bluuebunny/crossref_metadata_2025 huggingface dataset:
GCM Selection & Ensemble Design: Best Practices and Recommendations from the EURO-CORDEX Community
Authors: Sobolowski Stefan ,   EURO-CORDEX CMIP6 GCM Selection & Ensemble Task Team
Published: March 2024

High resolution climate information is critical for the research community and the downstream vulnerability, impacts, adaptation, and climate services communities (VIACS). Coordinated ensembles generated by initiatives such as the World Climate Reseaerch Program's Coodinated Regional Downscaling Experiments (CORDEX) provide consistent and comparable information for the present as well as future scenarios. CORDEX is the initiative responsible for delivering regional climate data over fourteen different domains encompassing all land areas of the globe. And its output forms the basis for downstreams impacts assessments, adaptation planning and climate services development. This talk will focus on the European CORDEX initiative (hereafter EURO-CORDEX), an established framework of European regional climate modelers, and its coordinated effort to build regional climate ensembles for the years to come. In its first phase (2014 until now), EURO-CORDEX produced a rich ensemble of regional climate simulations under different representative concentration pathway scenarios. The EURO-CORDEX dataset is hosted in global and European databases and fed into the Regional Atlas of 6th IPCC Assessment Report. However, this ensemble and others like it suffered from several shortcomings, which the community seeks to address in the next phase of production. Chief among these is the oft cited criticism that the selection of GCMs that provide input to the regional climate models was not robust and that the resulting ensemble represents an “ensemble of opportunity”. Here we will show how the community has addressed these shortcomings and present a toolkit, which can be used for evaluating the suitability of GCMs for downscaling. The utility of this toolkit extends well beyond the regional climate and VIACS communities to include researchers interested in researching model biases, constraining future change and exploring so-called future storylines. The toolkit is open-source and the community encourages contributions and sugestions for imporvement. Therefore a short tutorial is also included as part of this talk. 
Effects of the Initial Soil Moisture Contents on Rill Erodibility and Critical Shear Stress of the Clay-rich Soils  
Authors: deviren saygin selen , Ari Fikret , Temiz Cagla , Arslan Sefika , Unal Mehmet Altay , Erpul Gunay
Published: March 2024

Rill erosion is one of the most significant water erosion types in the agricultural areas as a complex type of concentrated flow erosion process. And, it is known that hydraulic conditions are closely related to rill development in terms of the initial soil moisture contents. However, the impact of the subsoil hydrology on sediment discharge potentials is somewhat entangled. Thus, many recent studies point out that the change in soil erosion depends on hydrological conditions in the subsoil and suggest that the evaluation of those changes would increase the success of soil erosion estimates to more efficiently manage natural resources. This study was aimed to investigate the effects of different soil moisture settings (referred as dry, saturated and drainage) on rill erodibility (Kr) and critical shear stress (τcr) values of the soils as the significant variables of process-based WEPP model, and the relations between basic soil properties (e.g. particle size distribution, aggregate stability, soil mechanical cohesion, organic matter etc.) and these model variables for the heavy textured 12 soil types (clay contents change between 33 and 52 %). Flume experiments were performed by using a V-shaped mini-flume apparatus, which was 0.046 m wide, 0.5 m long, and 0.12m deep, specifically designed for rill experiments. Two V-shaped channels with a length of 0.2 m were cemented to the flumes, one on each side. The soil samples were packed in boxes to attain natural bulk densities of the soils after passing through a 2 mm screen opening. The slope steepness was set to 3% for the slope bed and the flow rate was controlled with a flow meter from 0.10 L min-1 to 0.65 L min-1. Within the scope of the study, the mechanical soil cohesion values of the soils were determined by the fluidized bed approach. Obtained results clearly showed that the initial moisture contents had significant effects on sediment concentrations. The lowest Kr values were observed for the drainage condition in all soils while the highest Kr value was obtained for the soils with higher clay than silt content in the saturated conditions. Under dry conditions, on the contrary, the latter reversed and there was the highest Kr value for the soils having higher silt contents than clay. The inverse relationship between Kr and τcr was very pronounced and the highest τcr value was measured under drainage conditions. In addition, it was observed that there were significant correlations between rill erodibility (Kr) and silt contents and mechanical soil cohesion variables of the soils. Conclusively, rill erodibility potential of the soils observed under concentrated flow conditions had statistically close relationships with initial moisture conditions and primary physical soil properties (p
Democratizing soil erosion modelling: A Jupyter Notebook approach
Authors: Peñuela Andres
Published: March 2024

Soil erosion is a widespread environmental challenge with far-reaching implications for agricultural productivity, water quality and ecosystem health. Addressing this complex issue requires the use of modelling tools that empower diverse stakeholders, such as researchers and decision-makers, to simulate soil erosion systems under different scenarios. For these tools to be effective, not only they need to make good predictions, but they need to be accessible and educational, so users, regardless of their technical skills and modelling expertise, can understand and even more importantly, trust the model. In traditional soil erosion modelling, the primary emphasis to build trust is by demonstrating the model’s ability to replicate past observations, and less attention is given to build trust by providing an educational and exploratory experience. We introduce a project that aims at democratizing soil erosion modelling, making it more accessible and trustworthy to researchers, educators, decision-makers, and local communities. Leveraging the versatility and accessibility of Jupyter Notebooks, we are developing iMPACT-erosion, a soil erosion modelling toolbox to support education, land management and informed decision making. A series of dedicated Notebooks not only explain and simulate the main soil erosion processes but guides users through the main steps to enhance the credibility of the model results, i.e. sensitivity analysis, model calibration, uncertainty analysis, model evaluation and scenario analysis. The integration of interactive visualization enhances this experience by facilitating exploration of both the model configuration and the soil erosion system's response under different scenarios/decisions. This model development approach is not confined to the field of soil erosion and offers the potential to facilitate knowledge transfer and collaboration between model developers and decision makers in various domains.
Morphological variation of the beach under the construction of submerged breakwaters-a case study in Pintung coastal area of Taiwan
Authors: Hsu Hung-Chu
Published: March 2024

The need to stabilise and protect beaches and coastlines is important due to the increasing recreational activities in the coastal zone. In Taiwan, the coastal area is hit by about four typhoons a year, and the large waves caused by the typhoons often lead to coastal disasters and beach erosion. The beach could also be the buffer zones against the large wave attack and coastal flooding and erosion. Although the gravel beaches have a great advantage over the sandy beaches in terms of energy absorption capacity, this advantage disappears under the strong wave attack during the typhoon season in Taiwan. The gravel is carried offshore, and it is difficult to return to the beach under the swell wave. During the extreme wave induced in typhoon conditions associated with storm surge, it causes gravel beach closer to the steep nearshore zone, which may then be irreversibly evacuated downslope. The extreme waves bring breaking waves high up on the beach, creating the step-reflecting berms. Energy reflection can thus contribute to further downslope transport of gravel to depths from which it can no longer be recovered by fair-weather waves. The gravel beach can be very steep, accompanied by a typically narrow surf zone and an energetic shore break.The FuAng coast in the south of Taiwan has suffered severe beach erosion since the construction of breakwaters in 2015. The strong reflection creates partial standing waves that scour the sediment at the toe of the beach. In addition, the mixed sand and gravel beach is washed offshore during storms and cannot be brought back to the beach by the weak swell wave. The aim of this paper is to analyse the erosion problem using the shoreline evolution from the satellite images, the variation of the beach profile in several sections and the volumetric variation of the bathymetry. An integrated coastal protection countermeasure using submerged detached breakwaters with artificial beach nourishment is proposed to mitigate the beach erosion problem. Physical experiment and numerical simulation are used to verify the proposed countermeasure. The results show that the proposed method can effectively protect the coast, prevent the beach erosion and form a salient to be a good buffer zone to prevent the wave impact.
Easy Volcanic Aerosol version 2: progress toward an updated volcanic aerosol forcing generator
Authors: Khanal Sujan , Toohey Matthew , Aubry Thomas , Neufeld Domenic
Published: March 2024

The Easy Volcanic Aerosol (EVA) family of simple models offers an approach to the generation of stratospheric aerosol fields from estimates of volcanic emissions. EVA takes as input a time series of volcanic eruption data, including the mass of sulfur injected into the stratosphere and location of the eruptions, and outputs aerosol optical properties as a function of time, latitude, height and wavelength based on a simple box-model of stratospheric transport. These aerosol properties are tailored for use as volcanic aerosol forcing in climate models. They are also useful as general quantitative estimates of the impact of volcanic eruptions on climate. EVA version 1 was based on observations of the aerosol from the 1991 Mt. Pinatubo eruption, while EVA_H was parameterized to improve agreement with a range of smaller magnitude eruptions observed over the 1979-2015 period, taking account of the estimated injection height of the emitted sulfur. Here, we present progress in the development of EVA version 2, which improves the fidelity of its output based on various important updates. The model accounts for bi-modal particle size distributions, in line with in-situ observations of Pinatubo aerosol plume. It can also account for the uncertainty in aerosol forcing due to the uncertainty in measurements of the refractive index of sulfuric acid solution. Further updates include implementation of a new method for incorporating injection height and its impact on aerosol growth and evolution. Improvements in the fidelity of aerosol properties is balanced with the aim of simplicity, making EVA2 well-suited for idealized model experiments as well as reconstructions of past volcanic forcing. We compare the results of EVA2 with observational data sets and quantify the impact of updates on reconstructions of volcanic forcing over periods relevant to upcoming CMIP7 experiments.
Precipitation regime changes in High Mountain Asia driven by cleaner air
Authors: Jiang Jie
Published: March 2024

High Mountain Asia (HMA) has experienced a spatial imbalance in water resources in recent decades, partly because of a dipolar pattern of precipitation changes known as South Drying–North Wetting. These changes can be influenced by both human activities and internal climate variability. Although climate projections indicate a future widespread wetting trend over HMA, the timing and mechanism of the transition from a dipolar to a monopolar pattern remain unknown. Here we demonstrate that the observed dipolar precipitation change in HMA during summer is primarily driven by westerly- and monsoon-associated precipitation patterns. The weakening of the Asian westerly jet, caused by the uneven emission of anthropogenic aerosols, favoured a dipolar precipitation trend from 1951 to 2020. Moreover, the phase transition of the Interdecadal Pacific Oscillation induces an out-of-phase precipitation change between the core region of the South Asian monsoon and southeastern HMA. Under medium- or high-emission scenarios, corresponding to a global warming of 0.6–1.1 °C compared with the present, the dipolar pattern is projected to shift to a monopolar wetting trend in the 2040s. This shift in precipitation patterns is mainly attributed to the intensified jet stream resulting from reduced emissions of anthropogenic aerosols. These findings underscore the importance of considering the impact of aerosol emission reduction in future social planning by policymakers.
The hypothesis of a lost Cenozoic “Himalandia” between India and Asia
Authors: Liu Liang , Liu Lijun , Morgan Jason , Xu Yi-Gang , Chen Ling
Published: March 2024

            The type of lithosphere subducted between India and Tibet since the Paleocene remains controversial; it has been suggested to be either entirely continental, oceanic, or a mixture of the two. As the subduction history of this lost lithosphere strongly shaped Tibetan intraplate tectonism, we attempt to further constrain its nature and density structure with numerical models that aim to reproduce the observed history of magmatism and crustal thickening in addition to present-day plateau properties between 83˚E and 88˚E. By matching time-evolving geological patterns, here we show that Tibetan tectonism away from the Himalayan syntaxis is consistent with the initial indentation of a craton-like terrane at 55±5 Ma, followed by a buoyant tectonic plate with a thin crust, e.g., a broad continental margin (Himalandia). This new geodynamic scenario can explain the seemingly contradictory observations that had led to competing hypotheses like the subduction of Greater India versus largely oceanic subduction prior to Indian indentation.
Mesoscale Convective Systems across Australia
Authors: Short Ewan , Lane Todd
Published: March 2024

A major aspiration of operational and research meteorology is to relate the average behaviour of convective-scale flows to the more predictable, larger-scale flows in which they occur. This goal is difficult, partly because convective flows often self-organize at mesoscales, with the dynamics of such mesoscale convective systems (MCSs) distinct from those at convective and synoptic scales. In this study we use a tracking algorithm to detect MCSs in Australian operational radar data, revealing regional, seasonal and sub-seasonal, i.e. synoptic, differences in organizational characteristics. Restricting to MCS observations with nominally two-dimensional mean system-relative flows, spatio-temporal organizational differences are generally well explained by theoretical ideas regarding the breakdown of two-dimensional overturning flows. Theoretically, breakdown is characterised by a single non-dimensional convective Richardson number R, which provides the ratio of thermodynamic potential energy to inflow kinetic energy. Specifically, 76% of MCS relative trailing-stratiform, up-shear tilted observations, nominally associated with primarily non-overturning system-relative flows, occur when R>5, whereas 72% of relative leading-stratiform, down-shear tilted observations, nominally indicating primarily overturning system-relative flows, occur when R
Annual evolution of the ice–ocean interaction beneath landfast ice in Prydz Bay, East Antarctica
Authors: Hu Haihan , Zhao Jiechen , Heil Petra , Qin Zhiliang , Ma Jingkai , Hui Fengming , Cheng Xiao
Published: March 2024

High-frequency observations of the ice–ocean interaction and high-precision estimation of the ice–ocean heat exchange are critical to understanding the thermodynamics of the landfast ice mass balance in Antarctica. To investigate the oceanic contribution to the evolution of the landfast ice, an integrated ocean observation system, including an acoustic Doppler velocimeter (ADV), conductivity–temperature–depth (CTD) sensors, and a sea ice mass balance array (SIMBA), was deployed on the landfast ice near Chinese Zhongshan Station in Prydz Bay, East Antarctica from April to November 2021. The CTD sensors recorded the ocean temperature and salinity. The ocean temperature experienced a rapid increase in late April, from −1.62°C to the maximum of −1.30°C, and then, it gradually decreased to −1.75°C in May and remained at this temperature until November. The seawater salinity and density exhibited similar increasing trends during April and May, with mean rates of 0.04 psu day−1 and 0.03 kg m−3 day−1, respectively, which was related to the strong salt rejection caused by freezing of the landfast ice. The ocean current observed by the ADV had mean horizontal and vertical velocities of 9.5±3.9 cm s−1 and 0.2±0.8 cm s−1, respectively. The domain current direction was ESE (120°)–WSW (240°), and the domain velocity (79%) was 5–15 cm s−1. The oceanic heat flux (Fw) estimated using the residual method reached a peak of 41.3±9.8 W m−2 in April, and then, it gradually decreased to a stable level of 7.8±2.9 W m−2 from June to October. The Fw values calculated using three different bulk parameterizations exhibited similar trends with different magnitudes due to the uncertainties of the empirical friction velocity. The spectral analysis results suggest that all of the observed ocean variables exhibited a typical half-day period, indicating the strong diurnal influence of the local tidal oscillations. The large-scale sea ice distribution and ocean circulation contributed to the seasonal variations in the ocean variables, revealing the important relationship between the large-scale and local phenomena. The high frequency and cross-seasonal observations of oceanic variables obtained in this study allow us to deeply investigate their diurnal and seasonal variations and to evaluate their influences on the landfast ice evolution.
Climate Shifts: Measuring the Impact on Overnight Stays in Italy
Authors: Duong Nguyen Thanh Thanh , Guizzardi Andrea , Pons Flavio Maria Emanuele
Published: March 2024

This research quantitatively assesses the impact of climate change on Italy's tourism industry, emphasizing the consequential effects on enterprise turnover and local authorities' fiscal revenues. The study aims to enhance stakeholder capabilities through diagnostic skills, addressing both immediate and long-term climate impacts on overnight stays. Employing innovative statistical and predictive tools, supported by cutting-edge ICT technologies, the research explores the symbiotic relationship between climate dynamics and regional income.Utilizing a comprehensive database merging socio-economic and meteorological data, an econometric framework is established. Overnight stays serve as the dependent variable, with GDP and CPI as economic factors and climate data sourced from the ERA5 reanalysis dataset. Atmospheric variables include monthly climate indicators of 2-meter temperature, solar radiation and cumulated precipitation at the NUTS 2 level, and monthly weather regimes indices obtained from EOF analysis. Additionally, a categorical variable incorporating extreme events (floods, storms, heatwaves, cold spells) from the EM-DAT database is considered. The study spans January 1990 to August 2023, offering insights into the intricate relationships between climate change, economic impacts on tourism, and the historical and present causal links with overnight stays. These findings contribute to strategies promoting sustainability and resilience in tourism destinations amid climate change challenges.
An observational study on the microclimate and soil thermal regimes under solar photovoltaic arrays
Authors: Zheng Junqing , Luo Yong , Chang Rui , Gao Xiaoqing
Published: March 2024

The high demand for low-carbon energy sources to mitigate climate change has prompted a rapid increase in ground-mounted solar parks. The implementation of photovoltaic (PV) significantly impacted the local climate and ecosystem, which are both poorly understood. To investigate the effects of a typical solar park on the Gobi ecological system, local microclimate and soil thermal regimes were measured year-round under and between PV arrays, at an applied solar park sited in Xinjiang, China. Our results demonstrated their seasonal and diurnal changes. Under solar PV arrays, the mean annual net radiation and wind speed decreased by 92.68% and 50.53% respectively. In contrast, PV panels caused an increase of the rear sides air by 10.12% with 0.87°C. South-facing PV panels reduced wind speed with the prevailing northerly wind below. In addition, the relative humidity rapidly decreased when snow covered the ground, but slightly increased from April to September. We found the soil under PV panels was cooler and tended to be a sink of energy during spring and summer whereas was more often a source during autumn and winter compared with the soil between PV panels. Observed data developed the understanding of the energy processes of solar parks in Gobi ecosystems and provided evidence to support the sustainable management of the solar park.
References:
Zheng, J., Luo, Y., Chang, R., and Gao, X., 2023. An observational study on the microclimate and soil thermal regimes under solar photovoltaic arrays. Solar Energy. 266, 112159.
Size matters – small estuaries fringed by blue carbon ecosystems deliver disproportionately high dissolved carbon to the ocean
Authors: Reithmaier Gloria , Maher Damien T. , Holloway Ceylena , Correa Rogger E. , Santos Isaac R.
Published: March 2024

Blue carbon ecosystems, e.g., mangroves and saltmarshes, may help to mitigate climate change by storing atmospheric carbon. Most blue carbon studies focus on carbon burial in soils. However, lateral exports from blue carbon systems (termed outwelling) represents an additional carbon sink. We investigated dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and alkalinity (TA) outwelling rates as well as CO2 emissions from 18 estuaries fringed by mangroves and saltmarshes. On average, estuaries exported 344 ± 150 mmol m-2 y-1 DIC and 120 ± 55 mmol m-2 y-1 DOC. Carbon outwelling rates were ~20-times higher than estuarine CO2 emissions (33 ± 20 mmol m-2 d-1). Blue carbon ecosystems contributed 19 – 41 % to the overall carbon export to the ocean. In addition to wetland cover, estuary size and runoff were key drivers impacting carbon outwelling rates. Overall, small estuaries exported disproportionally high carbon loads, contributing up to 80% of the carbon outwelling from Australian estuaries. To improve global carbon budgets, it is crucial to consider carbon outwelling from small estuaries fringed by blue carbon ecosystems.
Forced Component Estimation Statistical Methods Intercomparison Project (ForceSMIP): First Results
Authors: Jnglin Wills Robert , Deser Clara , McKinnon Karen , Phillips Adam , Po-Chedley Stephen
Published: March 2024

Anthropogenic climate change is unfolding rapidly, yet its regional manifestation is often obscured by naturally occurring variability internal to the atmosphere and ocean system. A primary goal of climate science is to identify the forced response, i.e., spatiotemporal changes in climate in response to greenhouse gases, anthropogenic aerosols, and other external forcing, amongst the noise of internal climate variability. Separating the forced response from internal variability can be addressed in climate models by taking the average over a large ensemble, where the same model is run multiple times with small differences in initial conditions leading to different realizations of internal variability. However, there is only one realization of the real world, making it a major challenge to isolate the forced response in observations, as is needed for accurate attribution of historical climate changes, for characterizing and understanding observed internal variability, and for climate model evaluation.In the Forced Component Estimation Intercomparison Project (ForceSMIP), contributors utilized existing and newly developed statistical and machine learning methods to estimate the forced response during the historical period within individual ensemble members and observations, across nine key climate variables (sea-surface temperature, surface air temperature, precipitation, sea-level pressure, sea-ice concentration, zonal-mean atmospheric temperature, monthly maximum and minimum temperature, and monthly maximum daily precipitation). Participants had access to five CMIP6 large ensembles on which to train their methods, but they then had to apply their methods to individual evaluation members, the identity of which was hidden to all participants. Participants used methods including regression methods, dynamical adjustment, convolutional neural networks, linear inverse models, fingerprinting methods, and low-frequency component analysis, and all codes have been collected to make an open-access repository. The ForceSMIP submission period ends on March 1, 2024, and we will present first results showing how the different methods performed on climate models, what they assessed to the be the forced response in observations, and how the estimate of the forced response in observations compares with that in climate models.
Effects of climate, stand structure, soil characteristics and topography on leaf unfolding of trees in Switzerland
Authors: Ostovary Isabella , Bigler Christof
Published: March 2024

Leaf unfolding of trees is influenced by a wide range of environmental factors, such as climate, stand structure, soil characteristics, and topography. However, few studies have investigated the compound effects of those environmental factors. Furthermore, several factors, such as stand structure and soil characteristics, have not been sufficiently studied. In particular, the influence of water-holding capacity and the resulting soil-water balance on the phenological behaviour of adult trees is largely unexplored.This study aims to understand how interactions between multiple environmental factors, including climate, stand structure, soil characteristics, and topography, influence the phenological timing of Fagus sylvatica, Picea abies, Larix decidua and Tilia cordata. To understand the effects of these factors, field data on soil characteristics (depth, texture, bulk density, and organic carbon), topography (elevation, relief type, slope aspect and slope inclination) and stand structure (basal area, tree height and stand height) were collected at 52 long-term monitoring sites from a phenological network across all biogeographic regions of Switzerland. Data is currently being analysed using linear mixed-effects models.Preliminary results indicate that growing degree days, drought and elevation are the most important factors determining the timing of leaf unfolding across species. Among those factors, drought consistently seems to have the highest impact on advancing leaf unfolding. Other factors such as relief type, stand height and basal area appear to be relevant as well, but seem more species specific. For example, relief type, which can affect heat accumulation irrespective of weather conditions, seems important for Larix decidua, but not Fagus sylvatica. In contrast, there is reasonable evidence that competition parameters such as stand height and basal area affect Fagus sylvatica, but not Larix decidua.This study considerably improves our understanding about the compound effect of established as well as rarely investigated environmental factors on the timing of leaf unfolding across species throughout a wide range of environmental conditions.
Shifting of Western Disturbances winter precipitation over Western Himalayas
Authors: Pooja Pooja , Dimri Ashok Priyadarshan
Published: March 2024

The Indian Himalayan region receives an enormous amount of precipitation due to synoptic weather systems known as Western Disturbances (WDs). WDs are east-ward propagating systems embedded in the Subtropical Westerly Jetstream (SWJ). The main objective of this study is to investigate the change in magnitude and dynamics of WDs precipitation over the western Himalayan region. In this study, different observational datasets (IMD, AHRODITE, GPCP, GPCC, and ERA5) were selected to compare and assess the magnitude of WDs precipitation for the period 1987–2020 during the winters (DJF: December, January, and February). Further, to examine the structure of WDs precipitation at the pressure level of 200hPa, ERA5 Reanalysis datasets having a similar resolution of 25 km with the gridded dataset of the Indian Meteorological Department (IMD) are used for the analysis. WDs moisture sources from the Arabian Sea are assessed at 23 pressure levels (1000–200 hPa) for further understanding of WDs dynamics. Our study shows the daily shifting of WDs precipitation towards February during the winters and an intriguing decrease in daily WDs precipitation in recent years. During the study, we found that WDs precipitation contributed a significant amount of precipitation (~80%) over the Western Himalayan region of the Indian subcontinent. Using Theil-Sen method, trend analysis was performed, showing a decreased trend of WDs precipitation in recent years The present findings indicate that WDs have changed their precipitation characteristics and dynamics due to climate change. The number of active WDs days is decreasing. Our results show there is enough moisture present over the Bay of Bengal region other than WDs which helps in sustaining and replenishing glaciers over the Indian Himalayan region.
Forecast-based attribution for midlatitude cyclones
Authors: Ermis Shirin , Leach Nicholas , Sparrow Sarah , Lott Fraser , Weisheimer Antje
Published: March 2024

The widespread destruction incurred by midlatitude storms every year makes it an imperative to study how storms change with climate. The impact of climate change on midlatitude windstorms, however, is hard to evaluate due to the small signals in variables such as wind speed, as well as the high interannual variability in Atlantic storms.Here, we compare multiple severe midlatitude cyclones with both wind and precipitation impacts using forecast-based event attribution. We use a recent version of the ECMWF IFS ensemble prediction system which is demonstrably able to predict the storms, significantly increasing our confidence in its ability to model the key physical processes and their response to climate change.The comparably high resolution of our simulations, and the focus on individual case studies are particularly useful for dynamically driven events like storms. Our approach is able to combine a dynamical analysis of the storm in question with an analysis of past and future changes.Our results confirm trends of increased severity in storm impacts found in climate projections but add reliability to the forecasted structure and impacts of the storm. This indicates that forecast-based attribution is viable for reliable and fast attribution systems.
ProbShakemap: a Python toolbox for urgent earthquake source uncertainty quantification
Authors: Stallone Angela , Selva Jacopo , Cordrie Louise , Faenza Licia , Michelini Alberto
Published: March 2024

Seismic urgent computing aims at assessing the potential impact of earthquakes through rapid simulation-based ground-shaking forecasts. However, uncertainty quantification remains a significant challenge in this domain.While current practice accounts for the uncertainty arising from Ground Motion Models (GMMs), it neglects the uncertainty about the source model, which is only known approximately in the first minutes after an earthquake. Addressing this issue involves propagating earthquake source uncertainty from a multi-scenarios ensemble that captures source variability to ground motion predictions. In principle, this could be accomplished with 3D modelling of seismic wave propagation for multiple earthquake sources. However, full ensemble simulation is unfeasible under emergency conditions with strict time constraints.Here we present ProbShakemap, a Python toolbox which generates multi-scenario ensembles and delivers ensemble-based forecasts for urgent source uncertainty quantification. It implements GMMs to efficiently propagate source uncertainty from the ensemble of scenarios to ground motion predictions at a set of points, while also accounting for model uncertainty (by accommodating multiple GMMs, if available) along with their intrinsic uncertainty. Notably, ProbShakemap does not rely on any recorded data, and only requires the following event-specific information: latitude, longitude, magnitude and time. ProbShakemap incorporates functionalities from two open-source toolboxes routinely implemented in seismic hazard and risk analyses: the USGS ShakeMap software and the OpenQuake-engine.We quantitatively test ProbShakemap against past earthquakes, illustrating its capability to rapidly quantify earthquake source uncertainty.
Predictive ability assessment of Bayesian Causal Reasoning (BCR) on runoff temporal series
Authors: Zazo Santiago , Molina José Luis , Patino-Alonso Carmen , Espejo Fernando
Published: March 2024

The alteration of traditional hydrological patterns due to global warming is leading to a modification of the hydrological cycle. This situation draws a complex scenario for the sustainable management of water resources. However, this issue offers a challenge for the development of innovative approaches that allow an in-depth capturing the logical temporal-dependence structure of these modifications to advance sustainable management of water resources, mainly through the reliable predictive models. In this context, Bayesian Causality (BC), addressed through Causal Reasoning (CR) and supported by a Bayesian Networks (BNs), called Bayesian Causal Reasoning (BCR) is a novel hydrological research area that can help identify those temporal interactions efficiently.This contribution aims to assesses the BCR ability to discover the logical and non-trivial temporal-dependence structure of the hydrological series, as well as its predictability. For this, a BN that conceptually synthesizes the time series is defined, and where the conditional probability is propagated over the time throughout the BN through an innovative Dependence Mitigation Graph. This is done by coupling among an autoregressive parametric approach and causal model. The analytical ability of the BCR highlighted the logical temporal structure, latent in the time series, which defines the general behavior of the runoff. This logical structure allowed to quantify, through a dependence matrix which summarizes the strength of the temporal dependencies, the two temporal fractions that compose the runoff: one due to time (Temporally Conditioned Runoff) and one not (Temporally Non-conditioned Runoff). Based on this temporal conditionality, a predictive model is implemented for each temporal fraction, and its reliability is assessed from a double probabilistic and metrological perspective.This methodological framework is applied to two Spanish unregulated sub-basins; Voltoya river belongs to Duero River Basin, and Mijares river, in the Jucar River Basin. Both cases with a clearly opposite temporal behavior, Voltoya independent and Mijares dependent, and with increasingly more problems associated with droughts.The findings of this study may have important implications over the knowledge of temporal behavior of water resources of river basin and their adaptation. In addition, TCR and TNCR predictive models would allow advances in the optimal dimensioning of storage infrastructures (reservoirs), with relevant substantial economic/environmental savings. Also, a more sustainable management of river basins through more reliable control reservoirs’ operation is expected to be achieved. Finally, these results open new possibilities for developing predictive hydrological models within a BCR framework.
Optimizing impoundment operation of Three Georges Reservoir for enhancing hydropower output and reducing carbon emission
Authors: Zhou Yanlai , Ning Zhihao , Lin Fanqi , Chang Fi-John
Published: March 2024

Reservoir impoundment operation has far-reaching effects on the synergies between hydropower output, floodwater utilization, and carbon fluxes. However, there's a notable rise in flood risks, especially when advancing impoundment timings and lifting reservoir water levels. This study proposed a novel reservoir impoundment operation framework prioritizing flood prevention, hydropower generation, floodwater management, and carbon emission control. The Three Gorges Reservoir in the Yangtze River was selected as a case study. The results demonstrated that initiating impoundment on or after September 1st could ensure flood safety. The best scheme of reservoir impoundment operation could significantly boost synergistic benefits, enhancing hydropower output by 1.39 billion kW·h (5.3%) and the water impoundment rate by 10.2% while reducing carbon emissions by 51.65 GgCO2e/yr (15.8%) and increasing organic carbon burials by 10.03 GgCO2e/yr (10.3%), respectively, compared with the standard operation policy. This study not only provides scientific and technical support for reservoir impoundment operation benefiting water-carbon nexus synergies but also presents policymakers with viable options to pre-experience the risks and benefits for sustainable hydropower through adjusted impoundment schedules and reservoir water levels. 
Flapping Motion Configurations of Geomagnetotail Current Sheet
Authors: Shao Peng , Shen Chao
Published: March 2024

We explore the geometry of the flapping motion of geomagnetotail current sheet with the magnetic measurements of the Cluster (constellation) using a newly developed technique. The principal curvatures and directions of the surfaces of the flapping current sheet are successfully deduced by the normal field analysis (NFA). Results show that the directions with the minimum curvature of surfaces of flapping motion are approximately along the Sun-Earth line, while the ones with maximum curvature are mostly in the dawn-dusk plane. It is confirmed that the tail flapping motion is a wave arising in the Y-Z plane, but not bend along the Sun-Earth line. Furthermore, our calculations reveal that the maximum curvature radius of the flapping current sheet's surface along the X-axis is on the order of several dozen Earth radii. This implies that the flapping motion extends spatially over a range from several to a dozen Earth radii along the Sun-Earth direction.
Effect of Sampling Design on Characterizing Surface Soil Fingerprinting Properties.
Authors: Luna Maria , Koiter Alexander , Lobb David
Published: March 2024

Purpose: The characterization of soil properties is an important part of many different types of agri-environmental research including inventory, comparison, and manipulation studies. Sediment source fingerprinting (i.e., tracing) is a method that is increasingly being used to link sediment sources to downstream sediment. There is currently not a standard approach to characterizing sources and the different approaches to sampling have not been well assessed.Methods: Grid, transect, and likely to erode sampling designs were used to characterize the geochemical, colour, grain size distribution, and soil organic matter content at two sites under contrasting land uses (agricultural and forested). The impact of the three sampling designs on fingerprint selection, source discrimination, and mixing apportionment results was evaluated using a virtual mixture.Results: The sampling design had a significant impact on the characterization of the two sites investigated. While the number and composition of the fingerprints selected varied between sampling designs there was strong discrimination between sources regardless of the sampling approach. There were deviations in the expected apportionment results, but the overall patterns were similar across the three sampling designs.Conclusions: Despite having an impact on the characterization of sources, the sampling design used ultimately had little impact on the conclusions drawn from the final apportionment results. Continued work at the watershed scale is needed to fully evaluate the importance of source sampling on the sediment source fingerprinting approach.
Experimental transfer function of ground heat exchanger from thermal response tests using a deconvolution approach
Authors: Dion Gabriel , Pasquier Philippe
Published: March 2024

Ground-coupled heat pump systems exchange heat between a building and the surrounding ground. To simulate a ground heat exchanger (GHE), a transfer function is commonly used. This function represents the ground's capacity to exchange energy. Its use allows for the simulation of the ground's response to different heat load patterns. The heat transfer process is affected by key factors such as the ground's thermal properties and the groundwater flow. Accurate evaluation is critical for designing the GHE field to meet the thermal needs of a building for heating and cooling.The transfer function of the GHE represents its heat transfer over a time range from seconds to years of operation. The long-term component is usually defined by an analytical model, while the short-term component requires a more complex model to be evaluated. Indeed, analytical models do not accurately represent the transient heat transfer effects that occur in the borehole materials and heat transfer fluid. To avoid using thermal transfer models, the data from a thermal response test (TRT) can be used to retrieve an experimental transfer function. This study aims to outline the different applications of a deconvolution algorithm to retrieve a short-term transfer function from experimental TRT data.Applying a deconvolution algorithm to the outlet temperature signal of a TRT allows for estimation of the short-term response of the GHE without the need for a defined thermal model. The algorithm can iterate on the transfer function form, enabling accurate reconstruction of experimental temperature. One advantage of this method is that it only requires experimental data from a TRT to construct the transfer function.The methodology is applied to tests with constant and varying operating conditions, allowing to obtain one or more transfer functions depending on the number of operating conditions. Additionally, a deconvolution algorithm can be utilized to interpret distributed thermal response tests, helping in the identification of geological layers with the best thermal properties. This can assist system designers to reduce drilling costs for systems with multiple boreholes. Results present transfer functions that are smooth and close to ones obtained from a more advanced numerical model. Additionally, they can reconstruct experimental temperature precisely. It is worth noting that the transfer function curve is affected by groundwater flow, with larger flows resulting in a decrease in the curve for similar operating conditions.In conclusion, this research demonstrates the diverse applications of a deconvolution algorithm in interpreting a thermal response test across various geological settings, groundwater flow rates, operating conditions, and types of GHE. This leads to the estimation of a short-term transfer function, which can be used either to compute thermal parameters or validate various heating loads on the GHE through implementation in a simulation algorithm.
Modelling post-restoration spatiotemporal changes in peatland water table with optical satellite imagery
Authors: Isoaho Aleksi , Ikkala Lauri , Päkkilä Lassi , Marttila Hannu , Kareksela Santtu , Räsänen Aleksi
Published: March 2024

Remote sensing (RS) has been suggested as a tool for peatland monitoring. However, there have been only a few studies in which post-restoration hydrological changes have been quantified with RS-based modelling. To address this gap, we developed an approach to assess post-restoration spatiotemporal changes in the peatland water table (WT) with optical Sentinel-2 and Landsat imagery. We tested the approach in eleven northern boreal peatlands (six restored, and five control sites) impacted by forestry drainage in northern Finland using Google Earth Engine cloud computing capabilities. We constructed a random forest regression model with spatiotemporal field-measured WT data as a dependent variable and satellite imagery features as independent variables. To assess the spatiotemporal changes, we constructed representative maps for situations before and after restoration, separately for early summer wet and midsummer dry conditions. To further quantify temporal changes during 2013–2023, and to test statistical significance of restoration, we conducted a bootstrap hypothesis test for the areas near the restoration measures and similar areas in the control sites. The regression model had a relatively good fit and explanatory capacity (R2 = 0.61, RMSE = 6.98 cm). The WT maps showed that the post-restoration changes were not uniform and concentrated near the restoration measures. The bootstrap test showed that the WT increased more in the restored areas (5.8–9.4 cm) than in the control areas (0.1–4.5 cm). Our results indicate that restoration impact on surface hydrology can be quantified with optical satellite imagery and a machine learning approach in treeless peatlands.