Opened 5 months ago

Last modified 5 months ago

#3173 accepted help

fsmc_gb (beta) calculation

Reported by: awright Owned by: pmcguire
Component: JULES Keywords: fsmc_gb
Cc: Platform: JASMIN
UM Version:


Hello Patrick,

Do you know how fsmc_gb (beta or soil moisture availability factor = (theta - smwilt / smcrit - smwilt )) is calculated in JULES? Is it the average value of beta over the soil 4 layers or only down to the rooting depth based on the PFT type? How can I get more info about it?

Many thanks,


Change History (1)

comment:1 Changed 5 months ago by pmcguire

  • Status changed from new to accepted

Hi Azin:
It looks like fsmc_gb is computed in (for example, in JULES 5.2) in the following file:


Since the fsmc_shape and fsmc_mod variables are set to 0 in the ~\roses\u-al752\app\jules\rose-app.conf file, the code in smc_ext_jls_mod "calculates the soil moisture availability factor for each layer and weights with the root fraction to calculate the total availability factor, fsmc".

If you want to see all the occurrences of fsmc in the JULES 5.2 source tree, you could use grep, like this:

grep -ir fsmc /group_workspaces/jasmin2/jules/pmcguire/jules_build/jules-vn5.2

Does this help?
Patrick McGuire

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