Changes between Version 77 and Version 78 of DevelopmentActivities/ORCHIDEE-CNP


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Timestamp:
2016-03-04T14:42:05+01:00 (8 years ago)
Author:
dgoll
Comment:

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  • DevelopmentActivities/ORCHIDEE-CNP

    v77 v78  
    22= ORCHIDEE-CN-P (former branch ORCHIDEE-CNP) = 
    33 
    4 This page describes the work done to include the phosphorus cycle into ORCHIDEE. It is based on MERGE-OCN, which was extended and corrected as described here: https://forge.ipsl.jussieu.fr/orchidee/wiki/Branches/MergeOCN/Goll as well as a recruitment routine by S. Peng (ask him if you need infos) 
    5 The phosphorus cycle is an adaptation of the the model described by http://www.biogeosciences.net/9/3547/2012/bg-9-3547-2012.html 
    6  
    7  
    8 == modularisation of code used by nitrogen and phosphorus routines == 
    9 There are many aspects which the nutrient cycles have in common, for example root uptake kinetics, stoichiometric considerations, etc. To avoid the risks of introducing inconsistencies and redundant code, I started to write subroutines which are listed in the following. All subroutines are in stomate_phosphorus.f90. 
    10  
    11 === 1. root_conductivity === 
     4This page describes the phosphorus cycle in ORCHIDEE-CN-P.  
     5It is based on ORCHIDEE-CN, which was extended and corrected as described here: https://forge.ipsl.jussieu.fr/orchidee/wiki/Branches/MergeOCN/Goll as well as additional non-documented bugfixes to avoid negative pools due to machine precisions as well as bugs. 
     6 
     7The phosphorus cycle is an adaptation of the the model described by http://www.biogeosciences.net/9/3547/2012/bg-9-3547-2012.html . Nonetheless, the complexity was substantially increased due to the more detailed representation of the C and N cycle in ORCHIDEE compared to JSBACH. 
     8 
     9[[Image(ORC-CNP.png)]] 
     10Schematic representation of the key processes represented in ORCHIDEE-CNP 
     11 
     12 
     13== 1. Technical notes: the modularisation of code used by nitrogen and phosphorus routines == 
     14There are aspects which the nutrient cycles have in common, for example root uptake kinetics, stoichiometric considerations, etc. To avoid the risks of introducing inconsistencies and reduce redundant code, I introduced the following subroutines. All subroutines are in stomate_phosphorus.f90. 
     15 
     16=== 1.1 root_conductivity === 
    1217This subroutine calculates the uptake capacity of N & P per mass root according to the uptake kinetics of ammonia and nitrate used in OCN (Zaehle & Friend, 2010).  
    1318 
    14  
    15  
    16 === 2. f_XY_plant === 
     19=== 1.2 f_XY_plant === 
    1720This subroutine calculates the scaling functions based on the stoichiometric ratio of labile plant tissue (reserve, labile and leaf) which are used to scale root uptake, biological N2 fixation, and biochemical mineralization. It currently supports scaling functions based on the P-to-N ratio, N-to-C ratio and P-to-C ratio. All other combinations will cause a 'STOP', but could be easily implemented if needed. 
    1821  
    19 == New input files == 
    20  
    21 === USDA soil orders === 
     22== 2. Conceptual modifications to the nitrogen cycle == 
     23 
     24=== 2.1 soil mineral N concentration in soil solution === 
     25Following Smith et al (2014), I introduced the use of the maximum water holding capacity of soils (max_var_eau) to approximate pore space which to derive the average soil mineral N concentration in solution. The use of the actual water volume can not be recommended as we this would lead to high N concentration in soil water when soil water is very low. As we do not account for the inhibition of replenishment of mineral N in the soil solution around roots when soil water is scarce.  
     26 
     27=== 2.2 Biological N2 fixation (BNF) === 
     28We introduce a module which computes BNF as a function of NPP, tissue C:N, and tissue & N:P. This approach is based on Cleveland et al (1999), Thornton et al. (2007), and Goll et al. (2012). 
     29 
     30 
     31== 3. New input files == 
     32=== 3.1 USDA soil orders === 
    2233We use the USDA soil order map of Sun et al. (in revision) with the dominant soil order per pixel. The gap filling of the missing values was done like this 
    2334(see script /home/users/dgoll/ORC_data/USDA_soilorders/try_2_fill/fill_deserts.ksh): 
    … …  
    3142Figure 1: USDA soil orders: Alfisols(1), Andisols(2), Aridisols(3), Entisols(4), Gelisols(5), Histosols(6), Inceptisols(7), Mollisols(8), Oxisols(9), Spodosols(10),Ultisols(11), Vertisols(12) 
    3243 
    33 === GliM lithology === 
     44=== 3.2 GliM lithology === 
    3445We use the GliM lithology map by Hartmann & Moosdorf (2012). We account for subgrid scale heterogeneity by reading the fractional coverage of each of the 16 classes. 
    3546 
    … …  
    5465!    ! 16 - water bodies 
    5566 
    56 === Soil shielding (Hartmann et al. (2014) === 
     67=== 3.4 Soil shielding (Hartmann et al. (2014) === 
    5768The factor corrects the weathering flux where the active zone in the soil is disconnected from the bedrock.  
    5869 
    … …  
    6273 
    6374 
    64 == ISSUES == 
     75== 4.0 unresolved Issues == 
    6576 
    6677=== Reading in N inputs === 
    … …  
    7283 
    7384The problem is that ORCHIDEE already reads in fields of soil texture classes which were originally derived from soil orders. According to the soil texture classes, parameter related to soil hydrology are set. As the original data cannot be found anymore, ORCHIDEE will run with two independent sets of soil order specific parameters. Thereby inconsistencies between the phosphorus related parameters and the the hydrology related parameters can be introduced. The practice of reading in soil texture classes instead of soil orders is also problematic in respect of future developments and I suggest to change that. 
     85 
     86---- 
     87---- 
    7488 
    7589== HOWTO install/compile/run ORCHIDEE-CN-P for offline use with libIGCM. ==