Environmental Engineering Reference
In-Depth Information
Sofia experiment, 28 September - 3 October 2003
12
Wind speed at 10 m, RAMS6.0
Modelled wind speed - variability of measurements
Modelled wind speed + variability of measurements
Wind speed measured at 40 m
Wind speed measured at 20 m
10
8
6
4
2
0
271
272
273
274
275
276
277
Fig. 2.
Wind speed (modeled at 10 m height and measured at 20 and 40 m height)
Julian Day of 2003 (GMT)
The model predicts quite idealized symmetric diurnal variability of the wind
speed, despite the high horizontal resolution of 1 km. The vertical resolution of
minimum 50 m (which is standard for Numerical Weather Prediction models) is
course for Boundary Layer studies in complex terrain.
4. Conclusions
The predictions of RAMS for the surface heat flux are in good agreement with
measurements during the Sofia Experiment of 2003, while the surface wind speed
is largely over predicted. The measured complex diurnal variation pattern reflects
the mountain-valley circulation which is not captured by the model for this site.
RAMS is validated and performs well in many complex terrain conditions. A
problem to evaluate all models (RAMS, MM5, WRF, ALADIN) over Bulgaria is
the limited information from standard automatic meteorological stations, the
existence of only one aerological station in the country and the lack of Boundary
layer measuring campaigns with spatial coverage for scales above 2-3 km.
Acknowledgments
The work has been performed under the Project HPC-EUROPA (RII3-CT-
2003-506079), with the support of the European Community - Research Infrastructure Action
under the FP6 “Structuring the European Research Area” Programme. It is also part of
collaboration within COST Action 728 and supported by the Danish Council for Strategic
Research, Sagsnr 2104-08-0025 and the EU FP7 Marie Curie Fellowship VSABLA.
References
Batchvarova E. and S.-E Gryning, 2010. The ability of mesoscale models to predict vertical
profiles, D.G. Steyn and S.T. Rao (eds.),
Air Pollution Modeling and Its Application XX
, 103
DOI 10.1007/978-90-481-3812-8, 375-379.
Batchvarova E., X. Cai, S.-E. Gryning and D. Steyn, 1999: Modelling internal boundary layer
development in a region with complex coastline. Boundary-Layer Meteorology, 90, 1-20.
