62880 research outputs found
Sort by
Improving turbulent representation of shallow cumulus convection in the grey-zone
Get PDFShallow cumulus clouds are precursors to deep convection, which can lead to extreme weather
events that are difficult to forecast. Therefore, to more accurately predict these events, the preceding environment must first be accurately forecast. Advances in computational power have
enabled numerical weather prediction models to run with kilometre and sub-kilometer scale
grids. Such models can only partially resolve the dominant turbulent structures within the flow,
and therefore the unresolved turbulence still needs to be parametrized. Traditional parametrization schemes for shallow cumulus convection are not valid at these grid scales, as they rely on
the assumption that all turbulent motions are entirely subgrid scale. This gives rise to the grey-zone regime, which occurs when the scales of the dominant turbulent motions are comparable
to the grid length of the model. The aim of this work is to improve the model’s ability to capture
the effects, at coarse resolution, of the turbulent structures which transport heat, moisture, and
momentum to cumulus clouds, thereby mitigating the impact of the grey-zone.
The primary objective of this research is to develop a parametrization that enables the extension of large eddy simulation (LES) abilities to coarser grid scales, traditionally categorised
as grey-zone scales, while maintaining accuracy and low computational costs. The Met Office/NERC Cloud (MONC) LES model was used to produce high-resolution fields for three
case studies: an idealised dry convective boundary layer case, the Barbados Oceanographic
and Meteorological EXperiment (BOMEX) case, and the Atmospheric Radiation Measurement
(ARM) case. The dynamic Smagorinsky equations were applied to the resulting fields to produce flow-dependent Smagorinsky parameters. These parameters define the mixing length in
the model. By analysing their behaviour, significant variations in turbulent mixing have been
identified between the mixed layer, cloud-free environment, and in-cloud regions of the cloud-topped boundary layer (CTBL). The findings reveal that the Smagorinsky parameters for momentum, heat, and moisture are significantly influenced by both the flow regime and filter scale.
These dependencies are not accounted for in the standard model. A scale-adaptive relationship
between height and the Smagorinsky parameters could then be derived for each variable.
A novel parametrization scheme has been developed using these relationships to serve as a grey-zone adaption, enabling the model to capture the key flow dependencies without incurring high
computational expense. This aims to deliver the benefits of a dynamic Smagorinsky method but
negates the need to compute the parameters at each grid point and time step. The MONC model
was modified to include this parametrization in the subgrid scheme, and the resulting grey-zone
simulations demonstrated substantial improvements, particularly in terms of cloud initiation
time and cloud layer growth. Furthermore, the research underscores the importance of recognizing the variations in turbulent mixing lengths, as the dynamics of the turbulent flow in the CTBL are inherently linked to the grid scale, stability, and flow regimes. This parametrization
addresses the limitations of using fixed parameter values when modelling convective turbulence
in a CTBL. This research presents a significant step forward in addressing the challenges posed
by the grey-zone in modelling shallow cumulus convection. Valuable insights into the dynamics
of turbulent mixing in the CTBL offer a promising framework for advancing the capabilities of
LES models in the grey-zone regime
The impact of armed conflicts and forced migration on labour markets: systematic literature review and future research agenda
Get PDFThis study investigates how forced migration resulting from armed conflicts influences regional development, highlighting the double-edged impact it has on labor markets. This study, based on an inter-disciplinary systematic literature review of 70 rigorously-selected peer-reviewed publications over the last 10 years (2013-2023), confronts the findings of studies on migration, armed conflicts and labour markets to shed a light on the economic and social impact of forced migration on host countries, home countries and the migrants themselves. The selected sample of papers highlights the different ways in which forced migration resulting from 25 different armed conflicts affected labor markets. Four main thematic clusters emerge from the literature: the socio-economic impact of armed conflicts on labour markets, the professional development of forced migrants in host countries, the impact of armed conflicts on the labour force of home countries and the social and psychological aspects of forced migration. By bringing together insights from economics, social studies and international relations, the authors make policy recommendations on the combination of factors that allow for a smooth integration of forced migrants into host labour markets
From managerialism to toxic leadership: the moderating effect of ethical climate in the healthcare sector
Get PDFA hegemonic neoliberal ideology dominates all areas of work in Turkey, including healthcare. Though neoliberalism has been studied extensively from the perspective of meaning, values, and processes, managerial and leadership behavior dynamics require further research. This study analyzes the relationship between managerialism, toxic leadership, and ethical climate in an industry swept up by untamed neoliberalism, particularly in a nation where employment and human rights are ceremoniously protected. Through an analysis of medical doctors working in 207 public and private university hospitals in Turkey, we explored the role of managerialism and four distinct ethical climate types, resulting in the emergence of toxic leadership behaviors during the global pandemic. We theorize the extent to which toxic leaders emerge from managerialism. We further explain why the hegemonic Turkish leadership culture thrives in toxic behaviors such as paternalism, fealty, ingratiation, nepotism, and cronyism in the context of neoliberal expansion
Voice quality, pitch, and gender discrimination
No full textThis chapter explores the relationship between the voice and gender discrimination in popular culture and academic research, focusing on voice quality, uptalk, and pitch. After considering the historical backdrop where cisgender, male voices were taken as default in research and pointing to media examples where the voice operates as a site for gender bias, this chapter considers the extent to which research in phonetics and adjacent fields reinforces popular misconceptions, and how useful it is for combatting voice-related gender prejudice. Pointing to promising examples of research on women’s voices as well as gay, gender non-conforming and transgender voices, the chapter concludes by presenting recommendations for future research, and suggesting that this research be communicated to wider audiences to inform professional practices and begin wider discussions to combat the voice being invoked to excuse gender bias and discrimination
Bridging the Key Stage 2/3 transition gap: taking primary languages seriously
No full textIn the following opinion article, Rowena Kasprowicz explores emerging research evidence demonstrating that, with the right conditions, linguistic progression is possible at primary school. Reflecting on this evidence and in light of the challenges for Key Stage 2/3 transition, Rowena argues for the importance of i) reducing variation in primary languages provision, and ii) facilitating robust communication channels between sectors to ensure that children’s language learning experiences at primary school are taken seriously
Histories of future-makers: examining young informal vendors’ current and imagined lives and livelihoods in urban Tanzania
Get PDFAlthough the opportunities and challenges of the informal sector have received much attention in recent decades, understanding how the characteristics of informal work intersect with and shape youths’ imagined futures remains understudied. Addressing this gap is crucial, given region-specific increases in the number of youth entering the urban informal sector, particularly across sub-Saharan Africa. This paper focuses on in-depth ethnographic research undertaken in Arusha and Dar es Salaam, Tanzania, with 22 young informal vendors aged 15–35. Life-mapping interviews and participatory timeline diagrams were used to develop rich insights into participants’ past, present and imagined lives and livelihoods. It extends the concept of ‘being and becoming’, developed to examine the interwoven nature of youths’ present and future lives, by analysing how young vendors navigate the intersection of their past experiences, present realities, and future possibilities through informal work in urban spaces. The article highlights the complex temporality of youths’ informal livelihoods by exploring their goals and ambitions, income generating activities, experiences of customer-related challenges, and perspectives on self-employment. Through this, it argues that youths’ histories shape their futures as much as the unfolding of their lives in the present. It also positions young vendors as future-makers who actively construct their futures through informal work. In the context of growing socio-economic uncertainty, this paper provides a timely contribution to geographical perspectives on youth by examining how young vendors navigate, sustain, adapt, and reimagine their lives and livelihoods within increasingly uncertain urban contexts marked by high levels of informality
The notion of an illegal occupation in the ICJ’s Palestine Advisory Opinion
Get PDFIn its Advisory Opinion on the Legal Consequences arising from the Policies and Practices of Israel in the Occupied Palestinian Territory, including East Jerusalem, the International Court of Justice (ICJ) ruled not only that Israeli policies and practices in the occupied territory systematically violated international law, but also that Israel’s ‘continued presence’ (i.e. occupation) as such had become illegal, so that Israel was required to withdraw from the Occupied Palestinian Territories as rapidly as possible. The ICJ’s finding that Israel engaged in a sustained abuse of its position as an occupying power, through annexation of territory and frustration of Palestinian self-determination, was central to its reasoning, as was its holding that the legality of the occupation was to be judged against the jus ad bellum. This article unpacks the concept of an illegal occupation. It argues that, as matter of the jus ad bellum, it is only the right to self-defence that could, in theory, justify Israel’s continued occupation. Curiously, however, the Opinion does not mention self-defence, although it preoccupied many of the judges writing separately. The article argues that two approaches to the occupation’s ad bellum illegality are most persuasive: first, that the occupation could not meet the necessity and proportionality criteria of lawful self-defence; and, second, that even a valid self-defence claim can be vitiated by a predominant ulterior purpose
AdamZ: an enhanced optimisation method for neural network training
Get PDFAdamZ is an advanced variant of the Adam optimiser, developed to enhance convergence efficiency in neural network training. This optimiser dynamically adjusts the learning rate by incorporating mechanisms to address overshooting and stagnation, which are common challenges in optimisation. Specifically, AdamZ reduces the learning rate when overshooting is detected and increases it during periods of stagnation, utilising hyperparameters such as overshoot and stagnation factors, thresholds, and patience levels to guide these adjustments.
While AdamZ may lead to slightly longer training times compared to some other optimisers, it consistently excels in minimising the loss function, making it particularly advantageous for applications where precision is critical. Benchmarking results demonstrate the effectiveness of AdamZ in maintaining optimal learning rates, leading to improved model performance across diverse tasks
Employee flourishing and moral obligation in extreme conditions
Get PDFWe extend the extant call for a flourishing perspective by examining dynamic processes involving moral obligations of organizations, work meaningfulness, organizational responsiveness, and enabling conditions and their effects on employee flourishing in four studies from an emerging economy. Through a mixed-study design, we qualitatively explore (Study 1: N = 146), perceptions of employees about the moral obligations, enabling conditions, and responsiveness of their organizations during an extreme condition. We then conduct (in Study 2) an experiment with employees (N = 63) from the Kumasi metropolis in Ghana. The results of a 2 (high and low moral obligation) × 2 (facilitative and inhibitive enabling conditions) between-subjects design show that employees in high moral obligation organizations with facilitative enabling conditions reported perceptions of better flourishing than those in the other conditions. In Study 3, cross-sectional (N = 112), we examine the mechanism and dynamics by which moral obligation influences employee flourishing. Study 4, a replication (N = 81), shows a pattern similar to that of Study 2 in the Accra metropolis in Ghana. Consistent with the human flourishing theory, we discuss implications for future research
