AN INVESTIGATION OF THE DYNAMICS AND EVOLUTION OF ELEVATED STABLE LAYERS ABOVE BASIN TOPOGRAPHY
R. L. Coulter, J. D. Shannon, T. J. Martin, M. Pekour Argonne National Laboratory
ABSTRACT
The goal of the proposed research is to better define and understand the role of elevated stable layers (which form the transition region between
layers of different stabilities) in vertical transport and turbulence, particularly during nighttime and the morning and evening transitions. We will use a suite of remote sensors (radar wind profiler, sodar, lidar) and in situ measurements (tethersondes, airsondes, kites) to locate, define, and parameterize elevated stable layers over flatland and basin topography in urban areas and will test the hypotheses that (1) elevated stable layers play an important role in local circulations and vertical transport and mixing and (2) the dynamics and evolution of elevated stable layers during transition and nighttime periods are controlled primarily by moisture within the layer and the wind and temperature differences across the layer. The effects of basins and elevated terrain on dynamics within the elevated stable layer relative to flat terrain will be studied by using multiple measurement sites during two field studies: CASES-99 and the first Vertical Transport and Mixing effort. Scalar transport by turbulent vertical exchange through stable layers and by horizontal circulations induced by differences in stable layer heights will be studied by using high-resolution wind, temperature, and moisture data from a large suite of available sensors in each study.
