Laboratoire d’aérologie (CNRS, TOULOUSE)EDI group (Emissions-Depostion-Impacts, C. Liousse)

Measurements campaigns : IDAF/AMMA/SACCLAP and experiments in the LA combustion chamber (Mass, Chemical speciation of the aerosol,aerosol size/chemistry,physical properties, in air and in rains)

Activity in multiscale atmospheric chemistry modelling

Collaborations: Link with LAMP/LOA, ICTP (UNESCO) and TM4-TM5 group.

Strong collaborations with African Researchers : Ivory Coast, Senegal, Benin, Cameroon, South Africa, Niger, Mali, Congo : 6 shared phD at this time

Involvement in AMMA :

Modelling of African aerosol in the context of AMMA

Main scientific objectives :

Improving the characterization of aerosol mixture in the 3D models ….

• Sources and transport : cf Liousse presentation.• Physical and chemical state of the mixing• Optical and hygroscopic properties• Impact on regional budgets (transport / deposition)• Impact on regional radiative forcing

… for a better characterization of aerosol/chemistry/climate interactions over the region.

loca

lre

gio

nal

con

tin

enta

lg

lob

al

SOP LOPEOP

GAME(rad. Trans.)

ORISAMOD

MesoNH-C Met., 3- 40 km

+ ORISAM

TM4 (CTM, ~ 3°x 2° )

+ ORISAM

RegCM3 (Reg climate, 20 – 90 km.)

( + ORISAM in dev.)

Model used and developped space

time

sulphate

Water

SOAB

nitrate

pH

in each bin:

Absorption/

adsorption + internal equilibriu

m

Inorganic Condensable

H2SO4

NH3

HNO3

Organic Condensable

SOAASOAB

ORISAM Bessagnet et al, 2004

Cousin et al, 2005Liousse et al, 2005Mallet et al, 2005

COV

SO2

NOx

Gaseous chemistry

Dry and wet deposition

COUPLING COUPLING (Guillaume et al., 2007a)(Guillaume et al., 2007a)

TM4 (initial state)(Van Velthoven et al., 1996):

-3°x2° horizontal, -31 vertical levels (jsq. 10hPa),- 38 gaseous components-(+3 aerosol : sulfates, nitrates, ammonium without size distribution)-Emission : EDGAR3, POET (COV),-ECMWF,-Dry and wet deposition-Gaseous chemistry (Houweling et al., 1998)

BC(sea-salt,

dust)

OCp

Emissions

Aerosol sectional model

40nm 10µm

ORISAM = ORganic and Inorganic Sectional Aerosol Model

SOAA

ammonium

Development of ORISAM (Organic and Inorganic Spectral Aerosol model)(Bessagnet et al. 2004, Cousin et al. 2005, Liousse et al., 2005)

1

4

2

3

0.04-0.13µm 0.13-0.4µm 0.4-1.26µm 1.26-4µm 4-12.6µm 12.6-40µm

fine coarse

JJA Size/Chemistry from regional mass loads (Gg),(ground totals)

Sahara CA

WA SA

ORISAM/TM4 : Species Budgets over Africa

1

23

4

ORISAM/TM4 : size-resolved aerosol chemistry over Djougou in December

Guillaume et al., 2007

=>experimental results soon available for model validations…

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

jl ag sp ot nv dc jn fb mr ap my je

Measured BC 2005/2006 Measured BC 2006/2007 ORISAM-TM4 BC 2000

Example of comparisons :BC given by ORISAM/TM4 with 2000 emissionswith BC measured at Djougou/Benin

ORISAM TM4 : Wet deposition

0

10

20

30

40

50

60

70

80

90

100

µe

q/l

1995 1996 1997 1998 1999 2000 2001 2002

Years

C2H5COO

CH3COO

HCOO

SO4--

Cl-

NO3-

NH4+

Mg++

Ca++

K+

Na+

H+

Observed : IDAF network

0

10

20

30

40

50

60

70

80

90

100

JJA 2002

SOAB

SOAA

SO4--

Cl-

NO3-

NH4+

Mg++

Ca++

Na+

H+

ORISAM/TM4 : preliminary results

Yoboué, Galy et al., 2006

Eg: Species concentrations in rains at Lamto (JJA)

Size distribution in Ghent(Putaud)

RAD modelInternal mixtures

with 3 layers + Mie [Mallet, Pont et al., 2005]

Qe(

x)BC

Dust

OCp

SOA

Sulfates,Nitrates,

AmmoniumH2O

ORISAM / RAD

Optical properties calculationsSize resolved speciation

Qext

SSA

Assymetry parameter

Comparaisons of model results vs. Measured optical properties during AMMA

absorbing particles (SSA 0.85)

scattering particles (SSA 0.95)

BAe-146 SSA520 0.90 (S. Osborne, Met Office)

0.75 SSA520 0.99mean SSA520 = 0.90

ORISAM / Rad/ TM4

Nephelometer + Aethalometer

+ ORISAM / Rad / MesoNH

+ RegCM3

Aerosol single scattering albedo on Djougou (SOP0)

Regional climate impact of aerosols

Konaré , Solmon et al., in prep

RegCM3 : ( ICTP / UNESCO) Regional Climate Model ( res 20 to 90km)

Aerosol module : (SO4, BC,OC + dust module, Solmon et al;, 2006 ; Zakey et al., 2006)

+ Optical properties

JJA Precip Difference

(dust – no dust)

Average : 1969 – 2006

Dust climatic effect

on monsoon

Res 60 km

Biomass burning aerosols in RegCM

Simple representation for the moment

Used for budget and sensitivity studies to emissions, e.g sensitivity to emission inventory

On going developments

Anthropogenic radiative forcing and climatic impacts

RegCM3 / ORISAM coupling …

ON GOING WORK and perspectives (high temporal resolution emissions)

SOP0 : ORISAM-RAD-MesoNH simulations (19-20-21 Jan. 06) RegCM3 episode.

=>EOP 2005-2007 with ORISAM-RAD TM4 (3*2*month) and RegCM3 seasonal budgets and radiative forcings.

=>LOP ->RegCM3 and ORISAM-RAD-TM4 (2000-2010)Period interannual variability and regional climatic impact.

Interest in Intercomparaison studies !