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Diverse impacts of the Indian summer monsoon on ENSO among CMIP6 models and its possible causes
Get PDFThis study examines the performance of 52 models from phase 6 of the Coupled Model Intercomparison Project (CMIP6) in capturing the effects of the Indian summer monsoon (ISM) on the evolution of El Niño–Southern Oscillation (ENSO). The ISM's impacts on ENSO show a substantial diversity among the models. While some models simulate the strength of the impacts comparable to observations, others represent much weaker influences. Results indicate that the diversity is highly related to inter-model spread in interannual variability of ISM rainfall among the models. Models with a larger ISM rainfall variability simulate stronger ISM-induced anomalies in precipitation and atmospheric circulation over the western North Pacific during the monsoon season. As a result, these models exhibit larger wind anomalies induced by monsoon on the south flank of the anomalous circulation in the western Pacific, thereby influencing subsequent ENSO evolution more significantly by causing stronger air-sea coupling processes over the tropical Pacific
Solar wind interactions with comet C/2021 A1 Using STEREO HI and a data-assimilative solar wind model
Get PDFCometary tails display dynamic behavior attributed to interactions with solar wind structures. Consequently,
comet-tail observations can serve as in situ solar wind monitors. During 2021 December, Comet Leonard (C/2021
A1) was observed by the STEREO-A heliospheric imager. The comet tail exhibited various signatures of
interactions with the solar wind including bending, kink formation, and finally complete disconnection. In this
study, we compare the timing of these events with solar wind structures predicted by the Heliospheric Upwind
eXtrapolation model with a time-dependency (or HUXt) solar wind model using new solar wind data assimilation
(DA) techniques. This serves both to provide the most accurate solar wind context to interpret the cometary
processes, but also as a test of the DA and an example of how comet observations can be used in model validation
studies. Coronal mass ejections, stream interaction regions (SIRs), and heliospheric current sheet (HCS) crossings
were all considered as potential causes of the tail disconnection. The results suggest the tail disconnection at Comet
Leonard was the result of it crossing the HCS and into an SIR. The timing of these features agree better with the
DA model results than the non-DA model, showing the value of this approach. Case studies such as this expand
our understanding of comet–solar wind interactions, and in demonstrating the utility of DA for solar wind
modeling. We note that this could lead to comets acting as additional in situ measures for solar wind conditions for
regions where no in situ spacecraft are available, potentially improving solar wind DA in the future
‘We had always been partly one’: Locating the Ecopoetics of Wallace Stevens
Get PDFUntil recently, scholarship has struggled to situate Wallace Stevens within ecocritical
discussions. This thesis seeks to re-examine Stevens’s poetry in its engagement with what we now
recognise as ecocritical methodologies, in order to suggest that our scholarly understanding of
Stevens needs some reorientation. With a predominate focus on language, sound, and voice, I
explore how Stevens’s ecopoetics seek to expose and give agency to the voices of nonhuman
entities across his work. Throughout, the thesis acknowledges previous critical grounding of
Stevens’s work and philosophy around the relationship between imagination and reality, whilst
critiquing claims that this perspective is the only lens by which Stevens’s work may be read. By
analysing a range of Stevens’s works, inclusive of poetry, prose, and letters, I show Stevens’s
ecological consciousness to be key to the genesis and development of a poetics that enables the
more-than-human world to speak. Using a historical approach, I seek to locate his ecopoetics
across key areas of influence upon his work: Romanticism, Modernism, and contemporary
ecopoetics. From these readings, I align Stevens’s ecopoetics to both first-wave and second-wave
ecocriticism, using close reading of a selection of Stevens’s work to clarify some of the key
entanglements present within the field. As ecocriticism develops and broadens its focus, it is
essential that the field calls for new perspectives on established texts. Ecocritical reformulations
such as these allow scholarship to maintain currency within a changing world and invites new
ways of understanding our current situation within the ecological crisis
Morphological changes to fruit development induced by GA3 application in sweet cherry (Prunus avium L.)
Get PDFCherry (Prunus avium) fruits are important sources of vitamins, minerals, and nutrients in the human diet; however, they contain a large stone, making them inconvenient to eat ‘on the move’ and process. The exogenous application of gibberellic acid (GA3) can induce parthenocarpy in a variety of fruits during development. Here, we showed that the application of GA3 to sweet cherry unpollinated pistils acted as a trigger for fruit set and permitted the normal formation of fruit up to a period of twenty-eight days, indicating that gibberellins are involved in the activation of the cell cycle in the ovary wall cells, leading to fruit initiation. However, after this period, fruit development ceased and developing fruit began to be excised from the branch by 35 days post treatment. This work also showed that additional signals are required for the continued development of fully mature parthenocarpic fruit in sweet cherry
urbisphere-Berlin campaign: investigating multi-scale urban impacts on the atmospheric boundary layer
Get PDFFor next-generation weather and climate numerical models to resolve cities, both higher spatial resolution and sub-grid parameterizations of urban canopy-atmosphere processes are required. Key is to better understand intra-urban variability and urban-rural differences in atmospheric boundary layer (ABL) dynamics. This includes upwind-downwind effects due to cities’ influences on the atmosphere beyond their boundaries. To address these aspects a network of >25 ground-based remote-sensing sites was designed for the Berlin region (Germany), considering city form, function, and typical weather conditions. This allows investigation of how different urban densities and human activities impact ABL dynamics. As part of the interdisciplinary European Research Council Grant urbisphere, the network was operated from Autumn 2021 to Autumn 2022. Here we provide an overview of the scientific aims, campaign setup, and results from two days, highlighting multi-scale urban impacts on the atmosphere in combination with high-resolution numerical modeling at 100 m grid-spacing. During a spring day, the analyzes show systematic upwind-city-downwind effects in ABL heights, largely driven by urban-rural differences in surface heat fluxes. During a heatwave day, ABL height is remarkably deep, yet spatial differences in ABL heights are less pronounced due to overall dry soil conditions, resulting in similar observed surface heat fluxes. Our modeling results provide further insights into ABL characteristics not resolved by the observation network, highlighting synergies between both approaches. Our data and findings will support modeling to help deliver services to a wider community from citizens to those managing health, energy, transport, land-use and other city infrastructure and operations
Dissemination and persistence of antimicrobial resistance (AMR) along the wastewater-river continuum
Get PDFAntimicrobial resistance (AMR) is a global health hazard. Although clinical and agricultural environments are well-established contributors to the evolution and dissemination of AMR, research on wastewater treatment works (WwTWs) has highlighted their potential role as disseminators of AMR in freshwater environments. Using metagenomic sequencing and analysis, we investigated the changes in resistomes and associated mobile genetic elements within untreated wastewater influents and treated effluents of five WwTWs, and sediments collected from corresponding river environments in Oxfordshire, UK, across three seasonal periods within a year. Our analysis demonstrated a high diversity and abundance of antimicrobial resistance genes (ARGs) in untreated wastewater influents, reflecting the varied anthropogenic and environmental origins of wastewater. WwTWs effectively reduced AMR in the final effluent, with an average 87% reduction in normalised ARG abundance and an average 63% reduction in richness. However, wastewater effluents significantly impacted the antimicrobial resistome of the receiving rivers, with an average 543% increase in ARG abundance and a 164% increase in richness from upstream sediments to downstream sediments. The normalised abundance of the human gut-associated bacteriophage crAssphage was highly associated with both ARG abundance and richness. We observed seasonal variation in the resistome of raw influent which was not found in the effluent-receiving sediments. We illustrate the potential of WwTWs as focal points for disseminating ARGs and resistance-selecting chemicals, contributing to the elevation of environmental AMR. Our study emphasises the need for a comprehensive understanding of the anthropogenic impacts on AMR evolution and dissemination in wastewater and river environments, informing efforts to mitigate this growing public health crisis
Simultaneous sizing and energy management of multi-energy virtual power plants operating in regulated energy markets
Get PDFThis research analyses the case of a Virtual Power Plant (VPP) in regulated electricity markets, trading energy with the consumers and the grid under a Power Purchase Agreement (PPA). The VPP propagates the deployment of solar PVs while balancing its intermittency with a dispatchable power plant, which is assumed in this research to be a CCHP, supplying cooling, heating, and power. The VPP also integrates energy storage systems for a comprehensive assessment. Traditionally, the VPP concept has not been introduced in regulated markets, but it is widely researched in deregulated markets where VPPs trade energy with the electricity grid for profit maximisation. In regulated markets, a special architecture is proposed for a VPP that mediates between residential compounds and electricity grids for profit maximization and energy demand coverage, thus converting the compound into a power generator with minimum dependence on the grid for its energy demand. In the literature on aggregated energy systems in regulated markets, it is usually overlooked to perform detailed energy modelling and optimisation on an hourly level. Only basic rule-based frameworks for energy management are proposed. In this research, it is initially assumed that since the VPP integrates multi-energy components supplying heating, cooling and electricity, optimization of the output of each component for a common profit maximization, is necessary. However, in VPP-related literature, the capacity of each component, which is a main input for energy modelling, is traditionally assumed and not assessed. Therefore, the research aims to explore how to find the optimal capacity configuration of the residential VPP that achieves optimal profit. The paper analyses an iterative exhaustive search framework, integrating the 2-levels of energy optimisation (hourly profit maximisation objective) and capacities optimisation (Life cycle CAPEX & OPEX minimisation). Compared to baseline cases, where only energy optimisation is performed, and capacities are assumed and not assessed in terms of capital investment, the proposed framework achieved a higher annual profit by 3.1% and a payback period of 11 years. The results also provide comprehensive 3D charts drawing the relations between the achieved profit against capacities configurations, thus allowing high-level decision-making. The results also prove the hypothesis that hourly energy optimisation should not be performed without investment cost assessment and that targeting the minimization of investment costs will indirectly benefit the achieved profit
Anaemia in India and its prevalence and multifactorial aetiology: a narrative review
Get PDFThe prevalence of anaemia in India remains high in children, especially those in rural
areas, and in women of childbearing age, and its impairment of neurological development can
have serious lifelong effects. It is concerning that the most recent official data (2019–21) indicate an
increased prevalence compared with 2015–16. There is also considerable variability in childhood
anaemia between Indian states with socioeconomic factors, such as wealth and education contributing
to the risk of anaemia among adolescent women and their children. Dietary iron deficiency is
often regarded as the main contributor to anaemia but increasing evidence accumulated from the
authors’ ongoing literature database coupled with recent literature research suggests that it has a
multifactorial aetiology, some of which is not related to nutrition. This narrative review focused on
these multifactorial issues, notably the contribution of vitamin B12/folate deficiency, which also has
a high prevalence in India. It was also noted that the dietary intake of bioavailable iron remains
an important contributor for reducing anaemia, and the role of millets as an improved iron source
compared to traditional staple cereals is briefly discussed. The overall conclusion is that anaemia
has a multifactorial aetiology requiring multifactorial assessment that must include assessment of
vitamin B12 status
Providing charge emission for cloud seeding aircraft
Get PDFReleasing charge into natural droplet systems such as fog and clouds offers a route to influence their properties. To facilitate charge release across a wide range of altitudes and meteorological circumstances – such as developing clouds – a charge emitter has been developed for integration with the conventional cloud-seeding flares carried by crewed cloud-seeding aircraft. This allows charge emitters to be used alongside, or instead of, conventional particle releasing flares. The charge emitter flare system is self-contained and self-powered, and includes internal monitoring and recording of its operating parameters. Using this “flare emitter” approach, successful charge emission has been demonstrated in level flight, at 3 km altitude, likely to have exceeded natural ion concentrations by several orders of magnitude. This quantitative verification of successful charge emission can underpin further physically based experiments on the effectiveness of charge release in cloud seeding