Modeling the Stable Boundary Layer Depth and Quantifying its Uncertainty for Dispersion

Accurately modeling the depth of the atmospheric boundary layer (ABL) is critical for atmospheric transport and dispersion (AT&D) modeling. The stable boundary layer is present about half the time; therefore it is necessary to model it appropriately. We examine current methods for determining the depth of the stable ABL, particularly a recent formulation by Zilitinkevich, which has shown skill in estimating stable and neutral ABL depths when compared to large eddy simulations. Here we assess the sensitivity of ABL depth for the FFT07 field experiment during nighttime hours as well as for other available observations. Specifically, computation of the ABL depth during the nighttime hours is compared for various methodologies, including SCIPUFF simple diurnal calculations, WRF predictions, and the Zilitinkevich formulation. We consider new SBL parameterizations that could prove more accurate for AT&D. In addition, we consider the impact of the uncertainty of the calculation of the SBL depth on dispersion uncertainty. This study reveals the importance of further evaluation of theoretical advances in SBL depth formulations and the need for field studies to verify them.