Heat flux modelling

[Alexandru Guntner]

Hi all,

I have a question regarding the configuration of the climate parameters in PyWAsP. I know that the T-star stability model has been introduced in WAsp 12.8, but sometimes we still prefer to model the old heat flux over land parameter (in the EWA profile model) to match measured vertical profiles.

How can I do this in PyWAsP? I want to keep the latest flow model and change the heat flux. I tried this:

config = pw.wasp.Config("WAsP_12.10")
config.climate.set_profile_model(2) #WAsP 12.7 with EWA climate model
config.climate['off_hfx_land'] = 0

I find the explanation in the user guide a bit confusing. Sometimes WAsP 12.7 is referred to as "1", but then I also see that the numbers go from -1 to 3 (see link 1 and link 2). Can you give some clarifications on this, please?

Best regards

[Rogier]

Yes, we keep the strings like "WAsP_12.10" to make it simple to compare with WAsP GUI / WindPro. They are only set behaviour related to the fortran core. In practice, nothing has changed in the fortran between "Wasp 12.8" and "WAsP_12.10", because they were only impacting the WAsP GUI. So I understand it can be a bit confusing. But anyway, so you are nearly doing the right thing, but you want to use:

conf.climate.set_profile_model(1)
print(config.climate['off_hfx_land'])

if you use set_profile_model(2) it will read the heat flux values instead from the mesoclimate that you pass in the generalize and downscale routines, e.g. https://docs.wasp.dk/pywasp/latest/api_reference/wasp_autogen/pywasp.wasp.generalize.html

This is because the WAsP "EWA model" use constant heat fluxes, that were still set by the parameter arrays in the fortran, whereas the new model treats them a spatially varying inputs in the routines.

You can see a little bit in the docstring of set_profile_model, but admit the documentation is not super clear so will update it.

The default value of config.climate['off_hfx_land'] == -40. The script you included will set config.climate['off_hfx_land'] = 0 (you set the mean stability to zero, but the profile will still tend to the stable side because you have not set the rms_hfx_land to 0), see:

https://link.springer.com/article/10.1007/s10546-023-00803-3

Generally, I would not recommend using the old profile model, since it one of the easiests way to detoriate your modelling, see the distributions here:

https://zenodo.org/records/17668633/files/07 RogierFloorsDTU.pdf?download=1