Gloream workshop, Paris 2006

Setting of an experimental forecast system for air quality at ECMWF in the framework of the GEMS project :

implementation and first results

Forêt(1),(2) G., Monge(2) J-.L., Menut(2) L., Vautard(3) R., Beekmann(1) M.

(1) Laboratoire Inter-universitaire des Systèmes Atmosphériques (LISA)(2) Laboratoire de Météorologie Dynamique (LMD) (3) Laboratoire des Sciences du Climat et de l’Environnement (LSCE)

Context of this work

▪ 3D Chemical Transport Model are now used to assess air pollution from global to urban scales… nevertheless large uncertainties remains: external forcings : emissions, meteorology, chemical boundary conditions representation of dynamics : pollutants dispersion representations of chemical and physical mecanisms (gases and aerosols) numerical representation

▪ Great Potential for increasing CTM performances :

increasing number of teams working on AQ modelling increasing computing capacity multiplication of observations (satellites)

Synergetical approach via integrated projects : GEMS, PROMOTE

Gloream workshop, Paris 2006

A common will to ameliorate air quality modelling : The GEMS project

Purpose of GEMS (Global and regional Earth-system Monitoring using Satelliteand in-situ data) :

● Global Monitoring system for Greenhouse Gases (GHG)● Global Monitoring system for Reactive Gases (GRG)● Global Monitoring system for Aerosols (AER)● Regional Air-Quality Monitoring and Forecasting (RAQ)

Create a new European system for operationnal global monitoring of Atmospheric chemistry and to produce improved medium-range & short range air-chemistry forecasts.

GEMS sub-projects :

The GEMS RAQ sub project

▪ Provide, Evaluate NRT forecasts (gases and aerosols) at continental to regional scale, relying on global and regional assimilated fields

▪ Improve existing continental to regional scales air quality models, statistical post-treatment, and explore multi-model ensemble approaches

▪ Use of satellite information for air quality prognoses▪ Impact of the global change on regional air quality▪ European cooperation for data access, skill evaluation and forecasts comparisons▪ Evaluate health impact of air quality and produce dedicated products

Gloream workshop, Paris 2006

Objectives :

Several AQ model used for sensivity studies and cross-comparison exercices Recommandation for future RAQ modelling systems

Gloream workshop, Paris 2006

The CHIMERE-GEMS system (1/2)

Starting model version based on the operationnal PREV’AIR platform :(www.prevair.ineris.fr)

GFS/NCEPGlobal meteorological forecasts

MM5Regional meteorological

forecasts

CHIMERERegional CTM

Prognose hourly concentrations : gases (O3, NO2, CO, SO2…)

aerosols (Sulf, Nitrate,…)

EMEP emissions

USGS land use, land cover

LMDZ-INCA (gases)

GOCART (aerosols)

Large scale chemical forcing

from monthly climatology

● gaseous chemistry module● aerosols module● advection, turbulence● dry and wet deposition

http://euler.lmd.polytechnique.fr/chimere/

Gloream workshop, Paris 2006

The CHIMERE-GEMS system (2/2)

The CHIMERE-GEMS version :

Geographical GEMS domain [35°N-70°N; 15°E-35°W]Horizontal resolution 101x71 cells ; 0.5°x0.5°Vertical resolution 8 levels ; top at 500 hPa

New emission cadaster (from TNO; 6kmx6km over Europe) spring 2007Forecasted boundary chemical fields for gases (GRG) and aerosols (AER) june 2007

Meteorological forcing from Integrated forecasting System (ECMWF) Test over a summer period (2005) Installing an operationnal system at ECMWF

http://euler.lmd.polytechnique.fr/GEMSchimere

Impact of ECMWF meteorological forcing (1/6)

Simulation period : June/July/August 2005

Number of stations :~ 200 stations(urban+rural+peri-urban)

Skill scores of the forecasts for surface ozone daily peaks values (µg.m3)

Bias 3 2.3Cor 0.86 0.86Rms 17.3 17.1

Gloream workshop, Paris 2006

GFS IFS

Change of the meteorological forcing in the forecasting system

Global met. frcst GFS (NCEP) (1°x1°)

Regio. met. frcst MM5 (0.5°x0.5°)

Regio. Chem. rcstCHIMERE-GEMS

Global met. frcst IFS (ECMWF) (0.5°x0.5°)

Regional chem. frcstCHIMERE-GEMS

Gloream workshop, Paris 2006

bias rms

Impact of ECMWF meteorological forcing (2/6)

correlation

Example of ozone surface peaks time-series :

Gloream workshop, Paris 2006

Impact of ECMWF meteorological forcing (3/6)

Gloream workshop, Paris 2006

GFS meteorological forcing IFS meteorological forcing

[Number of simulated ozone peaks (> 180 µg.m-3) / number of observated peaks ] x 100

● blacks circles shows stations without peaks values above 180 µg.m-3

Impact of ECMWF meteorological forcing (4/6)

GFS meteorological forcing

GFS meteorological forcing

IFS meteorological forcing

IFS meteorological forcing

Number of forecasted but not observed peaks : False alert

Number of « well » forecasted peaks : correct alert

Gloream workshop, Paris 2006

Impact of ECMWF meteorological forcing (5/6)

Test ECMWF meteorological forcing for summer 2005 (6/6)

Exploratory analysis of differences between both meteorological forcings example of monthly mean differences maps (July 2005)

Gloream workshop, Paris 2006

2m Temperature (°C)Wind module (m/s)

Friction velocity (u*; cm/s) Relative humidity (%)[varIFS-varGFS]

Gloream workshop, Paris 2006

Devellopment of a new experimental forecast system based at ECMWF

Simulation period : July/August 2006

Number of stations :~ 200 stations(urban+rural+peri-urban)

Skill scores of the forecasts for daily peaks values (µg.m3)

Bias -1.1 -7.0Cor 0.89 0.89Rms 17.1 18.4

GFS IFS

What’s new ? New parallel version of CHIMERE is used The whole system is running remotely on ECMWF’s calculator (HPCD)

IFS (ECMWF) (0.5°x 0.5°)

CHIMERE-GEMS(parallel version)

120 h IFS forecast available

Timing (D-1) 6h30 pm (UT) (D-1) 9 pm (UT)

Beginning of the CHIMERE run on hpcd

(D-1) 9h45 pm (UT)

Chemical forecasts areAvailable (Day + 3)

Experimental forecast for summer 2006 at ECMWF

Gloream workshop, Paris 2006

Simulated surface ozone peaks for the 2006/07/26

NCEP/MM5/CHIMERE ECMWF/CHIMERE-GEMS

Gloream workshop, Paris 2006

Future works

Identifying main differences for the 2 differents meteorological forcings

increasing horizontal resolution of the model (parallel version)

Tests with the new TNO emission cadaster Sensivity tests to chemical boundary conditions forcings : differences between monthly global climatology and global chemical forecasts currently in test with LMDZ-INCA chemical forecasts

+ Implementation of the new model version : (spring 2007 ???) enhanced aerosol modules deep convection free-tropospheric version coupling with chimere-dust version better dust forcing …