Presentation of the EURODELTA III intercomparison exercise – evaluation of the chemistry transport models' performance on criteria pollutants and joint analysis with meteorology

Abstract. The EURODELTA III exercise has facilitated a comprehensive intercomparison and evaluation of chemistry transport model performances. Participating models performed calculations for four 1-month periods in different seasons in the years 2006 to 2009, allowing the influence of different meteorological conditions on model performances to be evaluated. The exercise was performed with strict requirements for the input data, with few exceptions. As a consequence, most of differences in the outputs will be attributed to the differences in model formulations of chemical and physical processes. The models were evaluated mainly for background rural stations in Europe. The performance was assessed in terms of bias, root mean square error and correlation with respect to the concentrations of air pollutants (NO2, O3, SO2, PM10 and PM2.5), as well as key meteorological variables. Though most of meteorological parameters were prescribed, some variables like the planetary boundary layer (PBL) height and the vertical diffusion coefficient were derived in the model preprocessors and can partly explain the spread in model results. In general, the daytime PBL height is underestimated by all models. The largest variability of predicted PBL is observed over the ocean and seas. For ozone, this study shows the importance of proper boundary conditions for accurate model calculations and then on the regime of the gas and particle chemistry. The models show similar and quite good performance for nitrogen dioxide, whereas they struggle to accurately reproduce measured sulfur dioxide concentrations (for which the agreement with observations is the poorest). In general, the models provide a close-to-observations map of particulate matter (PM2.5 and PM10) concentrations over Europe rather with correlations in the range 0.4–0.7 and a systematic underestimation reaching −10 µg m−3 for PM10. The highest concentrations are much more underestimated, particularly in wintertime. Further evaluation of the mean diurnal cycles of PM reveals a general model tendency to overestimate the effect of the PBL height rise on PM levels in the morning, while the intensity of afternoon chemistry leads formation of secondary species to be underestimated. This results in larger modelled PM diurnal variations than the observations for all seasons. The models tend to be too sensitive to the daily variation of the PBL. All in all, in most cases model performances are more influenced by the model setup than the season. The good representation of temporal evolution of wind speed is the most responsible for models' skillfulness in reproducing the daily variability of pollutant concentrations (e.g. the development of peak episodes), while the reconstruction of the PBL diurnal cycle seems to play a larger role in driving the corresponding pollutant diurnal cycle and hence determines the presence of systematic positive and negative biases detectable on daily basis

Der Beitrag des Ferntransports zu den PM10- und den NO 2-Konzentrationen in Deutschland unter besonderer Betrachtung der polnischen Emissionen

DER BEITRAG DES FERNTRANSPORTS ZU DEN PM10- UND DEN NO 2-KONZENTRATIONEN IN DEUTSCHLAND UNTER BESONDERER BETRACHTUNG DER POLNISCHEN EMISSIONEN Der Beitrag des Ferntransports zu den PM10- und den NO 2-Konzentrationen in Deutschland unter besonderer Betrachtung der polnischen Emissionen / Stern, Rainer (Rights reserved) ( -

Gauge parameter dependence in the background field gauge and the construction of an invariant charge

By using the enlarged BRS transformations we control the gauge parameter dependence of Green functions in the background field gauge. We show that it is unavoidable -- also if we consider the local Ward identity -- to introduce the normalization gauge parameter $\xi_o$, which enters the Green functions of higher orders similarly to the normalization point $\kappa$. The dependence of Green functions on $\xi_o$ is governed by a further partial differential equation. By modifying the Ward identity we are able to construct in 1-loop order a gauge parameter independent combination of 2-point vector and background vector functions. By explicit construction of the next orders we show that this combination can be used to construct a gauge parameter independent RG-invariant charge. However, it is seen that this RG-invariant charge does not satisfy the differential equation of the normalization gauge parameter $\xi_o$, and, hence, is not $\xi_o$-independent as required.Comment: 29 pages, LaTe

Can the Knowledge Society Turn Around 500 Years of Overfishing?

As early as 1491 in an Act of Parliament during the reign of Henry VII of England, overfishing and the capture of juveniles were recognized as root causes of declining fish catches, and since then, minimum capture sizes, closed seasons and areas, and gear restrictions have been implemented to address the problem. Over 500 years later, France has been sentenced by the European Court to pay €20 million in penalties for systematically ignoring minimum sizes set by the European Commission, and most stocks in European waters are at historically low levels and in danger of collapse. Clearly, fisheries management by authorities has not worked. Under modern top-down management, catches are often legalized above safe levels and below safe sizes because it is easier to risk the collapse of fish stocks than to generate short term social or political conflict. This practice has been termed “convenience overfishing” if observed in rich countries, where fishing is not economically important relative to the overall economy. In the face of such long-term, chronic failure of top-down management, maybe the time has come for a bottom-up approach to fisheries that is simple enough to allow stakeholders and the public to participate. The preconditions for such change seem good: consumers do care about seafood and the marine environment and there are several examples in other areas where consumer choice has altered the behavior of the food industry. Also, overfishing can be detected with a single fish in hand, because there is a body size at which most specimens of a given species have had a chance to reproduce, and where the catch is obtained with least impact on the population. These sizes are known for practically all food fishes, even for fillets, and can be easily controlled by traders, retailers and consumers with the respective knowledge. Details of and first experiences with such "common sense fisheries management" based on body sizes and stakeholder participation are presented

Proceedings of KogWis 2012. 11th Biannual Conference of the German Cognitive Science Society

The German cognitive science conference is an interdisciplinary event where researchers from different disciplines -- mainly from artificial intelligence, cognitive psychology, linguistics, neuroscience, philosophy of mind, and anthropology -- and application areas -- such as eduction, clinical psychology, and human-machine interaction -- bring together different theoretical and methodological perspectives to study the mind. The 11th Biannual Conference of the German Cognitive Science Society took place from September 30 to October 3 2012 at Otto-Friedrich-Universität in Bamberg. The proceedings cover all contributions to this conference, that is, five invited talks, seven invited symposia and two symposia, a satellite symposium, a doctoral symposium, three tutorials, 46 abstracts of talks and 23 poster abstracts

EURODELTA - Evaluation of a Sectoral Approach to Integrated Assessment Modeling - Second Report

The EURODELTA project is a continuing collaboration between the European Commission Joint Research Centre (JRC) at Ispra (Italy) and five air quality modeling teams at Ineris (France), the Free University of Berlin (Germany), Met.no (Norway), TNO (Netherlands) and SMHI (Sweden). This phase of Eurodelta investigates how different air quality models would represent the effect on pollutant impacts of applying, on a European scale, emission reductions to individual emission sectors. The reason for doing this is to test whether there are important sensitivities not captured by the sound science approach to air quality policy making on a European scale which is based on an integrated assessment (IA) approach and embodied in the IIASA RAINS/GAINS model. This study shows that there are important differences between sectors in the amount of concentration (deposition) reduction obtained by changing a pollutant emission. This difference is not accounted for in the present process used to evaluate future national emissions ceiling reductions for both beneficial effect and cost-effectiveness. This raises the possibility that, when national bodies consider how to implement an emission ceiling taking account of the information used in deriving that ceiling, choices might be made that are less effective than expected.JRC.DDG.H.4-Transport and air qualit

Improving the defect tolerance of PBF-LB/M processed 316L steel by increasing the nitrogen content

Nitrogen (N) in steels can improve their mechanical strength by solid solution strengthening. Processing N-alloyed steels with additive manufacturing, here laser powder bed fusion (PBF-LB), is challenging as the N-solubility in the melt can be exceeded. This degassing of N counteracts its intended positive effects. Herein, the PBF-LB processed 316L stainless steel with increased N-content is investigated and compared to PBF-LB 316L with conventional N-content. The N is introduced into the steel by nitriding the powder and mixing it with the starting powder to achieve an N-content of approximately 0.16 mass%. Thermodynamic calculations for maximum solubility to avoid N outgassing and pore formation under PBF-LB conditions are performed beforehand. Based on the results, a higher defect tolerance under fatigue characterized by Murakami model can be achieved without negatively influencing the PBF-LB processability of the 316L steel. The increased N-content leads to higher hardness (+14%), yield strength (+16%), tensile strength (+9%), and higher failure stress in short time fatigue test (+16%)

Invited Editorial: Health as a crucial driver for climate policy

Health impacts of climate change and the need to prevent them should be at centre stage of the ongoing debate on climate policies (1). We have specifically prepared this series of papers to be available for the COP151 conference in Copenhagen, to which the world looks to agree on targets and procedures to reduce greenhouse gas (GHG) emissions on the basis of fair burden-sharing between high and low-income countries

An operational model of joint attention - Timing of the initiate-act in interactions with a virtual human

Pfeiffer-Leßmann N, Pfeiffer T, Wachsmuth I. An operational model of joint attention - Timing of the initiate-act in interactions with a virtual human. In: Dörner D, Goebel R, Oaksford M, Pauen M, Stern E, eds. Proceedings of KogWis 2012. Bamberg, Germany: University of Bamberg Press; 2012: 96-97

Directional emission of white light via selective amplification of photon recycling and Bayesian optimization of multi-layer thin films

Over the last decades, light-emitting diodes (LED) have replaced common light bulbs in almost every application, from flashlights in smartphones to automotive headlights. Illuminating nightly streets requires LEDs to emit a light spectrum that is perceived as pure white by the human eye. The power associated with such a white light spectrum is not only distributed over the contributing wavelengths but also over the angles of vision. For many applications, the usable light rays are required to exit the LED in forward direction, namely under small angles to the perpendicular. In this work, we demonstrate that a specifically designed multi-layer thin film on top of a white LED increases the power of pure white light emitted in forward direction. Therefore, the deduced multi-objective optimization problem is reformulated via a real-valued physics-guided objective function that represents the hierarchical structure of our engineering problem. Variants of Bayesian optimization are employed to maximize this non-deterministic objective function based on ray tracing simulations. Eventually, the investigation of optical properties of suitable multi-layer thin films allowed to identify the mechanism behind the increased directionality of white light: angle and wavelength selective filtering causes the multi-layer thin film to play ping pong with rays of light