Zhang & Schaap Soil Ancillary files with SoilGrids

Hi Patrick,

I am setting up a global JULES run with WFDEI and want to use the Zhang & Schaap soil ancillary. I found the most recent file (based on time stamp) as:

/gws/nopw/j04/ncas_generic/users/pmcguire/ants/soil_ancil3/soil_WFDEI_ZhangSchaapH1_V1r_l1_2b.nc

I was wondering whether that file already has the correction for sand pixels applied?

Best,
Markus

Hi Markus
I just sent you an email I wrote about it on May 27, 2020. Yes, that file is the Loamy Sand version H1LS. That is the top level of the soil (level l1). Maybe you want to use another level that is deeper, like level l5?
You can look at the python code for V1r, referred to in the email, if you’re interested.
Patrick

Hi Patrick,

Oh, I see, we used l5 instead of l1 . Many thanks, I’ll use that one then!

Best,
Markus

Actually, I have another question. The new versions of JULES also require value for clay content, which is missing in the Zhang&Schaap files. I imported it from the latest Weynants file I found:

/gws/nopw/j04/ncas_generic/users/pmcguire/ants/soil_ancil3/soil_WFDEI_OLAM_PTFs1_V1j_l7_2.nc

Realising now that there are files for different layers, do I have to choose a specific Weynants file to get the right clay content for layer 5 of the Zhang & Schaap file, or are the clay content values constant over depth?

Many thanks again for your help!

Best,
Markus

Hi Markus
The Zhang & Schaap PTF is a discrete-texture PTF. So if the level7 discrete-texture is the same as the level5 discrete-texture for a particular grid cell, then the actual value of the clay contents doesn’t matter.
But if JULES is requiring clay content now, then you should probably use the level5 clay content even if you’re using a discrete-texture PTF.

The _2 substring in the Weynants file name is different than the _2b substring that I think is used in the standard soil-PTF JULES runs. You might want to check that you’re using the _2b version, which is for the lat/lon variable names instead of the latitude/longitude variable names, which might be needed for the JULES suite that you are adapting from.
Patrick

Hi Patrick,

When you say I should use clay content, are you talking about the Weynants file and the Zhang & Schaap file interchangeably? Because the variable “in_clay” in the Zhang & Schaap files doesn’t contain any proper values. Which is why I want to take the clay content from the Weynants file. So, my question was whether it is ok to take that field and whether the clay content input is the same for Weynants and for Z&S?

Best,
Markus

Hi Markus

Yes, I did mess up when I created the Z&S files, and the input variables aren’t in there. They are the same as for the Weynants, which you can use instead to get the input variables used in Z&S.

Patrick