Abstract
Atmospheric inversions are widely used in the optimization of
surface carbon fluxes on a regional scale using information from
atmospheric CO2 dry mole fractions. In many studies the
prior flux uncertainty applied to the inversion schemes does not
directly reflect the true flux uncertainties but is used to
regularize the inverse problem. Here, we aim to implement an
inversion scheme using the Jena inversion system and applying
a prior flux error structure derived from a model–data residual
analysis using high spatial and temporal resolution over a full year
period in the European domain. We analyzed the performance of the
inversion system with a synthetic experiment, in which the flux
constraint is derived following the same residual analysis but
applied to the model–model mismatch. The synthetic study showed
a quite good agreement between posterior and true
fluxes on
European, country, annual and monthly scales. Posterior monthly and
country-aggregated fluxes improved their correlation coefficient
with the known truth
by 7 % compared to the prior estimates
when compared to the reference, with a mean correlation of
0.92. The ratio of the SD between the posterior and reference
and between the prior and reference was also reduced by 33 % with a mean value
of 1.15. We identified temporal and spatial scales on which the
inversion system maximizes the derived information; monthly temporal
scales at around 200 km spatial resolution seem to maximize
the information gain.
Citation
ID:
202869
Ref Key:
kountouris2018atmospherictechnical