Ozone production due to emissions from vegetation burning     

Günter Helas  Jürgen Lobert  Dieter Scharffe  Luise Schäfer  Johann Goldammer  Jean Baudet  Brou Ahoua  Ayité-Lô Ajavon  Jean-Pierre Lacaux  Robert Delmas  Meinrat O. Andreae 《Journal of Atmospheric Chemistry》1995,22(1-2):163-174

Ozone has been observed in elevated concentrations by satellites over areas previously believed to be background. There is meteorological evidence, that these ozone plumes found over the Atlantic Ocean originate from vegetation fires on the African continent.In a previous study (DECAFE-88), we have investigated ozone and assumed precursor compounds over African tropical forest regions. Our measurements revealed large photosmog layers at altitudes from 1.5 to 4 km. Both chemical and meteorological evidence point to savanna fires up to several thousand km upwind as sources.Here we describe ozone mixing ratios observed over western Africa and compare ozone production ratios from different field measurement campaigns related to vegetation burning. We find that air masses containing photosmog ingredients require several days to develop their oxidation potential, similar to what is known from air polluted by emissions from fossil fuel burning. Finally, we estimate the global ozone production due to vegetation fires and conclude that this source is comparable in strength to the stratospheric input.  相似文献   

Airborne measurements of savanna fire emissions and the regional distributio of pyrogenic pollutants over Western Africa     

Helas  Günter  Lobert  Jürgen  Scharffe  Dieter  Schäfer  Luise  Goldammer  Johann  Baudet  Jean  Ajavon  Ayité-Lô  Ahoua  Brou  Lacaux  Jean-Pierre  Delmas  Robert  Andreae  Meinrat O. 《Journal of Atmospheric Chemistry》1995,22(1-2):217-239

We measured CO₂, CO, CH₄, H₂, and NO₂ in air masses polluted by savanna fires over Côte d'Ivoire, western Africa. Elevated concentrations of these trace gases were found in fire plumes and also in extensive haze layers. Trace gas mixing ratios ranged as high as 605 ppmv for CO₂, 14.8 ppmv for CO, 2.7 ppmv for CH₄, 4.2 ppmv for H₂, and 25 ppbv for NO₂. We compare our emission ratios to those obtained in previous field and laboratory studies. The emission ratios, expressed as an average and as a range or as an average only, were: dCO/dCO₂ 5.3×10^–2 (3–18×10^–2); dCH₄/dCO 5.3×10^–2; dH₂/dCO 2.4×10^–1 and dNO₂/dCO₂ 1.8×10^–4 (1.5–2.2×10^–4). The values found match those found during similar measurements, though our results point to rather vigorous burning in the savanna of western Africa.  相似文献