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1856 items found

10 20 50

GC Insights: Consistency in pyrocartography starts with color

Fire progression maps (FPMs) provide information regarding wildland fire spread (progress) through time to broad audiences. However, information regarding the best use of color to denote fire progression via maps is limited. This can potentially limit a map's ability to effectively communicate information by creating inconsistent messaging and accessibility challenges. Here, I provide color map recommendations to open a discussion towards consistent and accessible fire progression mapping.

Sedimentary ancient DNA insights into foraminiferal diversity near the grounding line in the western Ross Sea, Antarctica

Ancient foraminiferal DNA is studied in five Antarctic cores with sediments up to 25 kyr old. We use a standard and a new, more effective marker, which may become the next standard for paleoenvironmental studies. Much less diverse foraminifera occur on slopes of submarine moraines than in open-marine settings. Soft-walled foraminifera, not found in the fossil record, are especially abundant. There is no foraminiferal DNA in tills, suggesting its destruction during glacial redeposition.

Explaining the period fluctuation of the quasi-biennial oscillation

The paper addresses a fundamental but unresolved question about the tropical stratospheric wind oscillation: why does the period of the oscillation fluctuate irregularly? We use global reanalysis data to provide evidence that the oscillation period is primarily modulated by seasonal variations in small-scale atmospheric wave activity. The findings have implications for seasonal and climate predictions.

Mean ocean temperature change and decomposition of the benthic δ¹⁸O record over the past 4.5 million years

We reconstruct changes in mean ocean temperature (ΔMOT) over the last 4.5 Myr. We find that the ratio of ΔMOT to changes in global mean sea surface temperature was around 0.5 before the Middle Pleistocene transition but was 1 thereafter. We subtract our ΔMOT reconstruction from the global δ18O record to derive the δ18O of seawater. Finally, we develop a theoretical understanding of why the ratio of ΔMOT / ΔGMSST changed over the Plio-Pleistocene.

Quantified ice-nucleating ability of AgI-containing seeding particles in natural clouds

We analyzed the ability of silver iodide particles (a commonly used cloud-seeding agent) to form ice crystals in naturally occurring liquid clouds at −5 to −8 °C and found that only ≈ 0.1 %−1 % of particles nucleate ice, with a negative dependence on temperature. By contextualizing our results with previous laboratory studies, we help to bridge the gap between laboratory and field experiments, which also helps to inform future cloud-seeding projects.

Calcium is associated with specific soil organic carbon decomposition products

SOIL
DOI 10.5194/soil-11-381-2025
20 May 2025

This study shows that calcium (Ca) preserves soil organic carbon (SOC) in acidic soils, challenging beliefs that their interactions were limited to near-neutral or alkaline soils. Using spectromicroscopy, we found that Ca was co-located with a specific fraction of carbon, rich in aromatic and phenolic groups. This association was disrupted when Ca was removed but was reformed during decomposition with added Ca. Overall, this suggests that Ca amendments could enhance SOC stability.

Multifractality of climate networks

We have developed a systematic approach to study the climate system at multiple scales using climate networks, which have been previously used to study correlations between time series in space at only a single scale. This new approach is used to upscale precipitation climate networks to study the Indian summer monsoon and to analyze strong dependencies between spatial regions, which change with changing scales.

Social sensing a volcanic eruption: application to Kīlauea, 2018

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-25-1681-2025
13 May 2025

Protecting lives and livelihoods during volcanic eruptions is the key challenge in volcanology. Analysing social media usage during volcanic crises can help us better understand the impacts of volcanic eruptions and how warning messages are received and actioned, to eventually better protect those people and their livelihoods. Our work shows how social media data could be used in real time during a volcanic crisis to learn more about volcanic eruptions.

Surficial sediment remobilization by shear between sediment and water above tsunamigenic megathrust ruptures: experimental study

We propose a new mechanism of co-seismic sediment entrainment induced by shear stress at the sediment–water interface during major subduction earthquakes rupturing to the trench. Physical experiments show that flow velocities consistent with long-period earthquake motions can entrain synthetic marine sediment, and high-frequency vertical shaking can enhance this mobilization. They validate the proposed entrainment mechanism, which opens new avenues for paleoseismology in deep-sea environments.

Cold-water coral mounds are effective carbon sinks in the western Mediterranean Sea

Cold-water coral mounds are large structures on the seabed that are built by corals over thousands of years. They are regarded as carbonate sinks, with a potentially important role in the marine carbon cycle, but more quantitative studies are needed. Using sediment cores, we calculate the amount of carbon that has been stored in two mounds over the last 400 000 years. We provide the first numbers and show that up to 19 times more carbon is accumulated in mounds than on the common seafloor.

Speed-up, slowdown, and redirection of ice flow on neighbouring ice streams in the Pope, Smith, and Kohler region of West Antarctica

We used satellite observations to measure recent changes in ice speed and flow direction in the Pope, Smith, and Kohler region of West Antarctica (2005–2022). We found substantial speed-up on seven ice streams of up to 87 %. However, Kohler West Glacier has slowed by 10 %, due to the redirection of ice flow into its rapidly thinning neighbour. This process of “ice piracy” has not previously been directly observed on this rapid timescale and may influence future ice shelf and sheet mass changes.

The system of atmosphere, land, ice and ocean in the region near the 79N Glacier in northeast Greenland: synthesis and key findings from the Greenland Ice Sheet–Ocean Interaction (GROCE) experiment

The Greenland Ice Sheet represents the second-largest contributor to global sea-level rise. We quantify atmosphere, ice and ocean processes related to the mass balance of glaciers in northeast Greenland, focusing on Greenland’s largest floating ice tongue, the 79° N Glacier. We find that together, the different in situ and remote sensing observations and model simulations reveal a consistent picture of a coupled atmosphere–ice sheet–ocean system that has entered a phase of major change.

Missing the input: the underrepresentation of plant physiology in global soil carbon research

Plant physiology has been addressed by less than 10 % of peer-reviewed soil organic carbon research published in the last century. Thus, our understanding of soil carbon dynamics is overwhelmingly built on research that neglects the fundamental processes underlying organic carbon inputs. Active engagement of plant scientists in soil carbon research is imperative for shedding light on this blind spot and developing holistic policies that support soil carbon sequestration.

Graphical representation of global water models

Global water models contribute to the evaluation of important natural and societal issues but are – as all models – simplified representation of reality. So, there are many ways to calculate the water fluxes and storages. This paper presents a visualization of 16 global water models using a standardized visualization and the pathway towards this common understanding. Next to academic education purposes, we envisage that these diagrams will help researchers, model developers, and data users.

High probability of triggering climate tipping points under current policies modestly amplified by Amazon dieback and permafrost thaw

We investigate the probabilities of triggering climate tipping points under various emission scenarios and how they are altered by additional carbon emissions from the tipping of the Amazon and permafrost. We find that there is a high risk for triggering climate tipping points under a scenario comparable to current policies. However, the additional warming and hence the additional risk of triggering other climate tipping points from the tipping of the Amazon and permafrost remain small.

Cenozoic pelagic accumulation rates and biased sampling of the deep-sea record

We provide a new compilation of rates at which sediments deposited in the deep sea over the last 70 million years. We highlight a bias, linked to the drilling process, that makes it more likely for high rates to be recovered for younger sediments than for older ones. Correcting for this bias, the record shows, contrary to prior estimates, a more stable history, thus providing some insights on the past mismatch between physico-chemical model estimates and observations.

The energy-efficient reductive tricarboxylic acid cycle drives carbon uptake and transfer to higher trophic levels within the Kueishantao shallow-water hydrothermal system

In acidic hot springs off Kueishantao, Campylobacteria fix CO₂ by using the reductive tricarboxylic acid (rTCA) cycle, causing them to have an isotopically heavier biomass. Here, we report extremely low isotopic fractionation (of almost 0 ‰), which has never been reported in environmental samples. Moreover, the crab Xenograpsus testudinatus relies up to 34 % on campylobacterial biomass, highlighting the dependency of complex life on microscopic Bacteria in harsh environments.

High-resolution Holocene record based on detailed tephrochronology from Torfdalsvatn, north Iceland, reveals natural and anthropogenic impacts on terrestrial and aquatic environments

Questions remain about the past climate in Iceland, including the relative impacts of natural and human factors on vegetation change and soil erosion. We present a sub-centennial-scale record of landscape and algal productivity from a lake in north Iceland. Along with a high-resolution tephra age constraint that covers the last ∼ 12 000 years, our record provides an environmental template for the region and novel insight into the sensitivity of the Icelandic ecosystem to natural and human impacts.

Inter-model differences in 21st century glacier runoff for the world's major river basins

Glacier models have historically been used to understand glacier melt’s contribution to sea level rise. The capacity to project seasonal glacier runoff is a relatively recent development for these models. In this study we provide the first model intercomparison of runoff projections for the glacier evolution models capable of simulating future runoff globally. We compare model projections from 2000 to 2100 for all major river basins larger than 3000 km² with over 30 km² of initial glacier cover.

Stratospheric residence time and the lifetime of volcanic stratospheric aerosols

The climate impact of volcanic eruptions depends in part on how long aerosols spend in the stratosphere. We develop a conceptual model for stratospheric aerosol lifetime in terms of production and decay timescales, as well as a lag between injection and decay. We find residence time depends strongly on injection height in the lower stratosphere. We show that the lifetime of stratospheric aerosol from the 1991 Pinatubo eruption is around 22 months, significantly longer than is commonly reported.