bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity of the Antarctic Ice Sheet evolution to different Earth structures using a coupled 3D GIA - ice-sheet model under different future climate scenarios
Authors: van Calcar Caroline , Bernales Jorge , Berends Tijn , van der Wal Wouter , van de Wal Roderik
Published: February 2023

The projected decay of the Antarctic Ice Sheet (AIS) over the coming centuries will lead to uplift of the Earth's surface due to Glacial Isostatic Adjustment (GIA). GIA slows down grounding line migration and therefore has a stabilizing effect on the ice sheet evolution. GIA acts on timescales of decades to centennial depending on the magnitude of the mantle viscosity. The mantle viscosity is several orders of magnitude higher in East Antarctica than in West Antarctica and varies with one order of magnitude within West Antarctica. Studies of the AIS evolution over the last glacial cycle have shown that including lateral variations of the Earth's mantle viscosity can lead to 1.5-kilometer thicker ice in West Antarctica at present day. However, current projections do not include GIA, or they use a laterally homogeneous GIA model. One study applied a uniform high mantle viscosity under East Antarctica and a uniform low mantle viscosity under West Antarctica and showed that, on longer timescales of hundreds of years, mass loss projections of Antarctica may be underestimated because spatially uniform GIA models overestimate the stabilizing effect of GIA across East Antarctica. We developed a coupled GIA - ice-sheet model using the ice-sheet model IMAU-ICE, and a 3D GIA finite element model that includes lateral mantle viscosity variations, and a seismic model to determine the patterns of the viscosity. The results of projections for two IPCC scenarios show that including lateral variations in the Earth's mantle viscosity leads to local ice thickness differences of up to 600 meters in West Antarctica  2300. The results underline and quantify the importance of including this local feedback effect in ice-sheet models when projecting the long-term sea level contribution from Antarctica.
Comparison between a 20-year terrestrial and satellite gravity data at Mt. Etna volcano (Italy).
Authors: Samperi Luca , Pereira Ailin , Greco Filippo , Carbone Daniele , Contrafatto Danilo , Messina Alfio Alex , Mirabella Luca , Pacino Maria Cristina , Pereira Ayelén
Published: February 2023

Gravity measurements are increasingly used for high-precision and high-resolution Earth investigation. Recent times highlight the intention to combine both terrestrial and satellite data in order to reach higher accuracy for several purposes such as geological structures determination and geoid models construction.Here we present results of a comparison between a twenty-year (2002-2022) relative and absolute gravity data collected through the Microg LaCoste FG5#238 absolute gravimeter (AG), in the framework of repeated measurements in one station at about 1750 m above sea level and the satellite gravity data provided by CNES/GRGS RL05 Earth gravity field models, from GRACE and SLR data.The comparison allows to estimate the long-term correlation between the two dataset and a remarkably good fit was found in the long-term trend, revealing gravity changes most likely due to hydrological and volcanological effects.Our study shows how the combination of terrestrial and satellite data can be used to obtain a fuller and more accurate picture of the temporal characteristics of the studied processes. The combined use of these dataset results crucial especially in a harsh, unsteady and changing environment as well as the Etna volcano.
On the nature of electric field fluctuations in the near-Sun solar wind and its implication for the turbulent energy transfer at ion and electron scales
Authors: Franci Luca , Papini Emanuele , Del Sarto Daniele , Micera Alfredo , Stawarz Julia , Horbury Tim , Lapenta Giovanni , Lewis Harry , Salem Chadi , Landi Simone , Hellinger Petr , Matteini Lorenzo , Cicone Antonio , Piersanti Mirko , Innocenti Maria Elena , Maksimovic Milan , Burgess David
Published: February 2023

We model plasma turbulence in the near-Sun solar wind by means of a high-resolution fully kinetic simulation initialised with average plasma conditions measured by Parker Solar Probe during its first solar encounter. Once turbulence is fully developed, the power spectra of the plasma and electromagnetic fluctuations exhibit clear power-law intervals down to sub-electron scales. Our simulation models the electron-scale electric field fluctuations with unprecedented accuracy. This allows us to perform the first detailed analysis of the different terms of the electric field in the generalised Ohm's law (MHD, Hall, and electron pressure terms) at ion and electron scales, both in physical space and in Fourier space. Such analysis suggests rewriting the Ohm’s law in a different form, which disentangles the contribution of different underlying plasma mechanisms, characterising the nature of the electric field fluctuations in the different range of scales. This provides a new insight on how energy in the turbulent electromagnetic fields is transferred through ion and electron scales and seems to favour the role of pressure-balanced structures versus waves. We finally test our assumptions and numerical results by means of a statistical analysis using magnetic field, electric field, and electron density data from Solar Orbiter and Parker Solar Probe. Preliminary results show good agreement with our theoretical expectations inspired by our simulation.
Ice shelf-ocean interaction at shallow depths needs more attention
Authors: Richter Ole , Galton-Fenzi Ben , Naugthen Kaitlin , Timmermann Ralph
Published: February 2023

Understanding the processes involved in basal melting of Antarctic ice shelves is important to quantify the rate at which Antarctica will lose mass. Current research of ice shelf-ocean interaction highlights deep warm water intrusions and melting along narrow grounding lines. The majority of the ice, however, lies in much shallower waters. Here we analyse the vertical structure of previously published Antarctic-wide estimates of ice shelf basal melting derived from satellites and ice shelf buttressing derived from ice sheet flow modelling. The results show that ice shelf regions with a draft shallower than 500 m account for more than 60 % of the total basal mass loss and more than 30 % of the total buttressing flux response. The oceanic processes that drive melting in shallow regions might be very different compared to the ones at depth and how well these are represented in large-scale models of Antarctic ice shelf-ocean interaction is not clear. This gap should be addressed for more accurate predictions of the Antarctic response to climate change. 
'G-cubed' joint inversions for the thermochemical environment and melting regime beneath intra-plate volcanic regions
Authors: Afonso Juan , Zhang Anqi , Burcet Marti , Oliveira Beñat , Handley Heather , Klöcking Marthe
Published: February 2023

Although intra-plate volcanism is commonly attributed to the presence of thermal anomalies in the sublithospheric mantle (e.g. deep mantle plume, small-scale convection), recent geodynamic and geochemistry studies have emphasized the role of the thermochemical structure of the overlying lithosphere in dictating the type, timing and volume of surface volcanism in intra-plate environments. From the observational point of view, however, it has been difficult to formally link geophysical imaging techniques (e.g. seismic tomography) with geochemical data from erupted lavas to obtain an internally-consistent image of the thermochemical environment and melting regime responsible for intra-plate volcanism. Here we present the first geochemical-geophysical-geodynamic (‘G-cubed’) joint inversion approach capable of inverting both major and trace element lava compositions together with multiple geophysical datasets within a fully probabilistic framework. The result of this inversion is a complete thermo-chemical-dynamical model of the subsurface, including the melting regime. We illustrate the benefits and limitations of the method with a case study in eastern China. We show that our approach can successfully derive a thermochemical model that is fully consistent with all the inverted geochemical and geophysical data sets, providing fundamental constraints on the nature of the intra-plate volcanism and the underlaying mantle dynamics.  
Simultaneous O2 and CO2 Flux Measurements with Custom-made Branch Chambers for Fagus sylvatica
Authors: Knohl Alexander , Klosterhalfen Anne , Muhr Jan , Blei Emanuel , Bonazza Mattia , Fellert Dietmar , Manning Andrew , Markwitz Christian , Pickers Penelope A. , Tiedemann Frank , Tunsch Edgar , Yan Yuan
Published: February 2023

The O2:CO2 exchange ratio of plants is an only recently explored new plant trait and provides novel insights into the carbon cycle. Measurements of O2 fluxes at field sites are, however, scarce due to a number of technical challenges. This work presents unique field measurements of O2 and CO2 mole fractions and exchange fluxes of tree branches using a custom-made fully automated chamber system for quasi-continuous, high-precision measurements between Fagus sylvatica leaves and the atmosphere. Data from the vegetation period of 2021 in a temperate beech forest in Germany are shown.Four steady-state, open-throughflow branch chambers were part of a larger chamber measurement set-up that also included four stem and eight soil chambers that were connected via a custom-built valve switching system to a modified FC-2 Differential Oxygen Analyzer (Oxzilla, Sable Systems International), and an LI-820 analyzer (LI-COR Biogeosciences GmbH). Precision was 1.3 ppm for O2 and 0.3 ppm for CO2. Both analyzers were located in an air-conditioned hut. O2 and CO2 mole fractions were measured continuously and logged in 10-sec intervals. Chambers were measured sequentially with typical observation times of 20-45 min per chamber, i.e. long enough for the mole fractions to reach steady state and allowing for at least two full measurement cycles of all sixteen chambers per day. For data processing, a quality check routine was developed for the branch chamber measurements, where spikes and non-steady-state conditions were excluded, and finally leaf exchange fluxes were quantified.Diel, diurnal, and day-to-day variabilities were related to environmental and meteorological conditions. Further, the O2:CO2 exchange ratio on leaf-level was investigated for day- and nighttime. We could observe that the O2:CO2 exchange ratio varied stronger during nighttime than daytime and was affected mostly by the flux magnitude, the photosynthetically active radiation, and vapor pressure deficit. The exchange ratio was usually between 0.9 and 1.0 μmol μmol-1.Finally, we evaluated simulated photosynthetical O2 and CO2 fluxes of an extended version of the one-dimensional, multi-layer atmosphere-biosphere gas exchange model CANVEG based on the obtained measurements.
Continuity Constraints on the Atlantic Meridional Overturning Circulation
Authors: Fraser Neil , Fox Alan , Cunningham Stuart
Published: February 2023

In the subtropics, the Atlantic meridional overturning circulation (MOC) has the same strength and variability whether measured in depth- or density-space. Two different continuity budgets must therefore be satisfied north of the subtropics, one via diapycnal volume transport and the other via downward volume transport. However, as water can get denser without getting deeper (and vice versa), it is unclear why the integrated effect of these processes, the MOC, should have the same strength and variability in both depth- and density-space, provided one integrates these terms sufficiently far south (e.g. to 26 °N). Previous work has investigated the surface buoyancy forcing and mixing processes which drive diapycnal volume transport. Here, we use a suite of observational products and new analyses in a vorticity framework to study the magnitude and distribution of the various terms responsible for vertical volume transport, and gain further insight by also evaluating these terms using VIKING20X model output. We conclude that bottom Ekman transport and advection curl around the boundaries of the subpolar gyre, particularly around Greenland, are dominant drivers of downward vertical transport and hence crucial for closing MOC streamlines in depth-space, with much of the variability also projecting onto the MOC in density-space. As these processes are “spun-up” by the sub-polar gyre yet project onto the overturning, our results offer new insights into the coupling between the overturning and gyre circulations.
Slope instability mapping in glacier forefield environments of the Alps using standard and advanced DInSAR techniques
Authors: Jones Nina , Strozzi Tazio , Paul Frank
Published: February 2023

Global atmospheric warming and associated deglaciation effects lead to the increasing development of slope instabilities in glacier forefield environments. The primary drivers are debuttressing effects due to retreating glaciers, exposure of previously contained rock masses and thawing of permafrost. Such effects can lead to a decrease in slope stability and possible resulting failure in the generally rough and steep terrain encountered in high mountains, such as the densely populated European Alps, calling for extensive hazard analyses of such features.Within the framework of the ESA Regional Initiatives for the Alps, the AlpGlacier project analyses capabilities to monitor glaciers in the Alps from the Copernicus Sentinel satellites. The derived products are: (a) snow cover and (b) flow velocities, both on glaciers, as well as (c) pro-glacial lakes and (d) slope instabilities, both in glacier forefields. Synergies through a combination of sensors, with focus on Sentinel-1 and -2, are tested and sensor limits identified. The presented work focusses on the slope instability product. The specific challenges to detect slope instabilities are the highly variable rates of movement combined with the long-lasting presence of snow cover, requiring the application of diverse DInSAR processing approaches and a detailed visual analysis of the observed changes. We present a comparison of standard and advanced DInSAR methods using Sentinel-1 data to evaluate the possibilities and limitations to detect slope displacements in three selected study regions in the European Alps. The Mattertal region in Switzerland, Mont Blanc region in France/Italy and Ötztal Alps in Austria are characterised by steep relief, the occurrence of permafrost, dense infrastructure and known slope instabilities. All sites experience glacier retreat since the Little Ice Age that leads to the potential formation of glacier lakes and slope instabilities. Continuous Sentinel-1 acquisitions exist for each site, which are used in multiple DInSAR techniques to detect and map slope instabilities, allowing an assessment of the variability of detected surface motion and suitability of the applied methods.Results show a widespread distribution of slope instabilities moving at <2 cm/year to >30cm/year. Movements include soil and rock slides, rock falls, rock slope deformations as well as permafrost-related movements and rockglaciers. Time series extracted for exemplary movements occurring along retreating glaciers in each study region show distinct accelerations in the last 5 years that may be related to deglaciation effects. The results are validated with optical and SAR offset tracking methods.
Geochemical side effects of potential Managed Aquifer Recharge during infiltration of monovalent partial desalinated water into different dune sands
Authors: Braeunig Laura , Schloo Mareike , Burke Victoria , Greskowiak Janek , Massmann Gudrun
Published: February 2023

Managed Aquifer Recharge (MAR) with desalinated saline water is of increasing importance to mitigate groundwater overexploitation and improving its quality. Besides high energy demand, fully desalinated water needs to be post-treated to increase the total dissolved solids concentration for its further use. As a new approach, the aim of the cooperative project “innovatION” is the development of a monovalent-selective membrane capacitive deionization method to improve the ecological footprint and to deliver a purposeful removal of ions. Nonetheless, the infiltration of a water with different water chemistry than natural pore- or groundwater causes geochemical interactions between water and sediment. Here, we present first insights of geochemical water-sediment interactions during infiltration of a monovalent partial desalinated water (mPDW) into three different dune sediments from the barrier island Langeoog, Northern Germany, by conducted column experiments. The island of Langeoog was chosen as one of the demonstration sites of the project. The results of the column experiments show that ongoing processes such as cation exchange and calcite dissolution depend clearly on the sediment characteristics. The more pedogenically developed the infiltrating media is, the more complex the geochemical interactions get. Calcite dissolution takes place during infiltration into beach sediment with a higher carbonate content, whereas infiltration into decalcified brown dune sands shows accumulation/adsorption of Ca2+. Grey dune sands appear to be a suitable location for a potential MAR application on Langeoog due to less distinct geochemical reactions. Numerical investigation of the respective experiments is shown in a companion study by Schloo et al. (submitted to EGU2023). Trace element mobilization was shown to not just depend on shifting redox conditions but also on the chemical composition of the infiltrating water potentially linked to colloidal transport. Especially, As and V mobilization were periodically retained during mPDW infiltration. Nevertheless, all reactions are shown to be time limited during the experiments and unlikely to cause major problems, hence MAR with mPDW on Langeoog might be a suitable approach to secure the freshwater lens volume in future in an energy efficient way.
Technical Monitoring of Smart Storm Water Storage Systems
Authors: Dorner Wolfgang , Weber Andreas , Paudyal Rajan
Published: February 2023

The infiltration of surface water and excess water from floods requires numerous measures to prevent and avoid side effects in the groundwater. Besides all these physical measures, intensified monitoring will be necessary. As part of the project SmartSWS, a monitoring system as a set of local sensors for quantitative and qualitative parameters combined with remote sensing data from unmanned aerial systems will be developed, to monitor test installations of small stormwater storage with infiltration capacity (SmartSWS) in Southern Germany. While current monitoring strategies are based on a thinned-out network of stationary sensors, the infiltration of excess water runoff into the groundwater layer to compensate for drought effects requires dense monitoring. While local sensor installations can only provide punctual information but on a continuous basis, remote sensing data provides spatial information for time intersects. The idea of monitoring such a SmartSWS is based on sensor fusion of these spatially and temporarily covering data with a low-cost sensor network covering the industrial communication standards to allow installations in small rural catchments. The isolated location and environmental impacts of the SmartSWS require a high degree of reliability of the installed hardware in such environments. Reliable measurements are also required so that the installations can be monitored remotely, and the systems can operate autonomously most of the time. This will provide the basis for Big Data processing methods and data analytics to efficiently prepare the data for visualization to monitor the condition of the facility in real time so that interventions and the effectiveness of the concept can be shown.
Social & Physics Based Data Driven Methods for Wildfire Prediction
Authors: Lever Jake , Cheng Sibo , Arcucci Rossella
Published: February 2023

Twitter is increasingly being used as a real-time human-sensor network during natural disasters, detecting, tracking and documenting events. Current wildfire models currently largely omit social media data, representing a shortcoming in current models, as valuable and timely information is transmitted via this channel. By including this data as a real-time data source, we aim to help disaster managers make more informed, socially driven decisions, by detecting and monitoring online social media sentiment over the course of a wildfire event. This monitoring model is coupled to a real-time forecasting of wildfire dynamics.

Real-time forecasting of wildfire dynamics, which has attracted increasing attention recently in fire safety science, is extremely challenging due to the complexities of the physical models and the geographical features. Running physics-based simulations for large-scale wildfires can be computationally difficult. We propose a novel algorithm scheme, which combines reduced-order modelling (ROM), recurrent neural networks (RNN), data assimilation (DA) and error covariance tuning for real-time forecasting/monitoring of the burned area. An operating cellular automata (CA) simulator is used to compute a data-driven surrogate model for forecasting fire diffusions. A long-short-term-memory (LSTM) neural network is used to build sequence-to-sequence predictions following the simulation results projected/encoded in a reduced-order latent space. 

We implement machine learning in a wildfire prediction model, using social media and geophysical data sources with sentiment analysis to predict wildfire instances and characteristics with high accuracy. The geophysical data is satellite data provided by the Global Fire Atlas, and social data is provided by Twitter. In doing this, we perform our own data collection and analysis, comparing regional differences in online social sentiment expression.

The performance of the proposed algorithm has been tested in recent massive wildfire events in California.
Characterization of Mediterranean large-scale atmospheric circulation based on Jenkinson-Collison Weather Type classification.
Authors: Fernández-Granja Juan Antonio , Casanueva Ana , Bedia Joaquín , Brands Swen , Fernández Jesús
Published: February 2023

The evaluation of new generations of global climate models (GCMs) with respect to their large-scale circulation features is crucial for model development and has recently been brought into focus by the downscaling community, interested in the suitability of GCMs for downscaling purposes. In such evaluation experiments, additional uncertainties emerge from differences among the reference datasets used for evaluation, typically reanalyses. In this context, weather typing techniques are a useful tool for the classification of the full diversity of data into a few recurrent patterns that can serve as objective characterizations of either global or regional atmospheric circulation. A well-known weather typing classification algorithm is the Jenkinson-Collison Weather Type (JC-WT, Jenkinson and Collison 1977) approach. Although the methodology was originally developed for the British Isles (Lamb, 1972), the JC-WT approach can in principle be applied to any mid-to-high latitude region (Jones et al, 2013). Fernandez-Granja et al (2023) extended the limits of applicability from 23.5º to 80º latitude on both hemispheres, but the suitability of the method is questionable for certain seasons over some areas of the globe, such as the Mediterranean region in summer.In this study, we first explore the applicability of the JC classification over the Mediterranean by linking the JC-WTs with main northern hemisphere teleconnection indices and blocking conditions. Further, the diversity of JC-WTs and occurrence of the unclassified type are used to examine the suitability of the method. Results show that the application of the JC-WT classification is physically meaningful in large parts of the domain. Secondly, fundamental characteristics of the JC-WTs such as transition probabilities between consecutive types and persistence of the dominant JC-WTs (number of time-steps staying in the same type) obtained for five different reanalyses are compared. Important differences among reanalyses are found, especially in summer, which may bring additional uncertainties when the method is used in model evaluation experiments. References:Fernández-Granja, J. A., Brands, S., Bedia, J., et al (2023) Exploring the limits of the Jenkinson–Collison weather types classification scheme: a global assessment based on various reanalyses. Climate Dynamics. DOI: 10.1007/s00382-022-06658-7Jenkinson A., Collison F. (1977) An initial climatology of gales over the north sea. synoptic climatology branch memorandum. Meteorological Office, 62Jones P.D., Harpham C., Briffa K.R. (2013) Lamb weather types derived from reanalysis products. International Journal of Climatology 33(5):1129–1139. DOI: 10.1002/joc.3498Lamb H. (1972) British isles weather types and a register of daily sequence of circulation patterns 1861-1971. Meteorological Office, Geophysical Memoir 116:1–85
Soil N2O emissions: how much does soil structure matter?
Authors: Maillet Emile , Cousin Isabelle , Lacoste Marine , Grossel Agnes
Published: February 2023

Nitrous oxide (N2O) is a greenhouse gas almost 300 times more powerful than CO2 in terms of global warming potential, and it is also the first ozone-depleting substance emitted in the 21st century. Approximately 43% of N2O emissions are estimated to be due to anthropogenic activities worldwide, and 52% of this anthropogenic part come from cultivated soils. The main cause of anthropogenic emissions is nitrogen fertilization.The production, transfer and emission of N2O from soils are complex multifactorial processes, with a high spatial and temporal variability. Although N2O production in soils has multiple origins, the main source remains denitrification reactions during microbial respiration under anaerobic conditions. Thus, one of the major soil control factors is the availability of oxygen to soil organisms, which partly depends on the soil structure. The spatiotemporal variability of N2O emissions is explored by deterministic studies that focus either on the soil microstructure scale, i.e. the scale of N2O production and microorganism habitat, or on the macrostructure scale, to focus on fluids transfers. However, the influence of soil micro- and macrostructure studied together on N2O emissions is still poorly known, and represents the objective of this work.A multi-scale approach was adopted to better understand the determinism of N2O emissions. The spatial variability of N2O emissions at the field scale was estimated during a snap-shot campaign on the same soil type with contrasted structural states, induced by different agricultural practices (4 soil modalities crossing strip-till and tillage with compacted or uncompacted areas). 24 soil cylinders were collected in low and high N2O emission zones and were then scanned by using both X-ray macro- and micro-tomography. Quantitative morphological tools were used to describe soil structure at the macro and micro scales while simultaneously studying other soil properties influencing N2O emissions (air permeability, gas diffusivity, nitrogen, pH, soil texture, etc.). The 4 soil modalities studied showed contrasted N2O emissions along with contrasting macrostructural and gas transfer indices. The ongoing work is aimed at clarifying the relationships between multiscale soil structure, gas transfer and other soil factors on N2O emissions.
Exploring Siachen glacier thickness change over eastern Himalayas by integrating multispectral and SAR time-series dataset
Authors: Zhang Ruiyu , Jiang Mi , Li Gang
Published: February 2023

The change in ice thickness plays a primary role in measuring the glacier mass balance. Remote sensing techniques, such as optical and SAR instruments are regarded as powerful tools to monitor glacier thickness with different resolutions at a multi-scale. Despite great interesting, the temporal resolution becomes a main limitation to provide the continuous monitoring. In this paper, we for the first time integrate Sentinel-1/2 and GF-3 time-series dataset to enhance the temporal resolution. Also, the increased degrees of freedom from multi-source integration allow the full evaluation of three-dimensional glacier motion. Using data set ranging from January 2018 to December 2020, we use this methodology to explore the change in Siachen glacier thickness over the eastern Himalayas. More concretely, after estimating pixel offsets from individual sensors, the full three-dimensional flow velocity of glacier is first estimated by L1-norm minimization, followed by least-squares. The vertical velocity is then decomposed into Surface-Parallel Flow (SPF) of the glacier's movement along the glacier surface slope and non-Surface-Parallel Flow (nSPF) of the internal ice deformation and glacier thickness change. The seasonal and interannual variation of the flow velocity is also observed. We found a maximum thickness thinning velocity up to 23 cm/day in the lower middle portion of the glacier. The extracted time series demonstrate a remarkable temporal variability in flow velocities. Compared with the results estimated from the individual sensors, the integration improves the three-dimensional flow velocity by 26%, 19% and 4% in the east-west, north-south and vertical direction respectively. This study is of great significance for obtaining high temporal resolution and high accuracy glacier thickness changes using multi-source remote sensing data, and mitigating the disasters caused by glaciers.
Karst integration into groundwater recharge simulation in WaterGAP
Authors: Wan Wenhua , Döll Petra
Published: February 2023

Karst aquifers cover a significant portion of the global water supply. However, a proper representation of groundwater recharge in karst areas is completely absent in the state-of-art global hydrological models. This study, based on the new version of the global hydrological model WaterGAP, (1) presented the first modeling of diffuse groundwater recharge (GWR) in all karst regions using the global map of karstifiable rocks; and (2) adjusted the current GWR algorithm with the up-to-date databases of slope and soil. A large number of ground-based recharge estimates on 818 half degree cells including 75 in karst areas were compared to model results. GWR in karst landscapes assuming equal to the runoff from soil leads to unbiased estimation. The majority of simulated mean annual recharge ranges from 0.6 mm/yr (10th percentile) to 326.9 mm/yr (90th) in nonkarst regions, and 7.5 mm/yr (10th) to 740.2 mm/yr (90th) in karst regions. The recharge rate ranges from 2% to 66% of precipitation according to ground-based estimates in karst regions, while the simulated GWR produces global recharge fractions between 4% (10th) to 68% (90th) in karst areas while that in nonkarst areas rarely exceeds 25%. Unlike the previous studies that claimed global hydrological models consistently underestimate recharge, we observed underestimation only in the very humid regions where recharge exceeds 300 mm/yr. These very high recharge estimates are likely to include preferential flow and adopt a finer spatial and temporal scale than the global model. In karst landscapes and arid regions, we demonstrate that WaterGAP incorporating karst algorithm gives a worthy performance. 
A simplified agro-hydrological model for the computation of water fluxes and irrigation efficiency in rice areas 
Authors: Facchi Arianna , Rienzner Michele , Ottaiano Giovanni , Gilardi Giulio , Gandolfi Claudio
Published: February 2023

The main goals of agro-hydrological models are to estimate water fluxes in the soil-plant-atmosphere continuum (SPAC) and to support management and planning of the water resource over specific areas (a field, a farm, an irrigation district, a river catchment, etc.). Hydrological models are ‘physically-based’ (e.g., SWAP, HYDRUS, FLOWS) if they rely on an accurate mathematical description of processes taking place in the physical system, or are ‘conceptual’ (e.g., SWAT/SWAT+, DSSAT, IDRAGRA) when they are based on a simplified schematization of the physical system and the processes involved. The Richards’ equation (Richards, 1931), modified to include root water extraction, is applied by physically-based models to compute soil water movements, requiring the knowledge of the soil water retention, θ(h), and unsaturated conductivity, K(θ), curves, and the use of quite complex and computationally demanding numerical schemes to be solved. On the contrary, conceptual models are based on a bucket/cascade bucket approach to describe water movement into the soil.

Conceptual models are often applied for irrigation planning over large areas in a spatially distributed mode, since they require less data and a lower computational effort than physically-based models. However, when considering rice areas, the strong link between irrigation, soil characteristics and groundwater dynamics dictates the need of a rigorous way to compute soil water fluxes, from which the irrigation efficiency depends. This suggests the application of physically-based models or the development of a novel conceptual approach able to describe the effect of compacted soil layers and shallow groundwater conditions on the percolation/capillary rise dynamics.

This work presents a simplified soil water balance model for rice areas based on the Darcy equation. This approach allows the quantification of vertical fluxes based on a limited number of data that can be retrieved from existent data sources (depth and thickness of the less conductive layer within the soil profile, saturated soil hydraulic conductivity of this layer, ponding water level inside the paddy field and depth of the groundwater table). The new approach was validated comparing the water fluxes obtained with those achieved through a semi-distributed/mechanistic agro-hydrological model based on SWAP (https://www.swap.alterra.nl/) applied to a pilot rice district of about 1.000 ha in northern Italy (San Giorgio di Lomellina, Pavia).

This research was developed in the context of the MEDWATERICE (PRIMA Section2-2018) and RISWAGEST projects (Regione Lombardia, RDP 2014-20).
Major storms influence on the morphological evolution of a hybrid spit-tidal flat system in Argentina
Authors: Guisado-Pintado Emilia , Isla Manuel Fermin
Published: February 2023

Sandy coastal systems are very dynamic systems in which morphological changes occur over different time scales that ranges from hours to decades. However, it has been widely reported that major storms are the main responsible of the most significant changes in short to medium time scales. Major storms have been defined using a variety of environmental variables, but they are normally associated with high values of four main parameters: 1) Wave heights (Hs); 2) Duration (Du); or 3) Frequency (Fq); 4) Orientation (Or).In this study we aim to characterise types of major storms and to categorize morphological impacts over a hybrid coastal system. The study site, known as Punta Rasa, is located in the Samborombón bay in the outer part of the Río de La Plata estuary (Argentina) and corresponds to a zone of interaction between a large sandy spit and a backwash tidal flat system. Methods used combine statistical analysis of wave climate time-series, analysis of wave energy patterns through nearshore numerical modelling (SWAN) and comparison of pre- and post-storm morphological changes using satellite images derived indexes (e.g. NDWI).Results allowed to characterise four types of major storms impacting the study area: High-Energy Storms (HES), defined by an average storm Hs below the 1% exceedance (> 2.6 m), Long-Lived Storms (LLS) represented by an exceedance of the 1% of Du (> 60 hours), Storm Groups (SG) in which storm frequency is less than 6 days and Northeastern moderate storms (NMS) defined by their eastern, onshore oriented direction. Under HES and NSM storms erosional areas are dominant over depositional (62.34%), which most of the system showing shoreline retreat and a growth of the end spit area. For LLS and SG storms the morphological impact varies alongshore with a general flattens of the end spit (showing a ‘rounded-shape’ morphology) and erosional hotspots over the southeastern coastal section.
SOC sequestration affected by fertilization in rice-based cropping systems over the last four decades
Authors: Wang Shuhui , Sun Nan , Liang Shuo , Zhang Shuxiang , Meersmans Jeroen , Colinet Gilles , Xu Minggang , Wu Lianhai
Published: February 2023

Enhancing soil organic carbon (SOC) stocks through fertilization and crop rotation will contribute to sustaining crop productivity and mitigating global warming. Although it is known that cropping systems may affect SOC stocks by influencing the balance between C input and C decomposition, only few studies focused on the impact of different rice cropping systems on SOC stock changes in paddy soils. In this study, we analyzed the differences in SOC stocks and their driving factors in the topsoil (0–20 cm) with various fertilization measures in two rice-based cropping systems (i.e. rice-wheat rotation and double rice rotation systems) over the last four decades from seven long-term experiments in the Yangtze River catchment. The treatments include no fertilizer application (CK), application of chemical nitrogen, phosphorus and potassium fertilizers (NPK) and a combination of NPK and manure (NPKM). Results showed that during the last four decades, the topsoil SOC stock significantly increased by 8.6 t ha-1 on average under NPKM treatment in rice-wheat system and by 2.5–6.4 t ha-1 on average under NPK and NPKM treatments in double rice system as compared with CK. A higher SOC sequestration rate and a longer SOC sequestration duration were found in NPKM treatment than that in NPK treatment in both cropping systems. The highest relative SOC stock percentage (SOC stock in fertilized treatments to CK) was observed under the NPKM treatment in both cropping systems, though no significant difference was found between these two cropping systems. However, the fertilization-induced relative increase of the SOC stock was 109.5% and 45.8% under the NPK and NPKM treatments, respectively in the rice-wheat system than that in the double rice system. This indicates that the rice-wheat system is more conducive for SOC sequestration. RF and SEM analyses revealed that the magnitude and influencing factors driving SOC sequestration varied between two systems. In the double rice system, continuous flooding weakens the influence of precipitation on SOC sequestration and highlights the importance of soil properties and C input. In contrast, soil properties, C input and climate factors all have important impacts on SOC sequestration in rice-wheat system. This study reveals that the rice-wheat system is more favorable for SOC sequestration despite its lower C input compared to the double rice system in China’s paddies.
Probabilistic climate emulation with physics-constrained Gaussian processes
Authors: Bouabid Shahine , Sejdinovic Dino , Watson-Parris Duncan
Published: February 2023

Emulators, or reduced complexity climate models, are surrogate Earth system models that produce projections of key climate quantities with minimal computational resources. Using time-series modeling or more advanced machine learning techniques, statistically-driven emulators have emerged as a promising venue, producing spatially resolved climate responses that are visually indistinguishable from state-of-the-art Earth system models. Yet, their lack of physical interpretability limits their wider adoption. In fact, the exploration of future emission scenarios still relies on one-dimensional energy balance models which can lack the flexibility to capture certain climate responses.Here, we propose a statistically-driven emulator that hinges on an energy balance model. Using Gaussian processes, we formulate an emulator of temperature response that exactly satisfies the physical thermal response equations of an energy balance model. The result is an emulator that (1) enjoys the flexibility of statistical machine learning models and can be fitted against observations to produce spatially-resolved predictions (2) has physically-interpretable parameters that can be used to make inference about the climate system. This model shows skilfull prediction of annual mean global distribution of temperature, even over scenarios outside the range of observed emissions of greenhouse gases and aerosols during training — improvement in RMSE of 27% against the energy balance model and of 60% against a physics-free machine learning model. In addition, the Bayesian nature of our formulation provides a principled way to perform uncertainty quantification on the predictions.We outline how the probabilistic nature of this emulator makes it a natural candidate for detection and attribution studies and discuss extension to a precipitation emulator also incorporating physical constraints. We hope that by combining the ability of machine learning techniques to capture complex patterns with the interpretability of energy balance models, our work will produce a reliable tool for efficiently and accurately exploring future climates.
PARATUS case-study Bucharest. A new seismic risk assessment model.
Authors: Toma-Danila Dragos , Armas Iuliana
Published: February 2023

Bucharest can be considered Europe's most endangered capitals due to earthquakes. Intermediate-depth events occurring in the Vrancea Area, with magnitudes greater than 7, can significantly affect Bucharest. In the XXth century, the city experienced two major damaging earthquakes: in 1940 and 1977. But lessons were not fully learned. The number of vulnerable buildings is highly considerable: over 30% are built before 1963 (of which 22%, before 1941). The increased complexity of our society and new challenges among which climate change, pandemics and globalization are new problems to address. In this context, multi-hazard and multi-risk analyses are more than ever necessary.If the 1977 earthquake generated numerous research with the aim of quantifying the vulnerability of the building stock and improving seismic design, social vulnerability to seismic risk was addressed only after 2000 by the Risk Research Center, University of Bucharest, based on a repeated spatial vulnerability assessment at city-level. Applying the additive approach of the multi-criteria and decision-making analysis in GIS, the spatial social vulnerability was identified by indicators of social and economic metrics, among which social capital and inequality, distance analysis, and on empirical taxonomies: gender, age, social status, ethnicity, type of housing, etc., based on 1992, 2002 and 2011 census data. Calibrating results using remote sensing and social surveys, helped identify vulnerable hotspots and the dynamic of social differences at city level.  Superimposed on these detailed vulnerability maps for Bucharest based on computed vulnerability indices, a critical decision-making tool for safe access routes in the emergency intervention was developed supported by large sets of traffic and network data, time-dependent analysis, and seismic loss-estimations. This tool, called Network-Risk, uses a state-of-the-art network analysis methodology embedded in GIS, with the potential of integrating live traffic data.All these topics will be continued in the recently started PARATUS European Project, where Bucharest is a case-study area. In our presentation, we talk about the new data and procedures that we consider for seismic risk assessment (among which new exposure data from a recent census or retrieved from remote sensing missions using deep learning, new data collecting procedures, vulnerability models and city-scale ShakeMap development) and which are the challenges – especially in the nowadays context.
Identifying tipping points and threshold values for ecosystem functioning in northern peatlands during the climate crisis (PEATFLAMES)
Authors: Andrews Luke , Słowiński Michał , Roberts Harry , Marcisz Katarzyna , Kołaczek Piotr , Halaś Agnieszka , Łuców Dominika , Lamentowicz Mariusz
Published: February 2023

Peatlands are globally important carbon sinks and stores. Climate change threatens to alter carbon cycling in some regions of the Northern Hemisphere, causing them to become net sources of atmospheric carbon, exerting a positive feedback upon global climate. Furthermore, enhanced drying, increased human activity and vegetation succession in response to a warming climate have increased the frequency of wildfires in some peat-bearing regions, including areas underlain by permafrost. Such events can cause thousands of years’ worth of formerly stable carbon to be rapidly released into the atmosphere, imparting further climate warming. The future response of peatlands to climate warming and wildfire remains uncertain, and as a result peatlands are rarely included in Earth System Models, despite their importance in the global carbon system. Understanding how changes in climate and anthropogenic activity in the past affected peatland ecosystem functioning will improve our understanding of how these sensitive ecosystems may respond to future projected changes and thus reduce this uncertainty. Our project aims to assess how warming, drought and wildfire have impacted the resilience of peatlands and permafrost in the Northern Hemisphere over the past c. 2000 years. Several peat cores spanning a latitudinal gradient covering several regions including Russia, Poland, the Baltic states and Scandinavia will be analysed using multiple palaeoecological proxies at high resolution to reconstruct past changes in wildfire frequency, hydrology and vegetation. This will allow us to define baselines and threshold values for ecosystem shifts relevant to future projected changes in climate. 
The effect of Nature Based Willow system deployment at a catchment scale for flood control
Authors: Sarkar Basu Arunima , Gill Laurence
Published: February 2023

Extreme hydro-meteorological events have caused massive devastations in European territories. The rising frequency and severity of hydro-meteorological events such as floods appear to be associated with climate change and land cover change. Flooding can be broadly classified into three types, fluvial flooding, pluvial flooding and coastal flooding. Fluvial flooding occurs when rivers and streams break their banks and water flows out onto the adjacent low-lying areas (the natural floodplains). Many factors are responsible in understanding the impact of rainfall events to fluvial flooding. The factors are size and slope of catchment, permeability of the soil, urbanization and soil compaction, presence of dams upstream to the floodplain and degree to which water can be stored in the dam and the rate of water release.Pluvial flooding occurs when the amount of precipitation received exceeds the capacity of storm water drainage systems or the capacity of ground to absorb it.Due to urbanization process, the surface cover of the land alters leading to increasing impervious areas and decreasing infiltration of the soilThe main focus of the research is to understand the effect of willow plantation at a catchment scale for improving pervious areas for flood control. Willow plants have shown high rate of evapotranspiration and improved infiltration. Willow based systems are used to understand the improvement in the rate of evapotranspiration and infiltration in the presence of appropriate climate and representative soil conditions in Ireland.The willow systems are being monitored in the western, eastern and northern catchments in Ireland which are regulating the evapotranspiration and also the rate of infiltration at a catchment scale. A statistical rainfall runoff model has been deployed to understand the rainfall-runoff relationship. The evapotranspiration has been estimated based on the Penman–Monteith equation, which requires values of mean temperature, wind speed, relative humidity and solar radiation at daily scale. An inter-comparison for rainfall-runoff relationship is made for estimating the percentage change for improvement in runoff in the presence and absence of the willow plantations.