Evidence for Nearly Complete Decoupling of Very Stable Nocturnal Boundary Layer Overland

Concentrations of (222)Rn at 0.1 m and 6.5 m height above ground level and (222)Rn flux density were measured during nights characterized by strong cooling, light winds and clear sky conditions in the Carpathian Basin in Hungary. A very stable boundary layer (vSBL) formed on 14 nights between 15 August and 3 September 2009. On 12 nights, an estimated 72% (s.d. 20%) of (222)Rn emitted from the surface since sunset was retained within the lowest 6.5 m above the ground until sunrise the following morning. On two nights an intermittent increase in wind speed at 9.4 m height was followed by a rise in temperature at 2.0 m height, indicating a larger atmospheric motion that resulted in (222)Rn at 0.1 m around sunrise being the same as around the preceding sunset. It does not seem to be rare in a large continental basin for a vSBL to be nearly completely decoupled from the atmosphere above for the entire period from sunset to sunrise. © 2011, Springer. The original publication is available at www.springerlink.co

Evidence for Nearly Complete Decoupling of Very Stable Nocturnal Boundary Layer Overland

Concentrations of 222Rn at 0.1m and 6.5m height above ground level and 222Rn flux density were measured during nights characterized by strong cooling, light winds and clear sky conditions in the Carpathian Basin in Hungary. A very stable boundary layer (vSBL) formed on 14 nights between 15 August and 3 September 2009. On 12 nights, an estimated 72% (s.d. 20%) of 222Rn emitted from the surface since sunset was retained within the lowest 6.5m above the ground until sunrise the following morning. On two nights an intermittent increase in wind speed at 9.4m height was followed by a rise in temperature at 2.0m height, indicating a larger atmospheric motion that resulted in 222Rn at 0.1m around sunrise being the same as around the preceding sunset. It does not seem to be rare in a large continental basin for a vSBL to be nearly completely decoupled from the atmosphere above for the entire period from sunset to sunris

Climate control of terrestrial carbon exchange across biomes and continents

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Real-world wintertime CO, N2O, and CO2 emissions of a central European village

Although small rural settlements are only minor individual sources of greenhouse gases and air pollution, their high overall occurrence can significantly contribute to the total emissions of a region or country. Emissions from a rural lifestyle may be remarkably different than those of urban and industrialized regions, but nevertheless they have hardly been studied so far. Here, flux measurements at a tall-tower eddy covariance monitoring site and the footprint model FFP are used to determine the real-world wintertime CO, N2O, and CO2 emissions of a small village in western Hungary. The recorded emission densities, dominantly resulting from residential heating, are 3.5, 0.043, and 72 µg m−2 s−1 for CO, N2O, and CO2, respectively. While the measured CO and CO2 emissions are comparable to those calculated using the assumed energy consumption and applying the according emission factors, the nitrous oxide emissions exceed the expected value by a magnitude. This may indicate that the nitrous oxide emissions are significantly underestimated in the emission inventories, and modifications in the methodology of emission calculations are necessary. Using a three-dimensional forward transport model, we further show that, in contrast to the flux measurements, the concentration measurements at the regional background monitoring site are only insignificantly influenced by the emissions of the nearby village

Terrestrial ecosystem process model Biome-BGCMuSo v4.0: summary of improvements and new modeling possibilities

The process-based biogeochemical model Biome-BGC was enhanced to improve its ability to simulate carbon, nitrogen, and water cycles of various terrestrial ecosystems under contrasting management activities. Biome-BGC version 4.1.1 was used as a base model. Improvements included addition of new modules such as the multilayer soil module, implementation of processes related to soil moisture and nitrogen balance, soil-moisture-related plant senescence, and phenological development. Vegetation management modules with annually varying options were also implemented to simulate management practices of grasslands (mowing, grazing), croplands (ploughing, fertilizer application, planting, harvesting), and forests (thinning). New carbon and nitrogen pools have been defined to simulate yield and soft stem development of herbaceous ecosystems. The model version containing all developments is referred to as Biome-BGCMuSo (Biome-BGC with multilayer soil module; in this paper, Biome-BGCMuSo v4.0 is documented). Case studies on a managed forest, cropland, and grassland are presented to demonstrate the effect of model developments on the simulation of plant growth as well as on carbon and water balance

European Emissions of Halogenated Greenhouse Gases Inferred from Atmospheric Measurements

European emissions of nine representative halocarbons (CFC-11, CFC-12, Halon 1211, HCFC-141b, HCFC-142b, HCFC-22, HFC-125, HFC-134a, HFC-152a) are derived for the year 2009 by combining long-term observations in Switzerland, Italy, and Ireland with campaign measurements from Hungary. For the first time, halocarbon emissions over Eastern Europe are assessed by top-down methods, and these results are compared to Western European emissions. The employed inversion method builds on least-squares optimization linking atmospheric observations with calculations from the Lagrangian particle dispersion model FLEXPART. The aggregated halocarbon emissions over the study area are estimated at 125 (106–150) Tg of CO₂ equiv/y, of which the hydrofluorocarbons (HFCs) make up the most important fraction with 41% (31–52%). We find that chlorofluorocarbon (CFC) emissions from banks are still significant and account for 35% (27–43%) of total halocarbon emissions in Europe. The regional differences in per capita emissions are only small for the HFCs, while emissions of CFCs and hydrochlorofluorocarbons (HCFCs) tend to be higher in Western Europe compared to Eastern Europe. In total, the inferred per capita emissions are similar to estimates for China, but 3.5 (2.3–4.5) times lower than for the United States. Our study demonstrates the large benefits of adding a strategically well placed measurement site to the existing European observation network of halocarbons, as it extends the coverage of the inversion domain toward Eastern Europe and helps to better constrain the emissions over Central Europe