[ferret_users] undesirable missing_value

[David Wang <climater@xxxxxxxxx>]

Hey Ferreters,

i was intending to make the temperature at each level below some depth 
horizontally uniform. the script i wrote is as simple as this:

use levitus_climatology.cdf
set region/@T
let newtemp = IF z[g=temp] LE 1000 THEN temp \
   ELSE temp[x=@ave,y=@ave]+0*temp

list/x=140w/y=0 temp, newtemp   ! testing
shade/z=2000 newtemp               ! testing

I don't understand why LIST command shows that the variable newtemp has 
all missing value flags below 1000m (which is not what's supposed to 
be), while a shaded plot at 2000 m does show an uniform temperature field.

thanks,
- d.