Streams are allowed to be created for files without a mesh file that have more than one gridcell

[ekluzek]

You can create streams for stream files that don't have a mesh that comes with them (by meshfile='none'). This works fine for datasets that are a single data point. But, you can also enter files that have more than one data point, and it doesn't abort with an error, nor handle the data in a meaningful way. So I think it should do a simple check and if the stream variables on the file have dimensions beyond time -- it should abort with an error.

An example of this is that there are options to DATM_CO2_TSERIES for latitude bands, that can be turned on, but it doesn't handle the latitude bands correctly. It looks like it only uses one of the latitude bands (probably the first or the last).

[ekluzek]

The corollary is allowed, and I think it shouldn't be either.

       if (.not.  ESMF_MeshIsCreated(stream_mesh)) then
          sdat%stream(ns)%mapalgo = 'none'
       else

The purpose of giving a mesh for a stream is to do the mapping. If you don't want to do a mapping -- then don't give a mesh and have mapalgo == "none". I don't think there is a reason to allow none when a mesh file is provided.