GEMS-AerosolWP_AER_4: Evaluation of the

model and analysisLead Partners: NUIG & CNRS-LOA

Partners: DWD, RMIB, MPI-M, CEA-IPSL-LSCE,ECMWF, DLR (at no cost)

Objectives of WP_AER_4

1. To assist the groups involved in WP_AER_1 and WP_AER_2 in their choices for aerosol source and assimilation datasets and parametrisations

2. To perform usual internal quality checks on model simulations

3. To perform validation of model output for predicted aerosol optical and aerosol-sensitive radiative properties

4. To perform validation of model output for predicted aerosol physical and chemical properties

5. To quantify the efficiency of satellite aerosol retrievals and global model aerosol analysis for the characterization of regional aerosol pollution events in liaison with the air quality sub-project

Task 4.1: Assessment of diagnostics and skill scores Lead: MPI-M, Partners: CNRS-LOA, ECMWF, CEA-IPSL-LSCE

• Introduction of a number of scores to evaluate the skill of the different model versions

• Review of existing techniques; Taylor diagram: provides a concise statistical summary in terms of correlation, root-mean-squatre difference, ratio of variances, «Figures of merit »,..;

• Adaptation of the skill scores developped for the AeroCom aerosol module intercomparison (correlation, bias, standard deviation, seasonality)

➲ Choice of the best aerosol model which will be implemented in the ECMWF model (LMDZ-LOA, LMDZ-INCA, and ECHAM-M7)

➲ Evaluation of the gain or loss in skill induced by the assimilation of a particular aerosol product or radiance

Task 4.2: Evaluation of aerosol radiative properties and associated radiative fluxes

Lead: DWD, Partners: RMIB, ECMWF, CNRS-LOA, MPI-M

• AOD routinely measured at AERONET-PHOTONS stations, 10 GAW sites and additional regional stations

• Algorithm to derive AOD in the UV-B from direct sun observations with Brewer spectrophotometers recently developed (Cheymol and De Backer, 2003). Several instruments have time series back to the mid 1980’s

• Data from the American ARM (ECMWF) and the French SIRTA site (CNRS-LOA) will be used for evaluating the radiation fluxes at the surface

• Vertical distribution of aerosol properties from freely available lidar measurements (CALIPSO mission, SHADE, SAFARI field campaigns)

• Validation of the direct broadband radiative effect of aerosols by comparison with the GERB TOA broadband flux measurements within the area viewed by MSG

GAW network, 22 global stationsAERONET/PHOTONS sites > 1 year of data

SIRTA: cloud, aerosol, and radiation observatory in Palaiseau, France

Active and passive remote sensing instruments including radars, lidars, and radiometers

In operation since 1999

Task 4.3: Evaluation of aerosol physico-chemical properties

Lead: NUIG, Partners: DLR (at no cost)

• EMEP: high-resolution network over Europe (level-1, -2, -3 sites); PM10 & PM2.5 + major inorganic ions

• IMPROVE: similar network over the United States (all major ions, total organic carbon and element carbon, PM2.5 & PM10)

• Global coverage through the GAW network (total number concentration of aerosols, major chemical components,…)

➲ Will provide spatial validation on daily to monthly to yearly time scales;

➲ Level-3 supersites will be used for validation of a more extensive range of aerosol parameters (large-scale international experiments of duration of 4-6 weeks); FP5 QUEST project; DLR Falcon research aircraft (INCA,…) for validation of tropospheric aerosol profiles.

EMEP network 2001

IMPROVE network in 2002

Task 4.4: Analysis of the model results with respect to air quality

Lead: CNRS-LOA

• Analysis and comparison of ground-based, satellite-derived aerosol observations, and ECMWF reanalysis :– Particulate matter mass concentrations recorded in France and Europe

will be analysed in order to identify the major pollution events in the last 3 to 5 years

– AOD measured continuously (in clear-sky conditions) from AERONET/PHOTONS

– Satellite aerosol observations derived from POLDER-2/ADEOS-2 (February to September 2003) and MODIS on TERRA/AQUA (from mid-2000 to present)

➲ Assessment of efficiency of optical measurements for the monitoring of aerosol pollution events;

➲ Possibility of use of satellite AOD as an indicator to discern air quality categories over Europe? Link with RAQ sub-project of GEMS.

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D_AER_4.1.Report: Diagnostics

and skill scores

D_AER_4.3.Database: aerosol

Physical and chemical properties

D_AER_4.2.Database: aerosol-related

radiative quantities

D_AER_4.4.Evaluation of aerosol analysis by the successive

preliminary versions of the ECMWF model

CHOICE OF THE BEST AEROSOL MODEL

AER_4Evaluation of the model and

analysis

D_AER_4.5.Preliminary report on the utility of satellite data

and global model analysis for air quality monitoring

EVALUATION OF GAIN OR LOSS IN SKILL

INDUCED BY THE ASSIMILATION

TASK 4.1.

VALIDATION OF THE AEROSOL PROPERTIES FROM GROUND-BASEDAND SATELLITE DATA

TASK 4.2. - 4.3. 4.4