TY  - JOUR
AU  - Williams, J. E.
AU  - Scheele, M.P.
AU  - van Velthoven, P.F.J.
AU  - Cammas, J.-P.
AU  - Thouret, V.
AU  - Galy-Lacaux, C.
AU  - Volz-Thomas, A.
TI  - The influence of biogenic emissions from Africa on tropical tropospheric ozone during 2006: a global modeling study
JO  - Atmospheric chemistry and physics
VL  - 9
SN  - 1680-7316
CY  - Katlenburg-Lindau
PB  - EGU
M1  - PreJuSER-5446
SP  - 5729 - 5749
PY  - 2009
N1  - The authors acknowledge the EU integrated project AMMA (African Monsoon Multidisciplinary Analysis) for the support network and funding. Based on a French initiative, AMMA was built by an international scientific group and is currently funded by a large number of agencies, especially from France, the United Kingdom, the United States and Africa. It has been the beneficiary of a major financial contribution from the European Community Sixth Framework Research Programme. Detailed information on scientific co-ordination and funding is available on the AMMA International Web site at www.amma-international.org. We are also grateful to Hans Schlager (DLR), Gerard Ancellet (Service d'Aeronomie) and the Facility for Airborne Atmospheric Measurements (FAAM) for permission to use the measurements taken during the AMMA measurement campaign. We also acknowledge both the POET and RETRO EU projects for providing the emission inventories for both used in this study and the INSU-CNRS (France), the European Network of Excellence ACCENT and the ICG Forschungszentrum Julich (Germany) for providing the transportation and maintenance costs of the MOZAIC instrumentation onboard the Air Namibia aircraft. The MOZAIC database is managed by ETHER (CNES and INSU-CNRS, France). Finally, we thank the two anonymous referees who made suggestions which improved the readability of the manuscript.
AB  - We have performed simulations using a 3-D global chemistry-transport model to investigate the influence that biogenic emissions from the African continent exert on the composition of the troposphere in the tropical region. For this purpose we have applied two recently developed biogenic emission inventories provided for use in large-scale global models (Granier et al., 2005; LathiSre et al., 2006) whose seasonality and temporal distribution for biogenic emissions of isoprene, other volatile organic compounds and NO is markedly different. The use of the 12 year average values for biogenic emissions provided by LathiSre et al. (2006) results in an increase in the amount of nitrogen sequestrated into longer lived reservoir compounds which contributes to the reduction in the tropospheric ozone burden in the tropics. The associated re-partitioning of nitrogen between PAN, HNO3 and organic nitrates also results in a similar to 5% increase in the loss of nitrogen by wet deposition. At a global scale there is a reduction in the oxidizing capacity of the model atmosphere which increases the atmospheric lifetimes of CH4 and CO by similar to 1.5% and similar to 4%, respectively. Comparisons against a range of different measurements indicate that applying the 12 year average of LathiSre et al. (2006) improves the performance of TM4_AMMA for 2006 in the tropics. By the use of sensitivity studies we show that the release of NO from soils in Africa accounts for between similar to 2-45% of tropospheric ozone in the African troposphere, similar to 10% in the upper troposphere and between similar to 5-20% of the tropical tropospheric ozone column over the tropical Atlantic Ocean. The subsequent reduction in OH over the source regions allows enhanced transport of CO out of the region. For biogenic volatile organic C1 to C3 species released from Africa, the effects on tropical tropospheric ozone are rather limited, although this source contributes to the global burden of VOC by between similar to 2-4% and has a large influence on the organic composition of the troposphere over the tropical Atlantic Ocean.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000268876600020
UR  - https://juser.fz-juelich.de/record/5446
ER  -