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ADOQA – CONESUD
May 11, 2005
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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)
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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).
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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.
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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.
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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.
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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.
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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.
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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).
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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).
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.
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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).
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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.
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ADOQA – CONESUD milestones
1. Collecting and evaluating the required data (emission,
measurements).
2. Adapting the numerical platform MM5/Polair3D/EnKF to the
specific cases.
3. Validating by comparison to observations, for representative
weather conditions.
4. Workshop on air quality modelling, in Cordoba, 2006.
We try to fulfill 1 & 2 in 2005.
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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.