CMCC-NEMO team - 2013 actions

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members

Name	Institution	%	Position
Marcello Vichi	CMCC, Bologna	20	CMCC NEMO officer ad interim
Tomas Lovato	CMCC, Bologna	20	post-doc
Esteban Gutierrez	CMCC, Bologna	20	junior scientific programmer
Dorotea Iovino	CMCC, Bologna	20	junior scientist
Pier Giuseppe Fogli	CMCC, Bologna	20	senior scientific programmer
Italo Epicoco	CMCC, Lecce	20	scientist
Silvia Mocavero	CMCC, Lecce	20	scientist

total weeks :

40 weeks (=1 man-year)

Summary:

The major developments completed during 2013 consisted in CMCC-1a and CMCC-6. CMCC-1a was added as a sub-activity of CMCC-1 that continues in 2014. The two developments have been tested and ready to be merged. CMCC-6 is however not completely finalized as it relies on the merging of the new BDY code in the trunk. This will be completed in 2014

Action	Brief description	Status	Branch name	Trac ticket n°	Wiki page name	Reviewer(s)	Review status	Nb of weeks	Ready for merge/ If "NO", reason and status for 2014
CMCC-1a	Scalability	Continuation	https://forge.ipsl.jussieu.fr/nemo/browser/branches/2013/dev_r3948_CMCC_NorthFold_Opt	https://forge.ipsl.jussieu.fr/nemo/ticket/1150		A. Coward	DONE		YES
CMCC-1b	Scalability: MPI-OPENMP	Continuation	https://forge.ipsl.jussieu.fr/nemo/browser/branches/2013/dev_r4017_CMCC_MPI_OpenMP	https://forge.ipsl.jussieu.fr/nemo/ticket/1151					NO The hybrid OpenMP/MPI approach has been implemented for the Gyre configuration and scalability studies are on going. The development will be continued in 2014 See further notes at CMCC.1 below
CMCC-2	Masks	Started							See notes in the status line below
CMCC-3	Data assimilation	Not Started							See notes in the status line below
CMCC-4	Divergence damping	Continuation							See notes in the status line below
CMCC-5	Vertical stability	Not started							See notes in the status line below
CMCC-6	BC for TOP	Continuation	https://forge.ipsl.jussieu.fr/nemo/browser/branches/2013/dev_r3996_CMCC6_topbc?rev=	https://forge.ipsl.jussieu.fr/nemo/ticket/1143		Ethe	DONE		YES
CMCC-7	AGRIF	Not Funded							See notes in the status line below

CMCC.1 Scalability Optimization

Motivation: Improve NEMO scalability.
Status: Partly closed. The feasibility study related to the introduction of the PETSc library has been concluded. From this study it has been deduced that a consistent manpower is needed. Since this effort is not available using the currently funded projects, the activity related to the introduction of PETSc into the NEMO code will be sustained when new project funds will be achieved. A report on the results of this study is available and will be provided at the November merge party.
XIOS has been validated on the CMCC Sandy Bridge systems (ATHENA).
Main tasks:
* Introduction of a new software layer in the NEMO stack software exploiting numerical optimized and parallel libraries such as pBLAS, ScaLAPACK and PETSc.
* Continuation of the implementation of hybrid parallel approach based on the functional parallelism for the tracers, momentum equations and 3D domain decomposition.
* Test performances of XIOS on CMCC architectures
System Reviewer:
Deadline: 2013
Priority: Medium
Principal investigator: Italo Epicoco

CMCC.2 Modification of masks

Motivation: Expand the modification of masks to the EEN scheme
Status: The modification of masks has been implemented for the energy and for the enstrophy conserving schemes. The implementation for the energy and enstrophy (Arakawa) conserving scheme has not been tested and therefore still cannot be implemented officially. The PI left CMCC and the development is suspended.
Main tasks: Evaluate the impact of fmask on the EEN scheme and eventually make modifications.
Science Reviewer: Gurvan Madec
Deadline: 2013
Priority: High
Principal investigator: Srdjan Dobricic

CMCC.3 Direct interface with data assimilation

Motivation: Interface with data assimilation systems
Status: The direct interface with the data assimilation requires a simple method for the deallocation of the memory once it is not necessary. This should be done in order to reduce the size of the executable. In NEMO this is possible only for he working arrays, but when coupled with a data assimilation scheme the deallocation of the memory of many arrays that are not necessary for restarting Nemo becomes very complicated. The solution for this problem would completely change the form of the Nemo code and currently is not feasible.
Main tasks: Develop software interface that will avoid the writing to the disk, provide the possibility to use a different domain decomposition in Nemo and the data assimilation, reduce the memory usage of Nemo when it is inactive.
Science Reviewer: MetOffice
Deadline: 2013
Priority: Medium
Principal investigator: Srdjan Dobricic

CMCC.4 Divergence damping filter operator

Motivation: Additional diffusion on only the divergent component of the velocity could reduce the numerical noise at the high model topography (step topography, deep convection, etc.).
Status: The divergence damping operator is implemented in the ASM package. It has also been implemented and tested in the dynamics package in Version 3.4, but the documentation is still missing. Therefore, it was not implemented. The PI left CMCC and the development is suspended.
Main tasks: Add a routine that will apply the divergence filter in addition to the horizontal diffusion of the velocity.
System Reviewer:
Science Reviewer:
Deadline: 2013
Priority: High
Principal investigator: Srdjan Dobricic

CMCC.5 Vertical stability of increment fields

Motivation: Modify the increment field in order to reduce the vertical instabilities.
Status:The vertical stability of the increments is implemented in Version 3.3 and has not been updated in the newest version. Also the documentation is still missing.
Main tasks: Modify the ASM code to add the diagnostics of the vertical stability and the modificatyions to the increment fields. The PI left CMCC and the development is suspended.
System Reviewer:
Science Reviewer: Met Office
Deadline: 2013
Priority: Medium
Principal investigator: Srdjan Dobricic

CMCC.6 Surface and lateral boundary conditions for tracers

Motivation: Add generic interfaces for surface and lateral boundary conditions for BGC tracers (river input, atmospheric deposition, open boundary conditions).
Status: started in 2012, first implementation waiting for the final choice of BDY
Main tasks: Port the interface used for transport routines to the surface and boundary condition routines currently used for T and S.
System Reviewer: C. Ethe'
Science Reviewer: C. Ethe', ??
Deadline: 2013
Priority: High
Principal investigator: Marcello Vichi

CMCC.7 Testing of AGRIF: scalability and usage with biogeochemical variables

Motivation: evaluate AGRIF performances in realistic domains and utilization with the BFM
Status: this activity has not been funded and will not be undertaken for this year
Main tasks: check performances of AGRIF with an Atlantic refinement; assess the compatibility with BFM variables and the related computational overhead
System Reviewer:
Science Reviewer: Dorotea Iovino
Deadline: 2013-2014
Priority: Medium
Principal investigator: Marcello Vichi and Italo Epicoco