topographic effect on soil temperature

Hi,
I am using the latest version of CTSM with self define resolution at 0.05°.

I have found a topographic correction coefficient for downward shortwave radiation (2.5 minutes) and want to apply it to soil temperature simulation. I multiplied this topographic correction coefficient to `forc_solad_col` in SurfaceRadiationMod.F90, extracting the corresponding correction coefficients for grid points based on the running grid and time step.

However, the soil temperature did not show the corresponding spatial topographic effects. So, my question is:

1. Is this because the operational grid unit of SurfaceRadiation.F90 is the resolution of the radiation data (0.5°)?
2. If I wanna add some topographic effects to the soil temperature which variable should I modify?

I have a troubleshooting suggestion that you could investigate:
Since you applied the 2.5-minute topographic correction to forc_solad_col, then I would add 'write' statements throughout the code where forc_solad_col gets used to see how your change affects other variables. This may give you further insight into why you see no effect on the soil temperature and whether you should try modifying another variable.

slevis said:

I have a troubleshooting suggestion that you could investigate:
Since you applied the 2.5-minute topographic correction to forc_solad_col, then I would add 'write' statements throughout the code where forc_solad_col gets used to see how your change affects other variables. This may give you further insight into why you see no effect on the soil temperature and whether you should try modifying another variable.

Click to expand...

Thanks for your suggestion @slevis ,

This before, I found out that there are some debug things to do.

I made this test with I2000 case in 0.05 deg, after apply this topographic correction, I found some topographical effect on some grids (none spin-up?) in TSOI col1, such as red rectangle and some of the low value area in the middle as shown in the picture.

My topographic correction coefficient in the last figure is with much more spatial terrain feature.

Is this because there is lack of spin-up time? I think the soil temperature may take more time for forcing data influence. I only run this results for 5 days at a cold start, or I think, maybe it needs more time to make grids transition smoother, or with more topographical effect as the coefficient.

Many thanks if you can help me to evaluate this result.

An update, after about 11 months running, the bloky effect disappeared, but topographic effect I think may need more time for forcing data influencing.