French Organization in Atmospheric Chemistry Data

Assimilation

P. Ricaud, L3AB, Bordeaux, FranceD. Cariolle, CERFACS, Toulouse, France

And French colleagues

March 2004

-> Poster by L. El Amraoui, Assimilation of O3 and N2O from Odin

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Background

8 models MOCAGE, ROSE/MSDOL, REPROBUS, CHIMERE,

POLAIR, MIMOSA, MIPLASMO-assimilé, Kattatov 4DVAR

2 main assimilation methods Sequential, variational

8 satellite and aircraft data sets GOMOS, SCIAMACHY, MIPAS, SMR, OSIRIS,

MOPITT, IMG, MOSAICAbout 10 laboratories

Paris, Toulouse, Bordeaux, Orléans, NiceMore than 30 people involved

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Background -2-

Assimilation techniques applied through scientific themes Dynamical and chemical processes in the UTLS O3 and precursors O3 monitoring Aircraft impacts in the atmosphere Pollution and emission

Organization of the atmospheric community Expertise of one lab to be used efficiently by

another one and widely benefits to the entire community

Developement of a common tool (?)

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PALM -1-

PALM: Projet d’Assimilation par Logiciel Multiméthode

Developped for the MERCATOR (oceanography) assimilation programme at CERFACS (Toulouse)

2 objectives Easy development of assimilation schemes Exchange of software modules between

different teamsAble to assemble an assimilation chain as

a sequence of independent software modules

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PALM -2-

Modularity and readibility of the applications

Portability of the PALM softwareEasier evolution of the assimilation

schemesUse pre-defined tools (linear algebra units,

linear interpolation, …)Parallelism

Exchange of PALM unitsExchange of methods and assimilation

schemes

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Further informations

http://www.cerfacs.fr/~palm

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What has been done with PALM so far?

CERFACS: T. Morel and S. MassartAssimilation method: 3D-VAR (-> 4D-VAR)Model: MOCAGE (Météo-France)Satellite data set: GOME O3

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Expertise Centres :Obs. operators

Direct models and methodology

Satellites:GOMOS, Odin,

MOPITT, …

Models: REPROBUS, MIMOSA, …

PALM

Assimilation chains

2 PALMed chains:MOCAGE & MSDOL/REPROBUS

MOCAGE & LMDz

Research chains : Other chains in various labs

OperationalGMES

Non OperationallASSET, SAF O3External

links

Organization

Methodology:Optimal estimation, 3D and 4DVAR, …

EtherData Base

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Short-term project

Observation operators GOMOS O3 Odin/SMR O3 and N2O MOPITT CO

Models MOCAGE (already done) MSDOL/REPROBUS

Methods 3D-VAR -> 4D-VAR Optimal interpolation

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Mid-Term Project

Multi-instrument and/or multi-platform Consistancy and covariance error

O3 Constraints

O3 -> windsN2O -> NOy

Short-lived species and/or families Cly: HCl, ClO, ClONO2NOy: N2O, HNO3, NO2, NO3

Radiances and/or brightness temperatures No retrievals required

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Status

Proposed to the CNRSPositive feedbacksStill under discussion

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Ackowledgements

SA, ParisLMD, ParisLSCE, ParisENPC, ParisCERFACS, ToulouseMétéo-France, ToulouseLA, Toulouse CNES, ToulouseL3AB, BordeauxLPCE, OrléansACRI, Nice