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Spatial Modelling of Aerial Survey Data Reveals an Important European Storm‐Petrel Hotspot and Its Underlying Drivers Within the North‐East Atlantic
Get PDFDetermining the distribution and population size of marine species is crucial for conservation and management. However, for many species, the abundance and at sea distribution are poorly known because of their large geographic ranges, high mobility and cryptic breeding habits. This is especially true for small pelagic seabirds such as the European storm‐petrel. Large‐scale observer‐based aerial surveys were conducted over four summers in the North‐East Atlantic extending 200 nautical miles from the coast of Ireland. Species distribution models were produced using generalised additive models with a combination of static and dynamic environmental variables to assess the impact of survey altitude on storm‐petrel detectability, and to model their abundance and distribution. Reduced storm‐petrel detectability was identified at higher survey altitudes and rougher seas, and an at‐sea abundance of 154,044 (95% CI: 94,347–452,299) individuals was estimated. Our results reveal fine‐scale variation in the spatial distribution of storm‐petrels and highlight the unsuitability of foraging radius distribution models for such species. Storm‐petrels were found to avoid coastal areas, which we speculate is linked to the avoidance of large coastal avian predators during the day. Although the continental shelf edge was highlighted as a significant feature in the distribution of this pelagic species, a more prominent hotspot was identified in neritic areas, 20–40 km off the south and south‐west coasts of Ireland in a region highly influenced by shelf fronts, coastal currents, upwellings and eddies in the summer months. The identified hotspot has global significance since Ireland holds more than 20% of the entire European storm‐petrel breeding population
Advancing ocean monitoring and knowledge for societal benefit: the urgency to expand Argo to OneArgo by 2030
Get PDFThe ocean plays an essential role in regulating Earth’s climate, influencing weather conditions, providing sustenance for large populations, moderating anthropogenic climate change, encompassing massive biodiversity, and sustaining the global economy. Human activities are changing the oceans, stressing ocean health, threatening the critical services the ocean provides to society, with significant consequences for human well-being and safety, and economic prosperity. Effective and sustainable monitoring of the physical, biogeochemical state and ecosystem structure of the ocean, to enable climate adaptation, carbon management and sustainable marine resource management is urgently needed. The Argo program, a cornerstone of the Global Ocean Observing System (GOOS), has revolutionized ocean observation by providing real-time, freely accessible global temperature and salinity data of the upper 2,000m of the ocean (Core Argo) using cost-effective simple robotics. For the past 25 years, Argo data have underpinned many ocean, climate and weather forecasting services, playing a fundamental role in safeguarding goods and lives. Argo data have enabled clearer assessments of ocean warming, sea level change and underlying driving processes, as well as scientific breakthroughs while supporting public awareness and education. Building on Argo’s success, OneArgo aims to greatly expand Argo’s capabilities by 2030, expanding to full-ocean depth, collecting biogeochemical parameters, and observing the rapidly changing polar regions. Providing a synergistic subsurface and global extension to several key space-based Earth Observation missions and GOOS components, OneArgo will enable biogeochemical and ecosystem forecasting and new long-term climate predictions for which the deep ocean is a key component. Driving forward a revolution in our understanding of marine ecosystems and the poorly-measured polar and deep oceans, OneArgo will be instrumental to assess sea level change, ocean carbon fluxes, acidification and deoxygenation. Emerging OneArgo applications include new views of ocean mixing, ocean bathymetry and sediment transport, and ecosystem resilience assessment. Implementing OneArgo requires about $100 million annually, a significant increase compared to present Argo funding. OneArgo is a strategic and cost-effective investment which will provide decision-makers, in both government and industry, with the critical knowledge needed to navigate the present and future environmental challenges, and safeguard both the ocean and human wellbeing for generations to come
Dynamics and Temporal Variability of the North Atlantic Current in the Iceland Basin (2014–2022)
Get PDFThe North Atlantic Current (NAC) is a major source of heat toward the subpolar gyre and northern seas. However, its variability and drivers are not well understood. Here, we evaluated 8 years of continuous daily measurements as part of the international program Overturning in the Subpolar North Atlantic Program to investigate the NAC in the Iceland Basin. We found that the NAC volume and freshwater anomaly transport and heat content (HC) were highly variable with significant variability at timescales of 16–120 days to annual. Intraseasonal to short interannual variability was associated with mesoscale and intermittent mesoscale features abundant in the region. Composites analysis revealed that strong NAC periods were associated with less eddy kinetic energy in the Iceland Basin, which was consistent with the presence of frontal-like structures instead of eddy-like structures. On longer timescales, the westward migration of the eastern boundary of the subpolar North Atlantic (SPNA) gyre favors a stronger NAC volume transport and HC in the region. Stronger zonal wind stress triggers a fast response that piles water up between the SPNA and subtropical gyres, which increases the sea surface height gradient and drives the acceleration of the NAC. The strengthening of the NAC increases the heat and salt transport northward. During our study period, both heat and salt increased across the moorings. These observations are important for understanding the heat and freshwater variability in the SPNA, which ultimately impacts the Atlantic meridional overturning circulation
Indicators of Global Climate Change 2024: annual update of key indicators of the state of the climate system and human influence
Get PDFIn a rapidly changing climate, evidence-based decision-making benefits from up-to-date and timely information. Here we compile monitoring datasets (published at https://doi.org/10.5281/zenodo.15639576; Smith et al., 2025a) to produce updated estimates for key indicators of the state of the climate system: net emissions of greenhouse gases and short-lived climate forcers, greenhouse gas concentrations, radiative forcing, the Earth's energy imbalance, surface temperature changes, warming attributed to human activities, the remaining carbon budget, and estimates of global temperature extremes. This year, we additionally include indicators for sea-level rise and land precipitation change. We follow methods as closely as possible to those used in the IPCC Sixth Assessment Report (AR6) Working Group One report.
The indicators show that human activities are increasing the Earth's energy imbalance and driving faster sea-level rise compared to the AR6 assessment. For the 2015–2024 decade average, observed warming relative to 1850–1900 was 1.24 [1.11 to 1.35] °C, of which 1.22 [1.0 to 1.5] °C was human-induced. The 2024-observed best estimate of global surface temperature (1.52 °C) is well above the best estimate of human-caused warming (1.36 °C). However, the 2024 observed warming can still be regarded as a typical year, considering the human-induced warming level and the state of internal variability associated with the phase of El Niño and Atlantic variability. Human-induced warming has been increasing at a rate that is unprecedented in the instrumental record, reaching 0.27 [0.2–0.4] °C per decade over 2015–2024. This high rate of warming is caused by a combination of greenhouse gas emissions being at an all-time high of 53.6±5.2 Gt CO2e yr−1 over the last decade (2014–2023), as well as reductions in the strength of aerosol cooling. Despite this, there is evidence that the rate of increase in CO2 emissions over the last decade has slowed compared to the 2000s, and depending on societal choices, a continued series of these annual updates over the critical 2020s decade could track decreases or increases in the rate of the climatic changes presented here
Estimating the impact of SESRO operation on phytoplankton growth in the River Thames at Wallingford: application of Eutrophication Risk Modelling
No full textThis project is focussed on predicting the potential impacts that a proposed new reservoir near Abingdon, Oxfordshire, may have on the algal community of the middle reaches of the River Thames. The study combines the physical and chemical outputs of a Thames 1-D model with algal growth thresholds in flow, water temperature, light and soluble reactive phosphorus (SRP) concentrations, to assess effects on algal community structure, succession and bloom risk
A novel framework for analyzing rainy season dynamics in semi-arid environments: a case study in the Peruvian Rio Santa basin
Get PDFIn semi-arid regions, the timing and duration of the rainy season determines plant water availability, which directly impacts food security. Rainy season metrics, which aim to define and, in some cases, predict the onset and end of seasonal rains, can support agricultural planning, such as scheduling planting dates and managing water resources. However, these metrics based on precipitation time series do not always accurately reflect plant water availability, and the variety of available metrics can complicate the selection of the most suitable one. Furthermore, a metric's ability to capture observed vegetation variability can indicate its applicability over larger spatial or temporal scales. This study introduces a new bucket-type metric that incorporates a simplified water balance, accounts for both accumulation and storage, and also takes interannual legacy effects into account. We evaluate its performance against seven commonly used rainy season metrics, both calibrated and uncalibrated, using 18 years of the satellite-derived Normalized Difference Vegetation Index (NDVI) from the semi-arid Rio Santa basin in the Peruvian Andes. Our results demonstrate that calibrating metrics using vegetation data significantly enhances their ability to capture rainy season dynamics, with the bucket metric outperforming others in both accuracy and robustness. Furthermore, we examine the sensitivity of all metrics to variations in rainfall intensity and frequency under future climate scenarios, using a previously published high-resolution dataset specifically designed for the Rio Santa basin which provides historical (1981–2018) rainfall data and future projections (2019–2100) based on 30 statistically downscaled CMIP5 models for the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios, respectively. While most rainy season metrics exhibit expected correlations in response to climatic changes, some established metrics display physically inconsistent behavior due to methodological artifacts, highlighting their limitations in assessing hydroclimatic changes. In addition to the sensitivity analysis, we evaluate long-term trends in rainy season characteristics. Statistically downscaled CMIP5 ensemble projections for the future period suggest only a slight delay in the rainy season end, with no consistent trends in onset timing. Instead, interannual variability and ensemble spread remain the dominant influences. Our findings emphasize the need for careful calibration of metrics across diverse climate scenarios and different locations to ensure their reliability for agricultural planning, policymaking, and climate adaptation strategies. By providing a novel framework for evaluating rainfall metrics, this study offers a scalable approach that can be readily applied to other semi-arid regions
Using Stable Isotopes to Assign Origin of White‐Chinned Petrels Killed by Longline Fisheries
Get PDFIncidental capture (bycatch) of seabirds in longline and trawl fisheries is one of the main threats to many albatrosses and large petrels. The White‐chinned Petrel ( Procellaria aequinoctialis ) has a circumpolar distribution and is the seabird species killed most frequently by fisheries in the Southern Ocean. In an attempt to identify provenance, stable isotope values ( δ 13 C and δ 15 N) in feathers from White‐chinned Petrels killed in longline fisheries off Brazil, South Africa and New Zealand were compared with those from petrels breeding at five major colonies (South Georgia, Prince Edward, Crozet, Kerguelen and Antipodes Islands). Feather δ 15 N, and to a lesser extent, δ 13 C values in feathers differed among breeding birds sampled at South Georgia, Antipodes Islands and the three Indian Ocean colonies. Given that adult feathers are moulted primarily in temperate waters, away from their colonies, this confirms that most adults from these three regions winter in different areas. Discriminant function analysis of stable isotope values indicated that most petrels killed off Brazil and South Africa were from Atlantic and Indian Ocean populations, respectively. Birds killed in New Zealand fisheries in summer were assigned to populations from all three oceans, with few assigned to the Antipodes; however, we lacked stable isotope data from the Auckland Islands, which is the most likely source population. Identifying the origin of bycaught birds is essential for determining which populations are affected by human activities and for prioritising conservation efforts. This includes targeting of mitigation regulations, monitoring of compliance and bycatch rates, and ensuring cooperation between breeding and non‐breeding range states to ensure best practices are adopted in national fisheries and in the high seas
Global importance of nitrogen fixation across inland and coastal waters
No full textBiological nitrogen fixation is a key driver of global primary production and climate. Decades of effort have repeatedly updated nitrogen fixation estimates for terrestrial and open ocean systems, yet other aquatic systems in between have largely been ignored. Here we present an evaluation of nitrogen fixation for inland and coastal waters. We demonstrate that water column and sediment nitrogen fixation is ubiquitous across these diverse aquatic habitats, with rates ranging six orders of magnitude. We conservatively estimate that, despite accounting for less than 10% of the global surface area, inland and coastal aquatic systems fix 40 (30 to 54) teragrams of nitrogen per year, equivalent to 15% of the nitrogen fixed on land and in the open ocean. Inland systems contribute more than half of this biological nitrogen fixation
Challenges and opportunities for high-temperature mine thermal energy storage with focus on regulatory barriers for implementation
Get PDFMine thermal energy storage (MTES) is an innovative solution to use flooded mines to temporarily store heat during periods of low heating demand for later use during periods of high demand. Its implementation has associated technical and regulatory challenges that must be tested and understood. The PUSH-IT project is piloting the implementation of high-temperature thermal energy storage in aquifers, boreholes and mines. Two MTES sites are being assessed, a demonstration site in Bochum (Germany) and a follower site in Cornwall (UK). This paper presents a summarised review of the regulatory frameworks and barriers for MTES development in these two countries
Evaluating water levels from the Surface Water and Ocean Topography (SWOT) mission in a hyper‐tidal coastal and estuarine environment
Get PDFThe launch of the Surface Water and Ocean Topography (SWOT) satellite in December 2022 started a new era of swath altimetry, introducing an unprecedented global data set of high-resolution two-dimensional water level imagery. During its initial calibration and validation phase (cal/val), SWOT conducted daily observations for 3 months providing unparalleled insights into the high variability of water levels at daily and kilometer scales, far surpassing capabilities of past and current altimeters. Here, this novel data set is evaluated in the hyper-tidal coastal-estuarine environment of the Bristol Channel-Severn Estuary. SWOT total water levels (TWLs) are assessed against data from a network of in-situ water level gauges (WLGs) and compared to the performance of the CryoSat-2 satellite altimeter. In this region, CryoSat-2 water levels agree well with WLG data, with a Root Mean Square Difference (RMSD) of 0.17 m. Comparisons of SWOT Level 3 low rate 2 km (L3) total water level with WLG data reveal constant offsets that scale with water elevation, attributed to the spatial difference between the measurements. Once corrected, L3 TWLs achieve RMSDs ranging from 0.059 to 0.150 m against individual gauges. Overall, the scaled L3 data exhibit an RMSD of 0.137 m, a regression slope of 0.99 and offset +0.044 m, demonstrating that SWOT delivers high-quality water level data in these dynamic and challenging environments. SWOT's altimetry images reveal complex, changing spatial patterns across the Land-Ocean Aquatic Continuum. These daily measurements resolve fast-changing processes, such as river discharge events, sandbank movements and storm surges — phenomena missed by the 21-day cycle of the SWOT science phase
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