Serena Falasca (1,2) and Gabriele Curci (1,2) Air quality high resolution simulations of Italian urban areas with WRF-CHIMERE Serena Falasca (1,2) and Gabriele Curci (1,2) serena.falasca1@univaq.it Department of Physical and Chemical Sciences, University of L’Aquila, L’Aquila, Italy. Centre of Excellence CETEMPS, Department of Physical and Chemical Sciences, University of L’Aquila, L’Aquila, Italy. European Geosciences Union General Assembly 2017 Vienna | Austria | 23–28 April 2017

Motivation and Aim of the study KEY POINTS The entity of urban population and the expectation of its growth in the next decades WHO defines "Air pollution" as a major environmental risk to human health The European Directive 2008/50/EC on ambient air quality and cleaner air for Europe encourages the use of modeling techniques to support the observations in the assessment and forecasting of air quality. BACKGROUND AND MOTIVATION The ultimate aim of this work: development and assessment of an air quality modeling tool (WRF + CHIMERE) at high resolution

THE DOMAINS Land Use Categories d01 d02 METHOD d03 d04 Horizontal Resolution   dx = dy WRF (km) dx = dy CHIMERE (°) d01 (EUR) 36 0.5 d02 (ITA) 12 0.12 d03 (North-West of Italy) 4 0.04 d04 (Urban Area of Milan) 1.3 0.015

Simulations The increase of the horizontal resolution  Label  dx = dy (°) EUR 0.5 ITA 0.12 NWI 0.04 MI 0.015 The reallocation of anthropogenic emissions  Label Reallocation of emissions CTNNF N CTNGC Y d04 The use of Urban Schemes for WRF simulations   Label Urban Scheme (WRF namelist option) CTNGC None SLUCM Single Layer Urban Canopy Model (1) BEP Building Environment Parameterization (2) Increasing the complexity d04

The increase of the horizontal resolution: comparisons Jan 2010 Jul 2010 CHIMERE RESULTS 24 h mean PM10 (µg/m3) Station ID: IT1812A Zone: Rural Type: Background Maximum daily 8 h mean O3 (µg/m3) Station ID: IT1466A Zone: Suburban Type: Background OBS EUR ITA NWI MI

The reallocation of emissions: comparisons Emission flux of PM10 at 12:00 UTC for January 2010 Emissions inventory: CTN (5 x 5 km) CTNNF Emissions inventory: CTN (5 x 5 km) + CTNGC GlobCover Land Use dataset

24 hour mean PM10 (µg/m3): Difference CTNGC-CTNNF The reallocation of emissions: comparisons 24 hour mean PM10 (µg/m3): Difference CTNGC-CTNNF Mean Maximum 25 6 CHIMERE RESULTS Jan 2010 6 25 Jul 2010 25

Maximum daily 8 h mean O3 (ppb): Difference CTNGC-CTNNF The reallocation of emissions: comparisons Maximum daily 8 h mean O3 (ppb): Difference CTNGC-CTNNF Mean Maximum CHIMERE RESULTS 2.5 20 Jan 2010 -5 20 2.5 Jul 2010 -5

The use of Urban Schemes: comparisons Jan 2010 Jul 2010 24 hour mean PM10 (µg/m3) CHIMERE RESULTS Station ID: IT0776A Zone: Urban Type: Traffic Maximum daily 8 hour mean O3 (µg/m3) Station ID: IT0706A Zone: Urban Type: Background OBS CTNGC SLUCM BEP

The use of Urban Schemes: comparisons 24 h mean PM10 (µg/m3): Maximum difference SLUCM-CTNGC BEP-CTNGC CHIMERE RESULTS 20 20 Jan 2010 10 10 Jul 2010

The use of Urban Schemes: comparisons 24 h mean PM10 (µg/m3): Mean difference SLUCM-CTNGC BEP-CTNGC 2.5 2.5 CHIMERE RESULTS Jan 2010 -10 -10 0.5 0.5 Jul 2010 -1.5 -1.5

The use of Urban Schemes: comparisons Maximum daily 8 h mean O3 (ppb): Maximum difference BEP-CTNGC SLUCM-CTNGC CHIMERE RESULTS 25 25 Jan 2010 12.5 12.5 Jul 2010

The use of Urban Schemes: comparisons Maximum daily 8 h mean O3 (ppb): Mean difference SLUCM-CTNGC BEP-CTNGC 7.5 7.5 CHIMERE RESULTS Jan 2010 0.5 0.5 Jul 2010 -7 -7

CONCLUSIONS High resolution simulations of an urban area in Italy have been performed using the reallocation of anthropogenic emissions and different urban schemes The use of the reallocation of anthropogenic emissions for high resolution simulations allows a more realistic reproduction of the emission fluxes and therefore of the concentrations of the pollutants. Benefits of the reallocation of anthropogenic emissions are relevant for simulations of urban areas. Future work: use characteristic morphologic parameters for the simulated urban areas

ACKNOWLEDGEMENTS This work is carried out in the frame of the "Smart Clean Air City L'Aquila" project, Italian Ministry of the Economic Development, codice programma n. M/0007/03/X23. The computational resources were provided by CINECA in the frame of IscraC projects NMTFEPRA e PANCIA.

WRF physics options SUPPLEMENTARY MATERIAL Physics Category (namelist.input option) Scheme (namelist.input option) Shortwave radiation (ra_sw_physics) RRTMG (4) Longwave radiation (ra_lw_physics) microphysics (mp_physics) WSM6 (6) Surface layer (sf_sfclay_physics) Revised MM5 Monin-Obukhov (1) Planetary Boundary Layer (bl_pbl_physics) Bougeault and Lacarrere (BouLac) (8) Land Surface (sf_surface_physics) Unified Noah land-surface model (2) SUPPLEMENTARY MATERIAL