Changes between Version 1 and Version 2 of 2014WP/2014_System Simplification_v2


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Timestamp:
2014-02-05T13:59:44+01:00 (7 years ago)
Author:
gm
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  • 2014WP/2014_System Simplification_v2

    v1 v2  
    1 '''Note on possible system simplification''' 
     1'''Note on system simplification''' 
     2[[BR]] 
     3[[BR]] 
    24 
    35'''Motivation''': 
    46 
    57We 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. 
     8The 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 
    610 
    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  
     11possibly 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). 
    1513And this with a removing of obsolescent features and a cleaning of the code. 
    1614 
    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) 
     15Timing: 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) 
    1816 
    19 '''* core action (supported by all system team)''' 
     17Notations:  
    2018 
    21 '''- desired, but subject to discussion ''' 
     19   '''*'''  core action (supported by all system team) 
    2220 
    23 '''? feasible but all conditions required are not yet met  ''' 
     21   '''-'''  desired, but subject to discussion 
    2422 
    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''' 
    2627 
    27 '''*''' • default : non-linear free surface ('''planned''' '''in 2014''') 
     28'''*''' '''non-linear free surface''': by default ('''WP 2014''') 
    2829 
    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''') 
    3032 
    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 ?) 
    3234 
    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''') 
    3436 
    35                 - tracer solved as thickness weighted tracer: D,,t,,(e,,3t,, T) ('''planned''' '''2014''') 
     37                !-  thickness weighted quantities in the outputs ('''WP2014''') 
    3638 
    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).   
    3840 
    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?)  
    4042 
    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 ?) 
    4244 
    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 
    4446 
    45 '''*''' • sea-ice : embedded sea-ice as default 
     47                !-  suppress levitating sea ice with virtual salt fluxes. (2014 ?) 
    4648 
    47                 - suppress levitating sea ice with virtual salt fluxes. (2014 ?) 
     49                !-  Suppress levitating sea ice with mass exchange (?)  CICE issue… 
    4850 
    49                 - Suppress levitating sea ice with mass exchange (?)  CICE issue… 
     51                !-  need land-fast ice ('''WP 2014''') 
    5052 
    51                 - need land-fast ice ('''planned''' '''2014''') 
     53                !- need BDY compatibility with embedded sea-ice …. (who when?) 
    5254 
    53                 - need BDY compatibility with embedded sea-ice …. (who when?) 
     55'''-'''  tracer advection scheme: diminish their number (?).  
    5456 
    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 ?) 
    5660 
    5761'''-''' • vertical physics:  simplification versus diversity