¡
¡
¡
¡
„
0
„
2
„
1
„
3
x
2
x
1
x
3
x
0
Adjoint
Transport
Forward
Transport
Forward
Transport
Measurement
Sampling
Measurement
Sampling
ÒTrueÓ
Fluxes
Estimated
Fluxes
Modeled
Concentrations
ÒTrueÓ
Concentrations
Modeled
Measurements
ÒTrueÓ
Measurements
Assumed
Measurement
Errors
Weighted
Measurement
Residuals
D
/(Error)
2
Adjoint
Fluxes
=
„
Flux
Update
4-D Var Iterative Optimization Procedure
Minimum of cost function
J
Figure showing minimization approach with the 4-D Var method.