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In this work we looked at the projected change in bottom water oxygen content in an ensemble of ocean climate change models of the North Western European Shelf. What emerged is that, 1. oxygen decreases in all models, 2. in the models with the most warming, a change in circulation patterns is tied to the emergence of low oxygen hotspots in the Eastern North Sea, and, 3. in relatively shallow coastal areas increasing in primary production partially mitigates oxygen decline.

Combining hydrodynamic simulations and annotated videos, we separated which hydrodynamic variables that determine reef cover are engineered by cold-water corals and which not, which is typically difficult. Around coral mounds hydrodynamic zones create a typical reef zonation, restricting corals from moving deeper (the expected response to climate warming). But non-engineered downward velocities in winter (e.g., deep winter mixing) seem more important for coral reef growth than coral engineering.

The physical pump transporting atmospheric CO₂ to ocean consists of two parts: The first absorbs CO₂ to the upper mixed layer by rise of atmospheric CO₂. This amount of anthropogenic carbon is calculated. From this, its capacity at present is 1.3 Gtons/year declining to 0.4 for CO₂ above 600 ppm. The second sink transports anthropogenic DIC by thermohaline circulation. This pump increases from 1.9 at present to 5 Gtons/year at 800 ppm , The total pump is not switched off by acidification.

The global ocean is losing oxygen due to warming. The Indian Ocean is however gaining oxygen in large parts of the basin, and its naturally occurring oxygen minimum zone is not expanding. This rather unexpected response is explained by the unique ocean circulation of the Indian Ocean, which is bounded by a continent to the north but connected to the Pacific Ocean by the Indonesian Throughflow.

This study investigates methane dynamics in the Wadden Sea. Our measurements revealed distinct variations triggered by seasonality and tidal forcing. Methane budget was higher in warmer seasons, but remained surprisingly high in colder seasons. Methane dynamics were amplified during low tides, flushing the majority of methane into the North Sea or released to the atmosphere. Methanotrophic activity was also elevated during low tide but mitigated only a small fraction of the methane efflux.

Permafrost thaw initiates thermokarst landscape formation, resulting in distinct new habitats, including degraded permafrost soil, thermokarst lake sediments, and lake water. These distinct habitats harbored differentiated bacterial communities that originated from the same source, differing in diversity, assembly mechanisms, and environmental influences. The results implied ecological consequences of permafrost degradation in the face of further climate change.

In the deep-sea, the interaction between benthic fauna (tracemaker) and substrate can be preserved as traces (i.e., lebensspuren) which are common features of deep seafloor landscapes, rendering them promising proxies to infer biodiversity. No general correlation could be observed between traces and benthic fauna. However, local correlation was observed between specific stations. Density was either positively or negatively correlated with tracemaker densities, depending on the traces.

Fatty alcohols (FAs) are major components of surface lipids in plant leaves and serve as surface-active aerosols. Our study on the aerosol size distributions in a forest suggested that secondary FAs (SFAs) originated from plant waxes, and that leaf senescence status is likely an important factor controlling the size distribution of SFAs. This study provides new insights into the sources of primary biological aerosol particles (PBAPs) and their effects on the aerosol ice nucleation activity.

A chemical kinetics theory is proposed to explain the non-monotonic relationship between temperature and biochemical rates. It revealed some problems in the popular macromolecular rate theory, and is more consistent with our current understanding of proteins that they may denature reversibly as a function of temperature. Our results imply that plants, microbes and animals may be able to perform optimally under different temperatures by adjusting their internal substrate for enzymatic processes.

The marine CO₂ system can be measured independently and continuously by BGC-Argo floats since numerous pH sensors have been developed to suit on these autonomous measurements platforms. By applying the Argo correction routines to float-pH data acquired in the subpolar North Atlantic Ocean, we report the uncertainty and lack of objective criteria associated with the choice of the reference method as well the reference depth for the pH correction.

We used chamber-flux systems to directly measure methane and carbon dioxide exchange between the ocean or sea ice and the atmosphere during an icebreaker-based expedition to the Central Arctic Ocean in summer 2021. These measurement-based constraints inform climate modeling and carbon budgets. The methane exchange measurements, the first such made in the CAO, are lower than previous estimates and imply that the CAO is an insignificant contributor to Arctic methane emission.

the geological record is complex regardless of whether it is the result of biotic or abiotic processes. Overlapping and repeating chemical reactions occur over time, producing objects with exotic shapes or compositions distinct from the norm. Assessing the geological history is crucial particularly given the ubiquitous presence of life throughout the planet's surface and crust. We provide a detailed description to unravel the material's intricate history and evaluate the role of microorganisms.

Calcifying phytoplankton (coccolithophores) utilize a life cycle in which they can grow and divide in two different phases. These two phases (HET and HOL) vary in terms of their physiology and distributions, with many unknowns about what the key differences are. Using a combination of lab experiments and model simulations we find that nutrient storage is a critical difference between the two phases, and that this difference allows them to inhabit different nitrogen input regimes.

Human CO₂ emissions are modifying ocean carbonate chemistry, causing ocean acidification, and likely already impacting marine ecosystems. Here, we added CO₂ in intertidal pools at the start of emersion to investigate the influence of future ocean acidification on net community production (NCP) and calcification (NCC). By day, adding CO₂ fertilized the pools (+20 % NCP). By night, pools experienced net community dissolution, a dissolution that was further increased (+40 %) by the CO₂ addition.

Dissolved carbon monoxide (CO) surface concentrations were first measured at 14 stations in the Ria Formosa Lagoon system in May 2021. Ria Formosa was a source of atmospheric CO. Microbial consumption accounted for 83 % of the CO production. The results of a 48-hour irradiation experiment with aquaculture effluent water indicated that aquaculture facilities in the Ria Formosa Lagoon seem to be a negligible source of atmospheric CO.

The ocean is both impacted by climate change and helps mitigate its affects through taking up carbon from the atmosphere. We used a machine learning approach to investigate what controls open ocean carbon uptake in the Northeast Pacific. Marine heatwaves that lasted 2–3 years increased uptake, while the Alaskan Gyre controlled uptake over 10-year time periods. The trend from 1998–2019 suggests carbon uptake in the Northeast Pacific open ocean is increasing.

We carried out parallel year-round observations of pH and related ocean parameters in five stations around the Japan coast. It was found that short-term acidified situations with Ω_ara less than 1.5 occurred at four of five stations. Most of such short-term acidified events were related to the short-term low salinity event, and the extent of short-term pH drawdown at high freshwater input was positively correlated with the nutrient concentration of main rivers that flows into the coastal area.

The coastal seafloor naturally contains trace metals, which are sensitive to changes in oxygen concentrations in seawater: trace metal contents increase with decreasing oxygen concentrations. Studies have used those trace metals as indicators for declining oxygen concentrations in coastal waters. Here we show that in fjords, this relationship works well on longer (decadal) time scales but poorly on shorter (seasonal) time scales. We attribute this to other processes influencing the trace metals.

Post a 1980’s heavy pollution, a long-term inorganic carbon increase in the Elbe Estuary (1997–2020) was fuelled by phytoplankton and organic carbon production in the upper estuary, due to improved water quality. A recent drought (2014–2020) modulated the trend, extending water residence time, dry summer season into May, and enhancing production of inorganic carbon in the estuary. However, the annual inorganic carbon export to coastal waters decreased in the drought period.

The IPCC has called for the rapid development of CO₂ removal strategies. Coastal Enhanced Weathering (CEW) via the addition of the common mineral olivine to coastal waters is one promising approach. Olivine releases trace metals that can affect organisms like phytoplankton. We exposed phytoplankton to olivine products and observed no negative effects. These data indicate that CEW with olivine will likely not be harmful to phytoplankton, suggesting it to be safe for them at large scales.

We undertake a sensitivity study of three different parameters on the simulation of net ecosystem exchange during the snow-covered non-growing season at an Arctic tundra site. Simulations are compared to eddy covariance measurements, with near-zero NEE simulated despite observed CO₂ release. We then consider how to parameterise the model better in Arctic tundra environments on both sub-seasonal timescales and cumulatively throughout the snow-covered non-growing season.

The global loss of coral reefs is one of the most visible impacts of climate change on the marine environment. Here we show that during a widespread bleaching event, corals release significant amounts of dissolved organic carbon that then blankets the seafloor. We further posit and provide experimental evidence of how this altered carbon cycle may accelerate reef decline. This highlights how coral bleaching transforms local ecosystem functions.

The strong seasonal increases of Hg in aboveground biomass during the growing season and the lack of changes observed after senescence in this salt marsh ecosystem suggest physiologically controlled Hg uptake pathways. The Hg sources found in marsh aboveground tissues originate from a mix of sources, unlike terrestrial ecosystems where atmospheric GEM is the main source. While belowground plant tissues mostly take up Hg from soils. Overall, the salt marsh currently serves as a small net Hg sink.

Water availability is essential for vegetation functioning, but the depth of vegetation water uptake is largely unknown due to sparse ground measurements. This study correlates the vegetation growth with soil moisture avaialbility globally to infer to vegetation water uptake depth using only satellite-based data. We find that the vegetation water-uptake depth varies across climate regimes and vegetation types and also changes during dry months on a global scale.

Methane is a potent greenhouse gas and hence it is important to understand its sources and sinks in the environment. Here we present new data from organic-rich surface sediments below an oxygen minimum zone off the coast of California (Santa Barbara Basin) demonstrating the simultaneous microbial production and consumption of methane, which appears to be an important process preventing the build-up of methane in these sediments and the emission into the water column and atmosphere.

We analyzed how leaf wax hydrogen isotopes in continental and marine sediments respond to climate along one of the strongest aridity gradients in the world, from hyperarid to humid along the Chilean coast Chile. We found that under extreme aridity, the relationship between hydrogen isotopes in waxes and climate is non-linear, suggesting that we should be careful when reconstructing past hydrological changes using leaf wax hydrogen isotopes to avoid overestimating how much climate has changed.

This work describes an experimental system used to replicate environmental conditions in marine or aquatic systems for the purposes of examining the effects of potentially harmful conditions on organisms and communities. The system is capable of manipulating temperature and salinity in real-time (or other conditions such as CO₂) using an automated programming interface that controls the regulation of manipulated water. Here we show the accurate performance of the system.

We derive high-resolution terrestrial CO₂ fluxes over India from 2012 to 2020. This is achieved by utilizing satellite-based vegetation indices and meteorological data in a data-driven biospheric model. The model simulations are improved by incorporating soil variables and SIF retrievals from satellite instruments and relate them to ecosystem productivity across different biomes. The derived flux products better explain the flux variability compared to other existing model estimates.

This study aims to estimate how much oceanic oxygen has been lost and its uncertainties. One major source of uncertainties comes from the statistical gap-fill methods. Outputs from earth system models are used to generate synthetic observations where oxygen data is extracted from the model output at the location and time of historical oceangraphic cruises. Reconstructed oxygen trend is approximately two thirds of the true trend.

We investigated the effect of the El Niño-Southern Oscillation (ENSO) on biogenic volatile organic compound (BVOC) emissions from plants. ENSO events can cause a significant increase in these emissions, which have a long-term impact on the Earth's atmosphere. Persistent ENSO conditions can cause long-term changes in vegetation, resulting in even higher BVOC emissions. We link ENSO-induced emission anomalies with driving atmospheric and vegetational variables.

The mechanisms of soil CO₂ flux in dry desert soils are not fully understood. Yet studies conducted in desert ecosystems rarely discuss potential errors related to using the commonly used flux chambers in dry and bare soils. The conventional deployment practice of the chambers underestimated the instantaneous CO₂ flux by up to 50 % and the total daily CO₂ uptake by 35 %. This suggests that desert soils are a larger carbon sink than previously reported.

The year 2022 was unique in that the summer heat wave and drought led to a widespread reduction of vegetation growth at high elevation in the European Alps. This impact was unprecedented in the southwestern, warm and dry part of the Alps. Over the last two decades, water has become a co-dominant control of vegetation activity in areas that were, so far, primarily controlled by temperature, and the growth of mountain grasslands has become increasingly sensitive to moisture availability.

Using a numerical model, we revealed that a large proportion of nutrients in a semi-enclosed sea (Seto Inland Sea, Japan) comes from the Pacific Ocean and supports the growth of more than half of phytoplankton in the sea. Such results imply that the human-made management of nutrient load from the land needs to consider the presence of oceanic nutrients that act as a background concentration and are not controlled by human activity.