[[PageOutline]] Last edited [[Timestamp]]

'''Author''' : AUTHOR_NAME

'''ticket''' : #937

'''Branch''' : [https://forge.ipsl.jussieu.fr/nemo/browser/branches/BRANCH_NAME BRANCH_NAME]

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=== Description ===
Mercator-1 : Improvment of OBC's

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=== Testing ===
Testing could consider (where appropriate) other configurations in addition to NVTK].

|| NVTK Tested || !'''YES!''' ||
|| Other model configurations || !'''NO!''' ||
|| Processor configurations tested || [ sette layouts ] ||
|| If adding new functionality please confirm that the [[BR]]New code doesn't change results when it is switched off [[BR]]and !''works!'' when switched on || !'''NO!''' ||

(Answering UNSURE is likely to generate further questions from reviewers.)

'Please add further summary details here'

 * Processor configurations tested
 * etc----

=== Bit Comparability ===
|| Does this change preserve answers in your tested standard configurations (to the last bit) ? || !'''NO !''' ||
|| Does this change bit compare across various processor configurations. (1xM, Nx1 and MxN are recommended) || !'''YES!''' ||
|| Is this change expected to preserve answers in all possible model configurations? || !'''NO!''' ||
|| Is this change expected to preserve all diagnostics? [[BR]]!,,!''Preserving answers in model runs does not necessarily imply preserved diagnostics. !'' || !'''NO!''' ||

If you answered !'''NO!''' to any of the above, please provide further details:

 * Which routine(s) are causing the difference?
 * Why the changes are not protected by a logical switch or new section-version
 * What is needed to achieve regression with the previous model release (e.g. a regression branch, hand-edits etc). If this is not possible, explain why not.
 * What do you expect to see occur in the test harness jobs?
 * Which diagnostics have you altered and why have they changed?Please add details here........

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=== System Changes ===
|| Does your change alter namelists? || !'''YES!''' ||
|| Does your change require a change in compiler options? || !'''NO!''' ||

 * namelist changes: 
   * nam_tide: Simplifications in the definition of tidal waves. Add a flag and time_scale to activate linear ramping of tidal motions.
   * nambdy_tide: Add a new option to read tidal boundary data from 2d file given on data domain.
   * nambdy: Add new options for bdy: Flags and times cales to apply relaxation on tracers and baroclinic velocities. 
   * nambdy_index: Simplify definition of analytical segments.
 * About compiler options: Code update does not require any change in compiler options. Yet, we noticed that results are not reproductible unless the lowest level of optimization is used.

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=== Resources ===
!''Please !''summarize!'' any changes in runtime or memory use caused by this change......!''

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=== IPR issues ===
|| Has the code been wholly (100%) produced by NEMO developers staff working exclusively on NEMO? || !'''YES!''' ||