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Assesing the Impact of Physics Parameterizations in WRF to Develop a Rain Erosion Damage Atlas for Wind Turbines in Germany
No full textExpansion of Antarctic Bottom Water driven by Antarctic warming in the last deglaciation
No full textPast atmospheric CO2 fluctuations are thought to be intricately tied to ocean circulation changes involving Southern Ocean and North Atlantic dynamics. The ocean’s capability to store carbon has been linked to the expansion and contraction of southern-sourced waters, but their provenance and structure remain poorly characterized in the past. Here we present neodymium isotope data from the Weddell–Enderby Basin, placing constraints on the spatiotemporal distribution of Antarctic Bottom Water in the Atlantic and Indian sectors of the Southern Ocean over the past 32,000 years. Our data reveal that glacial Antarctic Bottom Water was substantially contracted, with large volumes of the deep Southern Ocean occupied by carbon-rich Circumpolar Deep Waters sourced from the Pacific Ocean, conducive for lowering atmospheric CO2. During the last deglaciation, Antarctic Bottom Water expanded in two steps coinciding with Antarctic warming. This expansion drove Southern Ocean destratification, which possibly contributed to contemporaneous atmospheric CO2 rises. Different from the view that the North Atlantic processes dominated deglacial deep South Atlantic water-mass changes, our results indicate only limited influence from northern-sourced waters. Instead, Antarctic Bottom Water dynamics played a critical role in regulating deep ocean circulation and thereby carbon exchange between the deep Southern Ocean and the atmosphere
Numerical simulation output: Potential impacts of marine carbon dioxide removal on ocean oxygen
No full textSupplementary data to Mohanty et al. (2024): Detection and Tracking of Carbon Biomes via Integrated Machine Learning Methods
No full textInterannual variability of net primary productivity in the northwest African coastal upwelling system and their relation to Dakar Niños
No full textStressfield and displacements for generic volcanic edifices and the case-study Anak Krakatau derived from the commercial finite-element software ABAQUS
No full textOyster-mussel differences in cadmium accumulation linked to molecular weight distribution of Cd-binding proteins
No full textMarine bivalves are key seafood resources and biomonitors, yet closely related species show striking differences in cadmium (Cd) accumulation. While toxicokinetics suggest these differences are largely driven by Cd uptake, given consistently low elimination across species, the molecular mechanisms remain poorly understood. Here, we applied size-exclusion chromatography hyphenated to inductively coupled plasma-mass spectrometry (SEC-ICP-MS) and stable isotope tracing to characterize cytosolic Cd-binding proteins in three oysters (Crassostrea gigas, C. hongkongensis, C. angulata) and three mussels (Perna viridis, Mytilus coruscus, and M. galloprovincialis) common in Chinese coastal waters. Oysters generally exhibited higher tissue Cd (up to tenfold higher than mussels) but stored a smaller fraction in the cytosol (35-48 %) compared to mussels (66-74 %), with oyster C. angulata being an exception (70 %). The molecular size distribution of cytosolic Cd-binding proteins also differed markedly: oysters bound a large share of Cd to high molecular weight proteins (>44 kDa, 35-72 %), whereas mussels relied more on medium or low molecular weight proteins, with P. viridis showing over 60 % Cd bound to low molecular weight ligands (similar to 2 kDa). Stable isotope tracing further showed that newly accumulated Cd rapidly adopted species-specific binding patterns similar to pre-existing Cd, indicating fast intracellular equilibration. In contrast, essential metals such as Cu and Zn showed more dispersed binding across protein sizes, and Pb exhibited weaker, less specific associations. These results demonstrate that interspecific differences in Cd burdens are closely linked to protein size-dependent binding strategies. Such mechanistic insights strengthen cross-species assessments for food safety and environmental monitoring
Analysis and Visualization of Unit Test Traces With Kieker and ExplorViz
No full textTesting software and understanding how software systems evolve are essential for maintaining code quality and identifying changes that affect program behavior. We present an approach for visually analyzing unit test execution traces in the context of software evolution. These traces are collected using the Peass (Performance Analysis of Software Systems) tool in conjunction with Kieker and OpenTelemetry. We use ExplorViz, a web-based software visualization tool, to visualize the collected trace data alongside data from static program analysis. Visualizing how unit tests interact with evolving codebases over time enables insights into changes in test coverage and the impact of refactoring or feature additions to program behavior. We showcase our approach experimentally using the OpenHAB Zigbee binding as the system under test
Perspectives for Best Practices in boron-based CO2 Reconstruction
No full textKey Points:
- Boron isotopes are an important marine paleoclimate proxy to reconstruct past ocean pH and atmospheric carbon dioxide in geological time
- Sources of uncertainty of past CO2 estimation shifts from primarily modern oceanography to seawater chemistry and biology beyond 20 Myrs
- Encouragement of collaborative and inclusive future efforts to strengthen the boron isotope community
Since atmospheric carbon dioxide (CO2 ) is a key driver of global temperatures over geological time, determining past CO2 and fluxes among Earth's carbon reservoirs is critical in resolving drivers and feedbacks within Earth's climate system. Such CO2 reconstructions are challenging prior to ice core records of the last 800 kyrs, and yet it is beyond this time where the most promising analogs for our warmer, higher CO2 future lie. Amongst proxies for past CO2 reconstruction, boron isotopes (delta 11B, primarily measured in foraminiferal carbonate) have become one of the most well-established, having demonstrated their ability to replicate atmospheric CO2 during periods where ice core estimates are available for comparison. Although analytical reproducibility across laboratories has greatly improved in recent years, the approaches taken to derive CO2 estimates from these boron isotope measurements remain variable. For example, there are significant inconsistencies in how seawater temperature, boron isotope, and elemental composition are estimated, in how a second carbonate system parameter is used to constrain the carbonate system, in how ecophysiological imprints on proxy signals are accounted for, and in how uncertainties are quantified and propagated. The need to better harmonize practices in the community motivated a series of virtual workshops and a PAGES-supported meeting, and ultimately this AGU Special Collection "Advances and Best Practices in Boron-based Paleo-CO2 Reconstruction." In this synthesis article, we briefly summarize the history of approaches to address these issues, current limitations and strengths of the proxy, and highlight some important points to consider when applying the boron isotope proxy
Origin of the King's Trough Complex (North Atlantic): Interplay between a transient plate boundary and the early Azores mantle plume
No full textThe King's Trough cuts into an area of thickened oceanic crust associated with the 45°N melting anomaly at the Mid-Atlantic Ridge. Here we present a comprehensive geochemical data set and new 40Ar/39Ar age and bathymetric data from magmatic rocks from the King's Trough and the smaller Peake and Freen Deeps to the east and from the Gnitsevich Seamounts located to the west. The samples can be roughly divided into two groups: (a) Lavas dredged from the King's Trough (45.5–37.5 Ma) and Gnitsevich Seamounts (10–11 Ma) as well as cored rocks from the thickened oceanic crust, possessing mainly alkali basaltic, geochemically enriched compositions typical for ocean island basalts and (b) Lavas from the Peake and Freen Deeps exclusively showing depleted, normal MORB signatures. It is proposed that the current 45°N anomaly represents a remnant of the early Azores plume, which has also caused the regional thickening of the oceanic crust by plume-ridge interaction. Following the jump of the plate boundary between the Eurasian and the Iberian/African plates to this region ∼37 Ma ago, the King's Trough opened from east to west as a graben structure by oblique extension, thereby cutting into the young plateau of thickened crust. The largest extension took place at its eastern end, outside of the area of plume-influenced, thickened crust with the opening of the ultra-deep Peake and Freen Deeps. The lavas obtained from these deeps have depleted geochemical signatures consistent with being derived from the regular upper mantle by decompression melting.
Plain Language Summary
The King's Trough, a huge canyon-like structure on the seafloor, is located ∼300 km east of the Mid-Atlantic Ridge in the eastern North Atlantic Ocean. The origin of the trough has long been debated. The through cuts into an area of thickened oceanic crust, which forms an elevated plateau that is centered around the 45°N melting anomaly at the Mid-Atlantic Ridge. There, ridge lavas show a geochemical composition indicative of the involvement of material presumably upwelling from the deeper Earth's mantle (a so-called “mantle plume”). Based on age and geochemical data from lavas sampled from the elevated plateau, including King's Trough, it is proposed that this plume represents an earlier branch of the well-known Azores mantle plume. Following the jump of the plate boundary between the Eurasian and the Iberian/African plates to this region ∼37 Ma ago, the King's Trough opened as a graben structure by extension, thereby cutting into the young plateau. At ∼20–23 Ma, the boundary relocated to its current position (the Azores-Gibraltar Fracture Zone) further south, which probably caused branching of the plume eventually leading to the cessation of the King's Trough opening and the contemporaneous formation of the Azores Plateau.
Key Points
The geochemical 45°N anomaly at the Mid Atlantic Ridge has formed a plateau of thickened oceanic crust by plume-ridge interaction
King's Trough formed ∼37–20 million years ago as a graben structure by oblique extension, cutting into the plateau of thickened crust
Lavas from the trough and surrounding seamounts being similar to those of the Azores support derivation from a common Azores plume sourc