Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics
NERC Open Research ArchiveNot a member yet
55023 research outputs found
Sort by
Accounting for model parameter uncertainty provides more robust projections of dissolved organic carbon dynamics to aid drinking water management
Get PDFChanges in climate and human behaviour impact catchment hydrology and the export of nutrients including dissolved organic carbon (DOC), with consequences for drinking water supply. In this study, we projected future river discharge and DOC dynamics under three Shared Socioeconomic Pathways (i.e., different futures of climatic conditions, socio-economic development and adaptation to climate change) and quantified change relative to a baseline for two contrasting catchments: one in Sweden and one in Ireland. For this, we used the Generalised Watershed Loading Functions Model (GWLF) with an integrated DOC module (GWLF-DOC) and drove it with data from an ensemble of global climate models, taking into account variability derived from multiple model parameter sets. We assessed the relative contribution of each of these two factors (climate input data and model parameterisation) to the total uncertainty in predictions. Projections for river discharge differed between the two sites in magnitude, variability and direction of change depending on the future scenario and time period. In contrast, DOC was always projected to show increases in concentration throughout the annual cycle and over time, with the highest levels by the end of the century, for scenarios with greater warming and low mitigation efforts. Future climate data provided the dominant source of uncertainty in all of our projections. However, the DOC model parameters, which respond to temperature and soil moisture conditions, became more influential in scenarios of higher climatic variability. Our approach highlights the benefits of incorporating often ignored parameter uncertainty in climate change impact assessments for both interpreting outputs and communicating results to water managers
Anthropogenic water withdrawals modify freshwater inorganic carbon fluxes across the United States
Get PDFQuantifying inorganic carbon fluxes to and from freshwater environments is essential for the accurate determination of the total amount of carbon exported to both the atmosphere and oceans. However, understanding of how anthropogenic freshwater withdrawals perturb land-freshwater-ocean and freshwater-atmosphere inorganic carbon fluxes is limited. Using the United States (US) as an exemplar, we estimate that fresh surface water withdrawals across the country during the year 2015 resulted in a median gross dissolved inorganic carbon (DIC) retention flux of 8.2 (uncertainty range: 6.7–9.9) Tg C yr–1, equivalent to 28.3% of the total export of DIC to the oceans from US rivers. The median gross retention flux due to fresh groundwater withdrawals was 6.9 (uncertainty range: 5.3–8.8) Tg C yr–1, over eight times the magnitude of the DIC flux to the oceans by US subterranean groundwater discharge. The degassing of CO2 supersaturated groundwater following withdrawal emitted 3.6 (uncertainty range: 2.2–5.5) Tg of CO2 yr–1, 112% larger than previous estimates. On a county level, these CO2 emissions exceeded CO2 emissions from major emitting facilities across 45% of US counties. Reported results and a data analysis framework have important implications for the accurate development of carbon budgets across the US and around the world
Antarctica’s Thwaites Glacier and sea-level rise - Results from the International Thwaites Glacier Collaboration (ITGC) [Environment Audit Committee call for evidence]
No full textExecutive Summary:
Change to Thwaites Glacier in West Antarctica, sometimes referred to as the “Doomsday Glacier”, over the coming decades and centuries will have profound implications for global sea-level rise and coastal communities around the world. Over the past six years, our research on the glacier has unveiled a complex and rapidly changing environment.
Thwaites Glacier’s retreat has accelerated considerably over the past 40 years. Although a full collapse is unlikely to occur in the next few decades, our findings indicate it is set to retreat further, and faster, through the 21st and 22nd centuries, potentially leading to a general collapse of the West Antarctic Ice Sheet in the 23rd.
Immediate and sustained climate change mitigation (decarbonisation) offers the best hope of delaying this ice loss and avoiding initiation of similar unstable retreat in marine-based sectors of East Antarctica
Underestimating global land greening: future vegetation changes and their impacts on terrestrial water loss
No full textThe growing demand for water presents a significant sustainability challenge. Understanding vegetation changes is crucial, as plants significantly influence water exchange through transpiration. However, global climate models show considerable uncertainty in predicting future vegetation trends ranging from −0.007 to 0.083 m2 m⁻2 decade⁻1, impacting water management. Here, we apply an emergent constraint method to reduce uncertainty in global vegetation projections for the period 2015–2100 from a climate model ensemble (Coupled Model Intercomparison Project Phase 6 [CMIP6]), focusing on the leaf area index (LAI). Our approach reduces uncertainty in global LAI projections by 37.7%–53.1%. We find that this uncertainty is primarily due to incomplete representations of the CO2 fertilization effect. Our results also show that models underestimate future LAI increases by 28.2%–32.1%, leading to underestimated water loss from increased transpiration. These findings improve predictions of future vegetation and transpiration, providing valuable insights for policymakers to adjust water management strategies and better prepare for water-related challenges
Salinity-redox covariation in Mississippian Bowland Shale (Craven Basin, UK) controlled by eustasy and climate
No full textChanges in watermass properties can be monitored in real time in modern depositional systems, but reconstruction in deep-time systems is difficult. Here, we analyze long-term changes in salinity (B/Ga, Sr/Ba, and S/TOC) and redox conditions (FeHR/FeT, Fepy/FeHR, and Corg/P) in the upper unit of the Mississippian Bowland Shale Formation, Craven Basin, UK. Variations in paleosalinity and redox in the Upper Bowland Shale were tightly coupled to fourth-order glacio-eustatic cyclicity. At basinal sites (borehole MHD and outcrop HC), transgressive to highstand packages (‘marine bands’) were associated with weakly hypersaline to normal marine, euxinic bottom-water conditions. In contrast, falling-stage and lowstand packages were deposited under normal-marine salinity and fluctuating euxinic to ferruginous anoxic conditions punctuated by (sub)oxic events. HC, located within a bathymetric low, exhibits significantly higher Corg/P (∼100) than MHD (<50), located on an intrabasinal high, due to the more limited influence of oxygen-bearing hyperpycnal flows in the deep basin. A sharp shift to brackish conditions near the top of the HC section reflects the basinward progradation of the Pendle Paleodelta in response to long-term eustatic fall. In the relatively more proximal (landward) and stratigraphically younger COM borehole, the pattern of salinity-redox covariation in response to sea-level cyclicity is different: highstands were associated with normal-marine salinity and euxinic conditions, whereas lowstands exhibit shifts toward brackish, oxic bottom-water conditions, reflecting shoaling of this site into the ocean-surface layer and influence from the nearby Pendle deltaic system. The ultimate driver of late Mississippian sea-level fluctuations was growth and decay of Gondwanan icesheets during an early phase of the Late Paleozoic Ice Age, with interglacial stages potentially being marked by a shift toward stronger evaporation within the climatically sensitive zone occupied by the Craven Basin (∼10–15°S paleolatitude). Our findings provide new insights into the sea-level-redox-salinity dynamics of marginal-marine basins during a major ice age
Poleward displacement of the Southern Hemisphere Westerlies in response to Early Holocene warming
Get PDFRecent intensification of the Southern Hemisphere Westerlies has resulted in important changes to ocean circulation, Antarctic ice shelf stability and precipitation regimes in the continents abutting the Southern Ocean. Efforts to resolve the natural behaviour of the Westerlies over sub-millennial to millennial-timescales are critical to anticipating future changes with continued 21st Century warming. Here we present an ~11,000 year diatom-inferred sea salt aerosol and multiproxy geochemical record preserved in lake sediments from Cape Horn (56°S) which documents warm conditions and stronger-than-present Westerlies in the Early Holocene (10 000–7500 calibrated years before present) at this site. Combined with other regional records, we demonstrate that the Westerlies were poleward of their current position during the Early Holocene. This poleward migration of the Southern Hemisphere Westerlies in response to peak Holocene warmth provides an analogue for future warming and greater impacts on the southern high latitudes and global climate in the coming decades
A cosmopolitan invader – Choreutis sexfasciella (Lepidoptera, Choreutidae) – in Cyprus: first record, molecular characterization, and a reared parasitoid
Get PDFThe Banyan Leaf Skeletonizer moth, Choreutis sexfasciella (Sauber, 1902) (Lepidoptera: Choreutidae), is reported from Cyprus for the first time from Ficus microcarpa L.fil. and F. benjamina L. trees in urban areas of Larnaca, Limassol, and Paphos. C. sexfasciella was originally described from the Philippines and has rapidly extended its range in the last five years into several Mediterranean countries as well as into North America. DNA barcode sequencing of several specimens from Cyprus has demonstrated that they are closely related to North American specimens. The parasitoid wasp Elasmus cf. cyprianus Ferrière, 1947 (Hymenoptera: Eulophidae) has been reared from leaves infested with larvae of C. sexfasciella . The observed socioeconomic impacts of the non-native moth and the potential use of its parasitoid as a biological control agent are discussed
Observations reveal changing coastal storm extremes around the United States
No full textUnderstanding extreme storm surge events that threaten low-lying coastal communities is key to effective flood mitigation/adaptation measures. However, observational estimates are sparse and highly uncertain along most coastal regions with a lack of observational evidence about long-term underlying trends and their contribution to overall extreme sea-level changes. Here, using a spatiotemporal Bayesian hierarchical framework, we analyse US tide gauge record for 1950–2020 and find that observational estimates have underestimated likelihoods of storm surge extremes at 85% of tide gauge sites nationwide. Additionally, and contrary to prevailing beliefs, storm surge extremes show spatially coherent trends along many widespread coastal areas, providing evidence of changing coastal storm intensity in the historical monitoring period. Several hotspots exist with regionally significant storm surge trends that are comparable to trends in mean sea-level rise and its key components. Our findings challenge traditional coastal design/planning practices that rely on estimates from discrete observations and assume stationarity in surge extremes
Oceanic drivers of UK summer droughts
Get PDFUK droughts are projected to become more frequent under climate change, reinforcing the need to understand their underlying causes. Our study examines oceanic drivers of UK summer droughts and the associated teleconnection pathways. Specifically, we evaluate statistical links between standardized precipitation and streamflow indices for the UK and two North Atlantic Sea surface temperature (SST) patterns which have previously been linked to the influx of freshwater into the subpolar region. Our findings reveal that the North Atlantic SST influences UK hydrology up to 1.5 years in advance by altering the position of the North Atlantic Current, which is coupled to the location of the North Atlantic summer jet stream. The long lead time of this teleconnection pathway can inform UK drought forecasting across seasonal to interannual timescales and ultimately contribute to the advancement of sustainable water resource management in the face of increasing drought risks in the UK
[NRFA/NGLA] 42nd annual report to the UK Surface and Groundwater Archives Committee: 2024/2025
No full textThis report has been produced by the National River Flow Archive (NRFA), hosted by the UK Centre for Ecology & Hydrology (UKCEH), and the National Groundwater Level Archive (NGLA), hosted by the British Geological Survey (BGS). The document forms the Archives’ annual report of activities to the UK Surface and Groundwater Archives (SAGA) Committee, for the period March 2024 – March 2025. The report is submitted for discussion at the 42nd Annual Meeting of the SAGA Committee on 5th March 2025
Data sources:
Access Repository Dashboard
Do you manage NERC Open Research Archive? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!