Abstract
Two versions of the NOGAPS model are used to generate normal-mode balanced datasets. The various forces that act on gravitational modes are then examined to determine the modes whose coefficient time tendencies are significantly smaller than terms which force them. Those modes are said to be balanced. Results for three different equivalent depths are presented. They indicate that only modes with natural periods shorter than one day appear balanced. That balance is adiabatic. These results agree with those reported by Errico for the NCAR CCM.
