id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
844	IMPORTANT:  Some enhacements	arango		"Added coupled of enhancements:

* Added the capability to write surface air temperature ('''Tair''') to history, quicksave and average, output NetCDF files. Sometimes it is advantageous to write out the air temperature used in the net surface heat fluxes when '''BULK_FLUX''' or atmospheric coupling is activated.

 The standard input script '''roms.in''' includes:
 {{{
...
Hout(idTair) == F       ! Tair               surface air temperature
...
Qout(idTair) == F       ! Tair               surface air temperature
...
Aout(idTair) == F       ! Tair               surface air temperature
}}}
 '''Warning:'''  All the ROMS standard input files were modified to include the logical switches to write out surface air temperature including the one on the '''test''' repository.

 Code was added to the output routines '''def_avg.F''', '''wrt_avg.F''', '''wrt_his.F''', and '''wrt_quick.F'''.  The files def_his.F and def_quick.F already have the definitions for adding '''Tair'''.

* Modified diag.F and '''close_io.F''' to provide more information when ROMS blows-up.  The '''blowup_string''' in '''diag.F''' stores the reason why the model is blowing-up.  For example, we can get:
 {{{
 Blowing-up: Saving latest model state into  RESTART file
     REASON: MaxDensity =  9.1E+03
}}}

* Updated ESMF coupling input script '''coupling_esmf.in''' to include the nested grid number ('''!NestedGrid''' keyword) when merging field from DATA and ESM components.
 {{{
! Weighted coefficients for the merging of DATA component fields with the same
! field from other ESM components. Melding coefficients are positive and MUST
! add to unity. They are read from an input NetCDF file ('WeightsFile'). The
! user needs to specify the NetCDF variable names for the weights for the DATA
! ('VnameDATA') and ESM ('VnameESM') components. Also, specify which grid
! ('NestedGrid') needs a merged field from DATA and ESM components. Currently,
! the weight values are only needed by the atmosphere component.

WeightsFile(atmos) =  meld_weights_atm.nc
  VnameDATA(atmos) =  data_weight
   VnameESM(atmos) =  ocean_weight
 NestedGrid(atmos) =  1
}}}
 It is possible to couple directly with one of the nested grids only, for example:

[[Image(https://www.myroms.org/trac/landsea_temp.png, center, 600)]]

 Here, the red box is the regional ROMS grid, while the black domains are the atmospheric coarser (45km) and finer nest (15km) grids. The coupling between the ROMS and the atmospheric model can be done with either the coarser grid ('''!NestedGrid(atmos)=1''') or the refined grid ('''!NestedGrid(atmos)=2''').  The DATA component is used to provide SST in grid cells not covered by ROMS.  The weighted coefficients are used to meld DATA (SST from HyCOM) and ROMS components.

* Added new item ('''debug_write''') to coupling metadata file '''coupling_esmf.dat''' to specify which excanged field(s) are written into NetCDF files during debugging ('''!DebugLevel > 2''') to avoid generating lot and lots of files:  
 {{{
'SST'
  'sea_surface_temperature'                        ! standard name
  'sea surface temperature'
  't(:,:,N,itemp)', 'ROMS'                         ! source variable, ROMS
  'C'                                              ! source units
  'Center'                                         ! source grid-cell
  'tsea', 'COAMPS'                                 ! destination variable, COAMPS
  'K'                                              ! destination units
  'Center'                                         ! destination grid-cell
  'SST'                                            ! DATA Model file variable
  'bilinear'                                       ! regridding method
  'none'                                           ! unmapped extrapolation method
  .TRUE.                                           ! connected to coupler
  .FALSE.                                          ! debug write into a NetCDF file
  273.15d0                                         ! importing add offset
  1.0d0                                            ! importing scale
}}}
"	upgrade	closed	major	Release ROMS/TOMS 3.9	Nonlinear	3.9	Done