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Nesting GEOS-CHEM with a regional air pollution model for Greece. Maria Tombrou, Elissavet Bossioli, Anna Protonotariou, Elena Flocas and Aggeliki Dandou University of Athens Christos Giannakopoulos National Observatory of Athens. What we Know.
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Nesting GEOS-CHEM with a regional air pollution model for Greece Maria Tombrou, Elissavet Bossioli, Anna Protonotariou, Elena Flocas and Aggeliki Dandou University of Athens Christos Giannakopoulos National Observatory of Athens 1
What we Know • Critical factors for high levels of photochemical pollutants in the GAA: • poor ventilation • frequent appearance of the sea breeze • intense solar irradiation • intense anthropogenic activities • The long range transport of ozone precursors, from the Western European continent over the Eastern Mediterranean, contributes significantly in high ozone concentrations. What we don’t know • It is unclearyet which mechanism contributes the most • the reasons for underestimating ozone concentration during episodes 2
Emission inventory (area anthropogenic) NOX (moles/h/4km2) 4
Emission inventory (biogenic) Isoprene (kg/h/36km2) Terpenes (kg/h/36km2) 5
Numerical experiments (MM5/UAM) • Base case: only anthropogenic emissions • Numerical experiments: • Biogenic emissions • VOC’s speciation in urban areas and aged plumes • Background O3 concentration levels • Various sets of meteorological fields (different nesting, urban sector effects on the wind speed and diffusion coefficient, increase the depth of first layer) 6
Diurnal variation of O3 concentrations at a suburban station of Athens on 14.09.94 7
FIG. 7 : Diurnal variation of O3 concentrations as calculated by GEOS –CHEM over Greece (1-6) on 14.09.94. FIG. 7 : Diurnal variation of O3 concentrations as calculated by GEOS –CHEM over Greece (1-6) on 14.09.94. FIG. 7 : Diurnal variation of O3 concentrations as calculated by GEOS –CHEM over Greece (1-6) on 14.09.94. FIG. 7 : Diurnal variation of O3 concentrations as calculated by GEOS –CHEM over Greece (1-6) on 14.09.94. Diurnal variation of O3 by GEOS – CHEM over Greece (1-6) 14.09.94 8 FIG. 7 : Diurnal variation of O3 concentrations as calculated by GEOS –CHEM over Greece (1-6) on 14.09.94. FIG. 7 : Diurnal variation of O3 concentrations as calculated by GEOS –CHEM over Greece (1-6) on 14.09.94.
surface 850mb 700mb 500mb 24.06.98 9
24 6 GEOS – CHEM results 24 6 98 10
Concentrations of O3 (μgr/m3)at 15:00LST Boundary inflow from GEOS-CHEM Boundary inflow constant 11
Concentrations of O3 (μgr/m3)at 15:00LST Boundary inflow from GEOS-CHEM Boundary inflow constant 12
Future work • Develop the nesting capability for the Mediterranean region (1ox1o) • Insert EMEP emissions over Europe and the new inventory of Greece (at the appropriate levels) • Link GEOS-CHEM with CAMx; UAM • Perform O3 sensitivity runs 13