Waves in the Equatorial Stratosphere Generated by Tropospheric Heat Sources

Abstract

Observational evidence suggests that there may be long-period, large-scale variations in the intensity of the latent heat release in the equatorial zone. In this study a diagnostic numerical model is used to show that a standing wave oscillation of narrow longitudinal extent in the diabatic heat source in the troposphere can generate the global-scale propagating waves observed in the equatorial stratosphere. In particular, a heating oscillation which is symmetric about the equator can account for the eastward-moving Kelvin-wave mode, and a source which is antisymmetric can account for the westward-moving, mixed Rossby-gravity wave mode.