THE VERTICAL GRID
Three-dimensional output is provided about 25 constant pressure
surfaces spanning from 1000 mb to 25 mb, at intervals of 50 mb,
with 25 mb intervals added in lowest 2.0 km and at the tropopause
jet level. (Also, atmospheric fields near the surface, i.e. within
or near the boundary layer, are provided on alternative levels
described later in the detailed description of the output fields.)