Changes between Version 1 and Version 2 of 2014WP/2014_SystemSimplification_v2
- Timestamp:
- 2014-02-05T13:59:44+01:00 (10 years ago)
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2014WP/2014_SystemSimplification_v2
v1 v2 1 '''Note on possible system simplification''' 1 '''Note on system simplification''' 2 [[BR]] 3 [[BR]] 2 4 3 5 '''Motivation''': 4 6 5 7 We need to simplify the code for maintenance, robustness and future evolution (change in time stepping, …etc). This means fewer options, and a consensus on the default (and thus well validated) set of numerics. 8 The idea is to change the current most used choices from : [[BR]] 9 linear filtered free surface zps ocean with TVD, "Madec" iso-neutral diffusion, and standard equation of state ; levitating sea-ice with virtual salt fluxes 6 10 7 The idea is to change the current most used choices from : 8 9 linear filtered free surface zps ocean with TVD, "Madec" isoneutral diffusion, and standard equation of state ; levitating sea-ice with virtual salt fluxes 10 11 possibly to : 12 13 Non linear (vvl), split-explicit (ts) free surface, mixte zps/s-coordinate ocean with 3rd order advection (UBS), "Griffies" isoneutral diffusion ; embedded multi-category sea-ice (exact fluxes). 14 11 possibly to :[[BR]] 12 Non linear (vvl), split-explicit (ts) free surface, mixte zps/s-coordinate ocean with 3rd order advection (UBS with rotation of the diffusive part along iso-neutral surfaces), "Griffies" iso-neutral diffusion ; embedded multi-category sea-ice (exact fluxes). 15 13 And this with a removing of obsolescent features and a cleaning of the code. 16 14 17 Timing: ideally, no more than 2 years from now(to be ready for CMIP6, and on time for the foreseen evolution of the time stepping)15 Timing: achievement within 2 years from now for NEMO v4.0 (to be ready for CMIP6, and on time for the foreseen evolution of the time stepping) 18 16 19 '''* core action (supported by all system team)''' 17 Notations: 20 18 21 '''- desired, but subject to discussion ''' 19 '''*''' core action (supported by all system team) 22 20 23 '''? feasible but all conditions required are not yet met ''' 21 '''-''' desired, but subject to discussion 24 22 25 '''CHANGE in paradigm''' 23 '''?''' feasible but all conditions required are not yet met 24 [[BR]] 25 [[BR]] 26 '''CHANGE in options used by default''' 26 27 27 '''*''' • default : non-linear free surface ('''planned''' '''in2014''')28 '''*''' '''non-linear free surface''': by default ('''WP 2014''') 28 29 29 '''*''' • remove filtered free surface and all associated solvers (if yes when? 2014?) 30 '''*''' '''filtered free surface''': remove it as well as all its associated solvers (if yes when? 2014?)[[BR]] 31 (required AGRIF with time-splitting, '''done''' in 2013) and deeply tested ('''WP 2014''') 30 32 31 (required AGRIF with time-splitting, '''done''' in 2013) and deeply tested ('''planned''' 2014)33 '''*''' '''vertical coordinate''' : default option mixte zps/s-tilde coordinate (thus with variable volume level), with mixte zps*/s*, mixte z/s, zps, z and s coordinate system as sub-option (same code used) (2014-2015 ?) 32 34 33 '''*''' • vertical coordinate : default option mixte zps/s-tilde coordinate (thus with variable volume level), with mixte zps*/s*, mixte z/s, zps, z and s coordinate system as sub-option (same code used) (2014-2015 ?)35 !- tracer solved as thickness weighted tracer: D,,t,,(e,,3t,, T) ('''WP 2014''') 34 36 35 - tracer solved as thickness weighted tracer: D,,t,,(e,,3t,, T) ('''planned''' '''2014''')37 !- thickness weighted quantities in the outputs ('''WP2014''') 36 38 37 - thickness weighted quantities in the outputs ('''planned''' '''2014''')39 !- no more substitute (domzgr_substitute.h90): all e3 always defined at before, now and after time steps ('''partly done''' in 2013, '''achieved''' in 2014). 38 40 39 - no more substitute (domzgr_substitute.h90): all e3 always defined at before, now and after time steps ('''partly done''' in 2013, '''achieved''' in 2014).41 !- adapte OFF line for tracer to variable volume (2015?) 40 42 41 - adapte OFF line for tracer to variable volume (2015?) 43 '''*''' linear ssh option set without optimization (i.e. starting from the non-linear case with minimal changes, not optimal changes), or linear case suppressed ?? We should probably keep a linear case for test cases. (2014-2015 ?) 42 44 43 '''*''' • linear ssh option set without optimization (i.e. starting from the non-linear case with minimal changes, not optimal changes), or linear case suppressed ?? We should probably keep a linear case for test cases. (2014-2015 ?)45 '''*''' sea-ice : embedded sea-ice as default 44 46 45 '''*''' • sea-ice : embedded sea-ice as default 47 !- suppress levitating sea ice with virtual salt fluxes. (2014 ?) 46 48 47 - suppress levitating sea ice with virtual salt fluxes. (2014 ?)49 !- Suppress levitating sea ice with mass exchange (?) CICE issue… 48 50 49 - Suppress levitating sea ice with mass exchange (?) CICE issue…51 !- need land-fast ice ('''WP 2014''') 50 52 51 - need land-fast ice ('''planned''' '''2014''')53 !- need BDY compatibility with embedded sea-ice …. (who when?) 52 54 53 - need BDY compatibility with embedded sea-ice …. (who when?) 55 '''-''' tracer advection scheme: diminish their number (?). 54 56 55 '''-''' • tracer advection scheme: diminish their number (?). Typically one module for 2^nd^/4^th^ order and one for a 3^rd^ order scheme, both associated with an optional flux limiter to ensure positivity. 57 !- Typically one module for 2^nd^/4^th^ order and one for a 3^rd^ order scheme, both associated with an optional flux limiter to ensure positivity. To be discussed 58 59 !- Addition of the rotation of the diffusive part of 3^rd^ order scheme (2015 ?) 56 60 57 61 '''-''' • vertical physics: simplification versus diversity