Estimates of CO2 fluxes for Cape Town
Nickless et al. (2018) recently provided the results of an atmospheric inversion carried out for the city of Cape Town with the objective of obtaining estimates of weekly CO2 fluxes at a spatial resolution of 1 km × 1 km. This approach incorporates the best information available on what the fluxes are believed to be from anthropogenic and natural sources, together with estimates of the uncertainty around these estimates, and uses measurements of CO2 concentrations to improve on these estimates. CO2 concentrations were measured, by means of Picarro Cavity Ring-down Spectroscopy (CRDS) analysers, from March 2012 until July 2013 at Robben Island and Hangklip lighthouses. These measurements allow the inversion to correct the prior estimates of the fluxes. The CO2 fluxes can be converted into CO2 concentrations by means of an atmospheric transport model – the inversion attempts to improve these modelled concentrations. Measurements at the Cape Point Global Atmospheric Watch Station were used to estimate the background CO2 concentration.