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 TOP BCs are implemented as concentrations specified at domain edges and trasported inside by winds Domain of the regional model (e.g. Chimere) NORTH Altitude WEST EAST SOUTH Latitude Longitude Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

Standard BCs to Chimere CTM MONTHLY mean climatologies from global models Gas LMDz-INCA Aerosol GOCART Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

What is the impact of BCs? 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 Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

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, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

Effect of hourly BCs on Chimere O3 EMEP average Chimere w/ Monthly BCs Chimere w/ Hourly BCs Only marginal improvement: Bias +0.3 ppb RMS -0.2 ppb r +0.02 Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

Anthropogenic vs Natural PM10 in Europe (year 2003) Anthropogenic PM10 Natural/Biogenic PM10 µg/m3 Chimere model results [Curci et al., in preparation] Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

Saharan dust event July 27-29, 2005 MODIS AOT 550 nm 24/07 25/07 26/07 27/07 28/07 29/07 Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

Saharan dust event July 27-29, 2005 Images from SEVIRI/MSG Sequence of RGB images composite with Brightness Temperatures Differences using InfraRed SEVIRI channels (IR 8.7, IR10.8, IR 12.0) : DUST appears Magenta Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

Saharan dust event July 27-29, 2005 GEOS-Chem hourly BCs to CHIMERE Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

Effect of hourly BCs on Chimere PM10 Comparison with EMEP ground obs Viznar (ES) 03°W Chaumont (CH) 07°E EMEP average 27/07 28/07 Chimere w/ std BCs Chimere w/ Monthly BCs Ispra (IT) 09°E Iskrba (SI) 14°E Chimere w/ Daily BCs 29/07 30/07 Chimere w/ Hourly BCs Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

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 THANKS FOR YOUR ATTENTION! Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila

Implementation of GEOS-Chem BCs to CHIMERE CTM global CTM Hourly or daily GEOS-Chem timeseries gas & aerosol (binary format)‏ ts_YYYYMMDD.bpch ts_YYYYMMDD.bpch ts_YYYYMMDD.bpch ts_YYYYMMDD.bpch If .not. conse-cutive run src/prep/ prep_boun.f90 Chimere pre-processing Hourly Chimere BC at domain edges (netCDF)‏ INI_CONCS.nc BOUN_CONCS.nc FILES Chimere core (Version 2008b) LEGEND Existing CODE New CODE Chimere BCs from GEOS-Chem Harvard University, 24/06/2018 Gabriele Curci, CETEMPS - U. L'Aquila