1. WEST AFRICAN MONSOON EXPERIMENT (WAM)
Focuses on both dynamical and chemical aspects of monsoon
European leadership (France, UK), U.S. involvement through NCAR (dynamics)
white paper is available
Chemical objective: What is the impact of the West African Monsoon on tropical chemistry and climate at local, regional and global scale?
biogenic, lightning, dust, biomass burning, growing urban emissions
convective processing
Three intensives planned during 2005
monsoon onset (April)
monsoon maximum (August)
late monsoon (October)
SOP 1 and 2
SOP 3

2. WESTERN AFRICA IS AN ACTIVE AND COMPLEX REGION OF THE TROPICS
Harmattan Flux
Dust
Savanna
Anthropogenic
Biofuel
Forest
Biomass Burning
Ocean
Monsoon Flux
Celine Mari, LA Toulouse

3. ATSR FIRE COUNTS

4. TROPOSPHERIC OZONE COLUMNS (Sep’96-Aug’97) [Martin et ., 2002]
GEOS-CHEM
TOMS (CCD)
DJF
MAM
JJA
SON
R = 0.75, BIAS = -1 DU

5. OZONE VERTICAL PROFILES OVER ABIDJAN
North African Dec-Feb ozone enhancement from biomass burning
Is seen by aircraft observations but not by TOMS
GEOS-
CHEM
TOMS
(distributed w/assumed standard profile)
MOZAIC
aircraft
data
Martin et al. [2002]

6. LOW SENSITIVITY OF TOMS IN LOWER TROPOSPHERE HAMPERS DETECTION OF OZONE ENHANCEMENTS FROM BIOMASS BURNING IN N AFRICA AND SE ASIA
TOMS sensitivity to ozone
(LIDORT radiative
transfer model)
TOMS standard profiles
S. Atlantic
profile
Abidjan profile
Martin et al. [2002]

7. MAXIMUM OZONE ENHANCEMENT FROM LIGHTNING PREDICTED OVER THE SOUTH ATLANTIC YEAR-ROUND
Difference between standard and no-lightning GEOS-CHEM simulations
Martin et al.
[2002]

8. PROPOSAL: TWO NASA WAM TROPICAL MINI-MISSIONS (January and August)
Scientific objective: quantify biomass burning and lightning influences on ozone and related species over western Africa, investigate convective processing during monsoon
Aura validation objective: obtain vertical profiles of ozone, H2O, CO, aerosols, other species (see Stan’s list) over western Africa under range of conditions – understand bias in solar UV backscatter instruments (TOMS). Expect high complementarity with TC3.
Need DC-8 + higher-flying aircraft (WB-57) operating from west coast of Africa (Ivory Coast, Benin). Minimum instrumentation includes ozone and precursors, aerosols
minimum of 40 flight hours per aircraft per deployment