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-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 2

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

Longitude

Alti

tude

NORTH

EAST WEST

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-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 3

MONTHLY mean climatologies from global models

Gas LMDz-INCA

Aerosol GOCART

What is the impact of BCs?

Chimere BCs from GEOS-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 4

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-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 5

Effect of hourly BCs on Chimere O3

Chimere BCs from GEOS-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 6

EMEP average

Chimere w/ Monthly BCs

Chimere w/ Hourly BCs

Only marginal improvement:

Bias +0.3 ppb RMS -0.2 ppb

r +0.02

Anthropogenic vs Natural PM10 in Europe (year 2003)

Chimere BCs from GEOS-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 7

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-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 8

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-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 9

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-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 10

Effect of hourly BCs on Chimere PM10 Comparison with EMEP ground obs

Chimere BCs from GEOS-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 11

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

29/07 30/07

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-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 12

Implementation of GEOS-Chem BCs to CHIMERE CTM

Chimere BCs from GEOS-Chem Harvard University, 4/14/09 Gabriele Curci, CETEMPS - U. L'Aquila 13

GEOS-Chem global CTM ts_YYYYMMDD.bpch ts_YYYYMMDD.bpch ts_YYYYMMDD.bpch ts_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 daily GEO

S-Chem timeseries gas & aerosol (binary format) ‏

Chimere pre-processing

Hourly Chimere

BC at domain edges (netCDF) ‏

If .not. conse-cutive

run