When preparing urban thermal parameters

[Yuan Sun]

Hi all,

I noticed that nlevurb in the latest CTSM is set as a variable according to surface data. The new surface data considers construction materials with nlevurb=10.

If I only have an average value for each urban landunit, how should I set values for thermal parameters?

For example, TK_WALL has four dimensions (nlevurb, numurbl, lsmlat, lsmlon), shall I set nlevurb = 5 and the values of TK_WALL for each nlevurb are the same?

Best,
Yuan

 

[oleson]

That sound reasonable if you only have a single value. The older version of the model had the same values of thermal conductivity and heat capacity for each layer in a given wall/roof. The THICK_WALL and THICK_ROOF parameters control the overall thickness of the walls and roof and the layers are divided evenly across the thickness.

 

[Yuan Sun]

That sound reasonable if you only have a single value. The older version of the model had the same values of thermal conductivity and heat capacity for each layer in a given wall/roof. The THICK_WALL and THICK_ROOF parameters control the overall thickness of the walls and roof and the layers are divided evenly across the thickness.

Hi Keith,

I got it. Thanks.

If using single values for thermal conductivity and heat capacity for wall and roof, it seems that no matter whether nlevurb is 5, 10, or other numbers, simulation outputs should be the same.

Best,
Yuan

 

[oleson]

Probably, it might not be bit for bit, but you could confirm that.

 

[Yuan Sun]

Probably, it might not be bit for bit, but you could confirm that.

Sure, I would compare the difference by setting nlevurb=3, 5, 10 for single values.

Best,
Yuan