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sst_update control only for domain 03

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Dear WRF community,

I wish to use sst_update option to replace LAI/SST for WRF. It is recommended in the user’s guide as follows:

auxinput4_inname = "wrflowinp_d<domain>"
auxinput4_interval = 360
io_form_auxinput4 = 2

Meanwhile, sst_update option is turned on.

sst_update = 1

Since I have three domains, how can I control sst_update to be used in such as only domain03?

Thanks in advance.
Is there a reason why you only need this for the 3rd domain, and why it would be necessary to not use the option for the first 2 domains?
The reason is that I only wish to update LAI/albedo for domain 03 (most inner domain). Is there a way to force domain 01, 02 not to update LAI/albedo?
If you are wanting to only update LAI/Albedo, we recommend not using the sst_update option, but instead creating a new auxiliary option for the variables you're interested in. Before describing the details, I'd like to say that we haven't tested this, and aren't sure it's going to work out without causing any problems, but you can give it a shot.

To do this, you would need to choose a new aux input number to use (say, 7). You will need to find the variables in the Registry.EM_COMMON and add that stream to it. Depending on which LAI you're using, for example, find:
state    real   LAI              ij     misc        1         -      i0124rh  "LAI"          "LEAF AREA INDEX"                   "m-2/m-2"
and change to:
state    real   LAI              ij     misc        1         -      i01247rh  "LAI"          "LEAF AREA INDEX"                   "m-2/m-2"
You'll then need to save the Registry.EM_COMMON file and clean your code (clean -a), reconfigure and recompile to incorporate the changes. You can then add that stream to your namelist.input file, and manipulate the start time for the first 2 domains to be something larger than the length of your run, so that the variable isn't advanced/updated during your run. For example, if you are running for 24 hours, you could use the following lines in the &time_control section:
auxinput7_inname = "name_of_your_choice_d<domain>"
auxinput7_begin_h = 25, 25, 0
io_form_auxinput7 = 2

You will need to play around with the settings to tune them to your particular interests. You likely can only do this is you have feedback turned off (feedback=0).

If this option doesn't work, then unfortunately we don't have another way to do this. You could potentially modify some code to get it to work, but we haven't worked on anything like that yet and don't have any code to provide to do so. If you are able to get it to work, please update this post for future users who may be interested. Thanks.