### Model initialization from ERA-Interim data: what happens with soil temperature?

Dear colleges,

I use COSMO - CLM model for seasonal simulations, driven by ERA -Interim data (so yinput_model=‘CM’). I was looking how model simulates soil temperatures (in comparison with observation data at different depths) and found very strange problem: initial soil temperature profiles looks completely different from soil temperature profiles in reanalysis data (both from T_SO in caf-files, both from the data, taken directly from ERA -Interim website). It seems that soil in model is initialized without usage of soil temperature from reanalysis.

When I’ve increased idbg_level, I get this messages:

variable 33 T_SO not needed for boundary fields 70

variable 34 W_SO not needed for boundary fields 70

So, am I right that soil temperature from reanalysis is not used for model initialization? If I am right, what should I do to use it? Maybe have I’ve forget some switches?

Thanks in advance,

Mikhail

You are right. Presently only the initial soil water is taken from the coarse grid model in climate mode (yinput_model=‘CM’ and itype_w_so_rel > 0) . The initial soil temperature is calculated as an exponential function between the T_S from the coarse grid model and the climatological T_CL from the external data set. The T_SO in the reanalyses data is presently not used.

You are right. Presently only the initial soil water is taken from the coarse grid model in climate mode (yinput_model=‘CM’ and itype_w_so_rel > 0) . The initial soil temperature is calculated as an exponential function between the T_S from the coarse grid model and the climatological T_CL from the external data set. The T_SO in the reanalyses data is presently not used.

You are right. Presently only the initial soil water is taken from the coarse grid model in climate mode (yinput_model=‘CM’ and itype_w_so_rel > 0) . The initial soil temperature is calculated as an exponential function between the T_S from the coarse grid model and the climatological T_CL from the external data set. The T_SO in the reanalyses data is presently not used.

Dear Burkhardt, thank you for the answer!

1) In this case, are there any possibility to use T_SO from reanalysis? Or it will be simpler to correct corresponding
LAF
-file before running
CCLM
?

2) If soil water content is taken from reanalysis, why I have message that “variable 34 W_SO not needed for boundary fields”?

Dear Burkhardt, thank you for the answer!

1) In this case, are there any possibility to use T_SO from reanalysis? Or it will be simpler to correct corresponding LAF -file before running CCLM ?

2) If soil water content is taken from reanalysis, why I have message that “variable 34 W_SO not needed for boundary fields”?

Dear Burkhardt, thank you for the answer!

1) In this case, are there any possibility to use T_SO from reanalysis? Or it will be simpler to correct corresponding
LAF
-file before running
CCLM
?

2) If soil water content is taken from reanalysis, why I have message that “variable 34 W_SO not needed for boundary fields”?

1) The best way would be to introduce an interpolation in the subroutine
```
init_multi_layer_cm
```

which is located in the module file
```
src_2d_fields.f90
```

. The line

t_so_lm(i,j,kso) = t_cl_lm(i,j) + (t_s_lm(i,j) - t_cl_lm(i,j)) * EXP(-zmls(kso)/2.8)

calculates T_SO by the exponential function I mentioned in my previous reply. At this place one may put the interpolation of T_SO of the reanalysis data. If you decide to do this it would be greatly appreciated. In case you succeed, please provide your changes to the CLM -Community. Please take into account that the lowest model level has the fixed value T_CL.

2) T_SO and W_SO are only used from reanalysis for initialization, during the further simulation they develop freely.

1) The best way would be to introduce an interpolation in the subroutine

`init_multi_layer_cm`

which is located in the module file`src_2d_fields.f90`

. The linet_so_lm(i,j,kso) = t_cl_lm(i,j) + (t_s_lm(i,j) - t_cl_lm(i,j)) * EXP(-zmls(kso)/2.8)

calculates T_SO by the exponential function I mentioned in my previous reply. At this place one may put the interpolation of T_SO of the reanalysis data. If you decide to do this it would be greatly appreciated. In case you succeed, please provide your changes to the CLM -Community. Please take into account that the lowest model level has the fixed value T_CL.2) T_SO and W_SO are only used from reanalysis for initialization, during the further simulation they develop freely.

1) The best way would be to introduce an interpolation in the subroutine
```
init_multi_layer_cm
```

which is located in the module file
```
src_2d_fields.f90
```

. The line

t_so_lm(i,j,kso) = t_cl_lm(i,j) + (t_s_lm(i,j) - t_cl_lm(i,j)) * EXP(-zmls(kso)/2.8)

calculates T_SO by the exponential function I mentioned in my previous reply. At this place one may put the interpolation of T_SO of the reanalysis data. If you decide to do this it would be greatly appreciated. In case you succeed, please provide your changes to the CLM -Community. Please take into account that the lowest model level has the fixed value T_CL.

2) T_SO and W_SO are only used from reanalysis for initialization, during the further simulation they develop freely.

Dear colleges,

I use COSMO - CLM model for seasonal simulations, driven by ERA -Interim data (so yinput_model=‘CM’). I was looking how model simulates soil temperatures (in comparison with observation data at different depths) and found very strange problem: initial soil temperature profiles looks completely different from soil temperature profiles in reanalysis data (both from T_SO in caf-files, both from the data, taken directly from ERA -Interim website). It seems that soil in model is initialized without usage of soil temperature from reanalysis.

When I’ve increased idbg_level, I get this messages:

variable 33 T_SO not needed for boundary fields 70

variable 34 W_SO not needed for boundary fields 70

So, am I right that soil temperature from reanalysis is not used for model initialization? If I am right, what should I do to use it? Maybe have I’ve forget some switches?

Thanks in advance,

Mikhail