NOC-NEMO team - 2011 actions

Last edited Timestamp?

members

Name	Institution	%	Position
Yevgeny Aksenov	NERC-NOC, Southampton	5
Steven Alderson	NERC-NOC, Southampton	25
Jeff Blundell	NERC-NOC, Southampton	15
Andrew Coward	NERC-NOC, Southampton	35	NOC NEMO officer
George Nurser	NERC-NOC, Southampton	5
Hedong Liu	NERC-NOC, Liverpool	15

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total weeks :
2+8+3+2+4+2+4+1+2+3+3 = 34 wk (NOCS) +?+?+? = 6 wk (NOCL)

Summary:

Action	Brief description	Status	Branch name	Trac ticket n°	Wiki page name	Reviewer(s)	Review status	Nb of weeks	Ready for merge
NOCS-01	User Interface		N/A
NOCS-02	System Maintenance		N/A
NOCS-03	Prather Advection	due 2012
NOCS-04	Salt and Mass fluxes	ongoing
NOCS-05	Embedded Sea-ice	ongoing
NOCS-06	Griffies + TOP	ready	2011/dev_r2782_NOCS_Griffies	#838		Gurvan			yes
NOCS-07	Configuration rationalisation	due 2012
NOCS-08	Timestepping vertical diffusion	due 2012
NOCS-09	MPP scalability	ready	2011/dev_r2855_NOCS_mppsca	#679
NOCS-10	Neptune Effect	ready	2011/dev_r2787_NOCS_NEPTUNE	#843
NOCS-11	Spectral Nudging	due 2012
NOCL-01	Horizontal Pressure gradient	ready?	2011/dev_r2802_NOCL_prjhpg
NOCL-02	Wetting and Drying	due 2012?
NOCL-03	Smagorinsky viscosity	ready?	2011/dev_r2802_NOCL_Smagorinsky
NOCL-04	Semi implicit bottom friction	ready?	2011/dev_r2802_NOCL_bfrimp
NOCL-05	Vertical PPM advection scheme	ready?	2011/dev_r2802_NOCL_vppm

'''NOCS.1 - User Interface'''

Provide support to users of NEMO. NOC will provide in depth support for code supplied by them.

Motivation: Shared daily support to users, web & paper documentation.
Main task: (2 wk)
Principal Investigator : Andrew Coward/Steven? Alderson (acc@…)

NOCS.2 - System maintenance

(a) Code Reviewing - Reviewing code from NEMO partners (2 w)
(b) Beta Testing - Beta testing of new versions (4 w)
(c) Collaboration - Time spent:

• hosting visitors from partner institutes on the NEMO system team
  
• travelling to partner institutes for exchange visits
  
• attending NEMO Steering, Developers and System Team meetings
  
• attending “merge party”
  (2 w)
  Principal Investigator : Steven Alderson (sga@…)
  

NOCS.3 — Prather advection

Motivation: The Prather advection scheme is currently the advection scheme of choice in other key modelling systems (MOM, ROMS etc.)
Main task: (3 wk)
(1) Implementation in the trunk+ NVTK + documentation (3 wk) v3.4 release
Principal Investigator : Andrew Coward/George? Nurser (acc@…)
Deadline : 22nd April 2011
Priority: Medium
Science Reviewer : Gurvan Madec (TBC)
System Reviewer : Rachid Benshila (TBC)

NOCS.4 — Revisit of mass and salt fluxes (end)

Motivation: As a consequence of the embedding of sea-ice into the ocean (see NOCS.5), the total mass of salt of the combined sea-ice/ocean system is conserved by removing a volume of water from the ocean when ice forms or adding a volume of water when it melts. When ice forms, salt contained in the water is returned to the ocean, less the salt retained in the ice itself. When ice melts, the salt contained is added back to the ocean.
Status: Implemented in 2010 but not finalised before the end of year merge. Code refresh and re-validation required.
Main task: (2 wk)
(1) Implementation in the trunk+ NVTK + documentation (2 wk) v3.4 release
Principal Investigator : Gurvan Madec (@noc.soton.ac.uk)
Deadline : 2nd February 2011
Priority: High
Science Reviewer : Chris Harris (TBC)
System Reviewer : Rachid Benshila (TBC)

=== '''NOCS.5 — Embedded sea-ice (including CICE)''' (end) ===

Motivation: Introduce fully embedded sea-ice (i.e. with sea-ice loading applied to the ocean) (Campin et al. OM 2008)
Status: Implemented in 2010 but not finalised before the end of year merge. Code refresh and re-validation required. The existing scheme to embed LIM2 and LIM3 will also be extended to include CICE (subject to the CICE interface entering the system)
Main task: (4 wk)
(1) Re-implement LIM2/3 solution into v3.3 + NVTK + documentation (3 wk) v3.4 release
(2) Extend solution to include CICE (subject to availability of finished interface) (2 wk) v3.4 release
Principal Investigator : Gurvan Madec/Steven? Alderson/Yevgeny? Aksenov (yka@…)
Deadline : 2nd September 2011
Priority: High
Science Reviewer : Chris Harris (TBC)
System Reviewer : Rachid Benshila (TBC)

NOCS.6 — Lateral ocean physics and TOP

Motivation: The Griffies's implementation of the Gent and McWilliams? eddy transport as a skew flux was implemented in 2010. This has the advantage that its numerical discretization can be written in terms of contributions from quarter cells – ‘triads’. This gives a tighter stencil, disallowing 2-gridpoint numerical noise that is permitted by the advective discretization. Following the the merge of TRA-TRC advection schemes that also occurred in 2010, the Griffies operator can now be extended to work with passive tracers.
Status: Ready to proceed as soon as the planned merge of t and s arrays has occurred.
Main task: (2 wk)
(1) Extend Griffies operator to work with passive tracers
(2) Implement Visbeck et al.'s formulation of spatially varying diffusivities as an alternative to the current formulation based on the Held and Larichev timescale and the Rossby radius as a lengthscale.
Principal Investigator : George Nurser (agn@…)
Deadline : 4th March 2011
Priority: High
Science Reviewer : Mercator (TBC)
System Reviewer : Rachid Benshila (TBC)

=== '''NOCS.7 — Rationalisation of support for ORCA configurations (including independence of vertical resolution) ''' ===

Motivation: A cleaning and enhancement of code support for global (ORCA) configurations is required to introduce configurations in common use across the community.
Main task: (4 wk)
(1) Support will be improved or added for ORCA1, ORCA05, ORCA025 and ORCA_R12 configurations in such a way that multiple vertical resolutions of each can be maintained.
(2) The use of .h90 files will also be suppressed.
Principal Investigator : Andrew Coward (acc@…)
Deadline : 19th August 2011
Priority: Medium
Science Reviewer : Not needed
System Reviewer : Paris (TBC)

NOCS.8 — Time stepping of vertical diffusion

Motivation: An improvement in the numerical treatment of vertical diffusion can be achieved by replacing the fully implicit scheme with a Crank-Nicholson scheme. This approach is widely used in other ocean models (e.g. ROMS, MARS...) and can be implemented relatively simply.
Main task: (1 wk)
(1) The replacement scheme will be implemented and its performance tested.
Principal Investigator : Andrew Coward (acc@…)
Deadline : 18th February 2011
Priority: Medium
Science Reviewer : Mercator (TBC)
System Reviewer : Paris (TBC)

NOCS.9 — MPP scalability. Implementation and testing of PRACE-type solution to increase scalability of the north-fold exchanges

Motivation: Investigations within the PRACE project identified the default north-fold exchange algorithm as a significant barrier to scalability. Alternatives to the

gather-scatter algorithm were tested and shown to improve scalability when large numbers of processors are used. A suitable version of the PRACE solution will be implemented.

Status: A v3.2 branch was started in 2010 and a solution was implemented and successfully tested for T,U,V and F point exchanges. Main task: (2 wk)
(1) Port existing scheme to v3.3 and consider methods for I-point exchanges.
Principal Investigator : Andrew Coward (acc@…)
Deadline : 18th June 2011
Priority: Medium
Science Reviewer : Mercator (TBC)
System Reviewer : Paris (TBC)

NOCS.10 — Neptune effect

Motivation: The Neptune effect (Holloway 1992) is a well established parameterisation of the interaction of eddies with topography. The parameterisation is often seen as essential in Arctic ocean simulations even in high resolution models. The improvments it provide to an ORCA1-LIM simulation is shown in Wang and Holloway (OM, 2009).
Status: Coded in v3.2. Main task: (3 wk)
(1) Add the parameterisation to the reference code
(2) Phase 1: Implement ready for v3.4 (NOCS team, 2wk)
(3) Phase 2: Test, document and report (v3.4) (NOCS team, 1wk)
Principal Investigator : Jeff Blundell (jeff@…)
Deadline : 18th February 2011
Priority: High
Science Reviewer : Mercator (TBC)
System Reviewer : Paris (TBC)

=== '''NOCS.11 — Implementation of spectral nudging''' ===

Motivation: Work by our Canadian colleagues has demonstrated the potential benefits of spectral nudging techniques to restore large scale gradients without suppressing meso-scale activity.
Status: Coded in v3.2. Requires porting to and testing and documenting in v3.4
Main task (3 wk)
Deadline : 22nd April 2011
Priority: High
Science Reviewer : Mercator (TBC)
System Reviewer : Paris (TBC)
Principal Investigator : Jeff Blundell (jeff@…)

=== '''NOCL.1 — Horizontal Pressure gradient''' ===

Motivation: Develop a new horizontal pressure gradient module for s-coordinate/partial s-coordinate with Pressure Jacobian formulation
Status: Coded in v3.2. Requires review, documenting and porting to v3.4 Main task (2 wk)
Deadline :
Priority: Medium
Science Reviewer : Paris, MetOffice? (TBC)
System Reviewer : Paris (TBC)
Principal Investigator : Hedong Liu (heau@…)

=== '''NOCL.2 — Wetting and Drying''' ===

Motivation: Add Wetting/Drying? functionality to NEMO for coastal ocean applications
Status: In preparation
Main task (26 wk)
Deadline : End of 2012
Priority: Medium
Science Reviewer : TBC
System Reviewer : TBC
Principal Investigator : Hedong Liu (heau@…) + ???

=== '''NOCL.3 — Smagorinsky viscosity''' ===

Motivation: Add Samgorinsky viscosity/diffusivity method
Status: Coded in v3.2 but need further modification and testing
Main task (? wk)
Deadline :
Priority: Medium
Science Reviewer : TBC
System Reviewer : TBC
Principal Investigator : Maria Luneva (mane1@…)

=== '''NOCL.4 — Semi implicit bottom friction''' ===

Motivation: Implement semi-implicit bottom friction method to stabilise tidal simulation
Status: Coded in v3.2 but need need review and importing to v3.4
Main task (2 wk)
Deadline : 31st Jan. 2011
Priority: High
Science Reviewer : Mercator(TBC)
System Reviewer : Paris(TBC)
Principal Investigator : Hedong Liu (heua@…)

=== '''NOCL.5 — Vertical PPM advection scheme''' ===

Motivation: Add vertical PPM option to the existing advection scheme setup
Status: Coded in v3.2 but need further debugging and testing
Main task (4 wk)
Deadline : End of Jan, 2010
Priority: High
Science Reviewer : Mercator(TBC)
System Reviewer : Paris(TBC)
Principal Investigator : Hedong Liu (heua@…)