Misplaced brackets in fwsoil equation

[penguian]

keyword_keepgit type_defect | by amu561

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In SUBROUTINE fwsoil_calc_std in cable_canopy.F90, the brackets are not placed correctly in this equation:

rwater = MAX(1.0e-9,                                                    &
            SUM(veg%froot * MAX(1.0e-9,MIN(1.0, real(ssnow%wb) -                   &
            SPREAD(soil%swilt, 2, ms))),2) /(soil%sfc-soil%swilt))

The (soil%sfc-soil%swilt) should be within the MIN() statetement. To correct this, the equation can be replaced with:

 rwater = MAX(1.0e-9,                                                    &
           SUM(veg%froot * MAX(1.0e-9, MIN( 1.0, real((ssnow%wb              &
           - SPREAD(soil%swilt, 2, ms))  / (SPREAD(soil%sfc, 2, ms)           &
           - SPREAD(soil%swilt, 2, ms)) ))) , 2))

This leads to a minor correction in fwsoil at soil moisture values above field capacity.

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Issue migrated from trac:236 at 2023-11-27 11:30:54 +1100

[penguian]

@[email protected] commented

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I spoke to Anna and I think this is just for the groundwater on case. I suggest we separate the steps as it is pretty hard to follow the logic here!

[penguian]

@[email protected] set milestone to 6. Report

[penguian]

@[email protected] commented

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If I understand the error, the denominator is constant along the soil layers but it needs to be included in the MIN(), and hence the SUM(). The MIN() should be on the ratio of (wb-swilt)/(sfc-swilt) and not just (wb-swilt).

[penguian]

@[email protected] commented

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I'll use Anna's suggestion and close it in the next few days

[penguian]

@[email protected] set keywords to keepgit