Version 12 (modified by rlod, 6 months ago) (diff)

Name and subject of the action

Last edition: 11/26/21 17:07:30 by rlod

The PI is responsible to closely follow the progress of the action, and especially to contact NEMO project manager if the delay on preview (or review) are longer than the 2 weeks expected.

  1. Summary
  2. Preview
  3. Tests
  4. Review


Action Validation of the TOP Antarctic Ice Sheet Tracer Module
PI(S) Person R.
Digest Validation of AIS iron source in eORCA1
Dependencies If any
Branch source:/NEMO/branches/{YEAR}/dev_r{REV}_{ACTION_NAME}
Previewer(s) O. Aumont, C. Ethé
Reviewer(s) O. Aumont, C. Ethé
Ticket #2656


  • NEMO trunk rev: 14723
  • Configuration : eORCA1

Validation of the TOP trcais.F90 module for representing the external source of biogeochemical tracers from icebergs and ice shelves, currently active for dissolved Fe.

The validation consists of activating the AIS source of Fe in the TOP namelist with open and non-open ice shelf cavities in eORCA1 configuration grid and comparing the results with a control experiment where the external source is not activated.

Each experiment have a duration of 10 years.


Describe flow chart of the changes in the code.
List the Fortran modules and subroutines to be created/edited/deleted.
Detailed list of new variables to be defined (including namelists),
give for each the chosen name and description wrt coding rules.

Documentation updates

Using previous parts, define the main changes to be done in the NEMO literature (manuals, guide, web pages, …).


Since the preview step must be completed before the PI starts the coding, the previewer(s) answers are expected to be completed within the two weeks after the PI has sent the request to the previewer(s).
Then an iterative process should take place between PI and previewer(s) in order to find a consensus

Possible bottlenecks:

  • the methodology
  • the flowchart and list of routines to be changed
  • the new list of variables wrt coding rules
  • the summary of updates in literature

Once an agreement has been reached, preview is ended and the PI can start the development into his branch.


Results of the validation experiments:
See attachment for plots of surface Fe anomalies (relative to CTL) for parameterized ice shelf cavities (Fig. 1) and resolved ice shelf cavities (Fig. 2) when activating Fe input from the Antarctic ice sheet (nn_ais_tr = 1, prescribed tracer concentration in iceberg and ice shelf).

  • The results for the parameterized ice shelf cavities are as expected with a net positive effect on surface Fe concentrations.
  • For the resolved ice shelf cavities, the results are more surprising as there are areas with a positive effect on surface iron concentrations and areas with a negative effect potentially induced by seawater circulation in the cavities. This point deserves further investigation.

The model outputs are available on jeanzay (idris)

  • CTL run : /gpfsstore/rech/omr/romr014/IGCM_OUT/NEMO/DEVT/clim/eOR1Si3Pv4-CLIM-CORE-CTL
  • ice shelf cavities parametrized (nn_ais_tr = 1): /gpfsstore/rech/omr/romr014/IGCM_OUT/NEMO/DEVT/clim/eOR1Si3Pv4-AISFe-PAR1
  • ice shelf cavities resolved (nn_ais_tr = 1): /gpfsstore/rech/omr/romr014/IGCM_OUT/NEMO/DEVT/clim/eOR1Si3Pv4-AISFe-CAV1


A successful review is needed to schedule the merge of this development into the future NEMO release during next Merge Party (usually in November).


  • Is the proposed methodology now implemented?
  • Are the code changes in agreement with the flowchart defined at preview step?
  • Are the code changes in agreement with list of routines and variables as proposed at preview step?
    If, not, are the discrepancies acceptable?
  • Is the in-line documentation accurate and sufficient?
  • Do the code changes comply with NEMO coding standards?
  • Is the development documented with sufficient details for others to understand the impact of the change?
  • Is the project literature (manual, guide, web, …) now updated or completed following the proposed summary in preview section?


Is the review fully successful? If not, please indicate what is still missing

Once review is successful, the development must be scheduled for merge during next Merge Party Meeting.

Attachments (5)

Download all attachments as: .zip