A Two-Dimensional Numerical Sensitivity Study of the Great Plains Low-Level Jet

Abstract

Abstract Observations have shown the existence of a diurnal oscillation of the wind profile in the springtime boundary layer of the central United States called the Great Plains low-level jet. This low-level jet is a mesoscale phenomenon that is not easily predicted by larger-scale numerical forecast models, which lack adequate resolution of the boundary layer. It has been postulated that this nocturnal jet can act as a triggering mechanism in the development of localized convective precipitation. If the mechanisms that cause this low-level jet are better understood and modeled, more accurate short-range local forecasts of these convective events could be made. The dominant forcing mechanisms in the development of the Great Plains low-level jet are the coupled frictional and thermal oscillations in the planetary boundary layer. In this study, a two-dimensional planetary boundary-layer model linked with a soil hydrology system is used to determine the sensitivity of the low-level jet to perturbations in th...