Code: Select all

```
ADJOINT Adjoint Model.
ANA_BSFLUX Analytical kinematic bottom salinity flux.
ANA_BTFLUX Analytical kinematic bottom temperature flux.
ASSUMED_SHAPE Using assumed-shape arrays.
AVERAGES Writing out time-averaged nonlinear model fields.
BACKGROUND Include background cost function.
BALANCE_OPERATOR Error Covariance Multivariate Balance Operator.
CURVGRID Orthogonal curvilinear grid.
DIFF_GRID Horizontal diffusion coefficient scaled by grid size.
DJ_GRADPS Parabolic Splines density Jacobian (Shchepetkin, 2002).
DOUBLE_PRECISION Double precision arithmetic.
FORWARD_MIXING Read in Forward vertical mixing for Tangent/Adjoint.
FORWARD_READ Read in Forward solution for Tangent/Adjoint.
FORWARD_WRITE Write out Forward solution for Tangent/Adjoint.
!FULL_GRID Considering observations at interior points only.
GLS_MIXING Generic Length-Scale turbulence closure.
IMPLICIT_VCONV Implicit Vertical Convolution Algorithm.
IS4DVAR Incremental strong constraint 4D-Var data assimilation.
KANTHA_CLAYSON Kantha and Clayson stability function formulation.
MASKING Land/Sea masking.
MIX_GEO_TS Mixing of tracers along geopotential surfaces.
MIX_S_UV Mixing of momentum along constant S-surfaces.
MPI MPI distributed-memory configuration.
NONLINEAR Nonlinear Model.
NONLIN_EOS Nonlinear Equation of State for seawater.
N2S2_HORAVG Horizontal smoothing of buoyancy and shear.
OBSERVATIONS Processing 4DVar observations.
OUT_DOUBLE Double precision output fields in NetCDF files.
POWER_LAW Power-law shape time-averaging barotropic filter.
PROFILE Time profiling activated .
K_GSCHEME Third-order upstream advection of TKE fields.
RADIATION_2D Use tangential phase speed in radiation conditions.
!RST_SINGLE Double precision fields in restart NetCDF file.
SALINITY Using salinity.
SOLVE3D Solving 3D Primitive Equations.
SPLINES Conservative parabolic spline reconstruction.
SPHERICAL Spherical grid configuration.
TANGENT Tangent Linear Model.
TS_U3HADVECTION Third-order upstream horizontal advection of tracers.
TS_U3HADVECTION_TL TL/AD third-order upstream horizontal tracer advection.
TS_C4VADVECTION Fourth-order centered vertical advection of tracers.
TS_C4VADVECTION_TL TL/AD fourth-order centered vertical tracer advection.
TS_DIF2 Harmonic mixing of tracers.
UV_ADV Advection of momentum.
UV_COR Coriolis term.
UV_U3HADVECTION Third-order upstream horizontal advection of 3D momentum.
UV_C4VADVECTION Fourth-order centered vertical advection of momentum.
UV_QDRAG Quadratic bottom stress.
UV_VIS2 Harmonic mixing of momentum.
VISC_GRID Horizontal viscosity coefficient scaled by grid size.
VCONVOLUTION Include vertical correlations in convolutions.
ZETA_ELLIPTIC Solving SSH elliptic equation in balance operator.
```

Nonetheless, I get the following error message:

Code: Select all

```
TLM: GET_STATE - Read v-space increments, t = 2193 00:00:00
(Grid 01, File: ocean_itl.nc, Rec=0001, Index=1)
- free-surface
(Min = -2.81705926E-02 Max = 2.77907880E-02)
- vertically integrated u-momentum component
(Min = 0.00000000E+00 Max = 0.00000000E+00)
- vertically integrated v-momentum component
(Min = 0.00000000E+00 Max = 0.00000000E+00)
- u-momentum component
(Min = -3.50023965E-02 Max = 3.09755988E-02)
- v-momentum component
(Min = -5.58496923E-02 Max = 3.39090215E-02)
- potential temperature
(Min = -3.78477034E-01 Max = 2.17940332E-01)
- salinity
(Min = -2.35268280E-02 Max = 5.59604732E-02)
TLM: GET_STATE - Read v-space increments, t = 2193 00:00:00
(Grid 01, File: ocean_itl.nc, Rec=0001, Index=2)
- free-surface
(Min = -2.81705926E-02 Max = 2.77907880E-02)
- vertically integrated u-momentum component
(Min = 0.00000000E+00 Max = 0.00000000E+00)
- vertically integrated v-momentum component
(Min = 0.00000000E+00 Max = 0.00000000E+00)
- u-momentum component
(Min = -3.50023965E-02 Max = 3.09755988E-02)
- v-momentum component
(Min = -5.58496923E-02 Max = 3.39090215E-02)
- potential temperature
(Min = -3.78477034E-01 Max = 2.17940332E-01)
- salinity
(Min = -2.35268280E-02 Max = 5.59604732E-02)
ADM: GET_STATE - Read latest adjoint state solution, t = 2193 00:00:00
(Grid 01, File: za_adj_001.nc, Rec=0001, Index=2)
- free-surface
(Min = -2.84382716E-05 Max = 6.53508152E-04)
- vertically integrated u-momentum component
(Min = -1.25437686E+03 Max = 1.43251412E+03)
- vertically integrated v-momentum component
(Min = -1.99218268E+03 Max = 1.40747070E+03)
- u-momentum component
(Min = -1.29402765E-02 Max = 1.46191528E-02)
- v-momentum component
(Min = -2.47037059E-02 Max = 1.81783417E-02)
- potential temperature
(Min = -6.74280091E-02 Max = 5.43788692E-02)
- salinity
(Min = -8.36367447E-03 Max = 7.47036749E-03)
NLM: GET_STATE - Read previous state initial conditions, t = 2193 00:00:00
(Grid 01, File: za_ini.nc, Rec=0002, Index=2)
- free-surface
(Min = -1.67400898E+00 Max = 1.64807835E+00)
- vertically integrated u-momentum component
(Min = -1.49075648E+00 Max = 6.44656120E-01)
- vertically integrated v-momentum component
(Min = -1.52064299E+00 Max = 8.20836836E-01)
- u-momentum component
(Min = -2.87649882E+00 Max = 2.72146996E+00)
- v-momentum component
(Min = -3.23322773E+00 Max = 2.28254094E+00)
- potential temperature
(Min = -5.35978216E+00 Max = 2.92327918E+01)
- salinity
(Min = 3.28323630E+01 Max = 3.68394618E+01)
- vertical viscosity coefficient
(Min = 0.00000000E+00 Max = 9.10820383E+01)
- temperature vertical diffusion coefficient
(Min = 0.00000000E+00 Max = 1.23642693E+02)
- salinity vertical diffusion coefficient
(Min = 0.00000000E+00 Max = 1.23642693E+02)
ADM: GET_STATE - Read previous adjoint state solution, t = 2193 00:00:00
(Grid 01, File: za_adj_001.nc, Rec=0001, Index=1)
- free-surface
(Min = -2.84382716E-05 Max = 6.53508152E-04)
- vertically integrated u-momentum component
(Min = -1.25437686E+03 Max = 1.43251412E+03)
- vertically integrated v-momentum component
(Min = -1.99218268E+03 Max = 1.40747070E+03)
- u-momentum component
(Min = -1.29402765E-02 Max = 1.46191528E-02)
- v-momentum component
(Min = -2.47037059E-02 Max = 1.81783417E-02)
- potential temperature
(Min = -6.74280091E-02 Max = 5.43788692E-02)
- salinity
(Min = -8.36367447E-03 Max = 7.47036749E-03)
<<<< Descent Algorithm >>>>
CG_DELTA not positive.
CG_DELTA = -2959.10090971697127 , outer = 1 , inner = 1
```

What can I do about it? Is this just due to to the artificial nature of my observations or a mistake in the model configuration or maybe a problem of I/O file handling...

Alas, I have two more (related) questions:

Is the value of obs_provenance of any relevance? I could not find that it is used somewhere in the code.

On what time basis are the modeled values and the observations compared? Is it just model snapshots versus the observations or can I specify a time averaging window for the model values?

I hope you can help me here.