Analysis of Model Results for the Turning of the Wind and Related Momentum Fluxes in the Stable Boundary Layer

The turning of wind with height and the related cross-isobaric (ageostrophic) flow in the thermally stable stratified boundary layer is analysed from a variety of model results acquired in the first Global Energy and Water Cycle Experiment (GEWEX) Atmospheric Boundary Layer Study (GABLS1). From the governing equations in this particular simple case it becomes clear that the cross-isobaric flow is solely determined by the surface turbulent stress in the direction of the geostrophic wind for the quasi-steady state conditions under consideration. Most models indeed seem to approach this relationship but for very different absolute values. Because turbulence closures used in operational models typically tend to give too deep a boundary layer, the integrated total cross-isobaric mass flux is up to three times that given by research numerical models and large-eddy simulation. In addition, the angle between the surface and the geostrophic wind is typically too low, which has important implications for the representation of the larger-scale flow. It appears that some models provide inconsistent results for the surface angle and the momentum flux profile, and when the results from these models are removed from the analysis, the remaining ten models do show a unique relationship between the boundary-layer depth and the surface angle, consistent with the theory given. The present results also imply that it is beneficial to locate the first model level rather close to the surface for a proper representation of the turning of wind with height in the stable boundary laye

Evidence cross-validation and Bayesian inference of MAST plasma equilibria

In this paper, current profiles for plasma discharges on the Mega-Ampere Spherical Tokamak (MAST) are directly calculated from pickup coil, flux loop and Motional-Stark Effect (MSE) observations via methods based in the statistical theory of Bayesian analysis. By representing toroidal plasma current as a series of axisymmetric current beams with rectangular cross-section and inferring the current for each one of these beams, flux-surface geometry and q-profiles are subsequently calculated by elementary application of Biot-Savart's law. The use of this plasma model in the context of Bayesian analysis was pioneered by Svensson and Werner on the Joint-European Tokamak (JET) [J. Svensson and A. Werner. Current tomography for axisymmetric plasmas. Plasma Physics and Controlled Fusion, 50(8):085002, 2008]. In this framework, linear forward models are used to generate diagnostic predictions, and the probability distribution for the currents in the collection of plasma beams was subsequently calculated directly via application of Bayes' formula. In this work, we introduce a new diagnostic technique to identify and remove outlier observations associated with diagnostics falling out of calibration or suffering from an unidentified malfunction. These modifications enable good agreement between Bayesian inference of the last closed flux-surface (LCFS) with other corroborating data, such as such as that from force balance considerations using EFIT++ [L. Appel et al., Proc. 33rd EPS Conf., Rome, Italy, 2006]. In addition, this analysis also yields errors on the plasma current profile and flux-surface geometry, as well as directly predicting the Shafranov shift of the plasma core.This work was jointly funded by the Australian Government through International Science Linkages Grant No. CG130047, the Australian National University, the United Kingdom Engineering and Physical Sciences Research Council under Grant No. EP/G003955, and by the European Communities under the contract of Association between EURATOM and CCFE

Eulerian and modified Lagrangian approaches to multi-dimensional condensation and collection

Turbulence is argued to play a crucial role in cloud droplet growth. The combined problem of turbulence and cloud droplet growth is numerically challenging. Here, an Eulerian scheme based on the Smoluchowski equation is compared with two Lagrangian superparticle (or su- perdroplet) schemes in the presence of condensation and collection. The growth processes are studied either separately or in combination using either two-dimensional turbulence, a steady flow, or just gravitational acceleration without gas flow. Good agreement between the differ- ent schemes for the time evolution of the size spectra is observed in the presence of gravity or turbulence. Higher moments of the size spectra are found to be a useful tool to characterize the growth of the largest drops through collection. Remarkably, the tails of the size spectra are reasonably well described by a gamma distribution in cases with gravity or turbulence. The Lagrangian schemes are generally found to be superior over the Eulerian one in terms of computational performance. However, it is shown that the use of interpolation schemes such as the cloud-in-cell algorithm is detrimental in connection with superparticle or superdroplet approaches. Furthermore, the use of symmetric over asymmetric collection schemes is shown to reduce the amount of scatter in the results.Comment: 36 pages, 17 figure

Quasi-thermal Comptonization and gamma-ray bursts

Quasi-thermal Comptonization in internal shocks formed between relativistic shells can account for the high energy emission of gamma-ray bursts. This is in fact the dominant cooling mechanism if the typical energy of the emitting particles is achieved either through the balance between heating and cooling or as a result of electron-positron pair production. Both processes yield sub or mildly relativistic energies. In this case the synchrotron spectrum is self-absorbed, providing the seed soft photons for the Comptonization process, whose spectrum is flat [F(v) ~ const], ending either in an exponential cutoff or a Wien peak, depending on the scattering optical depth of the emitting particles. Self-consistent particle energy and optical depth are estimated and found in agreement with the observed spectra.Comment: 10 pages, ApJ Letters, accepted for publicatio

Clothing in the Arctic: A Means of Protection, a Statement of Identity

The interest in clothing as a powerful item for cultural inquiry has recently increased among anthropologists. This has to do with its dual connection to habitat and cultural identity, allowing for ecological as well as symbolic analysis. The identification of contexts in which identity is communicated by means of clothing is considered an additional dimension to the study of clothing proper. Clothing is viewed as the most efficient means of non-verbal communication of cultural identity as well as culture-specific values and standards. The communicative power of clothing is especially salient in various inter-ethnic contexts. Referring to the Sami in northern Fennoscandia, clothing appears as an effective ethnic marker. At the same time the vitality of clothing as a material object is evident.Key words: clothing, ethnicity, SámiRÉSUMÉ. Demibrement, les anthropologues ont porté un intérêt de plus en plus marqué pour le vêtement en tant qu’article important dans l’investigation culturelle. Cela est dû au double rapport du vêtement à la fois avec l’habitat et avec l’identité culturelle, ce qui permet une analyse écologiqueainsi qu’une analyse symbolique. L’identification des contextes dans lesquels l’identité est transmise par le biais du vêtement est vue comme une dimension supplémentaire à l’étude du vêtement lui-même. On perçoit le vêtement comme le moyen le plus efficace de communiquer non verbalement l’identité culturelle ainsi que les valeurs et normes spécifiques à une culture donnée.La force communicative du vêtement se fait particulièrement remarquer dans divers contextes interethniques. En ce qui concerne les Samits de la Fennoscandie septentrionale, le vêtement apparaît comme une marque ethnique efficace. En même temps ressort la vitalité du vêtement en tant qu’objet matériel.Mots clés: vêtement, ethnicité, Samit

Ethnopolitics among the Sámi in Scandinavia: A Basic Strategy toward Local Autonomy

Communities in the far north face severe difficulties in trying to function as autonomous units due to the north-south axis in which northern resources are sought by southern industrial powers. Ethnopolitics as practiced by the Sámi in Scandinavia represent a political solution to those difficulties. For ethnopolitical processes to work to the advantage of the minority people, the communities must have a power base leading to local autonomy. Such autonomy is based typically on land and water rights. The entire ethnic minority is dependent on viable local communities leading to cultural pluralism, an effective defense against assimilation by the majority society. Cultural viability, firm land rights and institutionalized ethnopolitics provide the basis for strengthening local autonomies to such ends.Key words: Sàmi, ethnopolitics, local autonomy, land rights, cultural viabilityMots clés: Sami, ethnopolitique, autonomie locale, droits territoriaux, viabilité culturell

National Libraries and the Semantic Web: Requirements and Applications

Semantics are an integral part of bibliographic (meta-)data including authority files. So far, however, there have been only rudimentary attempts to make those data visible on the Semantic Web. This paper presents a sketch of what (national) libraries will need to supply in order to allow for broad use of their data on the Semantic Web. The main points are persistent URIs for all entities, a set of welldefined vocabularies to describe the data, and the provision of query interfaces suitable for the Semantic Web. In the final section three current projects from the German National Library are presented, in which the semantics of bibliographic data is presented using Semantic Web techniques

Exploring organizational capacity in a Sport for Development and Peace setting.

Recent Sport for Development and Peace (SDP) scholarship has noted the need for exploring organizational aspects in order to advance SDP theory and practice. One particular unexplored aspect of SDP is organizational capacity. Therefore, the purpose of this study was to explore elements of organizational capacity in SDP organizations operating programming in urban settings outside the top three metropolitan areas (New York, Los Angeles, and Chicago) of the United States. The researcher conducted semistructured interviews with Executive Directors of 17 nonprofit organizations. This qualitative inquiry was guided by Hall et al.’s (2003) three-dimensional framework on organizational capacity. Those three dimensions are: human resources capacity, financial resources capacity, and structural capacity. Findings from this study further our understanding of nonprofit capacity since there is a consensus among scholars that elements within each capacity dimension are context specific. Several elements emerged with each capacity dimension; (a) human resources capacity (board involvement, board recruitment, board retention, paid staff, finding roles, shared values and engagement, staff recruitment, staff retention, staff training, volunteer dependence, volunteer recruitment); (b) financial capacity (financial management, fundraising, financial campaigns, grant funding, special events, other revenue sources, expenses); and (c) structural capacity (partnership management, mutually beneficial relationships, memorandums of understanding, , partnership formation, organizational flexibility, internal structures, organizational culture, access to facilities, internal systems and procedures, strategic planning, plan implementation, and evaluation). Findings also indicated perceived connections between the capacity dimensions. Overall, this study contributes to Svensson and Hambrick’s (in press) call for an empirical and theoretical discussion on the nature of capacity in SDP. Findings in this study extend our understanding of organizational capacity among nonprofit sport organizations and highlight the lived experiences of SDP leaders within existing complex environments. The aim of this research was not only to identify elements of capacity within SDP, but also to explore how SDP organizations are trying to address existing capacity challenges. This study’s findings provide a foundation for future research on the nature of organizational capacity in SDP. Developing a better understanding of capacity in SDP is imperative for designing more effective capacity-building initiatives that help increase the ability of these organizations to fulfill their respective missions