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Timing of the Recent Migration and Intensification of the Southern Hemisphere Westerly Winds
Get PDFIn recent decades, the Southern Hemisphere westerly winds have strengthened and migrated south, attributed to greenhouse gas emissions and stratospheric ozone depletion. However, the onset and acceleration of these drivers is coincident with the start of the instrumental record, thus, hindering our ability to determine the significance of the recent trends. Here, we present a novel wind reconstruction based on marine diatoms preserved in an Antarctic Peninsula ice core, providing a unique record to reconstruct westerly winds across the Pacific sector of the Southern Ocean (SO). The annually resolved record provides clear evidence that a southward migration of the Pacific sector westerly wind belt occurred in the 1960s, coupled with a prolonged strengthening trend. The poleward shift and acceleration of the westerly winds across this SO sector is unprecedented in the context of the past 140 years and coincident with the anthropogenically induced increase in greenhouse gases and ozone depletion
Hydrological summary for the United Kingdom: March 2025
Get PDFThe monthly summary of hydrological conditions in the United Kingdom is compiled as part of the National Hydrological Monitoring Programme (a joint UKCEH and BGS enterprise). The report features contemporary data for rainfall, river flow, reservoir and groundwater levels in the form of maps and graphs. A commentary is provided on the status of the nation’s water resources and any notable hydrological events during the month. The National River Flow and National Groundwater Level Archives help provide an historical context for these contemporary assessments. Financial support for the production of the Hydrological Summaries is provided by Defra, the Environment Agency, the Scottish Environment Protection Agency, the Rivers Agency in Northern Ireland and the Office of Water Services
Local versus far-field control on South Pacific Subantarctic mode water variability
Get PDFIn the South Pacific Subantarctic mode water (SAMW) formation region, central and eastern pools of SAMW have been found to be linked to winter mixed-layer thicknesses that vary strongly interannually and out of phase across the basin. This mixed-layer variability is associated with peaks in sea level pressure variability at a quasi-stationary anomaly situated between the two pools. To investigate how surface forcing, as well as the propagation of upstream anomalies, affects the formation of these SAMW pools, a set of adjoint sensitivity experiments with a density-following feature are conducted. Adjoint sensitivities reveal that local cooling can lead to an increase in the SAMW pool volume through mixed-layer-depth changes and the lateral movement of the northern boundary of the pool. In addition, upstream warming along the Antarctic Circumpolar Current can lead to an increase in the SAMW pool volume through lateral density surface movement shifting the southern boundary polewards. The density properties are advected from upstream to the downstream pool over 1 year. Optimal conditions for SAMW formation involve a combination of local cooling and upstream warming of SAMW formation sites. Hence, South Pacific SAMW variability is particularly sensitive to atmospheric modes which lead to a dipole in heating across the formation sites
Hydrological summary for the United Kingdom: June 2025
Get PDFThe monthly summary of hydrological conditions in the United Kingdom is compiled as part of the National Hydrological Monitoring Programme (a joint UKCEH and BGS enterprise). The report features contemporary data for rainfall, river flow, reservoir and groundwater levels in the form of maps and graphs. A commentary is provided on the status of the nation’s water resources and any notable hydrological events during the month. The National River Flow and National Groundwater Level Archives help provide an historical context for these contemporary assessments. Financial support for the production of the Hydrological Summaries is provided by Defra, the Environment Agency, the Scottish Environment Protection Agency, the Rivers Agency in Northern Ireland and the Office of Water Services
Investigating the likelihood of a Lough Neagh bloom scenario happening in the Republic of Ireland (FTP-2024-04): EPA research evidence synthesis report
Get PDFEnvironmental, health and economic benefits of emission reduction in residential sector – a case study for Poland
No full textNumerous epidemiological and risk assessment studies have demonstrated that air pollution poses a substantial health and economic burden. Despite this, a small number of comprehensive assessments of the benefits of emission reductions in Central Europe have been conducted, simultaneously addressing improvements in air quality, public health and reductions in economic costs. This study shows the impact of the reduction in the usage of solid fuels within the residential sector, that is responsible for 80% of primary PM2.5 emissions in Poland. Three emissions scenarios were assessed with an atmospheric chemical transport model: the BASE case (with no modification to emissions), the OPTIMISTIC scenario (80% reduction in the usage of solid fuels within the residential sector), and finally the CONSERVATIVE scenario (60% reduction in the usage of solid fuels within the residential sector). The results show that there is a widespread exceedance of the WHO 5 μg/m3 recommended limit of annual mean PM2.5 concentration with 99% area of Poland exceeding it even for the OPTIMISTIC scenario. Nevertheless, the annual mean PM2.5 concentrations are lower by about 16% for the OPTIMISTIC run compared to the BASE case. The annual number of deaths related to PM2.5 concentrations decrease by more than 6000 people in the CONSERVATIVE scenario and nearly by 10 000 people in the OPTIMISTIC scenario compared to the BASE case
Shared environmental similarity between relatives influences heritability of reproductive timing in wild great tits
Get PDFIntraspecific variation is necessary for evolutionary change and population resilience, but the extent to which it contributes to either depends on the causes of this variation. Understanding the causes of individual variation in traits involved with reproductive timing is important in the face of environmental change, especially in systems where reproduction must coincide with seasonal resource availability. However, separating the genetic and environmental causes of variation is not straightforward, and there has been limited consideration of how small-scale environmental effects might lead to similarity between individuals that occupy similar environments, potentially biasing estimates of genetic heritability. In ecological systems, environments are often complex in spatial structure, and it may therefore be important to account for similarities in the environments experienced by individuals within a population beyond considering spatial distances alone. Here, we construct multi-matrix quantitative genetic animal models using over 11,000 breeding records (spanning 35 generations) of individually-marked great tits (Parus major) and information about breeding proximity and habitat characteristics to quantify the drivers of variability in two key seasonal reproductive timing traits. We show that the environment experienced by related individuals explains around a fifth of the variation seen in reproductive timing, and accounting for this leads to decreased estimates of heritability. Our results thus demonstrate that environmental sharing between relatives can strongly affect estimates of heritability and therefore alter our expectations of the evolutionary response to selection
A tiered assessment of human health risks associated with exposure to persistent, mobile and toxic chemicals via drinking water
Get PDFThere is increasing interest in chemicals which are persistent, mobile and toxic (PMT), primarily to protect drinking water. We present a tiered assessment of drinking water exposure and associated human health risks for 22 PMT substances. Worst-case exposure via drinking water is assumed to occur when wastewater is discharged to rivers which are then abstracted for water supply. Screening-level exposures assume daily per capita emissions based on REACH tonnage estimates, with removal in wastewater treatment calculated using SimpleTreat and no riverine dilution. Removal in water treatment was estimated for each substance assuming either conventional or advanced treatment processes. Higher tier spatially-resolved exposures used a gridded routing model which transfers chemical through the landscape based on flow directions derived from a 1 km digital elevation model. Emission was assumed to be proportional to population and no in-stream degradation was assumed. Exposures were calculated for 296 locations containing drinking water treatment works (WTWs) under mean discharge and Q95 (discharge exceeded 95% of the time). At low tiers, risk characterisation ratios (RCRs) were 1 for three substances under conventional treatment but were 1 for tetrachloroethylene (highest RCR) at up to 18 % of WTW locations under Q95 conditions assuming conventional treatment. However, RCRT was <1 for all locations assuming advanced treatment. Actual exposures will depend on catchment characteristics, but the model usefully allows prioritising higher risk chemicals and WTWs. Overall, the substances evaluated are unlikely to currently pose health risks, provided an appropriate level of water treatment is employed
Spatial distribution and isotopic signatures of N and C in mosses across Europe
Get PDFThe accumulation of nitrogen (N) in moss tissue has proven to be a reliable marker of increasing N deposition. However, this measurement does not offer additional data about the origin of pollution. In this respect, the analysis of the N isotopic ratios might be a helpful tool in providing supplementary information about the nature of the nitrogenous species in biomonitoring surveys. Furthermore, isotopic signatures have been extensively used in the study of N and carbon (C) biogeochemical cycles. The main purpose of this study was to determine N and C elemental contents and their stable isotopes in mosses to investigate atmospheric pollution patterns across Europe. We aimed at identifying the main N polluted areas and evaluating the potential use of isotopic signatures in the attribution of pollution sources at a regional scale. With these objectives in mind, >1300 samples from 15 countries from Europe, all of them participants of the ICP-Vegetation programme 2005–2006, were analyzed for their C and N contents and δ15N and δ13C. The results were compared to those derived from EMEP model, which provided modeled deposition and emission data, as well as to the predominant land uses at the sampling sites (based on CORINE Land Cover). This evaluation suggests that additional measurements of stable C and N isotopes in mosses could be a valuable tool in European environmental surveys. Such measurements not only provide useful information for identifying probable pollution sources but also enable the quantification of their contributions, serving as biological indicators of significant environmental processes. This study presents the first quantitative assessment of major atmospheric nitrogen (N) sources based on stable isotope analysis on a European scale, establishing a framework for evaluating historical changes in N across the region
Extreme precipitation associated with atmospheric rivers over West Antarctic ice shelves: insights from kilometre-scale regional climate modelling
Get PDFWe explore how atmospheric rivers (ARs) in a summer and winter case interact with the topography of the Amundsen Sea Embayment, West Antarctica, and deposit significant precipitation amounts. To do this we use results from three regional climate models (RCMs: MetUM, Polar-WRF, HCLIM) at a spatial resolution of 1 km. Estimates of snowfall associated with both events from all three RCM simulations compare well against observed snow height measurements over the Thwaites and Pine Island ice shelves. By contrast, snowfall estimates from ERA5 reanalysis for both events are severely underestimated (by 3–4 times) compared to the measurements. Outputs from the RCMs also show that the ARs may be associated with several millimetres of rain in both the summer and winter cases, although in the absence of in situ measurements of rainfall, this result cannot be directly verified. The RCM simulations suggest that rainfall during these events can fall directly as supercooled drizzle but also that rainfall is concentrated around steep terrain due to the interaction of ARs with complex orography. We also show that while the amount of MetUM-simulated snowfall was comparatively resolution-insensitive, the amount of rainfall simulated was not, with rainfall amounts over Thwaites Ice Shelf 4–16 times higher in 1 km simulations compared to 12 km simulations. Our work highlights that kilometre-scale models are useful tools to investigate the total precipitation amount and its partitioning into rain and snow over this globally important and climatically sensitive region, and it highlights the critical need for in situ observations of rainfall
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