Environmental Engineering Reference
In-Depth Information
1.17 Evaluation of RAMS6.0 Boundary-Layer
Simulation over Sofia (Bulgaria)
E. Batchvarova
1
, E. Pisoni
2
, and G. Finzi
2
1
NIMH, Bulgaria Academy of Sciences, Sofia, Bulgaria
Department of Electronics for Automation, Faculty of Engineering, University of Brescia, Italy
2
Abstract
The horizontal and vertical structure of the atmospheric boundary layer
over specific areas in Europe have been computed using appropriate high reso-
lution runs of RAMS6.0 mesoscale model for short periods. The areas and periods
were selected based on the availability of complex boundary layer experiments'
data, so that different parametrisations within model runs could be validated.
This paper discusses comparison of model results and measurements for the
city of Sofia, Bulgaria. The RAMS6.0 prediction for sensible heat flux during the
intensive campaign (28 September-3 October 2003) were very close to measure-
ments, while the 10 m wind speed was highly overestimated. The results showed
further that the diurnal variation of wind speed in the model is quite idealized and
the simulation cannot reflect the complex mountain-valley circulation pattern
typical for the city and the measurements site.
The results showed that even well validated over complex terrain models when
applied for “new” complex terrain conditions, do not ensure a success. Measurements
for model initial conditions, data assimilation and model validation are needed for
all applications of mesoscale models.
Keywords
Atmospheric boundary layer, Models' evaluation, Sofia experiment,
RAMS6.0, Urban meteorology
1. Introduction
Different meteorological models are available in the scientific community to be
used for weather forecast downscaling and drivers for Air Quality Models, as i.e.
MM5 (Grell et al., 1995), RAMS (Pielke et al., 1992), WRF (Grell et al., 2005).
Here RAMS was chosen as known for the successful simulations of meteorology
and turbulence over complex terrain (Batchvarova et al., 1999).
Presently, a worldwide effort is going on for better validation procedures and
philosophy. The well developed statistics for point by point comparisons is not
effective for validation of 3-D meteorological fields. Further studies are needed to
