[Wrf-users] Re: SST/sea ice/albedo/vegetation updates for nests in WRFV3

[WRF Help]

Technically the model would allow you to use interpolated 
data from the coarse grid
to update nest lower boundary conditions (one modification 
may be needed in
Registry.EM: add letter 'd' to variable ALBBCK in the 8th 
column to ask the model to
interpolate this field). But it is a good idea if you have 
data actually processed for the nest.
That means processing data  through WPS by setting nest 
start and end times the same
as the coarse domain. Once you have these nested files, 
running real.exe would
generate wrflowinp files for nests.

The output from avg_tsfc.exe utility can be used in two 
ways in program real. The first
is if one wants to use sf_surface_physics = 1 option in 
the model, this daily-average temp
is used as the lower boundary condition for the 5-layer 
soil model. If you don't have this
field, the program real will try to find a soil temp field 
to use.
The second use of this field is to have an alternative 
input to compute surface pressure.
If both are your interest, then you do not have to use 
this utility.

wrfhelp

On Wed, 9 Apr 2008 12:50:23 -0400 (EDT)
  Eric Altshuler <ela at cola.iges.org> wrote:
> Hello,
> 
> I have a question about how SST/sea 
>ice/albedo/vegetation updates are done for nests in 
>WRFV3. Are these fields interpolated from the coarse 
>domain to the nests, or does each nest have its own 
>wrflowinp_d<domain> file generated by real.exe? A related 
>question is: when running metgrid, should the start/end 
>times for nests be set to cover the entire simulation 
>period? Normally, when running metgrid, the ending times 
>for nests are set to be the same as the initial time, 
>because only the initial conditions for the nests would 
>be used in the WRF run. However, if several "static" 
>fields are to be updated on each nest's native grid, as 
>opposed to interpolating these fields from the coarse 
>domain, then it would seem necessary to generate metgrid 
>output on the nests for the entire simulation period.
> 
> An unrelated question: when is it necessary (if ever) to 
>run the WPS utility 'avg_tsfc.exe' to generate an average 
>surface temperature? Since the land surface 
>parameterization is responsible for predicting surface 
>temperature, it seems unnecessary (and inconsistent) to 
>specify the average surface temperature from an external 
>source. Is this utility only used with idealized surface 
>physics?
> 
> Thanks for your reply.
> 
> Best regards,
> 
> Eric L. Altshuler
> Assistant Research Scientist
> Center for Ocean-Land-Atmosphere Studies
> 4041 Powder Mill Road, Suite 302
> Calverton, MD 20705-3106
> USA
> 
> E-mail: ela at cola.iges.org
> Phone: (301) 902-1257
>Fax: (301) 595-9793
>