmospheric CO₂ Direct inversion of filtered data

Abstract

A two-dimensional atmospheric transport model with transport fields derived from a GCM is used to perform the inverse calculation of determining surface CO₂ sources from surface concentration data. The concentration data are filtered spatially and temporally with a minimum period of 6 months and a maximum spatial wave number of 5 in order to suppress the unbounded error amplification that occurs in such inverse problems. The distribution of sources and sinks is consistent with recent results concerning oceanic uptake of CO₂. The results also show an additional northern hemisphere sink that is interpreted as additional biotic growth and a seasonal tropical source that may represent seasonal burning of cleared biomass.