Merge OCN

This page describes the work done to include the nitrogen cycle into ORCHIDEE. The nitrogen cycle was introduced into ORCHIDEE by Sonke Zaehle a few years ago. This version called O-CN was not parallelized and is based on a obsolete version, so it will be progressively merged into a copy of trunk of ORCHIDEE with regular updates (synchronization with the trunk). The release is expected for the end of 2013.

Preliminary work : add extra dimensions for some carbon variables (October 2012)

Work done by Didier : the following variables (global) have now an extra dimension :

    turnover daily
    turnover_littercalc
    turnover_longterm
    biomass
    litter
    bm_to_litter
    bm_to_littercalc
    bm_sapl (parameter)
    bm_alloc

Some local variables need an extra dimension too :

lpj_cover	dilu_lit
lpj_establish	total_bm_sapl
stomate_lcchange	bm_new, biomass_loss, dilu_lit
stomate_litter	qd, litter_inc_PFT, litter_inc, litter_pft
stomate_lpj	tot_bm_to_litter, tot_live_biomass, bm_alloc, tot_turnover
stomate_soilcarbon	fluxtot, flux

Moreover, I need to add the following parameters :

INTEGER(i_std), PARAMETER :: nelements = 1    !! Number of isotopes considered 
INTEGER(i_std), PARAMETER :: icarbon = 1      !! Index for carbon  

About stomate_io : I didn't add the suffix '_n' like Sonke Zaehle did for the carbon variables. I think the restart of this version need to be compatible by the current ones. We should not add any suffix for carbon variables, only for nitrogen to keep the compatibility.

Test done : A simple binary comparison test was performed on Obelix. The tests are OK.

This work has been commited see [1025].

Meeting 24/04/2013

Present: Bertrand Guenet, Sebastiaan Luyssaert, Philippe Peylin, Ben Poulter, Nicolas Viovy, Nicolas Vuichard

Objective: To present and discuss the different steps and issues related to the merge of the OCN version into the Trunk.

NVui prepares some slides on the schedule (here?). Overall agreement on the actions listed.
During the meeting, the following scheme has been defined in order to clarify the history of the OCN version at LSCE within the last years

It is still unclear :

• what are the differences between OCN 0.70 and OCN 0.71 ?

• how the OCN 0.71 can work without the corrections made on the 0.70 version to produce OCN NV2 ?

Ben will try to know more on the differences between OCN 0.70 and 0.71. On his side, Nicolas Viovy will try to run OCN 0.71 with his own driver, for comparison with 0.70.

We also agree on using this wiki for exchanging information on the OCN version. Consequently, I have created, 4 wiki pages (for Bertrand, Nicolas Viovy, Ben and Nicolas Vuichard). Here are the links for each of them. Please, do not hesitate to use these pages to document your former changes on the code of OCN and those that you will do in the future.
Branches/MergeOCN/Guenet?
Branches/MergeOCN/Poulter
Branches/MergeOCN/Viovy?
Branches/MergeOCN/Vuichard