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Veröffentlichung TransCom N2O model inter-comparison - Part 2: Atmospheric inversion estimates of N2O emissions(2014)This study examines N2O emission estimates from five different atmospheric inversion frameworks based on chemistry transport models (CTMs). The five frameworks differ in the choice of CTM, meteorological data, prior uncertainties and inversion method but use the same prior emissions and observation data set. The posterior modelled atmospheric N2O mole fractions are compared to observations to assess the performance of the inversions and to help diagnose problems in the modelled transport. Additionally, the mean emissions for 2006 to 2008 are compared in terms of the spatial distribution and seasonality. Overall, there is a good agreement among the inversions for the mean global total emission, which ranges from 16.1 to 18.7 TgN yrg^'1 and is consistent with previous estimates. Ocean emissions represent between 31 and 38% of the global total compared to widely varying previous estimates of 24 to 38%. Emissions from the northern mid- to high latitudes are likely to be more important, with a consistent shift in emissions from the tropics and subtropics to the mid- to high latitudes in the Northern Hemisphere; the emission ratio for 0-30˚ N to 30-90˚ N ranges from 1.5 to 1.9 compared with 2.9 to 3.0 in previous estimates. The largest discrepancies across inversions are seen for the regions of South and East Asia and for tropical and South America owing to the poor observational constraint for these areas and to considerable differences in the modelled transport, especially inter-hemispheric exchange rates and tropical convective mixing. Estimates of the seasonal cycle in N2O emissions are also sensitive to errors in modelled stratosphere-to-troposphere transport in the tropics and southern extratropics. Overall, the results show a convergence in the global and regional emissions compared to previous independent studies.©Author(s) 2014. Quelle: http://www.scopus.comVeröffentlichung Critical Loads of Cadmium, Lead and Mercury and Their Exceedances in Europe(2015)In this chapter information is summarized on the assessment of the risk of impacts of cadmium, lead and mercury emissions and related depositions of these metals, with an emphasis on natural areas in Europe. Depositions are compared to critical loads to identify areas in Europe where critical loads are exceeded. Critical loads of cadmium, lead and mercury were based on (i) computations by 18 Parties to the Convention on Long-range Transboundary Air Pollution (LRTAP) and (ii) computations from available data on soil chemistry, meteorology and land cover for the other Parties. Two target years are considered, i.e. 2010 and 2020. Emissions for these years have been assessed in support of the negotiations for the review and possible revision of the Heavy metal protocol (Aarhus 1998). The relationship between emissions, depositions and critical load exceedances is analysed assuming the implementation of abatement techniques under Current LEgislation in 2010 (CLE2010) and in 2020 under Full Implementation of the Aarhus protocol (FI2020). Comparing the critical loads to atmospheric depositions in these years, shows that cadmium deposition is not a widespread risk in either years, that the computed risk of lead deposition affects about 22 and 16?% of natural European area in 2010 and 2020, respectively, and that mercury deposition is computed to affect an area of more than 74?% in both years.Quelle: http://link.springer.comVeröffentlichung Modelling approach for a PCB inventory in our environment(2016) Knetsch, GerlindeThe data of more than 100 monitoring programs in Germany for the substance group of persistent organic pollutants (POPs), including the polychlorinated biphenyls (PCBs) are to be used for a modelling approach for a PCB inventory.The application landscape of the Federation/Laender POP-Dioxin-Database, which is operated in the German Environment Agency, pursues an interdisciplinary approach and includes all these data. A cross-media evaluation and assessment of environmental data are necessary and relevant to the target system, compiling an inventory of PCBs in our environment. The question arises how the integrated modelling concept can control the knowledge-based methods, with the aim to assess the state of PCB contamination in context to PCB-footprints in the environment.
Quelle: Modelling approach for a PCB inventory in our environment / Gerlinde Knetsch. - Illustrationen. In: Proceedings of the 8th International Congress on Environmental Modelling and Software (iEMSs), July 10-14, 2016, Toulouse, France / Sabine Sauvage, José-Miguel Sánchez-Pérez, Andrea Rizzoli (Eds.). - Toulouse. - (2016), 1 Onlineressource (6 Seiten). - ISBN 978-88-9035-745-9