[Wrf-users] Differential operators on WRF-ARW grids

[Alan Norton]

To facilitate calculation of vorticity and other differential operators 
on WRF-ARW variables, we (i.e. VAPOR) are proposing to provide a utility 
that will interpolate variables from the WRF grid to a cartesian grid, 
and also to reinterpolate from a Cartesian grid back to the original WRF 
grid.  However we are concerned that there may be artifacts introduced 
at the lower and upper limits of the WRF grid wherever the Cartesian 
grid extends beyond the WRF grid.  We would like to hear feedback 
regarding good ways of doing this conversion.  Is it OK to extend 
downward and upward the bottom and top WRF variable values? Or will such 
extension introduce undesirable artifacts when differential operators 
are applied? 
Thanks,
-Alan Norton
VAPOR/NCAR