Changes between Version 12 and Version 13 of DevelopmentActivities/MergeOCN/Vuichard


Ignore:
Timestamp:
2014-02-04T13:59:43+01:00 (10 years ago)
Author:
nvuilsce
Comment:

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  • DevelopmentActivities/MergeOCN/Vuichard

    v12 v13  
    3434* '''Calculation of the anaerobic balloon - anvf'''. The two constants a and b are not specified in Li et al., 2000. OCN uses a=0.85 and b=1 without mention to any publication (see [source:branches/orchidee-N/ORCHIDEE/src_stomate/stomate_soilcarbon.f90@19#L711, here]). As mention in the code of OCN these parameters have been estimated temporarily and need to be tuned. Might be good to find the values used in DNDC... 
    3535 
    36 * '''Ammonium adsorption'''. It is based on Li et al. 1992, JGR, Table 4 using NH4 defined as the NH4+ concentration in the soil liquid, gN kg-1 soil (p. 9774) but Zhang et al. (2000) use also the same equation but in this paper NH4+ is defined as the [NH4+] in a soil layer in kgN ha-1. In OCN, NH4 seems defined as molNH4 m-3 of water ([source:branches/orchidee-N/ORCHIDEE/src_stomate/stomate_soilcarbon.f90@19#L742, see here]. It would be good to clarify this by checking what looks like the equation depending of the units we use. 
     36* '''Ammonium adsorption'''. It is based on Li et al. 1992, JGR, Table 4 using NH4 defined as the NH4+ concentration in the soil liquid, gN kg-1 soil (p. 9774) but Zhang et al. (2000) use also the same equation but in this paper NH4+ is defined as the [NH4+] in a soil layer in kgN ha-1. In OCN, NH4 seems defined as molNH4 m-3 of water ([source:branches/orchidee-N/ORCHIDEE/src_stomate/stomate_soilcarbon.f90@19#L742, see here]). It would be good to clarify this by checking what looks like the equation depending of the units we use. 
    3737 
     38* '''Ammonium adsorption''' (2). Li et al. (1992) defines FIXNH4 as the proportion of adsorbed NH4+. One may assume that consequently the NH4+ that is not adsorbed is NH4+ x FIXNH4 and that we want to consider this quantity for possible nitrification, transformation to ammonia, .... But in OCN, we do not multiply the state variable (SV) representing NH4+ by FixNH4 but by FixNH4/(1+FixNH4) ([source:branches/orchidee-N/ORCHIDEE/src_stomate/stomate_soilcarbon.f90@19#L746, see here]). This tends to assume that SV represents only the non adsorped NH4+ because