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Commonality between simulations using GFEDv2 and J3LRCv2 during summers of 2000 and 2006 using TM4. J.E.Williams, P.F.J. van Velthoven and Rinus Scheele. Differences in monthly emission fluxes for Africa. 2006. 2000. Peak in emissions shifts towards the summer period
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Commonality between simulations using GFEDv2 and J3LRCv2 during summers of 2000 and 2006 using TM4 J.E.Williams, P.F.J. van Velthoven and Rinus Scheele
Differences in monthly emission fluxes for Africa 2006 2000 Peak in emissions shifts towards the summer period for both years as seen by van der Werf et al., ACP, 2006.
Guinea South Africa
Changes in the Oxidation budget of CO • Twice the mass of the CO emitted in the tropics is oxidized 2006 Trop burden of CO : 396Tg CO (GFEDv2), 412TgCO (L3JRCv2) 2006: (CH4) = 10.55 yrs (GFEDv2), 10.72yrs (L3JRCv2)
Changes in the budget of O3 Changes in LT mimic the changes in NOx emissions where transport/processing effects alter UTLS O3 budget
Changes in chemical activity Multi-model ensemble means (Stevenson et al, 2006) are 4974233 Tg O3 yr-1, 4577291 Tg O3 yr-1, 953154 Tg O3 yr-1, 556154 Tg O3 yr-1 and 22.22.22 days
25.9°S, 28.2°E 1.3°S,38.6°E
6.2°N, 2.2°E Origin of air-masses seem to be independent on the season even though ITCZ shifts. Seen in trajectory studies (Mari et al, ACP, 2008)
Effects at other tropical locations : South America 5.8°N, 55.2°W
Conclusions • Some commonality does exist between the meteorology of 2000 and 2006 as exhibited by the distribution of the passive tracers/monthly mean temps. • Analysing at a higher frequency (weekly) for WAM period is necessary to determine true variability. • In general the seasonal differences in trace gases introduced as a result of applying the L3JRCv2 dataset have similarity between both years. The maximal concentrations for the AMMA measurement region occur over the South Atlantic Ocean. • Using L3JRCv2 increases the chemical activity of the model and increases methane lifetime by a few % as a result of CO (5% increase in the CO burden). • For 2006 the effect on the UTLS maybe somewhat weaker than the evaluation year. • Comparisons with seasonal sondes values in Africa reveals that the application of the L3JRCv2 dataset improves the correlation with sonde measurements for TM4 at the surface upto the middle troposphere. • The origin of air-masses effects to extent of the improvement when applying the new database (emission maps needed). • Most Shadoz sites are relatively unaffected by the increases in the emissions in Africa