Improve use of CCPP I/O reader in gravity wave drag schemes

[jimmielin]

From review of GW #292

For moving mountain

    ! Allocate mfcc. "desc%maxh" and "desc%maxuh" are from the file, but the
    ! model determines wavenumber dimension.
    allocate (desc%mfcc(desc%maxh, -desc%maxuh:desc%maxuh, &
                        -band%ngwv:band%ngwv), stat=errflg, errmsg=errmsg)
    if(errflg /= 0) then
      return
    endif

    ! Get mfcc data.
    call reader%get_var('NEWMF', file_mfcc, errmsg, errflg)
    if (errflg /= 0) then
      return
    end if

    ! original formulation is
    ! desc%mfcc(:,-desc%maxuh:desc%maxuh,-band%ngwv:band%ngwv) = file_mfcc(:,:,ngwv_file-band%ngwv+1:)
    ! where band%ngwv = 0 -- this cannot be handled directly by the
    ! ccpp i/o reader, so copy it in from the temporary array.
    desc%mfcc(:, -desc%maxuh:desc%maxuh, 0) = file_mfcc(:, :)

@nusbaume wrote:

It might be good to eventually figure out what exactly can't be handled by the pio_reader here (maybe worth including in the "future work" issue?).

For Beres/convective:

    call reader%get_var('MW', tmp_var1d, errmsg, errflg)
    if (errflg /= 0) then
      return
    end if
    desc%maxuh = size(tmp_var1d)
    deallocate(tmp_var1d, stat=errflg)

@nusbaume wrote:

It would be good to replace this and the code below with a get_dim method at some point. Maybe worth adding to the "future work" issue?

@peverwhee wrote:

can we get these from the file instead of hard-coding them? Maybe this is part of #321 ?

for the moving mountain initialization code as well.