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Dispersion modelling in complex terrain: Sensitivity studies with the CALMET model. Author : Matic Ivančič Milan Vidmar Electric Power Research Institute Ljubljana, 15.12.2011. CONTENTES. Introduction - air pollution modeling CALMET model Three different wind field initializations Results.
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Dispersion modelling in complex terrain: Sensitivity studies with the CALMET model Author: Matic Ivančič Milan Vidmar Electric PowerResearchInstitute Ljubljana, 15.12.2011
CONTENTES • Introduction - air pollution modeling • CALMET model • Three different wind field initializations • Results
INTRODUCTION • Air pollution modeling: • Advection with wind • 3D wind fields • Dispersion in cross-section • Stability of atmosphere • ALADIN - operative meteorological forecast in Slovenia
INTRODUCTION • ALADIN – CALMET – CALPUFF are online coupled • Two-days prediction are available on web: www.okolje.info
CALMET • Diagnostic wind model (DFW) • 3 main parts: • Initial field (first guess) • First step • Second step
First step • Kinematic effects of terrain • Slope flows • Blocking effects • 3D divergence minimization
Second step • Interpolation • Smoothing • O’Brien adjustment of vertical velocities • 2D divergence minimization
Divergence minimization • Varitional technique (Sherman 1978) • Minimization of following functional: • Strong condition: • New functional:
Divergence minimization • Solution with EL equations : • numerical solution forλ:
TEST AREA • Šoštanj basin • Biggest thermal power plant in Slovenia • 9 meteorological and air quality stations
9 surface stations – only 6 stations has representative wind data
3 DIFFERENT WIND FIELD INITIALIZATIONS A Data from surface stations and upper air data from radio-sounding B Meteorological analysis from ALADIN C Combination of data from surface stations and meteorological analysis from ALADIN
Experiment A • First guess: from measurements • First step: • Terrain effects • 3D divergence minimization • Second step: • Again interpolation of measurements
ExperimentB • First guess is prepared with data from model ALADIN • First step • Second step
ExperimentC • First guess: from model ALADIN • First step: • Terrain effects • 3D divergence minimization • Second step: • Import measurements with objective analysis procedure
CALPUFF results • Dispersion calculation of SO2
CONCLUSION • It is hard to judge which model initialization gives better results • Radio-sounding measurements are far away • ALADIN analysis have better space but time interpolation required • ALADIN predictions may improve results – hourly data • Case B: for areas without meteorological measurements and for predictions • Case C: maximum number of inputs
Acknowledgements • Author would like to thank the Environmental Agency of the Republic of Slovenia for providing all fields from ALADIN model
LITERATURE • Sherman, C. A., 1978: A mass-consistent model for wind fields over complex terrain. J. Appl. Meteor., 17, 312–319. • Scire J. S., F. R. Robe, M. E. Fernau, R. J. Yamartino, 2000: A User’s Guide for the CALMET Meteorological Model, Version 5, Earth Tech, Inc, Concord. • Scire J. S., D. G. Strimaitis, R. J. Yamartino, 2000: A User’s Guide for the CALPUFF Dispersion Model, Vesrion 5, Earth Tech, Inc, Concord.