Hi Grenville, thanks for your reply.
I am trying to use my own values for surface albedo (stash requests 244 and 245). The original albedo file used by the model, when ancil file is not specified, is a .land file. I haven’t been able to figure out what format that is exactly, but I am inputting a netcdf file with a manually added .land extension. I’m not sure this is the way to go to be honest - I had a discussion with Patrick about it here: Changing albedo climatology in JULES.
The file I am inputting is a copy of one of the albedo files in /work/y07/shared/umshared/ancil/atmos - I believe that is the destination the files are normally taken from when not manually specified - with some changes to the values.