There is potential value in being able to run CABLE standalone for one or more locations (sites) using forcing taken from ACCESS model simulations. This may be an easier option for investigating different behaviour between online and offline simulations as a step towards running global simulations.
This topic captures notes associated with this task.
Getting met forcing from ACCESS-ESM1.5
Timeseries output from grid-cells is needed. The list of grid-cells is supplied through the domain field defined in the STASHC file for an ACCESS-ESM1.5 run. Examples are DGTS_PT (21 locations, probably mostly flux towers), DCO2TS (locations of atmospheric CO2 monitoring sites), DCO2TSL (similar to DCO2TS but for variables defined on model levels rather than just at the surface).
The required time field in STASHC is TALLTS.
The variables to be output are listed in the STASHC file by section and number. This is what I have currently used to match up with what CABLE requires
| Section | Number | StashMaster | CABLE |
|---|---|---|---|
| 0 | 409 | SURFACE PRESSURE AFTER TIMESTEP | Psurf |
| 1 | 235 | TOTAL DOWNWARD SURFACE SW FLUX | SWdown |
| 2 | 207 | DOWNWARD LW RAD FLUX: SURFACE | LWdown |
| 3 | 230 | 10 METRE WIND SPEED ON C GRID | Wind |
| 3 | 236 | TEMPERATURE AT 1.5M | Tair |
| 3 | 237 | SPECIFIC HUMIDITY AT 1.5M | Qair |
| 5 | 216 | TOTAL PRECIPITATION RATE KG/M2/S | Rainf |
In an ESM1.5 set-up, the output is requested in the STASHC file using syntax like this:
&STREQ IMOD= 1, ISEC=0, ITEM=409, IDOM=33, ITIM=19, IUSE=12 /
In this case the DGTS_PT domain is the 33rd in the file, and the TALLTS time field is the 19th in the file. IUSE determines which output file the data is written to. In this case it goes to *.pg files.
If adding output requests to the STASHC file, remember to increase the number (NUM_REQ) at the top of the file
&STASHNUM NUM_REQ= 280, NUM_DOM=37, NUM_TIM=20, NUM_USE=12 /
Note that the radiation output will be at the 3 hourly radiation timestep. Other output will be half-hourly.
Update June 2024
CABLE standalone needs to be run with the temperature and specific humidity from the lowest ACCESS model level not the 1.5 m values. These stash outputs were used.
| Section | Number | StashMaster | CABLE |
|---|---|---|---|
| 16 | 4 | TEMPERATURE ON THETA LEVELS | Tair |
| 0 | 10 | SPECIFIC HUMIDITY AFTER TIMESTEP | Qair |
Note that since these are multi-level fields, a new output domain is required to specify the level. This has been set up for the pft-focussed 13-site set of grid-cells described in a later post.
Do we want to add the atmospheric CO2 concentration to that list? Is it possible to output it in that way?
Hi @clairecarouge , yes - at some point we will probably want to add CO2. At this stage I was just trying to document what I’d done so far.
Re-formatting ACCESS output for CABLE standalone site input
This documents the steps I used to convert ACCESS output to a file that CABLE standalone could use. Not all steps may be required and there will, no doubt, be better and more efficient ways to do this. The ACCESS output was for the DGTS_PT domain which is 21 grid-cells. The 9th in the list matches the approximate location of the Tumbarumba flux tower site.
After all this, CABLE ran and appeared to give plausible results. Now we just need a cleaner way of doing this.
The time variable needs more work. I note that the documentation says it should be double precision. In my reformatting I don’t seem to have enough precision - the timestep calculation was OK in my first run but when trying to restart and run for an extra year, it wasn’t OK, 1808s instead of 1800s.
Also from the restarted run, the log file tells me that the run goes from 2004 to 2005 but the output netcdf file has time running from 2001.
Set of grid-cells to focus on each pft
Chose a set of grid-cells for testing to represent each pft. If possible, used a grid-cell with tile fraction = 1.0 and land fraction = 1.0. If not, found a grid-cell with as large a fraction as possible and retaining a land fraction = 1.0.
For ESM1.5, these grid-cells were chosen. Domains for stash output are DTS_PFT for single level variables and DTS_PFTL1 for variables on atmospheric levels.
| PFT | E-W index | N-S index | Longitude | Latitude | Fraction |
|---|---|---|---|---|---|
| Evergreen needleleaf | 30 | 123 | 54.375 | 62.5 | 1 |
| Evergreen broadleaf | 155 | 68 | -71.25 | -6.25 | 1 |
| Deciduous needleleaf | 64 | 124 | 118.125 | 63.75 | 1 |
| Deciduous broadleaf | 160 | 57 | -61.9 | -20 | 0.9173 |
| Shrub | 80 | 50 | 148.1 | -28.8 | 0.7123 |
| C3 grass | 140 | 111 | -99.375 | 47.5 | 1 |
| C4 grass | 19 | 78 | 33.8 | 6.2 | 0.9818 |
| Tundra | 43 | 127 | 78.75 | 67.5 | 1 |
| Crop | 41 | 99 | 75 | 32.5 | 1 |
| Wetlands | 42 | 124 | 76.875 | 63.75 | 0.6975 |
| Bareground | 6 | 93 | 9.375 | 25 | 1 |
| Lakes | 27 | 108 | 48.75 | 43.75 | 1 |
| Ice | 73 | 9 | 135 | -80 | 1 |
Made a CABLE met file with all 13 grid-cells i.e. no longer required the cdo,selgridcell step above.
Running CABLE standalone for multiple sites identified a bug. See Defined ncid_mask for met data files with multiple sites. Fixes #306.
Creating an ACCESS ‘gridinfo’ file
CABLE standalone runs use ‘gridinfo_CSIRO_1x1.nc’ for some initial data or parameters/ancillary data if it is not available in met or restart files. For site runs, data is taken from the nearest 1 degree by 1 degree grid-cell. To ensure ACCESS values were used in the CABLE standalone tests, a new gridinfo file has been created at ACCESS resolution.
Most of the fields required for the gridinfo file are available from an ACCESS restart. For these tests, the ‘restart’ created for the start of the simulations was used (PI-PFT-01c.astart-01010101). Used /g/data/p66/rml599/Site-tests/conv2nc.tcl to convert this list of fields from the restart to netcdf
set fieldlist "3 11 13 27 28 29 30 31 32 33 90 95 98 142 143 144 230 231 232 233 234 235"
Output is /g/data/p66/rml599/Site-tests/access.astart101.nc
This table matches the variable in the gridinfo file with the field number from the restart and the variable name in access.astart101.nc
| Gridinfo | Field no. | access-file | Notes |
|---|---|---|---|
| area | Used cmorised areacella_fx | ||
| iveg | 95 | field1391 | On tiles, pick dominant |
| patchfrac | |||
| isoil | Set to 2 for all veg types except 17 when set to 9 | ||
| SoilMoist | 3 | sm | Convert from kg/m2 to m3/m3. Divide by soil layer thickness and rho_water (1000) |
| SoilTemp | 11 | soiltemp | |
| SnowDepth | Still to be added. Currently set to 0. | ||
| Albedo | Dummy value, 0.2 - not used but checked so needs to be sensible | ||
| LAI | 235 | temp_5 | On tiles so selected LAI for dominant veg type |
| SoilOrder | 230 | temp | Convert to integer |
| Ndep | 231 | temp_1 | Need to multiply by 365. |
| Nfix | 232 | temp_2 | |
| Pwea | 234 | temp_4 | |
| Pdust | 233 | temp_3 | |
| clay | 142 | field1630 | |
| silt | 143 | field1631 | |
| sand | 144 | field1632 | |
| swilt | 27 | field329 | |
| sfc | 28 | field330 | |
| ssat | 29 | field332 | |
| bch | 90 | field1381 | |
| hyds | 30 | field333 | Need to divide by 1000. |
| sucs | 33 | field342 | |
| rhosoil | Set according to isoil, 1600. for isoil=2, 910. for isoil=9 | ||
| cnsd | 32 | field336 | |
| css | Set according to isoil, 850. for isoil=2, 2100. for isoil=9 | ||
| albedo2 | 98 | field1395 |
Gridinfo_CSIRO_1x1.nc has monthly values for SoilMoist, SoilTemp and SnowDepth. Currently January values have been copied into all months since the other months are not being used.
Very ugly code to write an ACCESS gridinfo file is /g/data/p66/rml599/Site-tests/writegridinfo.F90. Output is /g/data/p66/rml599/Site-tests/gridinfo.access101.nc