Updated version 3 algorithms to include optimal observations (OPT_OBSERVATIONS). Here is a summary of the changes:
- Added new driver optobs_ocean.h.
- Introduced new internal CPP option OBSERVATIONS in globaldefs.h to differentiate between 4DVAR related applications that require to process observations. This cleaned nicely several drivers. Several files were changed to achieve this.
- Corrected extract_obs.F and ad_extract_obs.F to allow zero value depths, like when assimilating SST.
- Corrected ad_conv_2d.F, ad_conv_3d.F, tl_conv_2d.F, tl_conv_3d.F, and normalization.F for periodic applications. Many thanks to Julia for helping me fix this bug. Now, the normalization factors used in the spatial convolution are truely periodic. Both exact and randomization methods are working correctly in periodic applications. Also the land/sea masking behavior between exact and randomization methods exhibits similar behavior: there is no increase in the normalization factors next to the mask. Non-periodic application were fine, except for the mask issue. Since we needed to change the spatial convolutions you need to recompute your normalization coefficients to ensure symmetry and unity correlations.
- Renamed several CPP options in the tangent linear, representers, and adjoint models to the _NOT_YET to allow such options in the basic state (nonlinear model). These options included: BBL_MODEL, GLS_MIXING, MY25_MIXING, SEDIMENT, SSH_TIDES, and UV_TIDES.
- Added the capability to write background and observation cost function, cost function norm, and optimality property into 4DVAR output NetCDF file (MODname). This only applies to IS4DVAR and S4DVAR options.