Galin, V. Y., 1995b: AMIP run by the DNM GCM. Abstracts
of the First International AMIP Scientific Conference, Monterey, California,
36.
The model climate in the AMIP experiment was very different from reality
and that of most models compared: the west subtropical winds were strongly
underestimated; the field of sea-level pressure was very distinct from
reality, and so on. Now the reason for this is understood. The version
of the model for the AMIP experiment had an error in the Matsuno scheme:
for advection, horizontal velocities from timestep N were with the vertical
velocity from N-1 timestep. The equations for temperature and humidity
were written in the divergence form, but the velocities did not satisfy
the continuity equation. In advection of these values there was false forcing,
and this is the reason for a false cascade of energy from low to high frequency
and its dissipation there. After removing this error and making some other
changes (for example, including of horizontal diffusion of the fourth order
that effectively vanishes very high space frequencies) the AMIP experiment
was repeated. The new results indicate that there isn't much difference
between our model's climate and real data.