Northwest Europe Research Articles

Modeling atmospheric microplastic cycle by GEOS-Chem: An optimized estimation by a global dataset suggests likely 50 times lower ocean emissions

Modeling atmospheric microplastic cycle by GEOS-Chem: An optimized estimation by a global dataset suggests likely 50 times lower ocean emissions

Thunderstorm tracking in Northwest Europe for enhanced hazard preparedness

AbstractThe tracking of thunderstorms provides critical information on their frequency and behaviour for early warning, prediction and preparedness. Thunderstorm tracking has previously been constrained by the boundaries of a particular country or has focused on a particular category such as severe thunderstorms and mesoscale convective systems. However, less severe thunderstorms also pose a risk to life and property and occur more frequently and thus warrant inclusion in investigations of thunderstorm behaviour. In this paper, we present a new thunderstorm event catalogue, including all detected thunderstorms with at least three lightning flashes, derived from a tracking methodology applied to Northwest Europe within the bounds of 48° to 65°N and 15°W to 10°E between 2008 and 2018. The catalogue is based on ATDnet lightning flash data which was clustered into thunderstorms using a spatio‐temporal proximity assessment lightning clustering code written in the R coding language. The thunderstorm lightning clusters enabled the production of thunderstorm behaviour statistics such as speed, direction of movement, lightning flashes per minute and duration. This revealed that in winter, thunderstorms are shorter lived and move faster than in summer as well as more typically tracking from the west rather than from the south‐west. Thunderstorm behaviour characteristics were attributed to weather pattern types for the first time, providing probabilistic data that can be attributed to synoptic conditions. This can improve preparedness and early warning. Such results demonstrate how this new thunderstorm event catalogue, which includes all types and severities of thunderstorms unconstrained by political boundaries, can provide additional important information to enhance understanding of thunderstorm behaviour in the region. Our lightning clustering method may be useful for similar studies in other locales.

Spatial patterns of flower colour variation in native and introduced ranges of Convolvulus arvensis (Convolvulaceae) revealed by citizen-science data and machine learning.

Flower colour polymorphism refers to the presence of multiple colour variants in plant populations. Investigation of this phenomenon led to multiple discoveries, including the principles of heredity and the foundations of population genetics. I examined flower colour variation across native and introduced ranges of Convolvulus arvensis, which exhibits flower colour polymorphism (individuals have white or pink petals). To study flower colour variation of this species throughout large geographic scale, I used observations gathered from the iNaturalist platform. To handle a large amount of data, I trained a neural network to classify the plants' morphs based on photographs. After which I performed spatial analyses to examine the patterns of the colour frequency, also in relation to environmental factors. The results show that flower colours are polymorphic across the whole species range, but the frequency of pink versus white flowers varies. In the Palearctic, I observed geographic clines of colour morph frequencies: a higher frequency of the pink morph in populations from Northwest Europe, whereas in South and East Europe, towards the eastern edge of the range, the white morph was dominant. In contrast, pattern of colour distribution in North America (where the species is invasive) seems random, but the model indicates a link between higher proportions of pink morphs in mild and humid climates. The mechanisms behind the observed patterns remain largely unknown, as changes in a morphs' frequency are not strongly linked to abiotic factors. To understand the spatial pattern, a detailed investigation, accounting for the species' phylogeography is needed. This study provides another example of how the general public may collect data relevant to ecological studies, even when the data are not collected for a specific project.

Penultimate interglacial palynology of Flanders: A revised river evolution model

There are no Saalian Stage pollen records in Northwest Europe that not only cover an entire interglacial complex but also have been successfully correlated down to marine isotope substage level. The presented pollen record fills this knowledge gap. Three pollen sequences, sampled from a well-preserved Saalian Stage river terrace near Brussels (Belgium), together span most of an interglacial complex: two interglacial cycles and one interstadial separated by colder intervals. To date the pollen data, the authors present a multi-proxy supported river evolution model through which the correlation of the pollen record with the penultimate interglacial complex (Marine Isotope Stage (MIS) 7) becomes apparent. The authors further illustrate homotaxis—defined as the similarity between pollen diagrams that are not necessarily contemporaneous—by comparing MIS 7 with MIS 5 pollen data from the same area, convincingly curve-match the pollen record with marine isotope data, and point to similarities between Southern and Northwest European vegetation dynamics and climate variability during MIS 7.

Surface hazards in North-west Europe following sudden stratospheric warming events

Sudden stratospheric warmings (SSWs) have been linked to surface temperature anomalies, but how these connect to changes in the likelihood of specific weather extremes and their associated weather patterns remains uncertain. While, on average, it is true that cold surface temperatures follow SSW events, particularly in Northern Europe, there is considerable event-to-event variability. Over the British Isles and Central Europe, only around 45% of SSWs are followed by a colder than average period and a negative phase of the North Atlantic Oscillation, cautioning against an over-generalised approach to surface anomalies associated with SSWs. Focussing on more hazardous weather, which in winter is associated with cold extremes, we use reanalysis data to consider how SSWs impact temperature-related hazards; namely the frequency of snowy days, frost days and spells of extreme cold weather in 12 major European cities. In general, SSWs are associated with an increased risk of snow across most of western Europe, and that this is particularly significant in milder, more maritime locations such as London where in reanalysis, snowfall days are 40% more likely after an SSW. However, there is considerable variation in surface temperature anomalies between SSW events; the third of SSWs with the warmest surface anomalies are statistically more likely to have a decreased risk of snow, frost and persistent cold spells compared with non-SSW time periods. These warmer events are associated with a different temperature anomaly pattern, which is consistent in both reanalysis data and large ensemble CMIP6 models. We further show that these warm surface temperature anomaly SSWs are becoming more frequent, a trend which is consistent with background global warming. The varied surface anomalies associated with SSWs highlights the need to study their impacts in a probabilistic sense, and motivates further work to enable better prediction of the impacts of a given event.

Just Bad Quality or Just Good Quality? The Meaning of Macroscopic Growth Features of Timber in Ship-Archaeological Analyses

Abstract The particular macroscopic growth features of the timbers of Bremen-Cog, a late 14th-century cargo vessel, were the subject of a detailed analysis during the European Research Council (ERC) research project TIMBER at the University of Copenhagen. The unexpected depth of the results of this examination led to the feasibility study presented in this paper, which evaluates the meaning of macroscopic growth features in ship archaeological analyses. In the past, the perception of wood in ship-archaeological analyses often seems to be either ignored or strongly idealised causing macroscopic growth features to be missing in many cases as decisive analytical features. The idea of a shipwright, who personally chooses only the best material, was likely born out of an idealised image of the past and influenced by recent shipbuilding practices. Detailed advice on the choice of high-quality timber for shipbuilding only appeared during the 20th century, long after wood was superseded by steel for most vessels, and the competition for shipbuilding timber on the market had ceased. In some cases, this has produced a somewhat distorted interpretation of ships and shipbuilding. As a holistic approach to features of growth can provide information beyond timber quality, such as environmental influences and human impacts on this resource. In certain cases, such an approach can draw conclusions on economic and social circumstances. The information gathered from building timber can alter the interpretation of boats and ships. This paper discusses the demand for shipbuilding timber and its quality in northwest Europe, and aims to reflect on possible social, economic, or environmental reasons for the shipwright’s choices.

Equalizing solar panel adoption across immigrant groups

This study seeks to understand the difference in solar-panel adoption across country-of-birth groups in Australia. Households with a respondent born in Australia, New Zealand, or North-West Europe are more likely to own their home and to have solar panels than households with respondents born elsewhere. The solar-uptake difference is substantial at around five percentage points, based on the 2019–20 Survey of Income and Housing. Renting status accounts for around 35% of the explained solar-uptake difference across country-of-birth groups using the 2019–20 survey and higher proportions using earlier surveys. Results are robust to inclusion of variables for key influences on solar adoption, such as wealth. Detailed location variables account for further differences in solar adoption that are not captured by other controls. The key implication is that policy to promote solar-panel adoption on rental housing could also make a major contribution toward improving equality of solar-panel adoption for country-of-birth groups. The decomposition approach in this paper could be useful for future studies which can suggest policies to reduce inequality in other contexts.

Production of Long Hemp Fibers Using the Flax Value Chain

Hemp is finding a strong renewal of interest in the production of fine fibers for garment textiles. This resource of long-line fibers would come as a complement to the highly demanded flax fibers, whose large production in the north-west of Europe cannot be extended. In Normandy, where a complete industrial value chain exists for flax, it is intended to adapt it to hemp, and this was demonstrated from the field to the scutched fibers with a complete value chain. In this region, early harvesting is necessary to leave enough time for dew-retting and permit dry storage of stems before mid-September. An early-flowering variety (USO-31) was harvested using dedicated hemp equipment to obtain a 1 m parallel and aligned windrow that can be further processed by flax equipment. The scutching process as well as the fiber’s morphological and mechanical properties were particularly studied. Adapted scutching process parameters with reduced advancing speed and beating turbine velocity led to long fiber yields of about 18% of the stem mass. Stem yields were reaching about 6 tons/ha leading to a production of 1.1 tons/ha of long fibers. The tensile properties of the long fibers were highly sufficient for textile applications, and their thickness after hackling was in the range suitable for the production of fine yarns. Compared to other crops grown in Normandy, the hemp as produced in this 2020 case study provides good incomes to the farmer, higher than traditional crops such as wheat or barley, and the results of this study should encourage farmers to grow hemp for textile purposes.

Middle Palaeolithic occupation of the southern North Sea Basin: evidence from the Sandscaping sediments emplaced on the beach between Bacton and Walcott, Norfolk, UK

ABSTRACTDuring the summer of 2019, the Bacton to Walcott Coastal Management Scheme involved the emplacement on to the foreshore of 1.8 million cubic metres of sand and gravel dredged from the submerged sediments of the Palaeo‐Yare in the southern North Sea 11 km off Great Yarmouth. During the following 2‐year period, an active group of collectors identified Palaeolithic artefacts eroding from these sediments, including Levallois cores and flakes, and cordiform handaxes. In this paper, we present an analysis of the lithic artefacts, and consider the relationships between the different elements of the assemblage. We discuss its significance in the context of the Middle Palaeolithic record of northwest Europe and the light it shines on the human occupation of the submerged landscape of the southern North Sea during the later Middle Pleistocene. Interrogation of beach survey data shows the reworking of these sediments to the southeast towards Happisburgh where archaeologically significant exposures of the Cromer Forest‐bed Formation are located. The implications of the introduction of a Middle Palaeolithic assemblage to this stretch of the North Norfolk Coast are considered, highlighting the importance of continuing dialogue between researchers, local authorities and local communities for capturing information and monitoring this critical Palaeolithic resource.

Biostratigraphy of Bajocian–Oxfordian strata based on dinoflagellate cysts and ammonites from the Dalichai Formation, northeastern Iran

The Bajocian–Oxfordian Dalichai Formation of the Binalud Mountains (northeastern Iran) consists of marls, marly limestones and limestones that were sampled and studied in detail for their palynomorph and ammonite contents. Palynological studies enabled differentiation of three marine biozones (Cribroperidinium crispum, Dichadogonyaulax sellwoodii, and Ctenidodinium continuum) within the lower interval of the formation. The palynofacies analysis shows a gradual sea-level rise during the depositional period of the rock unit, while terrestrial palynomorphs (spores and pollen grains) revealed a predominantly tropical climate for the time interval. Furthermore, a large number of ammonites were recovered from the formation, based on which 12 families, 22 genera, 30 species and 12 biozones (Zigzag, Aurigerus, Retrocostatum, Discus, Bullatus, Gracilis, Anceps, Coronatum, Athleta, Transversarium, Bifurcatus, and Bimammatum) were differentiated. When comparing the dinoflagellate cyst zones with the ammonite zones, the Dichadogonyaulax sellwoodii dinoflagellate cyst zone was correlated with the ammonite zones of Zigzag, Aurigerus, Retrocostatum, Discus, Bullatus, and Gracilis and the Ctenidodinium continuum dinocyst zone was correlated with the Gracilis and Anceps ammonite zones. The dinocyst and ammonite assemblages of the Binalud Mountains are similar to assemblages described from northern and northeastern Iran (Alborz and Koppeh-Dagh basins) as well as Northwest Europe. This suggests marine connections between these sedimentary basins during the Bajocian–Oxfordian. Consequently, the integrated dinocyst and ammonite zonation established here can be utilized also in other parts of the northern Tethyan Realm. The diachroneity of the upper boundary of the Dichadogonyaulax sellwoodii Zone between the Binalud Mountains and Northwest Europe is however revealed by comparison with the ammonite zones.

Ammonites and stratigraphy of the “Wild Bed” (Middle Jurassic, Aalenian, Inferior Oolite) at Quarr Hill, Chideock, Dorset

The Inferior Oolite Formation, 'Wild Bed' of Quarr Hill, Chideock, Dorset is described in terms of ammonite biostratigraphy down to the resolution of biohorizons for a segment of the Aalenian Stage of the Middle Jurassic. A section is presented and descriptions of the ammonites of the families Graphoceratidae, Erycitidae, Hammatoceratidae and Lytoceratidae are made in conjunction with an assessment of available types along with new illustrations of specimens collected in-situ. Examples of other molluscs are cited and imaged. Lectotypes are designated for some of the species erected by S. S. Buckman from Chideock. Comparisons are made with successions in other areas of North-West Europe thus providing an improved correlation and relationships between different ammonite morpho-taxa.

From the Jura Arc to the Paris Basin: exploitation of jet as black raw material for making ornamental objects during the Magdalenian in the northwest Europe

From the Jura Arc to the Paris Basin: exploitation of jet as black raw material for making ornamental objects during the Magdalenian in the northwest Europe

The times they are a-changing. Reconsidering the occupation history and character of a 3rd millennium BCE settlement in the Lower Rhine Area

A re-analysis of soil micromorphology samples and radiocarbon dates was undertaken at the Middle to Late Neolithic settlement of N11, Hazerswoude-Rijndijk, in the Netherlands. The site, located on crevasse deposits of the river Rhine, was previously dated between 3200 and 2500 BCE. Our re-analysis allows us to place the occupation firmly in the 3rd millennium BCE, which holds implications for our understanding of a pivotal transformation process in Northwest European prehistory. At the same time, it presents us a very informative picture of domestic activities including both the remains of combustion next to a dwelling structure, dating to the first phase of occupation, and the dumping of organic waste with varying degrees of intensity throughout the whole habitation period. Finally, we have shown that a combined approach of archaeological soil micromorphology and a critical analysis of radiocarbon dating, can strengthen interpretations of site chronology and characterising socio-cultural processes.

The effect of uncertain river forcing on the thermohaline properties of the North West European Shelf Seas

Modeling studies and observations show that the thermohaline properties of the North West European Shelf Seas (NWESS) are sensitive to surface wind and heat flux forcing, as well as river outflows that transport fresh water from land to the ocean. In previous studies, it was assumed that the variability of the thermohaline properties in response to river outflow could be adequately sampled with a high-resolution, submesoscale permitting, long-term (i.e., 30-year) deterministic hindcast. In this study, we assume that the statistical distribution of the river forcing, rather than the time series of forcing itself, is adequately constrained by a 28-year history (1991 to 2018) of river forcing created specifically for our domain. In this way, we created an ensemble of 10 lower-resolution (≈7-km), short-term (i.e., 2.5 years) hindcast models that are forced with randomly perturbed river outflows and an ensemble of surface fluxes from the 10-member ECMWF ERA5 reanalysis (the ‘Test’ ensemble) as well with a companion ensemble that is forced with the ERA5 surface forcing fluxes but unperturbed river outflows (the ‘Base’ ensemble) for the June 2016 through December 2018 time period.In both ensembles, the modeled evolution of 25-hour averaged (to partially filter out tides) temperature and salinity is realistic with peaks in summer for sea surface temperature and in winter for salinity, and annual amplitudes that are comparable to those found in other studies of the NWESS. The increased mean and standard deviation of the sea surface and bottom salinity in the Test ensemble are partly an artifact of the assumption that the errors in river forcing have a log-normal distribution that mimics the episodic nature of river outflow with a positive mean and an asymmetrical shape with a long tail toward large values. For surface density, the standard deviation in the Test ensemble was below 0.5 kg/m3, covering an areal extent larger than that for the Base ensemble throughout the year. The annual cycle of the areal extent of density in that range had a peak in summer and minima in winter, in phase with that of the river outflow forcing. Overall, the effect of uncertain river forcing on the thermohaline properties in this study is small. In order to understand the true impact of river forcings, better temporal and spatial observations of river outflow are needed.

Meteotsunamis and other anomalous “tidal surge” events in Western Europe in Summer 2022

We investigate occurrences of anomalous tidal activity in coastal waters of north-west Europe during Summer 2022. Sightings of an anomalous “tidal surge” occurred on 18 June 2022 in Wales, followed by similar observations in Ireland, France, and Spain. Several anomalous long-wave events were also reported in south England and Wales in the morning of 19 July 2022. We analyzed surface and high-altitude air pressure fields, and sea level oscillations for both days. Our detailed analysis reveals that the 18 June events were a series of meteotsunamis, propagating over several countries in Western Europe and triggered by localized pressure perturbations, originating within a low-pressure area over the North Atlantic Ocean. A local analysis of the southern coast of Ireland suggests that Proudman resonance was the determinant mechanism that amplified the meteotsunami traveling eastward in the afternoon of 18 June. A similar analysis of the 19 July events suggests that the tidal surge reported in the UK and anomalous signals recorded in Ireland and France were episodes of seiching triggered by infragravity waves, resonated subharmonically by wind waves. Numerical simulations of the 18 June event were performed with Volna-OP2, which solves the non-linear shallow water equations using a finite volume discretization. The influence of the atmospheric wave velocity on the amplification of the sea surface elevation is analyzed.

Testate amoebae response and vegetation composition after plantation removal on a former raised bog

Extensive drainage of peatlands in north-west Europe for the purposes of afforestation for timber production and harvesting has altered the carbon balance and biodiversity value. Large-scale restoration projects aim to reinstate hydrological conditions to keep carbon locked up in the peat and to restart active peat growth. Testate amoebae are an informal grouping of well-studied protists in peatland environments and as microbial consumers play an important role in nutrient and carbon cycling. Using a space for time substitution approach, this study investigated the response of testate amoebae assemblages and vegetation composition after tree removal on a drained raised bog. There was a clear difference in microbial assemblages between open and a chronosequenceof restoration areas. Results suggest microbial recovery after rewetting is a slow process with plant composition showing a faster response than the microbial assemblage. Mixotrophic testate amoebae had not recovered seventeen years following plantation removal and the establishment of Sphagnum mosses in the wetter microforms. These results suggest that vegetation composition and Testate amoeba assemblages respond differently to environmental drivers at forest-to-bog restoration areas. Local physicochemical peat properties were a stronger driver of the testate assemblage compared with vegetation. Complete recovery of microbial assemblages may take place over decadal timescales.

Hidden transitions. New insights into changing social dynamics between the Bronze and Iron Age in the cemetery of Destelbergen (Belgium)

Urnfields were the common type of cemetery in the Late Bronze Age (LBA) and Early Iron Age (EIA) in much of Northwest Europe. Rarely are there clear social or chronological differences between burials apart from changing pottery types. The cemetery of Destelbergen stands out because of the relatively high prevalence of monumental ditches surrounding a selection of graves, indicating a certain status difference between the deceased. Strontium concentrations ([Sr]) combined with radiocarbon (14C) dates and spatial analysis bring to light clear differences between LBA and EIA traditions. The end of the LBA went hand in hand with the abandonment of the oldest part of the cemetery, which new 14C dates demonstrate was strict. Additionally, [Sr] reveal changing diets in individuals buried centrally within monumental ditches. In the EIA these individuals present significantly lower [Sr] than the surrounding burials, potentially the result of a diet richer in animal protein at the expense of plant-based food, a distinction not seen in LBA burials. Even though continuity and equality are reflected in the uniform burial tradition seen within urnfields, this paper’s analyses unlock subtle changes in social attitudes between the LBA and EIA and suggest increasing (dietary) social differentiation in the EIA.

A systemic framework of energy efficiency in schools: experiences from six European countries

Schools are complex physical and social institutions within national education systems. They account for significant energy consumption and like other buildings can demonstrate inefficient patterns of energy use. Poor energy performance of educational facilities is an intricate issue driven by complex causality of interconnected and dynamic factors. Addressing this issue requires a systemic approach, which is heretofore lacking. The aim of this research is to present and describe a systemic framework to facilitate energy reduction in schools across different European contexts. This transdisciplinary approach to sustainable energy use has been piloted in 13 post-primary schools located in six countries in northwest Europe. The research implements a series of planned activities and interventions, which help to unveil a systemic approach to improving energy efficiency in schools. The findings demonstrate how this approach, together with its ensuing methodologies and strategies, can contribute to reducing carbon emissions and improve knowledge and awareness around sustainable energy.

Plastics and Five Heavy Metals from Sea Beaches: A Geographical Synthesis of the Literary Information

Pollution of the oceans and seas, as well as their coastal zones, with plastics has become serious challenge, which is also related to the Anthropocene marine geology and geochemistry. Notably, plastics can bear heavy metals. The related knowledge is scattered through scientific publications, and, thus, it needs generalization. The present study synthesizes the published information about the geographical distribution of cadmium, chromium, mercury, nickel, and zinc associated with plastics on sea beaches. A bibliographical survey is undertaken, and the collected literary information is organized so as to document the principal localities of beached plastics bearing these metals. About twenty localities are established in many parts of the world, and the majority of them correspond to the coasts of the Atlantic and Indian oceans and their seas. Significant attention has been paid by the previous researchers to Northwest Europe and South and East Asia. The available information is enough to postulate the global extent of the problem of heavy metals association with plastics on beaches. Real or potential risks to the environment were reported in many cases. This review also shows that the industry of tourism, hospitality, and recreation contributes to the accumulation of such plastics. The analyzed literary information demonstrates several biases: for instance, Hg-bearing plastics on beaches were reported from the smaller number of localities relatively to the other metals, and the beaches and coastal recreational areas of many regions are yet to be studied in regard to heavy metals associated with plastics.

Parsing prehistoric patterns: Prospects and limitations of a big radiocarbon dataset for understanding the impact of climate on Late Palaeolithic and Mesolithic populations in northwest Europe (16–7.5 ka calBP)

Hunter-gatherer populations in northwest Europe were variably affected by Late Glacial and Early Holocene climate fluctuations and their effects on sea level and the environment. We investigate the impact of these fluctuations with a dates-as-data approach to a large radiocarbon dataset. Radiocarbon dates are used as a proxy for past human activity, the intensity, nature and archaeological visibility of which will indirectly influence date density. The significance of changes is explored using Kernel Density Estimates and model tested Summed Probability Distributions. Whereas previous studies have focused on smaller highly curated datasets to minimise research and preservation biases, our more inclusive approach maximises sample size, which is essential for these methods to reliably reflect underlying patterns. To deal with biases, we test subsets of the dataset that are potentially affected by differences in formation processes.The summed radiocarbon dataset follows the general fluctuations of climate conditions, showing increased activity in temperate periods and decreased activity during cold phases. Our results indicate significant periods of interest where the data deviates positively or negatively from our models. Notably we observe the impact of the Younger Dryas, Preboreal Oscillation and the 8.2 ka event on the density of hunter-gatherer activity. Additionally we see peaks in activity in our dataset during the Early and Late Boreal. Permutation testing of different regions in the research area shows these patterns are geographically differentiated.Our exploration of biasing factors indicates that we should be careful to interpret the abovementioned patterns, as different sampling processes and national policies may lie at the basis of several patterns. Furthermore, calibration artefacts may also cause issues at key parts of the timeline. Dates-as-data approaches require an understanding of the archaeology, the timing of external events, the impact of the calibration curve and how biases inherent to the dataset and research area may have influenced the formation of patterns in the result.