Vint command

[Steven Chan]

Hello,

I am wondering how "vint" command works over steep terrain. Let for
example, surface pressure over a certain point is like 825 hPa. I have
isobaric data between at 850 and 700. So does Grads try to interpolated
or set a constant value down from 700 hPa down to 825?

I am asking this because I am recently using vint command to try to
compute moisture flux divergences over North American monsoon region,
and some values I am getting is not reasonable, and appears to reflect
strongly vertical motion fields associated with steep terrain where the
grid point is.

Steven Chan