The Observation Impact and Sensitivity study is imbedded in "da_minimise_lz.inc" routine.
It starts with an input Adjoint Sensitivity to the initial conditions dF/dx either:
- generated by WRF Adjoint model, stored in a NetCDF file and read by "da_adjoint_sensitivity.inc", or
- defined by "da_adjoint_sensitivity.inc" (several options are available).
The routine "da_obs_sensitivity.inc" applies R-1 (for Observation Sensitivity) and then Dot Product with
initial innovations (for Observation Impact). Both Observation Sensitivity and Observation Impact are stored in "iv" for each observation.
"ktd"