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1826 items found

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A three-stage model pipeline predicting regional avalanche danger in Switzerland (RAvaFcast v1.0.0): a decision-support tool for operational avalanche forecasting

By harnessing AI models, this work enables processing large amounts of data, including weather conditions, snowpack characteristics, and historical avalanche data, to predict human-like avalanche forecasts in Switzerland. Our proposed model can significantly assist avalanche forecasters in their decision-making process, thereby facilitating more efficient and accurate predictions crucial for ensuring safety in Switzerland’s avalanche-prone regions.

Exploring climate stabilisation at different global warming levels in ACCESS-ESM-1.5

Governments are targeting net-zero emissions later this century with the aim of limiting global warming in line with the Paris Agreement. However, few studies explore the long-term consequences of reaching net-zero emissions and the effects of a delay in reaching net-zero. We use the Australian Earth system model to examine climate evolution under net-zero emissions. We find substantial changes which differ regionally, including continued Southern Ocean warming and Antarctic sea ice reduction.

Air quality modeling intercomparison and multiscale ensemble chain for Latin America

Latin America (LAC) has some of the most populated urban areas in the world, with high levels of air pollution. Air quality management in LAC has been traditionally focused on surveillance and building emission inventories. This study performed the first intercomparison and model evaluation in LAC, with interesting and insightful findings for the region. A multiscale modeling ensemble chain was assembled as a first step towards an air quality forecasting system.

Opinion: How will advances in aerosol science inform our understanding of the health impacts of outdoor particulate pollution?

This opinion paper explores how advances in aerosol science inform our understanding of the health impacts of outdoor particulate pollution. We advocate for a shift in the way we target PM pollution, focusing on the most harmful anthropogenic emissions. We highlight key observations, modelling developments, and emission measurements needed to achieve this shift.

Barchan swarm dynamics from a Two-Flank Agent-Based Model

Barchans are fast-moving sand dunes which form large populations (swarms) on Earth and Mars. We show that a small range of model parameters produces swarms in which dune size does not vary downwind – something that is observed in nature but not when using earlier models. We also show how the shape of dunes and the spatial patterns they form are affected by wind direction. This work furthers our understanding of the interplay between environmental drivers, dune interactions, and swarm properties.

Seafloor sediment characterization improves estimates of organic carbon standing stocks: an example from the Eastern Shore Islands, Nova Scotia, Canada

Quantifying how much organic carbon is stored in seafloor sediments is key to assessing how human activities can accelerate the process of carbon storage at the seabed, an important consideration for climate change. This study uses seafloor sediment maps to model organic carbon content. Carbon estimates were 12 times higher when assuming the absence of detailed sediment maps, demonstrating that high-resolution seafloor mapping is critically important for improved estimates of organic carbon.

A global analysis of the fractal properties of clouds revealing anisotropy of turbulence across scales

The shapes of clouds viewed from space reflect vertical and horizontal motions in the atmosphere. We theorize that, globally, cloud perimeter complexity is related to the dimension of turbulence also governed by horizontal and vertical motions. We find agreement between theory and observations from various satellites and a numerical model and, remarkably, that the theory applies globally using only basic planetary physical parameters from the smallest scales of turbulence to the planetary scale.

Energy transfer from internal solitary waves to turbulence via high-frequency internal waves: seismic observations in the northern South China Sea

With seismic data, we observed high-frequency internal waves (HIWs) with amplitudes of around 10 m. A shoaling thermocline and gentle slope suggest that HIWs result from fission. Remote sensing data support this. Strong shear caused Ri below 0.25 over 20–30 km, indicating instability. HIWs enhance mixing, averaging 10-4 m2s-1, revealing a new energy cascade from shoaling waves to turbulence, and enhancing our understanding of energy dissipation and mixing in the northern South China Sea.

Bringing it all together: science priorities for improved understanding of Earth system change and to support international climate policy

We propose a number of priority areas for the international climate research community to address over the coming decade. Advances in these areas will both increase our understanding of past and future Earth system change, including the societal and environmental impacts of this change, and deliver significantly improved scientific support to international climate policy, such as future IPCC assessments and the UNFCCC Global Stocktake.

The Earthquake Risk Model of Switzerland, ERM-CH23

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-24-3561-2024
17 October 2024

The Earthquake Risk Model of Switzerland (ERM-CH23), released in early 2023, is the culmination of a multidisciplinary effort aiming to achieve, for the first time, a comprehensive assessment of the potential consequences of earthquakes on the Swiss building stock and population. ERM-CH23 provides risk estimates for various impact metrics, ranging from economic loss as a result of damage to buildings and their contents to human losses, such as deaths, injuries, and displaced population.

Uncertainty-informed selection of CMIP6 Earth system model subsets for use in multisectoral and impact models

From running climate models to using their outputs to identify impacts, modeling the integrated human–Earth system is expensive. This work presents a method to identify a smaller subset of models from the full set that preserves the uncertainty characteristics of the full set. This results in a smaller number of runs that an impact modeler can use to assess how uncertainty propagates from the Earth to the human system, while still capturing the range of outcomes provided by climate models.

The spatio-temporal evolution of the Chongzhen drought (1627–1644) in China and its impact on famine

This study used 1802 drought and 1977 famine records from historical documents to reconstruct the spatial–temporal progression of the Chongzhen drought (1627–1644) in China and its impacts. We advance this research by reconstructing the annual spatial patterns and regional series of drought; demonstrating drought as the primary factor triggering famine; and identifying the transmission pathway of the drought’s impacts and how social factors, especially human responses, regulated these impacts.

Earth science for all? The economic barrier to European geoscience conferences

Conferences are key for knowledge exchange and networking. However, these events lack diversity, favoring wealthier countries and limiting opportunities for scholars from lower-income regions. Our study of the EGU meeting reveals that attendance is mostly influenced by a country’s income. To promote inclusivity, we suggest rotating event locations, offering affordable accommodations, and establishing travel funds. These steps can help create a more diverse and innovative scientific community.

The 2023 global warming spike was driven by the El Niño–Southern Oscillation

The rapid global warming of 2023 has led to concerns that it could be externally driven. Here we show that climate models subject only to internal variability predict such warming spikes but rarely (p~1.6 %). However, when a prolonged La Niña immediately precedes an El Niño, as occurred leading up to 2023, such spikes are not uncommon (p~10.3 %). Virtually all of the spikes occur during an El Niño, strongly suggesting that internal variability drove the 2023 warming.

Stable and unstable fall motions of plate-like ice crystal analogues

This study uses 3D-printed ice crystal analogues falling in a water–glycerine mix and observed with multi-view cameras, simulating atmospheric conditions. Four types of motion are observed: stable, zigzag, transitional, and spiralling. Particle shape strongly influences motion; complex shapes have a wider range of conditions where they fall steadily compared to simple plates. The most common orientation of unstable particles is non-horizontal, contrary to prior assumptions of always horizontal.

Characterizing nonlinear, nonstationary, and heterogeneous hydrologic behavior using ensemble rainfall–runoff analysis (ERRA): proof of concept

Here, I present a new way to quantify how streamflow responds to rainfall across a range of timescales. This approach can estimate how different rainfall intensities affect streamflow. It can also quantify how runoff response to rainfall varies, depending on how wet the landscape already is before the rain falls. This may help us to understand processes and landscape properties that regulate streamflow and to assess the susceptibility of different landscapes to flooding

Global-scale gravity wave analysis methodology for the ESA Earth Explorer 11 candidate CAIRT

We investigate the capabilities of a proposed satellite mission, CAIRT, for observing gravity waves throughout the middle atmosphere and present the necessary methodology for in-depth wave analysis. Our findings suggest that such a satellite mission is highly capable of resolving individual wave parameters and could give new insights into the role of gravity waves in general atmospheric circulation and atmospheric processes.

The effects of land use on soil carbon stocks in the UK

We collated a large data set (15 790 soil cores) on soil carbon stock in different land uses. Soil carbon stocks were highest in woodlands and lowest in croplands. The variability in the effects was large. This has important implications for agri-environment schemes seeking to sequester carbon in the soil by altering land use because the effect of a given intervention is very hard to verify.

Calibrating estimates of ionospheric long-term change

Long-term change in the ionosphere are expected due to increases in greenhouse gases in the lower atmosphere. Empirical formulae are used to estimate height. Through comparison with independent data we show that there are seasonal and long-term biases introduced by the empirical model. We conclude that estimates of long-term changes in ionospheric height need to account for these biases.

Review article: Drought as a continuum – memory effects in interlinked hydrological, ecological, and social systems

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-24-3173-2024
23 September 2024

Drought is a creeping phenomenon but is often still analysed and managed like an isolated event, without taking into account what happened before and after. Here, we review the literature and analyse five cases to discuss how droughts and their impacts develop over time. We find that the responses of hydrological, ecological, and social systems can be classified into four types and that the systems interact. We provide suggestions for further research and monitoring, modelling, and management.

Increasing aerosol optical depth spatial and temporal availability by merging datasets from geostationary and sun-synchronous satellites

In this study, for the first time, we combined aerosol data from six satellites using a unified algorithm. The global datasets are generated at a high spatial resolution of about 25 km with an interval of 30 min. The new datasets are compared against ground truth and verified. They will be useful for various applications such as air quality monitoring, climate research, pollution diurnal variability, long-range smoke and dust transport, and evaluation of regional and global models.

Methane retrieval from MethaneAIR using the CO2 proxy approach: a demonstration for the upcoming MethaneSAT mission

MethaneSAT is an upcoming satellite mission designed to monitor methane emissions from the oil and gas (O&G) industry globally. Here, we present observations from the first flight campaign of MethaneAIR, a MethaneSAT-like instrument mounted on an aircraft. MethaneAIR can map methane with high precision and accuracy over a typically sized oil and gas basin (~200 km2) in a single flight. This paper demonstrates the capability of the upcoming satellite to routinely track global O&G emissions.

Volcano tsunamis and their effects on moored vessel safety: the 2022 Tonga event

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-24-3095-2024
20 September 2024

The eruption of the Hunga Tonga–Hunga Ha’apai volcano in January 2022 triggered a global phenomenon, including an atmospheric wave and a volcano-meteorological tsunami (VMT). The tsunami, reaching as far as Callao, Peru, 10 000 km away, caused significant coastal impacts. This study delves into understanding these effects, particularly on vessel mooring safety. The findings underscore the importance of enhancing early warning systems and preparing port authorities for managing such rare events.

The 2020 European Seismic Hazard Model: overview and results

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-24-3049-2024
20 September 2024

The 2020 European Seismic Hazard Model (ESHM20) is the latest seismic hazard assessment update for the Euro-Mediterranean region. This state-of-the-art model delivers a broad range of hazard results, including hazard curves, maps, and uniform hazard spectra. ESHM20 provides two hazard maps as informative references in the next update of the European Seismic Design Code (CEN EC8), and it also provides a key input to the first earthquake risk model for Europe.

Large-sample hydrology – a few camels or a whole caravan?

We show that the differences between the forcing data included in three CAMELS datasets (US, BR, GB) and the forcing data included for the same catchments in the Caravan dataset affect model calibration considerably. The model performance dropped when the data from the Caravan dataset were used instead of the original data. Most of the model performance drop could be attributed to the differences in precipitation data. However, differences were largest for the potential evapotranspiration data.

The EarthCARE lidar cloud and aerosol profile processor (A-PRO): the A-AER, A-EBD, A-TC, and A-ICE products

ATLID (atmospheric lidar) is the lidar to be flown on the Earth Clouds and Radiation Explorer satellite (EarthCARE). EarthCARE is a joint European–Japanese satellite mission that was launched in May 2024. ATLID is an advanced lidar optimized for cloud and aerosol property profile measurements. This paper describes some of the key novel algorithms being applied to this lidar to retrieve cloud and aerosol properties. Example results based on simulated data are presented and discussed.

Can we reliably reconstruct the mid-Pliocene Warm Period with sparse data and uncertain models?

We have created a new global surface temperature reconstruction of the climate of the mid-Pliocene Warm Period, representing the period roughly 3.2 million years before the present day. We estimate that the globally averaged mean temperature was around 3.9 °C warmer than it was in pre-industrial times, but there is significant uncertainty in this value.

Biological and dust aerosols as sources of ice-nucleating particles in the eastern Mediterranean: source apportionment, atmospheric processing and parameterization

Ice nucleating particle (INP) concentrations are required for correct predictions of clouds and precipitation in a changing climate, but they are poorly constrained in climate models. We unravel source contributions to INPs in the eastern Mediterranean and find that biological particles are important, regardless of their origin. The parameterizations developed exhibit superior performance and enable models to consider biological-particle effects on INPs.

CO2 emissions of drained coastal peatlands in the Netherlands and potential emission reduction by water infiltration systems

Biogeosciences
DOI 10.5194/bg-21-4099-2024
20 September 2024

Drained peatlands cause high CO2 emissions. We assessed the effectiveness of subsurface water infiltration systems (WISs) in reducing CO2 emissions related to increases in water table depth (WTD) on 12 sites for up to 4 years. Results show WISs markedly reduced emissions by 2.1 t CO2-C ha-1 yr-1. The relationship between the amount of carbon above the WTD and CO2 emission was stronger than the relationship between WTD and emission. Long-term monitoring is crucial for accurate emission estimates.

Young and new water fractions in soil and hillslope waters

We use a 3-year time series of tracer data of streamflow and soils to show how water moves through the subsurface to become streamflow. Less than 50% of soil water consists of rainfall from the last 3 weeks. Most annual streamflow is older than 3 months, and waters in deep subsurface layers are even older; thus deep layers are not the only source of streamflow. After wet periods more rainfall was found in the subsurface and the stream, suggesting that water moves quicker through wet landscapes.

Representation learning with unconditional denoising diffusion models for dynamical systems

We train neural networks as denoising diffusion models for state generation in the Lorenz 1963 system and demonstrate that they learn an internal representation of the system. We make use of this learned representation and the pre-trained model in two downstream tasks: surrogate modelling and ensemble generation. For both tasks, the diffusion model can outperform other more common approaches. Thus, we see a potential of representation learning with diffusion models for dynamical systems.

Mesoscale permeability variations estimated from natural airflows in the decorated Cosquer Cave (southeastern France)

Conservation of decorated caves is highly dependent on airflows and is correlated with rock formation permeability. We present the first conceptual model of flows around the Paleolithic decorated Cosquer coastal cave (southeastern France), quantify air permeability, and show how its variation affects water levels inside the cave. This study highlights that airflows may change in karst unsaturated zones in response to changes in the water cycle and may thus be affected by climate change.

Precursors and pathways: dynamically informed extreme event forecasting demonstrated on the historic Emilia-Romagna 2023 flood

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-24-2995-2024
6 September 2024

Extreme rainfall is the leading weather-related source of damages in Europe, but it is still difficult to predict on long timescales. A recent example of this was the devastating floods in the Italian region of Emiglia Romagna in May 2023. We present perspectives based on large-scale dynamical information that allows us to better understand and predict such events.

Ice viscosity governs hydraulic fracture that causes rapid drainage of supraglacial lakes

Due to surface melting, meltwater lakes seasonally form on the surface of glaciers. These lakes drive hydrofractures that rapidly transfer water to the base of ice sheets. This paper presents a computational method to capture the complicated hydrofracturing process. Our work reveals that viscous ice rheology has a great influence on the short-term propagation of fractures, enabling fast lake drainage, whereas thermal effects (frictional heating, conduction, and freezing) have little influence.

Optimizing the iodide-adduct chemical ionization mass spectrometry (CIMS) quantitative method for toluene oxidation intermediates: experimental insights into functional-group differences

We introduce detailed and improved quantitation and semi-quantitation methods of iodide-adduct time-of-flight chemical ionization mass spectrometry (I-CIMS) to measure toluene oxidation intermediates. We assess the experimental sensitivity of various functional group species and their binding energy with iodide ions in I-CIMS. A novel classification approach was introduced to significantly enhance the accuracy of semi-quantitative methods (improving R2 values from 0.52 to beyond 0.88).

How is particulate organic carbon transported through the river-fed submarine Congo Canyon to the deep sea?

The land-to-ocean flux of particulate organic carbon (POC) is difficult to measure, inhibiting accurate modeling of the global carbon cycle. Here, we quantify the POC flux between one of the largest rivers on Earth (Congo) and the ocean. POC in the form of vegetation and soil is transported by episodic submarine avalanches in a 1000 km long canyon at up to 5 km water depth. The POC flux induced by avalanches is at least 3 times greater than that induced by the background flow related to tides.

The crucial representation of deep convection for the cyclogenesis of Medicane Ianos

Cyclone Ianos of September 2020 was a high-impact but poorly predicted medicane (Mediterranean hurricane). A community effort of numerical modelling provides robust results to improve prediction. It is found that the representation of local thunderstorms controlled the interaction of Ianos with a jet stream at larger scales and its subsequent evolution. The results help us understand the peculiar dynamics of medicanes and provide guidance for the next generation of weather and climate models.

Merging modelled and reported flood impacts in Europe in a combined flood event catalogue for 1950–2020

Long-term trends in flood losses are regulated by multiple factors, including climate variation, population and economic growth, land-use transitions, reservoir construction, and flood risk reduction measures. Here, we reconstruct the factual circumstances in which almost 15 000 potential riverine, coastal and compound floods in Europe occurred between 1950 and 2020. About 10 % of those events are reported to have caused significant socioeconomic impacts.

Late Quaternary glacial maxima in southern Patagonia: insights from the Lago Argentino glacier lobe

Investigating past glaciated regions is crucial for understanding how ice sheets responded to climate forcings and how they might respond in the future. We use two independent dating techniques to document the timing and extent of the Lago Argentino glacier lobe, a former lobe of the Patagonian Ice Sheet, during the late Quaternary. Our findings highlight feedbacks in the Earth’s system responsible for modulating glacier growth in the Southern Hemisphere prior to the global Last Glacial Maximum.

Cautionary remarks on the planetary boundary visualisation

Our paper examines the visual representation of the planetary boundary concept, which helps convey Earth’s capacity to sustain human life. We identify three issues: exaggerated impact sizes, confusing color patterns, and inaccessibility for colour-vision deficiency. These flaws can lead to overstating risks. We suggest improving these visual elements for more accurate and accessible information for decision-makers.

An increase in the spatial extent of European floods over the last 70 years

We use grid-based runoff from a hydrological model to identify large spatiotemporally connected flood events in Europe, assess extent trends over the last 70 years, and attribute the trends to different drivers. Our findings reveal a general increase in flood extent, with regional variations driven by diverse factors. The study not only enables a thorough examination of flood events across multiple basins but also highlights the potential challenges arising from changing flood extents.

Always on my mind: indications of post-traumatic stress disorder among those affected by the 2021 flood event in the Ahr valley, Germany

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-24-2837-2024
23 August 2024

Despite the visible flood damage, mental health is a growing concern. Yet, there is limited data in Germany on mental health impacts after floods. A survey in a heavily affected region revealed that 28 % of respondents showed signs of post-traumatic stress disorder 1 year later. Risk factors include gender, serious injury or illness due to flooding, and feeling left alone to cope with impacts. The study highlights the need for tailored mental health support for flood-affected populations.

Atmospheric H2 observations from the NOAA Cooperative Global Air Sampling Network

Hydrogen (H2) is a gas in trace amounts in the Earth’s atmosphere with indirect impacts on climate and air quality. Renewed interest in H2 as a low- or zero-carbon source of energy may lead to increased production, uses, and supply chain emissions. NOAA measurements of weekly air samples collected between 2009 and 2021 at over 50 sites in mostly remote locations are now available, and they complement other datasets to study the H2 global budget.

Absence of causality between seismic activity and global warming

It was recently suggested that global warming can be explained by the non-anthropogenic factor of seismic activity. If that is the case, it would have profound implications. We have assessed the validity of the claim by using a statistical technique that evaluates the existence of causal connections between variables, finding no evidence for any causal relationship between seismic activity and global warming.

Tipping point detection and early warnings in climate, ecological, and human systems

Tipping points are abrupt, rapid, and sometimes irreversible changes, and numerous approaches have been proposed to detect them in advance. Such approaches have been termed early warning signals and represent a set of methods for identifying changes in the underlying behaviour of a system across time or space that might indicate an approaching tipping point. Here, we review the literature to explore where, how, and which early warnings have been used in real-world case studies so far.

Sourcing and long-range transport of particulate organic matter in river bedload: Río Bermejo, Argentina

The transport of plant debris in rivers is an important part of the global carbon cycle and influences atmospheric carbon levels through time. We sampled plant debris at the bed of a lowland river and determined the sources as it is transported hundreds of kilometers. Plant debris can persist at the riverbed, but mechanical breakdown reduces its amount, and it is only a small fraction compared to the suspended load. This plant debris and transport patterns need further investigation globally.

ESD Ideas: Exoplanet, origins of life and biosphere researchers offer a perspective fundamental to ensuring humanity’s future

Scientists exploring the histories of planets and life are uniquely positioned to communicate a perspective that is fundamental to our survival: humanity is wholly embedded in Earth and its biosphere. There is no escaping our planet and its history. Only policies that build on this perspective will contribute to a flourishing future for humanity. We offer a few brief glimpses of this cosmic perspective and call on our colleagues to acknowledge the powerful stories emanating from their work.

Using historical temperature to constrain the climate sensitivity, the transient climate response, and aerosol-induced cooling

Using errors in climate model simulations this paper derives correction factors for the impacts of greenhouse gases and particles that bring these simulated temperature fields into agreement with an observational reconstruction of the Earth’s temperature. On average across eight models, a reduction by about one-half of the particle-induced cooling would be required, causing only 0.24 K of cooling since 1850–1899. The greenhouse gas warming simulated by several highly sensitive models would also reduce.

Continuous synchronization of the Greenland ice-core and U–Th timescales using probabilistic inversion

The first continuously measured transfer functions that quantify the age difference between the Greenland ice-core chronology 2005 (GICC05) and the U–Th timescale are presented. The transfer functions were generated using a novel probabilistic algorithm for the synchronization of proxy signals. The results greatly improve the accuracy and precision of previous synchronization estimates and reveal that the annual-layer counting error of GICC05 is less systematic than previously assumed.

Observation-inferred resilience loss of the Amazon rainforest possibly due to internal climate variability

We investigate whether the Amazon rainforest has lost substantial resilience since 1990. This assertion is based on trends in the observational record of vegetation density. We calculate the same metrics in a large number of climate model simulations and find that several models behave indistinguishably from the observations, suggesting that the observed trend could be caused by internal variability and that the cause of the ongoing rapid loss of Amazon rainforest is not mainly global warming.