Abstract
The structure of barotropically unstable disturbances in the Tropics is studied with a two-level quasi-geostrophic model. An Ekman layer is attached to the lower boundary. The equations are linearized and the most unstable mode is found numerically by using the initial value technique. Computations are made for a shear-zone wind profile and a jet profile; these fields are independent of height. The disturbance structure is found to be critically dependent on the absolute vorticity gradient in the mean flow. The predicted disturbance structures contain a number of features that are observed in tropical wave disturbances.
Present affiliation: Air Force Global Weather Central, Offutt Air Force Base, Nebr.
Present affiliation: U.S. Navy Fleet Weather Facility, London, England.
