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E. Bossioli 1, M. Tombrou 1, A. Protonotariou 1,

H. Flocas 1, C. Giannakopoulos 2, A. Dandou1

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�GEOS-Chem 3rd meeting

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Coupling GEOS-Chem with �a regional air pollution model �for Greece

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National Observatory of Athens, Greece

National and Kapodistrian University of Athens

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Motivation

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  • In relatively small domains, O3 predictions are very sensitive to the inflow boundary conditions [Hanna et al., 1998].
    • In cities, the contribution of the city activities to maximum O3 ranges between 10 and 30%.
  • Boundary conditions usually are taken fixed both in horizontal and vertical directions. Time invariant.

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Scope

  • To consider all the sources contributing to regional air pollution.

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  • To study the influence of different atmospheric circulations on regional air pollution.

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Methodology

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Step 1: GEOS-Chem application, by using the one-way nested grid formulation [Protonotariou et al., 2007].

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Step 2: Assignment of the GEOS-Chem hourly mixing ratios to the UAM-V horizontal and vertical boundaries.

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Step 3: Matching of the chemical mechanisms of GEOS-Chem and UAM-V chemical model, especially with respect to the organic part.

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Step 4: Application of the regional atmosphere PSU/NCAR Mesoscale model (MM5) and UAM-V.

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Step 1: GEOS-Chem application, by using the one-way nested grid formulation [Protonotariou et al., 2007].

Output: Hourly mixing ratios of all the species at the lateral boundaries of Greece

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GEOS-Chem

Resolution: 4o x 5o

Domain: whole globe

GEOS-Chem

Resolution: 1o x 1o

Domain:-20oE-45oW,22oN-74oN

Boundary Conditions

Mixing ratios of precursors and photo-oxidants species

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Step 2: Assignment of the GEOS-Chem hourly mixing ratios to the UAM-V horizontal and vertical boundaries.

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GEOS-Chem

Resolution: 4o x 5o

Domain: whole globe

GEOS-Chem

Resolution: 1o x 1o

Domain:-20oE-45oW,22oN-74oN

Boundary Conditions

Mixing ratios of precursors and photo-oxidants species

Horizontal: MM5/UAM-V system in Lambert Conformal space

11x9 cells (GEOS-Chem)

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147x147 cells; resolution 6kmx6km (UAM-V)

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Vertical

19 levels were used (30 in total) up to ~14km (GEOS-Chem)

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22 levels up to ~14km (UAM-V)

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Step 3: Matching of the chemical mechanisms of GEOS-CHEM and UAM-V chemical model, especially with respect to the organic part.

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GEOS-CHEM

Resolution: 4o x 5o

Domain: whole globe

GEOS-CHEM

Resolution: 1o x 1o

Domain:-20oE-45oW,22oN-74oN

Boundary Conditions

Mixing ratios of precursors and photo-oxidants species

Correspondence between GEOS-Chem chemistry and CB-IV-TOX (UAM-V)

9 inorganic + 16 organic (GEOS-Chem)

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9 inorganic + 10 organic (UAM-V)

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NO, NO2

NO, NO2

O3

O3

N2O5

N2O5

HNO3

HNO3

PNA

HNO4

H2O2

H2O2

CO

CO

SO2

SO2

NTR

R4N2

ISPD

MVK+MACR

FORM

HCHO

ALD2

ALD2

ALDX

RCHO

PAR

ALK4, C3H8, C2H6 acetone, ketone, propene

OLE

propene

ISOP

ISOP

PAN

PAN+PPN

PANX

MPAN

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If no information available

(Aromatics, Alcohols, internal olefins)

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CB-IV-TOX(ppb)

GEOS-CHEM (ppbC)

Default values

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Step 4: Application of the regional atmosphere PSU/NCAR Mesoscale model (MM5) and UAM-V.

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�GEOS-Chem 3rd meeting

GEOS-CHEM

Resolution: 4o x 5o

Domain: whole globe

GEOS-CHEM

Resolution: 1o x 1o

Domain:-20oE-45oW,22oN-74oN

Boundary Conditions

Initial and Boundary Conditions

Top concentrations

UAM-V

Resolution: 6km x 6km

Domain: (Greece)

19.04oE to 29.6oW; 34.41oN to 42.33oN

Emissions, land use etc

MM5

Europe (18x18km)

Greece (6kmx6km)

Fields of Meteorological

parameters

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Application

  • GEOS-CHEM model with the nesting procedure is applied over the period January-December 2001
  • Regional MM5/UAM-V models performed for selected days, representing 8 different types of synoptic scale atmospheric circulation
  • UAM-V model is applied twice for each synoptic category:

�GEOS-Chem 3rd meeting

    • Default boundary conditions constant in time and space (e.g. NO=0, NO2=1ppb, CO=100ppb, SO2=0, diurnal profile is only assumed for O3=20-30ppb winter, 35-50ppb summer)
    • Boundary conditions as derived from the coupling procedure

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LW

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SW

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NW

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ZONAL

CL

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OA

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CA

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HL

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850hPa~ 1450 m

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1-h O3 mixing ratios (2001)� LW SW NW Zonal CL OA CA HL�

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60m

2km

GEOS-Chem Northern edge of Greece

GEOS-Chem Southern edge of Greece

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GEOS-Chem

O3 mixing ratios at Aliartos station (northern Greece)

Measured

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GEOS-Chem

O3 mixing ratios at Finokalia station (Crete)

Measured

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O3

Results

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OA summer

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GEOS-Chem

Daily O3 mixing ratios

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OA summer

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3:00LST

21:00LST

15:00LST

9:00LST

3:00LST

21:00LST

15:00LST

9:00LST

Default

Coupling

Ground level mean 1-h O3 mixing ratios (ppb)

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OA summer

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3:00LST

21:00LST

15:00LST

9:00LST

Differences of mean 1-h O3 mix. ratios (ppb)

Coupling-Default

15:00LST

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HL summer

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GEOS-Chem

Daily O3 mixing ratios

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HL summer

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Ground level mean 1-h O3 mixing ratios (ppb)

Default

Coupling

3:00LST

21:00LST

15:00LST

9:00LST

3:00LST

21:00LST

15:00LST

9:00LST

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HL summer

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3:00LST

21:00LST

15:00LST

9:00LST

Differences of mean 1-h O3 mixing ratios (ppb)

Coupling-Default

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NW winter

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GEOS-Chem

Daily O3 mixing ratios

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NW winter

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Ground level mean 1-h O3 mixing ratios (ppb)

3:00LST

21:00LST

15:00LST

9:00LST

3:00LST

21:00LST

15:00LST

9:00LST

Default

Coupling

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NW winter

�GEOS-Chem 3rd meeting

Differences of mean 1-h O3 mix. ratios (ppb)

Coupling-Default

3:00LST

21:00LST

15:00LST

9:00LST

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Other pollutants…

SO2

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OA summer

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Default

Mean 1-h SO2 concentr. (ppb)

Differences of mean 1-h SO2 concentr.

(ppb)

Coupling-Default

3:00LST

21:00LST

15:00LST

9:00LST

3:00LST

21:00LST

15:00LST

9:00LST

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NW winter

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3:00LST

21:00LST

15:00LST

9:00LST

Default

Mean 1-h SO2 concentr. (ppb)

Differences of mean 1-h SO2 concentr.

(ppb)

Coupling-Default

3:00LST

21:00LST

15:00LST

9:00LST

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Higher altitudes

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Ground

Coupling-Default

Differences of mean 1-h O3 concentrations

(ppb)

3:00LST

21:00LST

15:00LST

9:00LST

2km

3:00LST

21:00LST

15:00LST

9:00LST

5km

3:00LST

21:00LST

15:00LST

9:00LST

NW

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O3 concentration profiles �at the boundaries of Greece�

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3:00 LST

the rich in ozone layer is not maintained in the UAM-V simulation

Limitations related with the description of the aloft and downward mixing processes in the UAM-V

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To stress your attention

  • The analysis of the influence of the large-scale background pollutants at the boundaries of Greece presents strong variation both horizontally and vertically. Significant variations are also evident among the various synoptic categories.

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  • Some limitations in regional models (e.g. downward mixing) prevent the significant influence of the coupling procedure to become evident

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Future work

  • Outcome of this meeting