150 research outputs found

    Hourly historical and near-future weather and climate variables for energy system modelling

    Get PDF
    Energy systems are becoming increasingly exposed to the impacts of weather and climate due to the uptake of renewable generation and the electrification of the heat and transport sectors. The need for high-quality meteorological data to manage present and near-future risks is urgent. This paper provides a comprehensive set of multi-decadal, time series of hourly meteorological variables and weather-dependent power system components for use in the energy systems modelling community. Despite the growing interest in the impacts of climate variability and climate change on energy systems over the last decade, it remains rare for multi-decadal simulations of meteorological data to be used within detailed simulations. This is partly due to computational constraints, but also due to technical barriers limiting the use of meteorological data by non-specialists. This paper presents a new European-level dataset which can be used to investigate the impacts of climate variability and climate change on multiple aspects of near-future energy systems. The datasets correspond to a suite of well-documented, easy-to-use, self-consistent, hourly- and nationally aggregated, and sub-national time series for 2 m temperature, 10 m wind speed, 100 m wind speed, surface solar irradiance, wind power capacity factor, solar power factor, and degree days spanning over 30 European countries. This dataset is available for the historical period 1950–2020 and is accessible from https://doi.org/10.17864/1947.000321 (Bloomfield and Brayshaw, 2021a). As well as this a companion dataset is created where the ERA5 reanalysis is adjusted to represent the impacts of near-term climate change (centred on the year 2035) based on five high-resolution climate model simulations. These data are available for a 70-year period for central and northern Europe. The data are accessible from https://doi.org/10.17864/1947.000331 (Bloomfield and Brayshaw, 2021b). To the authors’ knowledge, this is the first time a comprehensive set of high-quality hourly time series relating to future climate projections has been published, which is specifically designed to support the energy sector. The purpose of this paper is to detail the methods required for processing the climate model data and illustrate the importance of accounting for climate variability and climate change within energy system modelling from the sub-national to European scale. While this study is therefore not intended to be an exhaustive analysis of climate impacts, it is hoped that publishing these data will promote greater use of climate data within energy system modelling.</p

    Relative influence of changes in hydraulic conductivity with depth and climate change on estimations of borehole yields

    Get PDF
    Understanding the impact of climate change on borehole yields from fractured aquifers is essential for future management of groundwater resources. Although the impact of changes in hydraulic conductivity with depth (VKD) on groundwater levels is well established, the relative significance of climate change and VKD on borehole yield estimates is poorly understood. We hypothesize that VKD exerts a significant additional control on borehole yields under climate change which has not been considered in yield assessments to date. We developed a radial groundwater flow model of an idealised pumping borehole in the fractured Chalk aquifer of south-east England, and applied 11 VKD profiles based on a simple conceptual representation of variability in hydraulic conductivity with depth in the Chalk. For each VKD profile, we applied 20 climate scenarios and six constant pumping rates for the period 1962 – 2014. We then estimated borehole yields based on the derived lowest pumping water levels during key drought years (e.g. 1976). We show that VKD is more significant (p 0.1) in controlling lowest pumping groundwater levels. Hydraulic conductivity is as significant a control as climate on borehole yields, although responses are highly non-linear associated with pumping water level-pumping rate curves intersecting key yield constraints (e.g. pump intake depth, major inflow horizons). It is recommended that variations in hydraulic conductivity with depth are taken into consideration in future assessments of borehole yields under climate change when developing integrated water resources management plans. The approach presented is generic and can be applied across different aquifers where vertical heterogeneity is present

    The Effect of Regulatory Harmonization on Cross-border Labor Migration: Evidence from the Accounting Profession

    Full text link
    The paper examines the effect of international regulatory harmonization on cross-border labor migration. We analyze directives in the European Union (EU) that harmonized accounting and auditing standards. This regulatory harmonization should make it less costly for those who work in the accounting profession to move across countries. Our research design compares the cross-border migration of accounting professionals relative to tightly-matched other professionals before and after regulatory harmonization. We find that, on average, labor migration in the accounting profession increases relative to comparable professions by roughly 15% after harmonization. The findings illustrate that diversity in rules constitutes an important economic barrier to cross-border labor mobility and, more specifically, that accounting harmonization can have a meaningful effect on cross-border migration

    The SWAP Filter: A Simple Azimuthally Varying Radial Filter for Wide-Field EUV Solar Images

    Full text link
    We present the SWAP Filter: an azimuthally varying, radial normalizing filter specifically developed for EUV images of the solar corona, named for the Sun Watcher with Active Pixels and Image Processing (SWAP) instrument on the Project for On-Board Autonomy 2 spacecraft. We discuss the origins of our technique, its implementation and key user-configurable parameters, and highlight its effects on data via a series of examples. We discuss the filter's strengths in a data environment in which wide field-of-view observations that specifically target the low signal-to-noise middle corona are newly available and expected to grow in the coming years.Comment: Contact D. B. Seaton for animations referenced in figure caption

    Improved understanding of spatio-temporal controls on regional scale groundwater flooding using hydrograph analysis and impulse response functions

    Get PDF
    Controls on the spatiotemporal extent of groundwater flooding are poorly understood, despite the long duration of groundwater flood events and distinct social and economic impacts. We developed a novel approach using statistical analysis of groundwater level hydrographs and impulse response functions (IRFs) and applied it to the 2013/14 Chalk groundwater flooding in the English Lowlands. We proposed a standardised index of groundwater flooding which we calculated for monthly groundwater levels for 26 boreholes in the Chalk. We grouped these standardised series using k-means cluster analysis and cross-correlated the cluster centroids with the Standardised Precipitation Index (SPI) accumulated over time intervals between 1 and 60 months. This analysis reveals two spatially coherent groups of standardised hydrographs which responded to precipitation over different timescales. We estimated IRF models of the groundwater level response to effective precipitation for three boreholes in each group. The IRF models corroborate the SPI analysis showing different response functions between the groups. We applied identical effective precipitation inputs to each of the IRF models and observed differences between the hydrographs from each group. It is suggested this is due to the hydrogeological properties of the Chalk and of overlying relatively low permeability superficial deposits (recent unconsolidated sediments overlying the bedrock, such as clays and tills), which are extensive over one of the groups. The overarching controls on groundwater flood response are concluded to be a complex combination of antecedent conditions, rainfall and catchment hydrogeological properties. These controls should be taken into consideration when anticipating and managing future groundwater flood events. The approach presented is generic and parsimonious and can be easily applied where sufficient groundwater level and rainfall data are available

    Acute effects of cannabis on speech illusions and psychotic-like symptoms:two studies testing the moderating effects of cannabidiol and adolescence

    Get PDF
    Background Acute cannabis administration can produce transient psychotic-like effects in healthy individuals. However, the mechanisms through which this occurs and which factors predict vulnerability remain unclear. We investigate whether cannabis inhalation leads to psychotic-like symptoms and speech illusion; and whether cannabidiol (CBD) blunts such effects (study 1) and adolescence heightens such effects (study 2). Methods Two double-blind placebo-controlled studies, assessing speech illusion in a white noise task, and psychotic-like symptoms on the Psychotomimetic States Inventory (PSI). Study 1 compared effects of Cann-CBD (cannabis containing Δ-9-tetrahydrocannabinol (THC) and negligible levels of CBD) with Cann+CBD (cannabis containing THC and CBD) in 17 adults. Study 2 compared effects of Cann-CBD in 20 adolescents and 20 adults. All participants were healthy individuals who currently used cannabis. Results In study 1, relative to placebo, both Cann-CBD and Cann+CBD increased PSI scores but not speech illusion. No differences between Cann-CBD and Cann+CBD emerged. In study 2, relative to placebo, Cann-CBD increased PSI scores and incidence of speech illusion, with the odds of experiencing speech illusion 3.1 (95% CIs 1.3–7.2) times higher after Cann-CBD. No age group differences were found for speech illusion, but adults showed heightened effects on the PSI. Conclusions Inhalation of cannabis reliably increases psychotic-like symptoms in healthy cannabis users and may increase the incidence of speech illusion. CBD did not influence psychotic-like effects of cannabis. Adolescents may be less vulnerable to acute psychotic-like effects of cannabis than adults

    Anhedonia, apathy, pleasure, and effort-based decision-making in adult and adolescent cannabis users and controls

    Get PDF
    BACKGROUND: Cannabis use may be linked with anhedonia and apathy. However, previous studies have shown mixed results and few have examined the association between cannabis use and specific reward sub-processes. Adolescents may be more vulnerable to harmful effects of cannabis than adults. This study investigated (1) the association between non-acute cannabis use and apathy, anhedonia, pleasure, and effort-based decision-making for reward, and (2) whether these relationships were moderated by age-group. METHODS: We used data from the 'CannTeen' study. Participants were 274 adult (26-29 years) and adolescent (16-17 years) cannabis users (1-7 days/week use in the past three months), and gender- and age-matched controls. Anhedonia was measured with the Snaith-Hamilton Pleasure Scale (n=274), and apathy was measured with the Apathy Evaluation Scale (n=215). Effort-based decision-making for reward was measured with the Physical Effort task (n=139), and subjective wanting and liking of rewards was measured with the novel Real Reward Pleasure task (n=137). RESULTS: Controls had higher levels of anhedonia than cannabis users (F1,258=5.35, p=.02, ηp2=.02). There were no other significant effects of User-Group and no significant User-Group*Age-Group interactions. Null findings were supported by post hoc Bayesian analyses. CONCLUSION: Our results suggest that cannabis use at a frequency of three to four days per week is not associated with apathy, effort-based decision-making for reward, reward wanting, or reward liking in adults or adolescents. Cannabis users had lower anhedonia than controls, albeit at a small effect size. These findings are not consistent with the hypothesis that non-acute cannabis use is associated with amotivation

    Understanding and modelling wildfire regimes: An ecological perspective

    Get PDF
    © 2021 The Author(s).Recent extreme wildfire seasons in several regions have been associated with exceptionally hot, dry conditions, made more probable by climate change. Much research has focused on extreme fire weather and its drivers, but natural wildfire regimes—and their interactions with human activities—are far from being comprehensively understood. There is a lack of clarity about the 'causes' of wildfire, and about how ecosystems could be managed for the co-existence of wildfire and people. We present evidence supporting an ecosystem-centred framework for improved understanding and modelling of wildfire. Wildfire has a long geological history and is a pervasive natural process in contemporary plant communities. In some biomes, wildfire would be more frequent without human settlement; in others they would be unchanged or less frequent. A world without fire would have greater forest cover, especially in present-day savannas. Many species would be missing, because fire regimes have co-evolved with plant traits that resist, adapt to or promote wildfire. Certain plant traits are favoured by different fire frequencies, and may be missing in ecosystems that are normally fire-free. For example, post-fire resprouting is more common among woody plants in high-frequency fire regimes than where fire is infrequent. The impact of habitat fragmentation on wildfire crucially depends on whether the ecosystem is fire-adapted. In normally fire-free ecosystems, fragmentation facilitates wildfire starts and is detrimental to biodiversity. In fire-adapted ecosystems, fragmentation inhibits fires from spreading and fire suppression is detrimental to biodiversity. This interpretation explains observed, counterintuitive patterns of spatial correlation between wildfire and potential ignition sources. Lightning correlates positively with burnt area only in open ecosystems with frequent fire. Human population correlates positively with burnt area only in densely forested regions. Models for vegetation-fire interactions must be informed by insights from fire ecology to make credible future projections in a changing climate.We gratefully acknowledge support from the Leverhulme Centre for Wildfires, Environment and Society, who organized the virtual mini-workshop which initiated the writing of this paper. RKN is supported by the Leverhulme Centre. SPH and YS acknowledge support from the ERC-funded project GC2.0 (Global Change 2.0: Unlocking the past for a clearer future, Grant Number 694481). ICP, KJB and ND acknowledge support from the ERC-funded project REALM (Re-inventing Ecosystem And Land-surface Models, Grant Number 787203). JCH acknowledges funding from the ERC project SCATAPNUT (Grant Number 681885). This work is a contribution to the LEMONTREE (Land Ecosystem Models based On New Theory, obseRvations and ExperimEnts) project, funded through the generosity of Eric and Wendy Schmidt by recommendation of the Schmidt Futures program (SPH, YS and ICP)

    Immunosuppression and outcomes in adult patients with de novo acute myeloid leukemia with normal karyotypes

    Get PDF
    Acute myeloid leukemia (AML) patients rarely have long first remissions (LFRs; \u3e5 y) after standard-of-care chemotherapy, unless classified as favorable risk at presentation. Identification of the mechanisms responsible for long vs. more typical, standard remissions may help to define prognostic determinants for chemotherapy responses. Using exome sequencing, RNA-sequencing, and functional immunologic studies, we characterized 28 normal karyotype (NK)-AML patients with \u3e5 y first remissions after chemotherapy (LFRs) and compared them to a well-matched group of 31 NK-AML patients who relapsed within 2 y (standard first remissions [SFRs]). Our combined analyses indicated that genetic-risk profiling at presentation (as defined by European LeukemiaNet [ELN] 2017 criteria) was not sufficient to explain the outcomes of many SFR cases. Single-cell RNA-sequencing studies of 15 AML samples showed that SFR AML cells differentially expressed many genes associated with immune suppression. The bone marrow of SFR cases had significantly fewer CD

    Thermal limits of leaf metabolism across biomes

    Get PDF
    High-temperature tolerance in plants is important in a warming world, with extreme heat waves predicted to increase in frequency and duration, potentially leading to lethal heating of leaves. Global patterns of high-temperature tolerance are documented in animals, but generally not in plants, limiting our ability to assess risks associated with climate warming. To assess whether there are global patterns in high-temperature tolerance of leaf metabolism, we quantified Tcrit (high temperature where minimal chlorophyll a fluorescence rises rapidly and thus photosystem II is disrupted) and Tmax (temperature where leaf respiration in darkness is maximal, beyond which respiratory function rapidly declines) in upper canopy leaves of 218 plant species spanning seven biomes. Mean site-based Tcrit values ranged from 41.5 °C in the Alaskan arctic to 50.8 °C in lowland tropical rainforests of Peruvian Amazon. For Tmax, the equivalent values were 51.0 and 60.6 °C in the Arctic and Amazon, respectively. Tcrit and Tmax followed similar biogeographic patterns, increasing linearly (˜8 °C) from polar to equatorial regions. Such increases in high-temperature tolerance are much less than expected based on the 20 °C span in high-temperature extremes across the globe. Moreover, with only modest high-temperature tolerance despite high summer temperature extremes, species in mid-latitude (~20-50°) regions have the narrowest thermal safety margins in upper canopy leaves; these regions are at the greatest risk of damage due to extreme heat-wave events, especially under conditions when leaf temperatures are further elevated by a lack of transpirational cooling. Using predicted heat-wave events for 2050 and accounting for possible thermal acclimation of Tcrit and Tmax, we also found that these safety margins could shrink in a warmer world, as rising temperatures are likely to exceed thermal tolerance limits. Thus, increasing numbers of species in many biomes may be at risk as heat-wave events become more severe with climate change
    • …
    corecore