J. David Neelin
Quart. J. Roy. Meteor. Soc., 1988.
Abstract. A simple model is developed for time-mean, large-scale flow in the tropical boundary layer forced by vertical velocity at the top of the boundary layer. The model is formulated as an integral over the boundary layer and is closed by assuming the stress to be proportional to the boundary layer mass transport. Since vertical velocity is closely related to diabatic heating in the tropics, the model can also be forced by latent heating as measured by precipitation. In this case, the model can be made equivalent to the widely used Matsuno-Gill model by adding a Newtonian cooling term. This term can be shown to have little effect on the zonally asymmetric component of the flow and, in its absence, the boundary layer flow is decoupled from the flow at upper levels. It is suggested that the success of the Gill model for low-level flow is due to this effective decoupling. The model is quite successful at simulating GCM results for both the total climatology and El Niño anomalies. A second model, which takes into account some effects of vertical structure in the boundary layer, is also presented. The zonally symmetric component of the flow is shown to be poorly reproduced in these models.
Citation. Neelin, J. D., 1988: A simple model for surface stress and low-level flow in the tropical atmosphere driven by prescribed heating. Quart. J. Roy. Meteor. Soc., 114, 747-770.