Simulation of Stratospheric Water Vapor Trends: Impact on Stratospheric Ozone Chemistry

A transient model simulation of the 40-year time period 1960 to 1999 with the coupled climate-chemistry model (CCM) ECHAM4.L39(DLR)/CHEM shows a stratospheric water vapor increase over the last two decades of 0.7 ppmv and, additionally, a short-term increase after major volcanic eruptions. Furthermore, a long-term decrease in global total ozone as well as a short-term ozone decline in the tropics after volcanic eruptions are modeled. In order to understand the resulting effects of the water vapor changes on lower stratospheric ozone chemistry, different perturbation simulations were performed with the CCM ECHAM4.L39- (DLR)/CHEM feeding the water vapor perturbations only to the chemistry part. Two different long-term perturbations of lower stratospheric water vapor, +1 ppmv and +5 ppmv, and a short-term perturbation of +2 ppmv with an e-folding time of two months were applied. An additional stratospheric water vapor amount of 1 ppmv results in a 5–10% OH increase in the tropical lower stratosphere between 100 and 30 hPa. As a direct consequence of the OH increase the ozone destruction by the HOx cycle becomes 6.4% more effective. Coupling processes between the HOx-family and the NOx/ClOxfamily also affect the ozone destruction by other catalytic reaction cycles. The NOx cycle becomes 1.6% less effective, whereas the effectiveness of the ClOx cycle is again slightly enhanced. A long-term water vapor increase does not only affect gas-phase chemistry, but also heterogeneous ozone chemistry in polar regions. The model results indicate an enhanced heterogeneous ozone depletion during antarctic spring due to a longer PSC existence period. In contrast, PSC formation in the northern hemisphere polar vortex and therefore heterogeneous ozone depletion during arctic spring are not affected by the water vapor increase, because of the less PSC activity. Finally, this study shows that 10% of the global total ozone decline in the transient model run can be explained by the modeled water vapor increase, but the simulated tropical ozone decrease after volcanic eruptions is caused dynamically rather than chemically

Learning how to read? the value of lectures in the context of HE English Literature

The increasing pace of change in today’s teaching and learning, the challenging employability environments and the plethora of new technologies now at the disposal of teachers may seem to render obsolete the older teaching and learning methodologies. However, this reflective case study suggests that one of the oldest delivery modes of all, the lecture, remains a relevant and potentially valuable way of connecting with and supporting students in their learning, particularly in subjects where students are expected to read at length or otherwise to engage with extended and complex discursive modes. This case study offers evidence and arguments for reconsidering the role of lectures in teaching and learning higher education English Literature, taking as its evidence base levels 4 and 6 undergraduate English Literature modules delivered in 2017-18 and 2018-19 at the University of Greenwich. Rather than dismissing – as does much recent research – lectures as encouraging ‘passive’ learning, this reflective study proposes lecturing as a teaching methodology with unique potential

"The well-dissembled mourner": lightning's (dis)course in the still lives of Thomson's "Celadon and Amelia"

This essay investigates the sources and intertexts of a famous narrative episode in James Thomson's popular long poem "The Seasons" (1746), namely the sentimental tale of "Celadon and Amelia." From its first publication onwards, this episode was repeatedly excerpted, illustrated and re-told, especially in the late eighteenth and early nineteenth centuries. As such, this story (of two pastoral lovers who are parted when one is struck by lightning) has a long afterlife and is implicated in the Romantic configurations of cultural affect that dominate Western understandings of art and literature up to the present day. However, while its widespread influence on later writers, artists and readers has been extensively studied, the composite sources of the tale have yet to be fully recovered. This article therefore undertakes such a recovery. In doing so, it not only reveals the wide range of media on which Thomson drew, from newspapers and scientific discourse to poetry and devotional works, but also offers a challenge to a long-established critical tradition which reads the whole of “The Seasons” as dominated by movement and sequence. Instead, it is argued, the static or "statuesque" finale of the "Celadon and Amelia" episode is replicated in many places throughout the poem, moments which reflect Thomson’s competitive engagements with intertexts in a variety of static media, and which cumulatively represent an attack on the authenticity and memorial efficacy of conventional funerary genres such as sculpture and epitaph

Dissenting from Edward Young’s Night Thoughts: christian time and poetic metre in Anne Steele’s graveyard poems

Although the Particular Baptist poet Anne Steele (1718-1778) is little known today, this article argues that her poems on time and death offer valuable insights into wider religio-poetical representations of time in the mid-eighteenth century. Her verse both responds to and departs from the conventions of graveyard poetry as exemplified by Edward Young’s Night Thoughts (1742-6), demonstrating close engagement with this popular subgenre as well as an intelligent critique of its devotional poetics. As such, Steele’s writing foregrounds yet also problematises emerging distinctions between writing and religion, and thus argues for new methodologies in religious and literary history

A strategy for climate evaluation of aircraft technology: an efficient climate impact assessment tool ? AirClim

International audienceClimate change is a challenge to society and to cope with requires assessment tools which are suitable to evaluate new technology options with respect to their impact on climate. Here we present AirClim, a model which comprises a linearisation of the processes occurring from the emission to an estimate in near surface temperature change, which is presumed to be a reasonable indicator for climate change. The model is designed to be applicable to aircraft technology, i.e.~the climate agents CO2, H2O, CH4 and O3 (latter two resulting from NOx-emissions) and contrails are taken into account. It employs a number of precalculated atmospheric data and combines them with aircraft emission data to obtain the temporal evolution of atmospheric concentration changes, radiative forcing and temperature changes. The linearisation is based on precalculated data derived from 25 steady-state simulations of the state-of-the-art climate-chemistry model E39/C, which include sustained normalised emissions at various atmospheric regions. The results show that strongest climate impacts from ozone changes occur for emissions in the tropical upper troposphere (60 mW/m²; 80 mK for 1 TgN emitted), whereas from methane in the middle tropical troposphere (?2.7% change in methane lifetime; ?30 mK per TgN). The estimate of the temperature changes caused by the individual climate agents takes into account a perturbation lifetime, related to the region of emission. A comparison of this approach with results from the TRADEOFF and SCENIC projects shows reasonable agreement with respect to concentration changes, radiative forcing, and temperature changes. The total impact of a supersonic fleet on radiative forcing (mainly water vapour) is reproduced within 5%. For subsonic air traffic (sustained emissions after 2050) results show that although ozone-radiative forcing is much less important than that from CO2 for the year 2100. However the impact on temperature is of comparable size even when taking into account temperature decreases from CH4. That implies that all future measures for climate stabilisation should concentrate on both CO2 and NOx emissions. A direct comparison of super- with subsonic aircraft (250 passengers, 5400 nm) reveals a 5 times higher climate impact of supersonics

Impact of prescribed SSTs on climatologies and long-term trends in CCM simulations

Chemistry-Climate Model (CCM) simulations are commonly used to project the past and future development of the dynamics and chemistry of the stratosphere, and in particular the ozone layer. So far, CCMs are usually not interactively coupled to an ocean model, so that sea surface temperatures (SSTs) and sea ice coverage are prescribed in the simulations. While for future integrations SSTs have to be taken from precalculated climate model projections, for CCM experiments resembling the past either modelled or observed SSTs can be used. This study addresses the question to which extent atmospheric climatologies and long-term trends for the recent past simulated in the CCM E39C-A differ when choosing either observed or modelled SSTs. Furthermore, the processes of how the SST signal is communicated to the atmosphere, and in particular to the stratosphere are examined. Two simulations that differ only with respect to the prescribed SSTs and that span years 1960 to 1999 are used. <br><br> Significant differences in temperature and ozone climatologies between the model simulations are found. The differences in ozone are attributed to differences in the meridional circulation, which are in turn driven by weaker wave forcing in the simulation with generally lower SSTs. The long-term trends over 40 years in annual mean temperature and ozone differ only in the troposphere, where temperatures are directly influenced by the local SST trends. Differences in temperature and ozone trends are only found on shorter time scales. The trends in tropical upwelling, as a measure of the strength of the Brewer-Dobson circulation (BDC), differ strongly between the simulations. A reverse from negative to positive trends is found in the late 1970s in the simulation using observed SSTs while trends are positive throughout the simulation when using modelled SSTs. The increase in the BDC is a robust feature of the simulations only after about 1980 and is evident mainly in the tropics in the lower stratosphere

Risk Factors for Neurocognitive Functioning in Children with Autosomal Recessive Polycystic Kidney Disease

This mini review provides an overview of the issues and challenges inherent in autosomal recessive polycystic kidney disease (ARPKD), with a particular focus on the neurological factors and neurocognitive functioning of this population. ARPKD typically is discovered at the end of pregnancy or during the neonatal developmental period and occurs in approximately 1 in 20,000 live births. During the neonatal period, there is a relatively high risk of death, with many infants dying from respiratory failure. As the child ages, they experience progressive kidney disease and become increasingly vulnerable to liver disease, with many individuals eventually requiring dual organ transplants. This mini review provides a brief description of ARPKD and describes the various factors that place children with ARPKD at risk for neurological and neuropsychological impairment (e.g., a genetic condition leading to chronic kidney disease and eventual transplant; difficult-to-treat hypertension; eventual liver disease; possible dual transplantation of the kidneys and liver; chronic lung disease), including that these factors are present during a critical period of brain development. Further, the mini review discusses the available studies that have addressed the neurocognitive functioning in children with ARPKD. This paper concludes by providing the key clinical and research challenges that face the field of pediatric nephrology with respect to the clinical and scientific study of the neurocognitive functioning of children with ARPKD. Selected directions are offered in both the clinical and research arenas for this multiorgan chronic condition

MayDay: VestAndPage Workshop Concept, Theory and Practice

Considerations on how VestAndPage facilitate a workshop on Performance art. Text published in: "How We Teach Performance Art: University Courses and Workshop Syllabus", Edited by Valentin Torrens. Outskirts Press, July 2014. The book offers 42 different approaches to transmit the generative source of creativity in live action by internationally experienced practitioners, teachers and theorists of performance art from 21 countries. 340 pages full of ideas, points of view, methodologies, sensitivities, exercises and proposals to enjoy live practice with deeper involvement immersion, knowledge and study. The book begins with a clarification of the terms used to name this practice and continues with the cultural introductions previously to the appearance of the performance as an artistic differentiated activity. To see the performance's creative nature and its relation with the game; its communicative qualities and his perception. It's followed by a report on previous books and publications related to the pedagogies of the performance. Later, a description of education affiliations, inside the pedagogic common tendencies of performance courses. An approach to courses and workshop's characteristics. It's begun with the syllabus and the comments of the university courses and continues with the workshops. Some teachers have sent a text on their relation to the performance; in those cases, it's placed before the description of the syllabus, in order to complement, from the subjective intimacy, our best comprehension of his work and his course. After the entire syllabus, there is a small biographical summary of the authors and bibliography on performance

Parts and Wholes in Long Non-narrative Poems of the Eighteenth Century

This dissertation examines early-eighteenth-century understandings of literary length in order to shed new light on the structures of three long non-narrative poems of the period, James Thomson’s $\textit{The Seasons}$, Mark Akenside’s $\textit{The Pleasures of Imagination}$ and Edward Young’s $\textit{Night Thoughts}$. Readings of these poems demonstrate the sophistication with which British eighteenth-century writers used extensive literary structures to represent, explicate and communicate objects and ideas that seemed too vast or complex for comprehensive description or narration. Part I of the dissertation surveys, in chronological order, earlier and contemporary critical theories which inform the three poems, in particular those found in the writings of two major Whig critics, John Dennis and Joseph Addison (discussed in Chapter 1) and in the poetry of Alexander Pope (Chapter 2). Considered collectively, these may be understood to describe a ‘poetics of greatness’ whereby extensive verse is progressively abstracted from its traditional generic loci and becomes associated more broadly with ambitions and potential failures of comprehensive representation and perception, with the sublime, and with playful or witty complexity. Part II covers the three long poems. Chapter 3 argues that in $\textit{The Seasons}$ Thomson uses the figure of the maze to modulate allusively between stasis and motion, sublimity and playfulness, gesturing circumspectly towards a vast providential order. Chapter 4 offers close readings of two early Akenside poems and passages from Shaftesbury’s $\textit{Characteristics}$, a key source for $\textit{The Pleasures of Imagination}$. These reveal Akenside’s abiding concern with the fine line distinguishing sublime inspiration from ridiculous delusion, which informs self-reflexively the very structure of his sublime long poem. In Chapter 5, perceptions of $\textit{Night Thoughts}$ as too long provide the starting point for an account of how Young’s belief in the didactic function of poetry translates into a temporal, cumulative poetics designed to wear its repetitive $\textit{aperçus}$ on ‘life, death and immortality’, through the time of reading, into the heart of the reader. Just as in extensive classical genres like epic and georgic, these works invest structure with the task of transmitting an articulated experience or body of knowledge to the reader. As such, their parts are arranged coherently, if complexly, within the whole