One-Demensional Simulations of Stable Boundary Layer as observed in SABLES98

A number of one-dimensional simulations using a simplified second-order turbulence model is made using data obtained in the experience SABLES 98. This was a campaign held in Spain in September 98 and devoted to the characterization of the Stable Boundary Layer at the mid-latitudes.

Two nights are specially analyzed for this presentation: one in moderately stable conditions, but with near-surface runaway cooling, and one in strongly stable conditions, but with no near-surface runaway cooling.

Many factors intervene in these two nights, from inertial oscillations to internal gravity wave activity, or likely presence of gravity currents. Low level jets are showing both nights. Unstationarity of the turbulence is present. The selection of the more stationary periods during the nights has been made in order to simulate them with almost constant forcings, as a first part of the study, to be continued.

The results at standard timesteps and vertical grid sizes for meteorological models are reasonably satisfactory, moreover when no SBL similarity theory has been imposed anywhere. Sensitivity to time step and vertical resolution has been explored.