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How do I specify the SST pattern for aquaplanet mode?

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whannah
How do I specify the SST pattern for aquaplanet mode?

I've been trying to do this for awhile now, and I'm totally stumped! I want to specify the SST to something that is not zonally syymetric. To keep it simple I'm using the fv 1.9x2.5 resolution in both atm and ocn components. I've built a netcdf file identical to the standard sst input for the F_2000 compset. I started with the file - sst_HadOIBl_bc_1.9x2.5_clim_c061031.nc, which is located in inputdata/atm/cam/sst/. I've tried two methods that I can't get to work.

Method #1

First I tried setting the compset indentical to F_2000_CAM5_AQUAPLANET like this:

-user_compset 2000_CAM5_SLND_SICE_AQUAP_SROF_SGLC_SWAV

So I run the model for 1 day or two, and the SST is zonally symmetric. The problem here is that I can't figure out where this SST pattern is specified! I've looked through the input data, but I can't find it.

Method #2 

Alternatively, I figured I could accomplish the same result with the "data ocean" component. So, I set the compset like this:

compset_opt = "-user_compset 2000_CAM5_SLND_SICE_DOCN%DOM_SROF_SGLC_SWAV"

Then I set the SST_DATA_FILENAME variable to the path of my custom SST file:

./xmlchange -file env_run.xml   -id SSTICE_DATA_FILENAME -val   <PATH>/sst_aqua_ideal.v1.nc

This worked somewhat, the sfc temperature of the model output matched the input SST pattern. However, there was still land! I tried using a few things like "DLND%NULL" to turn off the land, but nothing has worked so far. I've also scoured the internet for instructions on this, but came up empty handed.

 

Any ideas how to make either of these methods work?

 

Thanks,

Walter

olson

 Walter,

 The aquaplanet SSTs are specified analytically in either

models/atm/cam/src/utils/cam_dom/sst_data.F90

 or

models/atm/cam/src/utils/cam_aqua/ocn_comp.F90

 depending upon your configuration.  There are 10 options specified.  "sst_option = 1" is the default.

 You could modify the code or find some way to ingest an SST dataset.  If you want to go the dataset

 route, maybe someone else can chime in here.

 

 

Jerry Olson

whannah

Thanks Jerry. I ended up getting the seccond method to work with my custom netcdf files to drive the data ocean model.

To turn off the land, I used the "null" option for the data land and ice models:

compset_opt = "-user_compset 2000_CAM5_DLND%NULL_DICE%NULL_DOCN%DOM_SROF_SGLC_SWAV"

But I also needed to change the input topography file. For the 1.9x2.5 grid, this file was:

inputdata/atm/cam/topo/USGS-gtopo30_1.9x2.5_remap_c050602.nc

I just copied this file and set all the variables to zero.

The model runs in this setup, but it's worth noting that the initial condition is still set by the "ncdata" namelist variable. I don't think this is too big of an issue as long as I discard the first few months of data.

whannah

I spoke too soon! I did another run, but I still had land-ish features. Turns out I also needed to modify the "domain" files for docn, dice, and dlnd. In this case dice was using the same file as docn. For the ~2deg FV core the files are here:

inputdata/share/domains/

I had to modify them so the land frac and mask were zero, and ocean fraction and mask were 1. Then I modified the docn, dice, and dlnd namelist files to point to these new domain files using the "domainfile" variable.

After doing all that I confirmed that the surface temperature of the model output exactly matches the input that I created.

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