ADOQA – CONESUD

1. ADOQA – CONESUD May 11, 2005

2. ADOQA CONESUD • Assimilation de données pour la qualité de l’air dans le Cône Sud • Data assimilation for air quality in South Cone • INRIA/ENPC CLIME team (F) • University of Cordoba (Arg) • Centro de Modelamiento Matemático (CMM, Chile) • Dirección Meteorológica de Chile (DMC, Chilean Weather Office) • Comisión Nacional de Energía Nuclear (CNEA, National commission for nuclear energy, Arg)

3. Context of collaborations • With Argentina • G.A. Torres, former ERCIM post-doctoral fellow: air quality forecast, data assimilation, application to Berlin, in cooperation with Fraunhofer-FIRST. • Submission of an EcoSud proposal: air quality forecast and data assimilation, application to the city of Cordoba (rejected). • Letter of Intent for participation in the framework of the Fr/Arg technical cooperation agreement. • With Chile • INRIA-CONYCIT project "AIRPOL": retroplume techniques for inverse modelling of arsenic sources in the Santiago basin. • The South American partners participate to a research network for the development and improvement of emission inventories by means of inverse modelling techniques (Inter American Institute for Global Change).

4. ADOQA – CONESUD Objective • To strenghten the cooperation in the areas of air quality modelling, data assimilation and forecast between five teams: • INRIA/ENPC CLIME team (F) • CMM and DMC (Chile) • University of Cordoba and CNEA (Argentina) • Application to regional and mesoscale air quality modelling in South America, focus on large urban centers and megacities.

5. ADOQA – CONESUD work basis • ADOQA-CONESUD builds on the expertise gathered by the partners to construct a numerical platform for air quality forecast. • Meteorological modelling: use of the meteorological solver MM5 (mesoscale meteorological solver, developed by University of Pennsylvannia). • Air quality modelling : Polair3D (developed by ENPC). • Data assimilation techniques: ensemble Kalman Filter. • All components have been integrated during the post-doctoral work of G.A. Torres for application to the city of Berlin.

6. Air quality forecast with Polair3D • -Polair3D is a 3D Chemistry-Transport Model (CTM) developed by ENPC. • -Part of a full air quality modelling system Polyphemus, freely available. http://www.enpc.fr/cerea/polyphemus • -Validated in different experiments: • regional (Paris, Lille, Marseille, Berlin), • continental (ozone forecast in Europe). • -Used at CMM for arsenic inverse modelling. • -Capable of variational (4DVAR) and sequential (EnKF) data assimilation.

7. Polair3D input data needs • Most important data sets are: • -Meteorological fields, required for the transport and deposition of pollutants, for photolysis computations: computed from global analyses (NCEP, ECMWF) and/or from outputs of mesoscale meteorological solver (MM5): this can be particularly difficult in complex terrain (e.g. Santiago basin). • -Emission inventory: difficult to collect, since emissions have various sources, some of which difficult to assess: industry, households, traffic, biogenic emissions. • -Background and initial conditions: provided by nesting regional runs with continental runs.

8. Polair3D: Ozone forecast at European scale Polair3D is routinely used for ozone forecast at European scale. It uses meteorological fields provided by ECMWF and EMEP emission inventory.

9. Polair3D: regional modelling, Berlin Work of G.A. Torres Polair3D uses MM5 meteorological fields and local emission inventory. Comparison between measurement at a ground station (red), Polair3d (blue).

10. Polair3D: inverse modelling of As, Santiago Reconstruction of As emissions (red areas) around Santiago. Obtained from 165 daily measurements made in Santiago (triangles). Most important source, Caletones, well detected, with 42kg/h instead of declared 50. Black dots in NW: undetected small sources (meteorological conditions, measurement & modelling noise).

11. Data assimilation by Ensemble Kalman Filter (EnKF) • -Air quality forecast requires an accurate knowledge of forcing by meteorology and emissions. • -This knowledge can be improved by comparing forecasted to measured concentrations. • -EnKF is a sequential data assimilation technique: each time a measured concentration is available, forcing terms are corrected in order to minimise the difference between forecast and observations. • -Propagation of model errors is performed by Monte-Carlo techniques: several forward runs are performed in parallel with perturbated inputs, to provide the require error statistics.

12. Data assimilation: EnKF Example of ozone measurement assimilation, application to Paris. Forward run without assimilation (yellow curve). Assimilated measurement (green dots). Analysis after assimilation (white curve).

13. ADOQA – CONESUD work tasks • -to develop and validate a numerical platform suited for operational use, for air quality forecast over Argentina and Chile, particularly for large urban centres and megacities: Santiago, Buenos Aires and Cordoba. • -Driving meteorological fields calculated using MM5, already at use at DMC and University of Cordoba. • -Pollutant dispersion and chemistry modelled by Polair3D, developed by ENPC, already at used by various teams. • -Ensemble Kalman (EnKF) data assimilation techniques, will be used to ingest measured data within the system.

14. ADOQA – CONESUD milestones • Collecting and evaluating the required data (emission, measurements). • Adapting the numerical platform MM5/Polair3D/EnKF to the specific cases. • Validating by comparison to observations, for representative weather conditions. • Workshop on air quality modelling, in Cordoba, 2006. • We try to fulfill 1 & 2 in 2005.

15. ADOQA – CONESUD resources • France to Chile: available from AIRPOL (INRIA/CONYCIT): one researcher, two weeks in Santiago. We are looking for support to a second researcher to come in Santiago. • Chile to France: available from AIRPOL: one researcher, two weeks in Paris. We are looking for support to a second researcher. • France <-> Argentina: new proposal to be submitted (currently Letter of Intent, France-Argentina technical cooperation agreement). • Chile <-> Argentina: IAI research network, CONESUD. • Workshop organisation: support from CONESUD program.