Biogenic emissions/sources

FIGURE 6.26 Structures of some oxygen-containing organics with biogenic emission sources. 

Note One Tg (teragram) is equivalent to 1 million metric tons. Continental biogenic sources includes animal, microbial, and foliage emissions SOURCE Finlcryson-Pitts Pitts (2000)... 

Other sources of river sulfate Include natural biogenic emissions to atmosphere delivered to land in rain (3%), votanism (8%) and pyrite weathering (11 %). 

Simoneit BRT, Organic matter of the troposphere—V Appfication of molecular marker analysis to biogenic emissions into the troposphere for source reconcih-xtions, JAtmos Chem 8 251—275, 1989. 

The composition and sources of particles are discussed in detail in Chapter 9. Major natural sources of particles include terrestrial dust caused by winds, sea spray, biogenic emissions, volcanic eruptions, and wild-... 

Particles collected in regions influenced by anthropogenic emissions and those in aged air masses where there has been ample opportunity for oxidation are even more complex than those in remote regions. Thus, they may contain not only the organics from biogenic emissions but also complex organics that either have been directly emitted from sources associated with human activities or have been formed in air from reactions of primary emissions. 

Simoneit, B. R. T., Organic Matter of the Troposphere—V Application of Molecular Marker Analysis to Biogenic Emissions into the Troposphere for Source Reconciliations, . /. Atmos. Chem., 8, 251-275 (1989). 

An alternative to the above described approaches is the radiocarbon method that allows a distinction of contemporary carbon (from biogenic emissions and combustion of biomass) and carbon from combustion of fossil fuels in particulate carbonaceous matter [15, 41,42]. In contrast to fossil fuels where the 14C isotope is completely depleted, CM emitted from WB shows a contemporary radiocarbon level. Radiocarbon measurements are often combined with measurements of complementary source specific tracers (macro-tracer) for additional information of source impacts [14, 43, 44]. 

There have been a number of studies of biogenic emissions of sulfur gases other than H2S reported in the literature. Most of these have been concerned with high productivity sources, such as salt marshes and tidal areas and are summarized in Table II. 

Table III. Biogenic Emissions of Sulfur Compounds from Inland Soils Source Montb of Emission Rate (g S nr2 yr1) Ref.

As with the finer-scale TAPM experience, it is vitally important to accurately include biogenic emissions. In Australia, concentrations of up to 60 ppb ozone are measured in country areas with no evident industry or vehicle sources. 

Could you also kindly try to elaborate a little more on your biogenic sources of emissions, because I think they may be on the low side, particularly if you restrict yourself to the sources which are occurring in the temperate zones. When you include the biogenic emissions of sulphur which are... 

Carbonyl sulfide is also the most abundant reduced sulfur gas in Earth s troposphere, but for completely different reasons. Volcanic sources of OCS are negligible by comparison with biogenic emissions, which are important sources of several reduced sulfur gases (e.g., OCS, H2S, (CH3)2S, (CH3)2S2, and CH3SH) in the terrestrial troposphere. Many of these gases are ultimately converted into sulfate aerosols in the troposphere, but OCS is mainly lost by transport into the stratosphere, where it is photochemically oxidized to SO2 and then to sulfuric acid aerosols, which form the Junge layer at —20 km in Earth s stratosphere. 

In an international effort, the Reactive Chlorine Emissions Inventory (Keene et al., 1999, and references therein) was compiled which includes chlorine emissions from the following four source-type classes (i) oceanic and terrestrial biogenic emissions (ii) sea salt aerosol production and dechlorination (iii) biomass burning and (iv) exclusively anthropogenic sources like industry, fossil fuel combustion, and incineration. They provide numbers from atmospheric burdens and fluxes for the individual species and sources. 

Biogenic sources of NO are generally too small to contribute signihcantly to pollution events. Biogenic emissions represent —5% of total NO emissions in the USA (compared to 50% of total VOCs) (Williams et al, 1992). Biogenic NO emissions can be important in intensively farmed regions, where soil emission of NO is enhanced by heavy use of fertilizers. 

Further measurements and calculations are necessary in order to improve the emission profiles of solvent use and to include additional emission sources such as evaporative losses of motor fuel, natural gas leakage, stationary fuel combustion and biogenic emissions to the CMB apportion analysis. 

The chemical composition of the atmosphere is determined by the emission of compounds from marine and terrestrial biospheres, anthropogenic sources and their chemistry and deposition processes. Biogenic emissions depend on physiologi-... 

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