Sensitivity of the seasonal cycle of CO 2 at remote monitoring stations with respect to seasonal surface exchange fluxes determined with the adjoint of an atmospheric transport model

Abstract

The adjoint model to a global three-dimensional atmospheric transport model can be used to efficiently perform a sensitivity analysis, i.e. the computation of the partial derivatives of a particular model output feature with respect to many control variables. We demonstrate this approach by investigating the dependence of the magnitude of the modeled seasonal cycle of CO 2 at remote monitoring stations with respect to the magnitudes of the seasonal cycle of the net CO 2 surface fluxes prescribed from a simple diagnostic terrestrial biosphere model. The technique results in global maps of those source regions that predominately influence the magnitude of the seasonal cycle at the different monitoring stations.