| 1 | WARNING: For now, the test case ICE_ADV2D only works if the logical "ll_neg" is set to FALSE in the routine icedyn_adv_umx.F90 |
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| 2 | (it is still unclear why) |
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| 3 | ------- |
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| 4 | Purpose |
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| 5 | ------- |
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| 6 | This demonstration case can serve different purposes: |
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| 7 | |
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| 8 | 1) The main one: study of the advection of a patch of ice in a bi-periodic channel with a slab ocean (i.e. 1 ocean layer) |
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| 9 | ==> set ln_icethd=false in namelist_ice_cfg |
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| 10 | |
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| 11 | 2) Secondary: study of ice thermodynamics in the same basin |
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| 12 | ==> set ln_icedyn=false in namelist_ice_cfg |
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| 13 | ==> eventually change usrdef_sbc.F90 in MY_SRC to fit your needs |
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| 14 | |
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| 15 | ----------- |
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| 16 | Experiments |
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| 17 | ----------- |
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| 18 | Two experiments can be configured: |
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| 19 | |
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| 20 | a) A simple channel at 3km horizontal resolution (slightly variable => +- 10%) |
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| 21 | ==> in MY_SRC/usrdef_hgr.F90, uncomment the part "variable scale factors" and comment part "constant scale factors" |
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| 22 | |
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| 23 | b) A simple channel at 3km horizontal resolution (constant scale factors) |
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| 24 | ==> in MY_SRC/usrdef_hgr.F90, comment the part "variable scale factors" and uncomment part "constant scale factors" |
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| 25 | |
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| 26 | ---------- |
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| 27 | How to run |
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| 28 | ---------- |
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| 29 | |
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| 30 | a) Compile and run the model once to get a mesh_mask.nc file with the following command: |
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| 31 | ../../../makenemo -r ICE_ADV2D -n ICE_ADV2D -m X64_ADA -j 4 |
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| 32 | mpirun ./nemo -np 1 |
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| 33 | |
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| 34 | b) Create the initial condition file for sea-ice (initice.nc) by running this python script: |
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| 35 | python ./make_INITICE.py |
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| 36 | |
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| 37 | c) Run the model a second time |
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| 38 | mpirun ./nemo -np 4 |
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| 39 | |
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| 40 | --------------- |
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| 41 | What to look at |
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| 42 | --------------- |
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| 43 | In case of purpose 1, One can test |
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| 44 | --- |
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| 45 | a) the advection scheme: Ultimate-Macho (ln_adv_UMx=T) versus Prather (ln_adv_Pra=T) |
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| 46 | for a square (ice concentration) or a gaussian (ice volume) |
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| 47 | with either a constant velocity (ln_dynADV2D=T) |
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| 48 | or a constant ice-atm. stress, thus velocity is calculated by rheology (ln_dynRHGADV=T) |
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| 49 | with 1 or 5 ice categories (jpl=1 or 5). |
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| 50 | (note that ln_dynADV2D=T only works with jpl=1) |
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| 51 | |
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| 52 | In case of purpose 2, one can test conservation of properties: |
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| 53 | --- |
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| 54 | b) ice should not change at all if surface fluxes = 0 and SST = freezing temperature |
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| 55 | |
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| 56 | -------------------------------------- |
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| 57 | Interpretation of the results (remarks) |
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| 58 | -------------------------------------- |
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| 59 | - Prather conserves the max values but also creates side lobes |
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| 60 | - UM does not conserve the max but does not create side lobes |
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| 61 | - The "unmoving" ice (if any) is due to ice rheology which states that ice mass below a certain thresold (1kg/m2) is considered to move at the ocean velocity (thus 0 m/s) |
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