History Output on the RTM Grid

As mentioned above, CLM3.0 also has the new capability to output RTM-related fields directly on the RTM grid (rather than interpolating them back to the model grid). We only briefly discuss this new aspect of the model. For RTM-grid related fields, the history interface is slightly different than for model grid related fields:

        call add_fld1d (fname='QCHANR', units='m3/s',  typexy='rof', &
             avgflag='A', long_name='RTM river flow', &
             ptr_roflnd=runoff%lnd)
     
        call add_fld1d (fname='QCHOCNR', units='m3/s', typexy='rof', &
             avgflag='A', long_name='RTM river discharge into ocean', &
             ptr_rofocn=runoff%ocn)

        typexy
             denotes that the output xy grid is the RTM runoff grid
             currently, the only valid values for typexy are 'clm' and 'rof'

        ptr_roflnd or ptr_rofocn 
             pointer to one-dimensional land or ocn runoff vectors

We note that typexy is an optional argument whose valid values are 'clm' or 'rof'. The default value for typexy is 'clm', which is why it does not appear in the calls to the normal model output fields. However, if typexy is set to 'rof' then either ptr_roflnd or ptr_rofocn must be supplied as arguments to add_fld1d. Note that runoff%ocn and runoff%lnd are not defined in clmtype (Section A.47) (as is the case for ptr_pft, etc.) but rather are defined in the RunoffMod (Section A.27).