The impact of climate change on the Great Plains low-level jet

Abstract

The Great Plains low-level jet is an important atmospheric phenomena that impacts midwestern agriculture. It has been linked to insect pest migration and it influences springtime precipitation. The Great Plains low-level jet is sensitive to parameters, such as soil moisture that may be altered under a doubled COg climate. The goal of this research was to determine the likely impact of the projected climate change, due to increased levels of CO2, on the Great Plains low-level jet, and to then assess the likely consequent impact on agriculture. In this study a three-dimensional, anelastic, hydrostatic atmospheric boundary-layer model was used to evaluate the effect of the projected on the Great Plains low-level jet. This evaluation involved two major steps, the first being to identify parameters that might change under climate change scenarios and to determine the sensitivity of the low-level jet to these parameters. The second step then involved evaluating the impact of several different possible climate change scenarios on the lowlevel jet. Finally, the possible implications for agriculture are discussed. Adding confidence to the study's conclusions, comparison with a spring 1992 synoptic episode, in which detailed observations of the lowlevel jet were made, indicated that the model was performing adequately. Results indicate that, except at extreme levels, soil moisture was the dominant factor to which the jet displayed sensitivity. The control levels of soil-moisture, used by the global climate models were either very wet or very dry. Thus, the response of the jet to GCM climate changes