1. GEMS Kick-Off Meeting, Hamburg Aerosols: WP1
Jean-Jacques Morcrette, Olivier Boucher
With contributions at ECMWF from:
Soumia Serrar: handling of surface field climatologies
Agathe Untch: implementation of tracers in dynamics
Peter Bechtold: implementation of tracers in convection
Anton Beljaars: implementation of tracers in vertical diffusion

2. GEMS AEROSOL Global Monitoring System Leader: O. Boucher

3. GEMS Aerosols
AER_1: Implementation of the direct physical aerosol model in the ECMWF model (O.Boucher, J. Feichter)
> implementation of parametrisations for tropospheric aerosols
> implementation of parametrisations for stratospheric aerosols
> implementation of new emission inventories
> implementation of aerosol optical properties
> production of test simulations
HC-MO, MPI-M, CEA-LSCE, ECMWF, SA-UPMC
AER_2: Refinement of aerosol emission sources (M.Sofiev)
> update and assimilation of the anthropogenic emission inventories of aerosol and its precursors
> assimilation of information on wild fires
> quantification of the wind-blown dust emission from desert areas
> quantification of the wind-blown sea salt emission
> sources of stratospheric aerosols
FMI, CEA-LSCE, MPI-M, SA-UPMC

4. GEMS Aerosols AER_3: Aerosol data assimilation (J-J Morcrette)
> adaptation of RT codes for SW and LW radiances in nadir geometry
> preparation and harmonisation of aerosol satellite data sets
> error covariance matrices
> test of a 1D-Var system using aerosol products
> test of a 1D-Var system using aerosol radiances
ECMWF, CEA-LSCE, HC-MO, SA-UPMC
AER_4: Evaluation of the model and analyses (C.O’Dowd, I. Chiapello)
> assessment of diagnostics and skill scores
> evaluation of aerosol radiative properties and associated radiative fluxes
> evaluation of aerosol physico-chemical properties
> analysis of model results with respect to air quality
NUIG, CNRS-LOA, CEA-LSCE, DWD, ECMWF, MPI-M, RMIB, SA-UPMC

6. GEMS Aerosols: products @ end of contract
Analysis of aerosol-related observations at ERA40 resolution (TL159 L60 [1.125 deg]2 or better) twice a day
Total optical thickness at ~0.55 mm OCEAN
Angstrom coefficient (or t at~ 0.865mm) “
Total optical thickness at ~0.55 mm LAND
From model 12-hour forecasts used in assimilation cycle
.Up to 15 mixing ratio profiles of aerosols, every 3 hours
sea salt bins st stage
desert dust 3 bins
organic bins nd stage
black carbon, carbonaceous 2bins
sulfate
fly ash
“stratospheric”
.Corresponding 2D-fields for sources and sinks

7. GEMS-AEROSOL: initial steps at ECMWF JJMorcrette, A. Benedetti, S
GEMS-AEROSOL: initial steps at ECMWF JJMorcrette, A.Benedetti, S.Serrar, A.Beljaars, P.Bechtold, A.Untch
Introduce aerosol prognostic variables in the Integrated Forecast System and assimilate global aerosol information
Instruments: MERIS, MODIS x 2, MISR, SEAWIFS, POLDER
R/T S
Modelling LMDZ
Sources/Sinks LMD-Inca
Data Assim DVar
Variables t, radiances
Validation AERONET

8. Development of a prognostic aerosol package in the ECMWF model
New routine
Modified routine
Unchanged (at present)

9. What has been done within the forecast model as of 20 June 2005
A. Untch: GFL fields (3D): NAERO fields for Aerosols
A. Beljaars: GFL in VDiff with Dt=1800 s
P. Bechtold: GFL in mass-flux scheme
S. Serrar: Gribbing 2D climate fields for LMD-Inca-type dust

10. What has been done within the forecast model as of 20 June 2005
JJMorcrette:
Configuration A: 6 aerosol types from Tegen et al. (1997) climatology moved around by dynamics, VDif, and convection (without sources and sinks)
Mainly used for preliminary testing and background error statistics
Stratospheric aerosols to be used this way together with config.B tropospheric aerosols
Configuration B: “real” prognostic aerosols
1/ Recomputing most relevant coefficients to have sea-salt and dust with (3,3) bins instead of (10,2) in LMDZ
(optical properties f(RH), deposition)
2/ New routines adapted from LMDZ
* AER_SRC: simple sea-salt and dust sources 3 bins each
* AER_DRYDEP : dry deposition by modification of source fluxes
* AER_SEDIMNT: sedimentation
* AER_SCAVIN : scavenging within clouds
* AER_SCAVBC : scavenging below clouds
3/ Importing AEROCOM expB climate fields for SS, DU, POM, BC, SU
NB: all the above work is mainly relevant to WP_AER1.1, and WP_AER1.4

11. What has been done within the forecast model as of 20 June 2005
24-hour FC with dyn, vdif, msflx
Configuration 1: Sea-salt
Climatology for 1 May

12. Surface source flux
Sedimentation flux
Configuration B: sea salt a la LMD-Z
Bin 1: 0.03 – 0.5 mm

13. Surface source flux
Sedimentation flux
Bin 2: 0.5 – 5 mm

14. Surface source flux
Sedimentation flux
Bin 3: 5 – 20 mm

15. What still has to be done within the forecast model as of 20 June 2005
Software/Scientific problems expected to be solved within 1/2 month(s)
within ECMWF
Find and correct the remaining problems in AER_SCAVIN, AER_SCAVBC
Introduce proper reading of LMD-Inca-dust fields
Run year-long experiments to check aerosol total mass conservation
GRIB and introduce the AEROCOM expB climate for SS, DU, POM, BC, SU (the idea is to quickly have a model to be run and compared to results in AEROCOM web-site

16. What could/should be discussed at the Kick-Off Meeting
Scientific approach
It might be possible to get quickly the full packages or at least some routines from the aerosol representations by MPI-M and LMD-Inca (both modal representations vs. LMD-Z bin representation).
PRO:
This might allow for a more informed choice of “final” GEMS-Aerosols configuration to be made, more quickly.
This might allow for more extensive comparisons with existing AEROCOM results (not discussed in GEMS-AER proposal)
CON:
This might require extra Table 210 space for archiving results from parallel-running parametrisations.
This might take “time and energy”.
This exercise will happen earlier than anything scheduled in WP_AER4 and is very likely to be done at/by ECWMF only.

17. What could/should be discussed at the Kick-Off Meeting
Strategy/Political problems
With the development of the first version of the global aerosol model going a bit faster than scheduled in the proposal, is it really necessary to wait more than a year to get a report on diagnostics and skill scores (WP_AER4_4.1) and a database of aerosol-related radiative quantities (WP_AER4_4.2).
With Olivier Boucher now at HC-MO, what is exactly happening of the work supposed to be carried out by CNRS-LOA? (WP_AER1, WP_AER3.2a, WP_AER3.3)
What should we start with in terms of stratospheric aerosols? Are those derived from Tanre et al. (1984) climatology really meaningful? Is there anything better in terms of time series with a global coverage?

18. Pandora’s box
In a first stage (~ko+6), the aerosols will not be interactive with the rest of the model: They will be passive tracers and will not have any impact on any of the other analysed field nor on the subsequent forecast.
In later stages, the aerosols will first be made interactive with radiation (direct effect, ~ko+12), then tests will be carried out aerosols interactive with cloud processes (indirect effects, ~ko+18):
How likely is it to introduce some systematic differences (errors?) in the first guess forecast? In the analyses?

19. END thank you for your attention!