63 | | |
64 | | == REPORT OF THE WORKING GROUP MEETING (January 30, 2014) == |
65 | | Participants : Rachid Benshila, Daley Calvert, Julien Calandreau, Jérome Chanut, Laurent Debreu, Christian Ethe, Rachel Furner, Claire Levy, Gurvan Madec, Sébastien Masson |
66 | | |
67 | | === 1) Discuss the update of the 3.6 version === |
68 | | ==== History : ==== |
69 | | * AGRIF version (and corresponding NEMO subroutines) has been updated by Julien Calandreau (INRIA) and Laurent Debreu |
70 | | |
71 | | * Jérome Chanut has made a lot of improvements and bug fixes in his Gilbraltar Strait configuration |
72 | | |
73 | | * Same for Sébastien Masson in the Pulsation ANR project |
74 | | |
75 | | * Other developments in LIM, PISCES |
76 | | |
77 | | ==== Bugs that have been identified and corrected since version 3.4 : ==== |
78 | | * zwork array (J. Chanut): a global array « zwork » was defined in the libmpp module and (due to a bug in the AGRIF converter) this led to several problems and in particular the update step was not performed … |
79 | | |
80 | | * Diffusion coefficients in the corners of the sponge layern were wrong (J. Chanut) |
81 | | |
82 | | * Scale factors were not correctly computed in the ghost cells (where it is assumed that we are in full steps) (J. Chanut) |
83 | | |
84 | | -> same problem for OBC |
85 | | |
86 | | * TKE (S. Masson): near the boundaries, spatial averaging operations led to wrong Kz in the first cell inside the high resolution domain. Extrapolation is possible but does not fulfill the requirement that with, a mesh refinement factor of 1, the obtained solution of the HR grid is identical to a solution computed without a zoom. S. Masson has implemented exchanges of TKE between coarse and fine grids. |
87 | | |
88 | | -> Same problem for GLS and for OBC |
89 | | |
90 | | * Asselin Filter (J. Chanut) : when updating the « after » (n+1) fields, the corresponding corrections of the « now » fields were not done. |
91 | | |
92 | | * arrays out of bound in procnames in MPI (wrong declarations of AGRIF profiles in agrif_declare_variables: jpi, jpj have been replaced by ncli,nlcj) |
93 | | |
94 | | ==== Bugs / Problems that have been identified ==== |
95 | | · The bathymetry connection check is not complete (add a check that the coarse grid bathy have been correctly updated) |
96 | | |
97 | | · Reproducibility is not guaranteed (due to MPI problem) when ln_spc_dyn is set to true in namelist (which means that we take 0 as special value for dynamics in interpolations/updates). |
98 | | |
99 | | · Recursive updates. When more than 1 zoom level are set, the update should start from the highest resolution grid and go recursively to the root grid. Laurent implemented changes that makes this possible. |
100 | | |
101 | | * Use of AGRIF for degradation online (problème de north pole, coarsening) |
102 | | |
103 | | * Average operators with update values |
104 | | |
105 | | * High order operators with coastlines |
106 | | |
107 | | * BDY problem have been solved |
108 | | |
109 | | ==== Improvements ==== |
110 | | * AGRIF and time splitting (OK for version 3.6, end of the year, Jérome) |
111 | | * only consider forward integration of the forcing mode permits to ensure volume conservation |
112 | | * without update of the parent grid right hand side |
113 | | * Performance of parallel runs |
114 | | * allows the distribution of the processors among the fine grids |
115 | | |
116 | | '''''Rachid Benshila''' is ready be in charge of the merge '' |
117 | | |
118 | | === 2) What are the known open problems ? (not to be solved for 3.6) === |
119 | | * Number of ghost cells ('''''L. Debreu''''') |
120 | | * Antartic problem (periodicity): require only one ghost cell instead of 2 |
121 | | * Number of required ghost cells for high order advection schemes may be larger than 2 |
122 | | * -> Remove hardcoding of the number of ghost cells, do the required modifications to the AGRIF “profiles” (Laurent) |
123 | | |
124 | | * North fold problem |
125 | | |
126 | | * Timings for each grid |
127 | | |
128 | | === 3) What are the main next developments? === |
129 | | * Coupling between grids at the level of the barotropic mode (in time splitting version) (Jérome) |
130 | | * requires some modification in the organization of the step routine of NEMO |
131 | | |
132 | | * Vertical grid refinement (Laurent) |
133 | | * Online coarsening for tracers using AGRIF (L. Debreu, G. Madec) |
134 | | * AGRIF with variable volume |
135 | | |
136 | | === 4) Nesting tools: === |
137 | | Two stages: |
138 | | |
139 | | a) for 3.6 version |
140 | | |
141 | | * agree on all the points: bathymetry smoothing, update of coarse grids (take the maximum as default) |
142 | | |
143 | | * Incorporate corrections done by Jean Marc |
144 | | |
145 | | * The nesting tools are only essential for the creation of bathymetry: |
146 | | * forcings can be interpolated on the fly |
147 | | * -> Do a list available tools for 3D interpolation (initialization / restart fields) |
148 | | * For 3.6 keep the 3D fields interpolation in nesting tools |
149 | | |
150 | | b) next version |
151 | | |
152 | | * The definition of vertical coordinates should be done outside NEMO |
153 | | |
154 | | * Nesting tools for the s coordinates |
155 | | |
156 | | ==== 5) Documentation: ==== |
157 | | * Update of the nesting tools 3.6 documentation |
158 | | |
159 | | * Update of the users guide: describes what is possible or not with AGRIF. |
160 | | |
161 | | * Documentation for nesting in NEMO/AGRIF: starts from the notes of Sebastien, then circulate the powerpoint |
162 | | |
163 | | * GMD paper |
164 | | |
165 | | === 6) Standard configuration and sanity tests === |
166 | | The standard configuration should: |
167 | | |
168 | | * Include more than one level of embedding (test of the recursive update starting from the finer resolution grid(s)) |
169 | | |
170 | | * Uses time splitting |
171 | | |
172 | | * Include a zoom in a sea ice area (Labrador Sea, LIM3) |
173 | | |
174 | | * Include a zoom with PISCES |
175 | | |
176 | | * Zoom in Perou Chili |
177 | | |
178 | | Sanitiy tests |
179 | | |
180 | | * Zoom with a mesh refinement of 1 |
181 | | |
182 | | * Test constancy preservation for tracers |
183 | | |
184 | | Longer visions of having AGRIF zoom in AMM |
185 | | |
186 | | S coordinates zoom inside a z coordinate parent grid. |