[...]... best define functional types and integrate state variables and properties in time and space? In: A.F Bouwman (Ed.) Approaches to scaling of trace gas fluxes in ecosystems Developments in Atmospheric Science 24 Elsevier, Amsterdam, pp 151-167 Sofiev, M (1999) Validation of model results on different scales In: A.F Bouwman (Ed.) Approaches to scaling of trace gas fluxes in ecosystems Developments in Atmospheric... species, deposition rates can be used to validate model results A discussion of validation tools is, however, outside the scope of this paper We refer to Heimann and Kaminski (1999) for a review of inverse modelling and atmospheric monitoring networks, Trumbore (1999) for a review of the use of isotopes and tracers in validation and scaling of trace gas fluxes, and to Sofiev (1999) for a discussion on validation... 1, US Department of Commerce, Washington, DC Conrad, R and F Dentener (1999) The application of the compensation point concepts in scaling of fluxes In: A.F Bouwman (Ed.) Approaches to scaling of trace gas fluxes in ecosystems Developments in Atmospheric Science 24 Elsevier, Amsterdam, pp 203-216 Cramer, W and A Fischer (1996) Data requirements for terrestrial ecosystem modelling In: B Walker and W... concentrations that are within the range o f - a factor of 4 or more for primary Towards reliable global estimates of emissions of trace gases and aerosols 19 pollutants as monthly or seasonal averages in flat terrain 10-100 km downwind of sources (Jones, 1986) However, trace gas fluxes may often involve some form of chemical processing in the atmosphere downwind of the point of emission, which may contribute... Office, Bracknell, UK Tegen, I and I Fung (1995) Contribution to the atmospheric mineral aerosol load from land surface modification Journal of Geophysical Research 100:18707-18726 Trumbore, S (1999) Role of isotopes and tracers in scaling trace gas fluxes In: A.F Bouwman (Ed.) Approaches to scaling of trace gas fluxes in ecosystems Developments in Atmospheric Science 24 Elsevier, Amsterdam, pp 257-274... atmosphere interface, inadequate accounting, and assessments of the source-sink strengths of these gases (Bouwman, 1990) The problems contributing to the latter factor are the unavailability of sensitive analytical devices for field measurements of trace gas fluxes, lack of effective sampling design for reducing variabilities in point measurements, and lack of proven mechanistic tools for reconciling flux... gradient of scalar entities (e.g., heat, water vapor, and gas) can be of the order of 102 to 103 m depending on the persistence of uniform surface terrain, type of vegetation, and surface cover Transport of gas entities downstream from the source is determined by the rate of turbulent mixing as wind blows steadily over the surface In situ identification of the source and trajectory monitoring of gas fluxes. .. Taylor and P Zimmerman (1995) A global model of natural volatile organic compound emissions Journal of Geophysical Research 100:8873-8892 Heimann, M and T Kaminski (1999) Inverse modelling approaches to infer surface trace gas fluxes from observed atmospheric mixing ratios ",: A.F Bouwman (Ed.) Approache to scaling of trace gasfluxes in ecosystems Developments in Atmospheric Science 24 Elsevier, Amsterdam,... conditional sampling, that do not require fast response analytical devices for measuring instantaneous gas concentrations, gas chromatography is most appropriate for analyzing CO2, CH4 and N20 Sampling of gases using chambers can be automated for continuous monitoring of surface gas fluxes, including CH4 and N20 fluxes from rice paddies (Schtitz et al., 1989; Bronson et al., 1997) In conjunction with... accuracy of the spatial data Finally, a combination of vegetation/land-cover data with climate and soil information may provide a basis for classification into functions Towards reliable global estimates of emissions of trace gases and aerosols |5 2.3 Uncertainties in the economic data on land use The major forms of economic land use activities generating emissions of trace gases include livestock production, . group included experts in the determination of gas fluxes, modellers, specialists in the use of isotopes and tracers, and researchers working on the compilation of regional and global inventories. identification of gaps in knowledge, and on finding solutions and determining future research directions. The book is the result of an international workshop on " ;Scaling of trace gas fluxes between. effort of a diverse group of scientists to review the state- of- the art in the field of scaling of fluxes of greenhouse gases and ozone and aerosol precursors. It focuses on identification of gaps