Gabriele Curci

CETEMPS – Univ. L’Aquila

gabriele.curci@aquila.infn.it

4th GEOS-Chem Users’ Meeting, Harvard University, April 7-10 2009

Gas & Aerosol boundary conditions to Chimere

from GEOS-Chem

With inputs from: Walter Di Nicolantonio and Alessandra Cacciari (CGS/CNR)

Boundary Conditions in regional CTMs

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

L'Aquila

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Domain of the regional model (e.g. Chimere)

LongitudeLa

titud

e

Alti

tude

NORTH

EASTWEST

SOUTH

BCs are implemented as concentrations

specified at domain edges and

trasported inside by winds

TOP

Standard BCs to Chimere CTM

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

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MONTHLY mean climatologies from global models

GasLMDz-INCA

AerosolGOCART

What is the impact of BCs?

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

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Test:

CTRL = reference run

NOBC = run w/ BC=0

Results for Ozone:

• Influence of BC expands from boudaries to the center in about 10 days

• BC contribute to a background of 50-60 ppbv

• Importance of BC depends on local photochemistry activity

Using GEOS-Chem hourly output for Chimere Boundary

Conditions• GEOS-Chem v. 8-01-02• GEOS-4, 4°x5° 30 levs• Dust emissions: scheme

implemented by Duncan et al. [2007], with DEAD emissions

• Saharan emissions reduced by a factor of 3 following Generoso et al. [2008]

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

L'Aquila

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Effect of hourly BCs on Chimere O3

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

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EMEP average

Chimere w/ Monthly BCs

Chimere w/ Hourly BCs

Only marginal improvement:

Bias +0.3 ppbRMS -0.2 ppb

r +0.02

Anthropogenic vs Natural PM10 in Europe (year 2003)

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

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Anthropogenic PM10 Natural/Biogenic PM10

µg/m3

Chimere model results [Curci et al., in preparation]

Saharan dust event July 27-29, 2005

MODIS AOT 550 nm

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

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24/07 25/07 26/07

27/07 28/07 29/07

Saharan dust event July 27-29, 2005

Images from SEVIRI/MSG

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

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Sequence of RGB images composite with Brightness Temperatures Differences using InfraRed SEVIRI channels (IR 8.7, IR10.8, IR 12.0) : DUST appears Magenta

Saharan dust event July 27-29, 2005

GEOS-Chem hourly BCs to CHIMERE

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

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Effect of hourly BCs on Chimere PM10 Comparison with EMEP

ground obs

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

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EMEP average

Chimere w/ std BCs

Chimere w/ Monthly BCs

Chimere w/ Daily BCs

Chimere w/ Hourly BCs

Viznar (ES) 03°W Chaumont (CH) 07°E

Ispra (IT) 09°E Iskrba (SI) 14°E

27/07 28/07

29/0730/07

THANKS FOR YOUR ATTENTION!

Conclusions on preliminary results:• Regional ozone simulation not really sensitive to BC details• Regional PM simulation very sensitive to Saharan dust events interesting to account for “natural” PM10 excedances

Follow ups of this work:• Comparison with ground data with PM speciation info (e.g. separate contribution from dust)• Comparison with AERONET: AOD at other wavelengths?• Test higher GEOS-Chem resolution (2°x2.5°)• More episodes and statistics on the longer term

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

L'Aquila

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Implementation of GEOS-Chem BCs to CHIMERE CTM

Chimere BCs from GEOS-ChemHarvard University, 21/04/23 Gabriele Curci, CETEMPS - U.

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GEOS-Chemglobal CTM ts_YYYYMMDD.bpchts_YYYYMMDD.bpchts_YYYYMMDD.bpchts_YYYYMMDD.bpch

src/prep/prep_boun.f90

INI_CONCS.nc BOUN_CONCS.nc

Chimere core(Version 2008b)LE

GE

ND FILES

Existing CODE

New CODE

Hourly or dailyGEOS-Chem

timeseriesgas & aerosol(binary format)

Chimerepre-processing

HourlyChimere BC at domain edges

(netCDF)

If .not. conse-cutive

run