Time series of CO2 mole fractions at a CarbonTracker observation
site. In the top panel, measured mole fractions (open black circles)
are plotted along with CarbonTracker simulated values (light blue
open circles). At some sites, there are observations that
CarbonTracker can not simulate successfully; these are shown as
filled red squares. The bottom panel shows a time series of
residualsthe difference between the simulated and measured mole
fractionsshown with dark blue open circles. These residuals should
be uncorrelated in time, unbiased (i.e., have a mean of zero), and
distributed normally. Also shown in the lower panel is the imposed
modeldata mismatch ("MDM", orange bars), which in part defines the
rejection criterion (see documentation).
Any model first guess value which is more than
three times the MDM away from zero, after accounting for potential
adjustments to the simulated value due to optimizing fluxes, is
rejected by the optimization system. Rejected values, if there are
any, are shown with filled red squares.
