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Engineered Conductive Polythiophene/Elastomer/rGO Membranes for Electro‐Mechanical Applications
No full textElectrically conductive polymers such as polythiophene (PTh) offer a combination of optical and electrical properties needed in the electronic industry. We report a processible method of fabricating conductive PTh membranes with the elastomer (styrene–isoprene–styrene, SIS) to increase the ductility of the membranes. Any conductivity compromised in the process of casting polymer blends is offset by the addition of reduced graphene oxide (rGO) fillers in the PTh/SIS blends. The resulting nanocomposite conductive membranes of PTh/SIS/rGO are assessed at different filler concentrations to determine their mechanical and electrical properties in comparison to the polymer–polymer films. Results reveal that the PTh/SIS/rGO films offer maximum tensile strength (4.01 MPa) and 1301% elongation at break compared to the polymer–polymer films. Additionally, the nano‐filled polymer membranes show high electrical conductivity at 1.45 × 10 −8 S/cm compared to the conductivity (1.01 × 10 −10 S/cm) of the corresponding polymer–polymer films. This increase in electrical conductivity in the PTh/SIS/rGO membranes is due to the formation of conductive channels in the nanocomposite, which show a high percolation threshold of 4% filler. The resulting membranes are conductive, strong, and ductile and can be considered for applications in stretchable electronics
Constraining uncertainties of the Zero Emissions Commitment with a large ensemble of UVic 2.10 climate model simulations
No full textAchieving global temperature stabilisation requires net-zero CO₂ emissions, a goal widely recognised within the scientific community. However, a critical and contested question remains: will the Earth's climate continue to warm due to thermal and biogeochemical inertia even after emissions cease? This phenomenon, known as Zero Emissions Commitment (ZEC), has been estimated to likely be 0.0 ºC with a multi-model spread of 0.3°C. Considering its magnitude, ZEC may represent a significant fraction of the remaining warming before the 1.5°C threshold is reached.
In an attempt to constrain uncertainties in ZEC estimates, this study presents findings from a large ensemble of simulations conducted using the University of Victoria Earth System Climate Model (UVic ESCM v2.10). The ensemble design systematically varies model parameters within observationally constrained ranges, targeting processes identified as having the largest potential influence on ZEC (Palazzo-Corner et al., 2023). These parameters include carbon cycle feedbacks, ocean heat uptake, and CO2 fertilisation effects, which are represented with appropriate and acceptable levels of complexity within the UVic ESCM.
In line with the CMIP7 emissions-driven experimental design focus, we employ the esm-flat10-zec as well as esm-flat20-zec, which uses a constant emission rate of 10 PgC/yr and 20 PgC/yr, respectively (Sanderson et al., 2024), with varying cumulative emission budgets. This approach allows for the exploration of ZEC parameter uncertainty under varying emission rates and carbon budgets, increasing our process-based understanding of the metric
flat10MIP: an emissions-driven experiment to diagnose the climate response to positive, zero and negative CO 2 emissions
No full textThe proportionality between global mean temperature and cumulative emissions of CO2 predicted in Earth system models (ESMs) is the foundation of carbon budgeting frameworks. Deviations from this behavior could impact estimates of required net-zero timings and negative emissions requirements to meet the Paris Agreement climate targets. However, existing ESM diagnostic experiments do not allow for direct estimation of these deviations as a function of defined emissions pathways. Here, we perform a set of climate model diagnostic experiments for the assessment of transient climate response to cumulative CO2 emissions (TCRE), the Zero Emissions Commitment (ZEC), and climate reversibility metrics in an emissions-driven framework. The emissions-driven experiments provide consistent independent variables simplifying simulation, analysis and interpretation, with emissions rates more comparable to recent levels than existing protocols using model-specific compatible emissions from the CMIP DECK 1pctCO2 experiment, where emissions rates tend to increase during the experiment, such that at the time of CO2 doubling in year 70, emissions are much greater than present-day values. A base experiment, “esm-flat10”, has constant emissions of CO2 of 10 GtC per year (near-present-day values), and initial results show that the TCRE estimated in this experiment is about 0.1 K less than that obtained using 1pctCO2. A subset of ESMs exhibit land carbon sinks that saturate during this experiment. A branch experiment, esm-flat10-zec, illustrates that both positive and negative ZEC effects are less pronounced under esm-flat10 than under 1pctCO2 – the magnitude of ZEC50 in ESMs is, on average, reduced by 30 % compared with 1pctCO2 branch experiments. A final experiment, esm-flat10-cdr, assesses climate reversibility under negative emissions, where we find that peak warming may occur before or after net zero and that the asymmetry in temperature at a given level of cumulative emissions between the positive and negative emissions phases is well described by ZEC in most models. Further, we find that existing probabilistic simple climate model (SCM) ensembles tend to overestimate temperature reversibility compared with ESMs, highlighting the need for additional constraints. We propose a set of climate diagnostic indicators to quantify various aspects of climate reversibility. These experiments were suggested as potential candidates in CMIP7 and have since been adopted as “fast track” simulations
Controls on Water-Magma Interactions at Hydraulically-charged Volcanic Islands
No full textThe interaction of rising magma with groundwater can produce phreatomagmatic explosions, which, given their enhanced explosivity and unpredictability, increase the hazard potential of volcanic eruptions. To investigate the link between groundwater occurrence and phreatomagmatism, we compare the volcanic record of Flores Island (Azores) with regional climate reconstructions. Flores is an ideal case study as it experienced multiple magmatic and phreatomagmatic eruptions during the Holocene and Pleistocene.
Our results show that at a broader scale (>10 ka), magmatic volcanism prevailed during dry/colder periods, whereas phreatomagmatism preferentially occurred during wet/warm periods. At a shorter timescale (<10 ka), however, water‐magma interactions were primarily controlled by variations in eruption rates, with rainfall variability having a secondary role, as phreatomagmatism occurred even during low precipitation periods. This study reinforces that on island volcanoes with perched aquifers and prone to monogenetic
volcanism, eruption rates rather than short‐term hydroclimate changes control the triggering of phreatomagmatism.
Key Points:
- Shifts between magmatic and phreatomagmatic activity over the life span of volcanic fields may reflect fluctuations in groundwater levels
- Long-term changes in hydroclimate influenced water-magma interactions at Flores Island but not on shorter timescales (Holocene)
- At ocean island volcanoes with perched aquifers, variations in the mass eruption rate are crucial for triggering phreatomagmatis
Early Emperor seamount evolution and geotectonics of the northwestern Pacific plate
No full textOur knowledge of the Cretaceous history of the northwestern Pacific plate relies on tectonic reconstructions that lack geochronologic and geochemical constraints due to the paucity of sampling in this area. We present new age and compositional data for samples from four Emperor seamounts: Meiji, Hanzei, Suizei, and Tenji. Tholeiites from Tenji (66 Ma) and Suizei (70 Ma) yield ages consistent with the expected age progression, whereas a trachytic sample from Hanzei (66 Ma, expected age of ca. 73 Ma) represents an alkalic post-shield event. The ridge-like morphology and depleted geochemistry of Meiji to Suizei seamounts and the age (78−75 Ma) and depleted composition of the volcanic elongated ridges (VERs) southeast of Detroit seamount (ca. 76 Ma) are consistent with plume-ridge interaction. The VERs account for the missing volume of volcanism expected from plume-ridge interaction for the oldest Emperor seamounts. A small seamount with mid-ocean ridge basalt−like geochemistry located east of northern Detroit seamount yielded an age of 100 Ma, representing a minimum age for the oceanic crustal sliver between the Emperor Trough and the Stalemate Fracture Zone. We propose ∼300 km of dextral offset along the Emperor Trough to explain the location of this older crustal sliver. Our new data provide important constraints on the poorly known early evolution of the Hawaiian-Emperor Seamount Chain and the Cretaceous Quiet Zone (Cretaceous Normal Superchron) geotectonic history of the northwestern Pacific plate
Conservation Ecology and Genetics of Western and Central Baltic Fish Species - Cruise No. AL632, 07.05.2025 – 19.05.2025, Kiel (Germany) – Kiel (Germany), CONSERFISH
No full textThe AL632 expedition investigated ecological conditions and long-term changes in the Baltic Sea,
focusing on Kiel Bight, Mecklenburg Bight, Arkona Basin, Bornholm Basin, and
Adlergrund/Rönnebank. The mission combined seafloor mapping, hydrographic surveys, plankton
sampling, and fishery assessments to contribute to one of the longest continuous ecological
datasets in the region (since 1986). Bathymetric mapping of Adlergrund revealed glacially formed
eskers, boulder fields, mussel beds, and associated benthic communities, with underwater video
confirming habitat complexity. Hydrographic data showed seasonal stratification, oxygen
depletion in deeper waters of the Bornholm Basin, and early oxygen decline in the western Baltic.
Plankton surveys indicated an unusually low abundance of cod larvae, raising concern for
recruitment. Fisheries work assessed cod, herring, sprat, and flatfish, with tissue and organ samples
collected for genetic, isotopic, and dietary studies. Results extended the 38-year cod time series,
confirming long-term declines in size and condition, linked to fisheries-induced evolution and poor
environmental conditions. Pilot trials of minimally invasive fishing gears in Adlergrund showed
potential for future protected-area monitoring. Overall, AL632 delivered critical baseline data for
international collaborations and conservation projects, while highlighting ongoing ecological
challenges to Baltic Sea biodiversity and fisheries sustainability
A global consistent database of plankton and detritus from in situ imaging by the Underwater Vision Profiler 5
No full textPlankton and detritus are essential components of the Earth’s oceans influencing biogeochemical cycles and carbon sequestration. Climate change impacts their composition and marine ecosystems as a whole. To improve our understanding of these changes, standardized observation methods and integrated global datasets are needed to enhance the accuracy of ecological and climate models. Here, we present a global dataset for plankton and detritus obtained by two versions of the Underwater Vision Profiler 5 (UVP5). This release contains the images classified in 33 homogenized categories, as well as the metadata associated with them, reaching 3,114 profiles and ca. 8 million objects acquired between 2008–2018 at global scale. The geographical distribution of the dataset is unbalanced, with the Equatorial region (30° S – 30° N) being the most represented, followed by the high latitudes in the northern hemisphere and lastly the high latitudes in the Southern Hemisphere. Detritus is the most abundant category in terms of concentration (90 %) and biovolume (95 %), although its classification in different morphotypes is still not well established. Copepoda was the most abundant taxa within the plankton, with Trichodesmium colonies being the second most abundant. The two versions of UVP5 (SD and HD) have different imagers, resulting in a different effective size range to analyse plankton and detritus from the images (HD objects >600 µm, SD objects >1 mm) and morphological properties (grey levels, etc.) presenting similar patterns, although the ranges may differ. Therefore, recommendations are provided for the appropriate use of this data when conducting studies. A large number of images of plankton and detritus will be collected in the future by the UVP5, and the public availability of this dataset will help it being utilized as a training set for machine learning and being improved by the scientific community. This will reduce uncertainty by classifying previously unclassified objects and expand the classification categories, ultimately enhancing biodiversity quantification. The dataset that constitutes this first release is available at SEANOE
Are near-inertial waves and instabilities with the North Equatorial Countercurrent responsible for moderate sea surface temperatures in the tropical North Atlantic?
No full textObservational and modelling studies of the tropical ocean mixed layer have shown a dominate role of the vertical diffusive heat flux due to turbulent mixing for maintaining sea surface temperature in the tropical Atlantic. Progress has been made in identifying ocean processes responsible for enhancing turbulent mixing in the upper stratified ocean. E.g., at the equator, the vertically sheared large-scale equatorial circulation provides an energy source that can overcome stratification and drive turbulence known as deep cycle turbulence. North of the equator, near-inertial waves and Tropical Instability Waves contribute to elevated shear at the base of the mixed layer which enhances turbulent vertical diffusive heat flux out of the mixed layer. In this contribution we exploit a large observational data base (22 month-long cruises) of upper-ocean turbulence, velocity, hydrographic and wind measurements to determine the seasonal variability of turbulent vertical diffusive heat flux due to near-inertial waves in the tropical eastern North Atlantic. We find that the average mixed-layer heat loss due to near inertial waves is 35 W/m^2 with larger heat loss during boreal summer and discuss the near-inertial energy budget. Additionally, we show that enhanced upper-ocean turbulence and mixed layer heat loss also occurs due to instabilities within the North Equatorial Countercurrent during boreal summer and autumn
Causes of Eurasian Winter‐Cooling During the Late 20th and Early 21st Century
No full textKey Points:
- Recent decadal Eurasian cooling was primarily due to internal variability
- North Atlantic Oscillation and Interdecadal Pacific Variability had significant impact on the Eurasian cooling
- Atmospheric intrinsic variability played a greater role in Eurasian cooling compared to multidecadal oceanic modes
Pronounced negative trends in wintertime near-surface temperature have been observed over Eurasia during 1993–2013. It is unclear whether the cooling was due to internal atmospheric variability or forced from either the ocean surface or changes in atmospheric composition. In this study, we use ensembles of atmosphere-model integrations for the period 1993–2013 to investigate the mechanisms of the wintertime cooling over Eurasia. We find that the cooling was primarily driven by intrinsic atmospheric variability, specifically the North Atlantic Oscillation, and to a lesser extent by multidecadal ocean variability such as the Interdecadal Pacific Variability. There was not much influence of the Atlantic Multidecadal Variability on Eurasian cooling. A dominant role for atmospheric variability as shown by our results implies limited predictability of decadal climate variability over Eurasia
Monitoring the Danish Straits using acoustic telemetry to understand how environmental drivers influence fish migrations in a major swimway
No full textThe Danish Straits, a region of ecological and economic importance, act as a major swimway for all fish moving between the Baltic Sea and Northeast Atlantic. The Straits’ environmental conditions are highly influenced by variable water exchange between the surrounding seas, which are characterized by strong environmental gradients, especially in temperature and salinity. Understanding how the environmental conditions in this area relate to fish migration timing is critical for evaluating potential stressors in a region undergoing rapid environmental change. Using acoustic telemetry data collected between 2019 and 2024 from receiver arrays in the Straits, and extracted environmental data from public databases, our study investigated the movement patterns of Salmo trutta, Anguilla anguilla, and Thunnus thynnus in this area in response to a suite of environmental variables, including seawater temperature and salinity, water current speed and direction, dissolved molecular oxygen, chlorophyll a, light intensity and the lunar cycle. Boosted regression trees were used to predict the presence of each species passing through the Danish Straits based on the environmental conditions and the relative importance of the influence of each environmental variable on the fish movements was determined. Results indicate that temperature is an important variable driving fish movements through the Straits, as well as productivity (chlorophyll a content) for tuna movements, and that the relative importance of the respective environmental variables differs between species. Our study will provide new ecological insights into fish movement patterns in the Danish Straits, highlighting the potential of interconnected acoustic telemetry infrastructures and growing aquatic receiver networks especially in fish-rich swimways, as our findings enhance the understanding of species-specific migration timing and may contribute to improved management strategies for these species