bluuebunny/crossref_metadata_2025 huggingface dataset:
Perennial crops increase soil carbon stocks in the topsoil compared to annuals by modifying enzymatic activities
Authors: Zong Mingming , Abalos Diego , Chen Ji , Liang Zhi , Elsgaard Lars , Jørgensen Uffe
Published: February 2023

Perennial crops can be as a sustainable alternative to annual crops owing to plant traits and management practices that improve productivity and may contribute to soil carbon (C) accumulation. However, our understanding of the mechanisms behind the potential differences in C stocks between perennials and annuals is incomplete, especially in terms of how the changers and drivers vary at different soil depths. Based on a 10-year cropping experiment in Denmark with perennials (tall fescue, grass-legume mixture) and annuals (triticale monoculture, triticale in a crop rotation), we investigated soil C stock changes and driving mechanisms at depths of 0-20 cm (topsoil) and 20-50 cm (subsoil). We observed that tall fescue and grass-legume mixture systems increased soil C stock by 6-20% in the topsoil as compared to annual crops. In the subsoil, the tall fescue system even enhanced soil C storage by up to 56%, but there was no difference in soil C stock between grass-legume mixture, triticale, and triticale in a rotation. Most importantly, we found that the major determinants of soil C stock depended on soil depth. In the topsoil, enzymes exerted a dominant effect on soil C stock. Perennials with low C/N for aboveground biomass and high root biomass seemed to depress oxidase (phenol oxidase and peroxidase) activities and stimulated the nutrient-acquiring enzymes (leucine amino peptidase, β-1,4-N-acetylglucosaminidase), thus depressing the decomposition of recalcitrant C and maintaining plant growth, which facilitated soil C storage. In the subsoil, microbial biomass, rather than the balance between functional enzymes, seemed to be controlling the soil C storage. In their entirety, our results highlight that it is feasible to enhance soil C storage in systems with perennials with higher aboveground biomass quality and root biomass. Furthermore, there is a link to biological drivers (i.e., extracellular enzyme activity and microbial biomass), which may play a differential role in topsoil and subsoil. With improved mechanistic understanding, such biological drivers of soil C stock for agricultural systems should be considered in Earth system models to improve the accuracy of predicting agricultural soil C dynamics.
Fluid Dynamics of the São Jorge Channel, Azores Plateau – First results of RV Meteor expedition M18
Authors: Schmidt Christopher , Zitoun Rebecca , Lever Mark A. , Schindlbeck-Belo Julie , Warwel Arne , Ramalho Sofia , Kaul Norbert , Klein Johanna , Adão Helena , Dillon Wayne , Schenk Johanna , Hübscher Christian , Terrinha Pedro , Hensen Christian
Published: February 2023

Young oceanic plateaus are important for fluid exchange between the lithosphere and the ocean. Increased heat fluxes can lead to a large-scale upwelling of fluids that play a role in global elemental cycles. In addition, variations in fluid chemistries can potentially influence the biomass and species compositions of microbial and benthic communities in sediments exposed to subsurface fluid flow. Yet, the present understanding of these young oceanic plateaus in terms of their fluid dynamics and their biogeochemical local and global impacts is limited. The goal of RV Meteor Expedition M186 in December 2022 was to investigate how subsurface fluids on the young Azores Plateau, Central North Atlantic, vary with respect to their flow rates, chemical compositions, and the prevalent on microbial and benthic communities at and below the seafloor. First data from the São Jorge Channel (Azores Plateau) show that fluid dynamics here are diffuse rather than focused, and that fluid chemical compositions nonetheless show strong local variations, over a small spatial scale of 65 km2, that could be related to differences in fluid origins and fluid flow paths. However, the connection of fluid conduits, heat flow data and biogeochemical data as well as their relation to faults visible in seismic data are rather complex. Our first results thus indicate that diffuse fluid flow on young oceanic plateaus is highly heterogeneous despite occurring over large sediment-covered areas. Thus, the role of fluids at young oceanic plateaus as an important intermediate between the lithosphere and the ocean cannot be generalized over large spatial and possibly temporal scales.
Evaluating the seismic activity of the Adriatic Sea region
Authors: Barbara Orecchio , Presti Debora , Scolaro Silvia , Totaro Cristina
Published: February 2023

The seismic activity occurred in the last decades in the Adriatic Sea region has been investigated by means of new hypocenter locations, waveform inversion focal mechanisms and seismogenic stress fields. After a preliminary evaluation of seismic distribution, the Bayloc non-linear probabilistic algorithm has been used to compute hypocenter locations for the most relevant seismic sequences and to carefully evaluate location quality and seismolineaments reliability. We also provided an updated database of waveform inversion focal mechanisms integrating data available from official catalogs with original solutions we properly estimated by applying the waveform inversion method Cut And Paste. This database has been used to compute seismogenic stress fields through different inversion algorithms. The seismic activity, mainly concentrated in the Central Adriatic region, indicates high fragmentation and different patterns of deformation. In particular, our results highlighted the presence of two NW-SE oriented, adjacent volumes: (i) the northeastern one, characterized by pure compressive domain with NNE-trending axis of maximum compression, and mainly W-to-NW oriented seismic sources; (ii) the southwestern one, characterized by a transpressive domain with NW-trending axis of maximum compression, where thrust faulting preferentially occurs on ENE-to-NE oriented planes and strike-slip faulting on E-W ones. We jointly evaluated seismic findings of the present study and kinematic models proposed in the literature for the Central Adriatic region. The present analysis, furnishing new seismological results provide additional constraints useful for better understanding and modeling the seismotectonic processes occurring in the Adriatic Sea region.
A naturally circular fibre: Sheep wool as a tool for assessing human and environmental exposure
Authors: Bortolu Sara , Azara Emanuela , Duce Pierpaolo
Published: February 2023

In the context of the Circular Economy, the enhancement of raw wool in new bioproducts represents an important challenge. Wool is the main by-product of sheep, although its production has decreased largely during the last decades. In addition, wools with coarse fiber diameter have little economic value since they are not adequate to be used in the textile sector and, when not transformed, wool needs to be treated as a special waste.Wool is by its nature a circular fiber. Due to its complex chemical composition, physical structure and mechanical properties, it represents a biodegradable renewable resource and can find various value-added applications beyond the textile industry. The technological characteristics make wool particularly suitable for different applications such as thermo-acoustic insulation, agricultural amendment, biomedical polymers, etc.Furthermore, it absorbs harmful pollutants, becoming a specific chemical indicator. In fact, it has been shown that wool fibers are good bio-indicators of the environmental status (soil, water and air pollution). The concentration of pollutants reflects either the feed and nutrition quality and the general health status of sheep as well as the climatic and environmental conditions. The sustainable and innovative alternative uses of this livestock waste could reduce and minimise keratinous waste disposal, reduce environmental impact and increase commercial process sustainability and circular economy.The aim of this research was to investigate the degree of contamination of Sarda sheep wool to understand if wool fiber can be a contamination source for both the environment and human health.Chemical analyses were carried out through Liquid chromatography Orbitrap mass spectrometry and Inductively coupled plasma mass spectrometry. Both analytical techniques were targeted for a wide range of micropollutants including pesticides, veterinary drugs and heavy metals. The results obtained in this study represent the first step for developing a new wool valorization chain.Wool analysis can be an important strategy for the biomonitoring of human exposure to pesticides and for evaluating the quality of wool-based products.
Late Quaternary climate variability in Madagascar and its connection to South-East Africa hydroclimate changes and atmospheric circulation patterns
Authors: Norström Elin , Smittenberg Rienk , Ekblom Anneli , Haberle Simon , Katrantsiotis Christos
Published: February 2023

Madagascar is characterized by high climatic heterogeneity and its topography plays a key role in modulating the regional hydroclimate variability in South and East Africa. However, knowledge on past climate of Madagascar very limited, in line with the general scarcity of paleoclimate records from the southern tropics and subtropics. We generated a 26 kyr paleoclimate record from Madagascar, located in the southwestern Indian Ocean spanning the Last Glacial Maximum (LGM) to the late Holocene. In particular, we present a deuterium/hydrogen isotopic ratio of terrestrial leaf waxes (δ2Hwax) from a sediment core taken from the central eastern part of the island near the capital Antananarivo. The δ2H records of both the aquatic and terrestrial plant derived n-alkanes exhibit similar long-term trends implying that they all record changes in the isotopic composition of source water, namely meteoric water that recharges soil and lake waters. In this tropical region, the δ2H variability of precipitation recorded by n-alkanes δ2H is mainly influenced by the amount effect resulting in lower values for periods with high rainfall. We observe five long-term trends: (i) stable and relatively dry conditions during the Last Glacial Maximum (LGM) (ii) gradually wetter conditions from 17.5 ka to 11.5 ka, especially during the Heinrich stadial 1 (HS1) and the Younger Dryas (YD) (iii) an arid interval from 11.5 ka to 8.5 ka, and (iv) a general trend to more humid climate until 3.0 ka, followed by (v) a drier interval until 1.0 ka. The Madagascar climatic signal is opposite to other records from South Africa and East Africa records especially during the YD and early to middle Holocene period. This regional dipole mode is consistent with the modern rainfall anomaly pattern associated with the variability of Mozambique Channel Trough and the migration of austral summer Intertropical Convergence Zone (ITCZ) position as a response to changes in local summer insolation orbital and/or Northern Hemisphere cold events, such as the YD and HS1.
Glacier decay boosts formation of new Arctic coastal environments – lessons learned from Svalbard
Authors: Kavan Jan , Strzelecki Mateusz
Published: February 2023

The consequences of accelerating climatic warming on Arctic landscape evolution are far-reaching. In Svalbard, glaciers are rapidly retreating after the Little Ice Age, which leads to exposing new coastal landscapes from marine-terminating glaciers. Precise quantification of these changes was limited until the complete dataset of Svalbard glacier outlines from 1930’s was made available. Here, we analyse the new Svalbard glacier change inventory data and demonstrate that glacier retreat was responsible for a major shift from marine-terminating towards land-terminating glaciers in the last century. This retreat also led to the formation of 922.9 km of new coastline since 1930’s (representing increase of 16.37% in coastline length) creating pristine landscapes governed by paraglacial processes and sediment-rich nearshore fjord environments. Recent palaeogeographical reconstructions suggest that such a mode of coastal evolution was dominant over the extended periods of the Holocene. Transitions from marine-terminating to land-based glaciers had significant implications for fjord circulation, biological production, state of marine ecosystems, biogeochemical cycles between land and seas, and CO2 budget in coastal waters. Still ongoing climate warming with associated further glacier retreat may lead to more coasts to be exposed in the future. Moreover, glacier retreat will likely cause collapse of Hornbreen-Hambergbreen glacier bridge leading to separation of Sørkappland and rest of Spitsbergen with severe consequences for regional ocean circulation and climate dynamics.New bays, new straits, new peninsulas and new islands, that have appeared in the last decades of unprecedented warming and associated decay of marine-terminating glaciers in the Arctic are predominantely uncharted and unexplored territories which foreshadow ice-free Arctic and other cold regions of the warmer future. The importance of transdisciplinary research exploring those deglaciated oases has never been more important than at present.Acknowledgement: The research leading to these results has received funding from the Norwegian Financial Mechanism  2014-2021: SVELTA - Svalbard Delta Systems Under Warming Climate (UMO-2020/37/K/ST10/02852) based at the University of Wroclaw.
Nitrogen losses from food production in the North China Plain compared to environmental targets
Authors: Meng Fanlei , Wang Mengru , Ronda Reinder , Strokal Maryna , Kroeze Carolien , Ma Lin , Xu Wen , Zhang Fusuo
Published: February 2023

North China Plain (NCP) is a region in China, with highly intensive food production and a hotspot of nitrogen (N) losses to the environment. Region-specific N management is, therefore, required to effectively reduce agricultural N losses. For this it is important to identify the N flows and environmental targets in the food chain (including crop production, animal production, food processing, and human consumption) at the county scale. We developed an integrated assessment N framework. It combines a food chain approach with an air quality model and groundwater model. We apply this method to quantify the relative contributions from parts of the food chain to N losses. We identify environmental targets to air and water in Quzhou, a typical agricultural county in the NCP. We found that N losses to the environment from the food chain were ~11 kt  in Quzhou in 2017. Approximately 80% of this amount is from crop and animal production, which is primarily caused by the low N use efficiency in crop production (28%) and animal production (18%). Ammonia (NH3) emissions to air (4.1 kt N) and N leaching (2.1 kt N), and direct discharges of manure to water (1.9 kt N) are the main contributors to the N losses in Quzhou. To meet the environmental targets for air quality (PM2.5) and groundwater quality, the NH3 emissions and N leaching need to be reduced by 55%, and 21-50%, respectively. Our findings indicate that better nutrient management is urgently needed to reduce agricultural N losses and to support Agriculture Green Development in NCP.
Quantifying the impact of 3D pore space morphology on diffusive mass transport in loam and sand
Authors: Weber Matthias , Prifling Benedikt , Ray Nadja , Prechtel Alexander , Phalempin Maxime , Schlüter Steffen , Vetterlein Doris , Schmidt Volker
Published: February 2023

Effective diffusion is an important macroscopic property for assessing mass transport in porous media. Numerical computations on segmented 3D CT images yield precise estimates for diffusive properties. On the other hand, geometrical characteristics of pore space like, e.g., porosity, specific surface area and further transport-related descriptors can be easily computed from 3D CT images and are closely linked to diffusion processes. In the present contribution, we consider six different soil samples of loam and sand, whose 3D microstructure is quantitatively investigated using univariate as well as bivariate distributions of geometrical descriptors of pore space. This information is used for investigating microstructure-property relationships by means of empirically derived regression formulas, where a particular focus is put on the differences between loam and sand samples. In this way, it is possible to obtain a deeper understanding for the relationship between the 3D microstructure of the pore space and the resulting diffusive properties due to the analytical nature of the prediction formulas. In particular, it is shown that formulas existing so far in the literature for predicting soil gas diffusion can be significantly improved by incorporating further geometrical descriptors such as geodesic tortuosity, chord length distribution or constrictivity. The robustness of these formulas is investigated by fitting the regression parameters on different data sets as well as by applying the empirically derived formulas to certain data that is not used for fitting. Among others, it turns out that a prediction formula based on porosity as well as mean and standard deviation of geodesic tortuosity performs best with regard to the coefficient of determination and the mean absolute percentage error. Moreover, it is shown that with regard to the prediction of diffusive properties the concept of geodesic tortuosity is superior to geometric tortuosity, where the latter is based on the skeleton of the pore space. 
Constraining land surface CO2 fluxes by ecosystem and atmospheric observations using atmospheric transport
Authors: Upton Samuel , Peters Wouter , Reichstein Markus , Botia Santiago , Gans Fabian , Kraft Basil , Bastos Ana
Published: February 2023

The growth rate of atmospheric CO2 mole fractions can be measured with high accuracy, but there are still large uncertainties in our ability to separate anthropogenic and natural sources and sinks. One major source of uncertainty is the net flux of carbon from the biosphere to the atmosphere, or Net Ecosystem Exchange (NEE). There are two major approaches to quantifying NEE; top-down approaches that typically use atmospheric inversions, and bottom-up estimates using process-based or data-driven terrestrial biosphere models, upscaled to the regional or global scale. Both approaches have known limitations. A system that harmonizes these approaches, providing a high-quality estimate of the spatial distribution of NEE, and an accurate integral of NEE at regional and global scales, would improve our ability to model the full carbon budget. With other component fluxes, a harmonized product could help improve our monitoring of regional and national greenhouse gas budgets, and thus verify the trajectory towards CO2 emission goals.This study builds upon our previous work that connected the bottom-up eddy-covariance model to top-down estimates of regional NEE from atmospheric inversions using fixed regional linear oper-ators. That work demonstrated that top-down estimates of atmospheric CO2 provide an important additional constraint to a data-driven bottom up model. The use of top-down constraints improved the regional and global upscaling of NEE, leveraging the strengths of the two different approaches. However, the previous work had a simplified computational link between the top-down and bottom-up fluxes of NEE, and did not access the very large volume of atmospheric observations of atmospheric CO2. Here, we replace the regional atmospheric inversion estimates of NEE with direct observations of the atmospheric mole fractions of CO2. The fixed regional linear operators are replaced by estimating the near-field sources of an observation using an atmospheric transport model. For training, the bottom-up model is run for the source locations. We apply this technique to observations from to tropical, extra-tropical and boreal tall-tower sites over different meteorological conditions where we infer NEE from the observed atmospheric mole fraction, corrected for CO2 background and non-biogenic CO2 fluxes. This inference is combined in the objective function with tower-level inferences, and directly used to update the bottom-up model. The model can ‘see’ more varied inputs in the dynamic footprints, and the size of our pool of training data is increased. The new process improves our ability to accurately infer the regional and global distribution of NEE by directly learning across spatial scales, using diverse observations of CO2.
The Modernity of Emergency Administration
Authors: Macchia Marco
Published: February 2023

What are the characteristics of emergency organisation? Emergency-generating events are extraordinary occurrences that do not fall under the general provisions of the administrative order, the resolution of which requires an ad hoc derogation from the existing order. Although it is not possible to make an exhaustive list of the events capable of generating an emergency, given also the variability of the historical and factual framework of reference, the different and heterogeneous origins of potential emergencies activate a reaction of the order that tends to be uniform. The reaction is the disruption of the order through suspension, which translates into a momentary freezing of the effectiveness of rules and principles, or exemption.Emergency must be distinguished from risk. While risk is inherent in the predictability of the event, which can be regulated by law insofar as it is referable to a general and abstract case, the emergency is configured as an unforeseen and unforeseeable situation that is normally not explicitly regulated by the law in force and that must be dealt with as an exception to the system of legally recognised values. The administrative organisation must know how to plan for possible emergencies in order to prevent them, or mitigate their possible effects, by working on the level of prevention. This requires experts. The lack of preventive planning in many sectors forces us to focus on emergency planning itself, which is not aimed at avoiding the emergency but, where it has already occurred, at responding in the most appropriate way. The civil protection plan must, in fact, identify the tasks and responsibilities of administrations, expert structures and organisations with regard to the activation of specific actions in the event of impending danger or emergency, ensuring clarity with regard to the chain of command. It must then define the human resources, materials and means necessary to deal with possible emergencies, thus planning upstream the available equipment.Downstream from the planning, the need for coordination of management competences between administrations emerges when the serious and extraordinary situation has already occurred. The competences inherent in the emergency change at the moment when the expected event materialises, thus creating a real dichotomy between the subject in charge of avoiding or reducing the severity of the emergency before it happens and the subject that materially deals with the emergency now in progress. In order to achieve specific objectives or for particular and temporary needs of operational coordination between administrations, commissioners perform extraordinary functions by managing large public resources. In short, emergency organisation has the most modern characteristics. It must be able to deviate from the system while respecting certain essential elements. It must be able to foresee risks and plan how to deal with emergencies. Finally, it is a mission administration that challenges complexity by coordinating a plurality of management skills. 
Updating vegetation information in a land surface model
Authors: Ruiz-Vásquez Melissa , Oh Sungmin , Brenning Alexander , Balsamo Gianpaolo , Boussetta Souhail , Arduini Gabriele , Reichstein Markus , Orth René
Published: February 2023

Vegetation plays a fundamental role in modulating the exchange of water, energy, and carbon fluxes between the land and the atmosphere. These exchanges are modelled with Land Surface Models (LSMs) which are part of numerical weather prediction systems to support the performance of weather forecasts. However, most current LSMs only utilise observed vegetation information in the form of mean seasonal cycles. The potential benefits of additionally including information about shorter-term vegetation anomalies and inter-annual variability are understudied.In this study, we update vegetation information in the HTESSEL (Hydrology Tiled ECMWF Scheme for Surface Exchanges over Land) model and investigate the resulting effects on the performance of simulated shallow and deep soil moisture as well as latent heat flux. The updated information includes an interactive observation-based leaf area index from Sentinel-3 and THEA GEOV2, and a land use/land cover map from ESA-CCI. The resulting simulations of soil moisture and latent heat flux are validated against global gridded observation-based datasets.Results show that the updated land surface information deteriorates the overall model performance for both latent heat flux and soil moisture in most regions across the globe. In a second step, we re-calibrate soil and vegetation-related parameters at each grid cell in order to adjust them to the new vegetation information. This leads to improved model performance and illustrates the benefits of updated vegetation information. Morover, we attribute the spatial variations of parameter perturbations resulting from the re-calibration to multiple land surface and climate characteristics. This highlights potential venues in model development to take static ecological and hydroclimatological information into greater consideration.Furthermore we compare the performances of local model calibration - performed for each grid cell individually - and global model calibration considering a single parameter set for all grid cells globally. We analyse the agreement of parameter calibrations obtained for shallow and deep soil moisture as well as latent heat flux.In summary, our results highlight that Earth-observation products of vegetation dynamics and land cover changes can improve land surface model performances, which in turn can contribute to more accurate weather forecasts.
Impact of deforestation on catchment hydrology and nitrogen losses
Authors: Chen Mufeng , Lausch Angela , Jomaa Seifeddine , Ghaffar Salman , Beudert Burkhard , Rode Michael
Published: February 2023

Forest status in natural catchment is substantially important for hydrology and water quality, but it has been increasingly altered by human activities and climatic factors. Due to recent rapid changes in forest cover, there is an urgent need for hydrological water quality models which can adapt to these changing environmental conditions. The objective of this study was to analyse the impact of rapid continuous forest decline on nitrogen losses in a temperate mountain range catchment using a dynamic setting of the HYPE (HYdrological Predictions for the Environment) model. The modified model was applied to the Große Ohe catchment, Germany, which has experienced severe forest dieback (caused by bark beetle infestations) and its recovery over the last three decades. The model was validated by using also additional 25 years data from an internal gauge station (Forellenbach) and two soil measurement sites. Three scenarios, namely, no forest change, deforestation with subsequent regeneration, and deforestation without regeneration, were compared to identify key factors influencing catchment discharge and nitrogen export due to deforestation and regeneration. Results showed that the model performed well at the Große Ohe catchment scale, with Nash-Sutcliffe Efficiency values of 0.77 and 0.57 for discharge and IN concentration, respectively, and percentage BIAS values of -11.6% and 0.5%, respectively, during the validation period. Similar good performances were also observed at other scales. The simulation results proved that the improved model was able to (1) well capture the timing of peak flows and the seasonal dynamics of inorganic nitrogen (IN) concentration, and more importantly, (2) reflect the first increasing and then decreasing trend of discharge and IN concentration, in accordance with the deforestation and forest regeneration, respectively. By comparing scenarios, after experienced forest dieback without regeneration, the discharge and IN concentration exports were 24.9% and 160%, respectively, greater than those of scenario without forest change. However, the discharge and IN concentration exports were only 3.63% and 39.6% greater, respectively, with the help of continuous regeneration, indicating that forest regeneration is important for restoring hydrological and water quality status in the catchment. Compared to non-change scenario, the deforestation scenario exhibited decreased annual plant uptake of 34.7%, and strong increase in annual denitrification and N mineralization suggesting that the increased nitrogen export was likely induced by the reduction in vegetation uptake and the increased availability of soil nitrogen from tree residues. Overall, the adapted mechanistic modelling under the changing catchment forest conditions can strongly support forest management in terms of water quality.
Estimating Fracture Network Damage After a Subsurface Detonation Using Geogenic Noble Gases.
Authors: Gardner W. Payton , Bauer Stephen J.
Published: February 2023

Noble gas release can be used to investigate the timing, location and magnitude of fracture creation.  Here, a numerical model of gas release and transport, resulting from fracturing events, is used to estimate first-order fracture network characteristics after subsurface detonation.  Released radiogenic noble gases after detonation of three different subsurface explosions of varying source characteristics were interpreted.  A broad suite of gases was sampled from 62 discrete sampling intervals in a 3-D array surrounding the explosion location using an automated field sampling system and a capillary inlet quadrupole mass spectrometer.  Gases analyzed include: 4He, 36,40Ar, 20Ne, N2, O2, NO and CO2/N2O.  Geogenic gas arrivals were observed in a subset of sampling locations.  All geogenic gas arrivals were observed in ports with explosive-derived gas arrivals.  Helium amount and arrival time were used to estimate fracture network damage using a numerical model which allows dynamic changes in fracture aperture, matrix porosity and permeability.  The amount of fracture damage was significantly different between the three different explosions and consistent with other observations of damage.  These results illustrate how geogenic noble gases can be used to understand damage, transport, and fracture creation in fracture networks, with implications for a variety of subsurface topics including hydraulic fracking, mine failure, earthquake and volcanic monitoring.
Coupled hydrothermal modelling of subsurface heating in the vicinity of high-power power cables under natural conditions
Authors: Durner Wolfgang , Simunek Jirka , Iden Sascha
Published: February 2023

In Germany, electricity from the wind power plants in the north must be transported to the south. This is done via underground cables that act as a heat source. We numerically simulated the coupled heating and drying by the cables in the bedding and the surrounding soil under natural boundary conditions. For this purpose, we used a modified version of the Hydrus-2D/3D software code, which enables the coupled modelling of water, vapour and heat flow. The water transport is described with the Richards equation. For heat transport, the processes of heat conduction, convective heat transport and the transport of latent heat are considered. The simulations were carried out in a 2D depth profile oriented orthogonally to the main direction of the cables. The simulations were carried out under atmospheric boundary conditions for the period 2016-2018, the latter being one of the driest years in Germany in recent history.  We found that warming leads to thermal vapour fluxes that are directed away from the cable, which can significantly reduce the water content of the material near the cable. The lowering of the soil water content reduces the thermal conductivity of the soil and can therefore lead to overheating of the cable with the risk of technical failure. However, the simulations indicate that even under the conditions of 2018, overheating of the cables is unlikely if the bedding material has sufficient thermal conductivity and the spacing between the individual cables is chosen wisely. Crucial for adequate modelling of the water and heat flow was the correct representation of the water retention curve in the dry soil, as the water head in the soil near the cable reaches values down to -105 J kg-1 and soil thermal conductivity changes rapidly at low water contents.
Reclamation of Saline and Sodic Soil: Effect of Irrigation Water Quality and Gypsum application form
Authors: Solomon Rashika , Arye Gilboa
Published: February 2023

Soil salinization has a detrimental effect on plant growth and contributes to agricultural land degradation. The ionic composition of the soil is a significant indicator of soil health. The soluble and exchangeable cation affects the physio-chemical properties of the soil, which in turn determine the suitability of the soil for agricultural use. Currently, soil salinization is one of the major threats to the agricultural productivity of arable lands in many regions of the world. The soils in arid and semi-arid regions having low precipitation and high evaporation rates, like the Negev Desert in Israel, are especially prone to high salinization. Due to the scarcity of fresh water, marginal irrigation water sources such as brackish water in conjunction with surface or subsurface drip irrigation are used extensively in these regions. In the long term, such practices are unsustainable, as precipitation and irrigation are too low to leach the accumulated salts from the active root zone. Salinity and sodicity already existing in many soils of semi-arid and arid regions are further exacerbated by such practices and the continued use might render the land uncultivable. Hence developing a sustainable and economical reclamation regime for saline-sodic soil is essential, while considering the available irrigation water quality in these regions. The main objective of this study was to develop a viable reclamation strategy by using locally available water resources, like brackish water, treated wastewater, desalinated water, and distilled water as rain simulation, with/without soluble or solid gypsum as an amendment. We used flow-through soil column experiments to study the cation transport and exchange in saline-sodic soil from Kibbutz Revivim, Israel (drip irrigated with brackish water for three decades) with four different water qualities and soluble gypsum. The results showed the effect of different water qualities and soluble/solid gypsum on the saturated hydraulic conductivity (Ks) and dynamics of cation exchange and transport in the soil. The transport of the major cations Na+, Ca2+, Mg2+, K+, and the Ks of the soil will be presented and discussed.Keywords: saline-sodic soil, soil reclamation, cation exchange, irrigation water quality, gypsum.
Training Deep Data Assimilation Networks on Sparse and Noisy Observations
Authors: Zinchenko Vadim , Greenberg David
Published: February 2023

Data Assimilation (DA) is a challenging and expensive computational problem targetting hidden variables in high-dimensional spaces. 4DVar methods are widely used in weather forecasting to fit simulations to sparse observations by optimization over numerical model input. The complexity of this inverse problem and the sequential nature of common 4DVar approaches lead to long computation times with limited opportunity for parallelization. Here we propose using machine learning (ML) algorithms to replace the entire 4DVar optimization problem with a single forward pass through a neural network that maps from noisy and incomplete observations at multiple time points to a complete system state estimate at a single time point. We train the neural network using a loss function derived from the weak-constraint 4DVar objective, including terms incorporating errors in both model and data. In contrast to standard 4DVar approaches, our method amortizes the computational investment of training to avoid solving optimization problems for each assimilation window, and its non-sequential nature allows for easy parallelization along the time axis for both training and inference. In contrast to most previous ML-based data assimilation methods, our approach does not require access to complete, noise-free simulations for supervised learning or gradient-free approximations such as Ensemble Kalman filtering. To demonstrate the potential of our approach, we show a proof-of-concept on the chaotic Lorenz'96 system, using a novel "1.5D Unet" architecture combining 1D and 2D convolutions.
Seismic tomography investigation at the Lipari-Vulcano complex (South Italy) provides new insights on the active degassing system
Authors: Totaro Cristina , Aloisi Marco , Ferlito Carmelo , Orecchio Barbara , Presti Debora , Scolaro Silvia
Published: February 2023

Seismic tomography represents a very powerful and effective tool to look at depths beneath volcanic systems thus helping to better understand their behavior. In particular, a key parameter useful to discriminate the presence of gas, fluids and melts is represented by the P-wave and S-wave velocity ratio. In the present study, we collected ~ 4400 crustal earthquakes that occurred in the last thirty years and we used the LOcal TOmography Software LOTOS to estimate the first 3D overall model of Vp, Vs and Vp/Vs for the Lipari–Vulcano complex belonging to the Aeolian islands system (southern Tyrrhenian sea). The investigated area has been characterized both in old and recent times by fumaroles, hydrothermal activity and active degassing. In particular, in the past decades several episodes of anomalous increases of fumarole temperature and strong degassing have interested the Vulcano Island, the latter of which started in September 2021.The results of the tomographic investigation indicate the presence of two main anomalies of low Vp and low Vp/Vs, clearly depicted up to ~ 8 km depths, and related to gas-rich materials beneath the central-northern sector of Vulcano and the western off-shore of Lipari, respectively.The anomaly beneath Vulcano is located in close correspondence with La Fossa caldera area and with the sector where fumaroles, hydrothermal activity and active degassing are widely documented. Moreover, beneath the western Lipari off-shore a new, previously undetected, volume of strong gas-concentration has been identified. Even if these two anomalies show almost the same intensity, no evidence of degassing activity is available for the latter one because of its location at sea depths where the relevant water column pressure may inhibit the observation of possible degassing processes.The obtained results furnished a picture of the spatial distribution of gas-filled volumes feeding the main degassing activity of the Lipari-Vulcano complex and allowed to highlight the main role played by volcanic gas in the whole system, thus furnishing invaluable constraints for improved modelling of the volcanic system and of its possible evolution.
Correlations between minor species in the Venus mesosphere from the SOIR/Venus Express spectrograph
Authors: Mahieux Arnaud , Yangambi Libote Aaron , Robert Séverine , Piccialli Ariana , Trompet Loïc , Vandaele Ann Carine
Published: February 2023

The Solar Occultation in the Infrared (SOIR) instrument was an infrared echelle grating spectrometer on board the Venus Express spacecraft of ESA that sounded the Venus mesosphere using the solar occultation technique [1] from 2006 to 2014. Working at very high resolution, it performed 500+ solar occultations during which many species could be targeted, wherein CO [1], H2O [2], HDO [3], HCl, HF [4], SO2 [5], OCS, SO3, H2S, CS [6], etc., aside from CO2 [7], the main atmosphere constituent. From the measured spectra, we could derive vertical profiles covering the 65 to 160 km region at maximum extent, each species being detected in specific altitude ranges, depending on the strength of their respective spectral absorption bands and concentrations. Temperature profiles were also derived considering the CO2 vertical profiles and the hydrostatic equation [7]. During each solar occultation, SOIR could measure up to four spectral intervals corresponding to the diffraction orders of the echelle grating, allowing us to simultaneously target specific species in different altitude regions. In this work, we are seeking correlations between the concentrations of the minor species, and between the minor species and the temperature profiles, that were measured simultaneously. We will summarize those possible concentration dependencies focusing on possible latitude or time trends. We will also report on possible temperature dependence on the concentrations of those species. [1] Vandaele , A.C., et al. (2016), Icarus, 272.[2] Chamberlain, S., et al. (2020), Icarus, 346.[3] Fedorova, A., et al. (2008), J. Geophys. Res., 113.[4] Mahieux, A., et al. (2015), Planet. Space Sci., 113-114.[5] Mahieux, A., et al. (2015), Planet. Space Sci., 113-114.[6] Mahieux, A., et al. (2023), Icarus, Under review.[7] Mahieux, A., et al. (2015), Planet. Space Sci., 113-114.
Large Scale Temporal and Spatial Characteristics of E-region Plasma Irregularities Measured by SIMONe Norway
Authors: Huyghebaert Devin , Chau Jorge L. , Spicher Andres , Ivarsen Magnus F. , Clahsen Matthias , Latteck Ralph , Vierinen Juha
Published: February 2023

Recently it has been shown that the SIMONe meteor radar network located in northern Norway is capable of measuring ionospheric E-region coherent scatter with spatial and temporal resolutions on the order of 1.5 km and 2 s (Huyghebaert et al, 2022).  These measurements are further studied, where the coherent scatter measurements are used as a tracer for large scale ionospheric phenomena, such as plasma density enhancements and ionospheric electric fields.  By applying 2D Fourier analysis to range-time-intensity data, we perform a multi-scale spatial and temporal investigation to determine the change in range over time of the large scale ionospheric structures (> 1 km) which are compared with the line-of-sight velocities of the small scale structures (< 10 m) determined from the Doppler shift of the coherent scatter.  The spectral characteristics of the structures are also investigated. This aids in characterizing the source of the structures and provides crucial information about how energy is redistributed from large to small scales in the E-region ionosphere.  Four different events are examined from June and July of 2022.Huyghebaert D, Clahsen M, Chau JL, Renkwitz T, Latteck R, Johnsen MG and Vierinen J (2022) Multiple E-Region Radar Propagation Modes Measured by the VHF SIMONe Norway System During Active Ionospheric Conditions. Front. Astron. Space Sci. 9:886037. doi: 10.3389/fspas.2022.886037
Modeling global radiative responses and aerosol composition changes in EC-Earth3 from detailed new-particle formation predictions
Authors: Svenhag Carl , Sporre Moa , Roldin Pontus , Nieradzik Lars , Yazgi Daniel , Olenius Tinja
Published: February 2023

Representing detailed atmospheric aerosol processes in global climate models has proven challenging from both a computational and a parameterization perspective. A recent study on different Earth System Models (ESM) responses to small changes in the precursors to new aerosol particle formation (NPF) showed that two different models can produce opposite radiative outcomes in response to the removal of isoprene emissions (atmospheric cooling versus warming; Sporre et al., 2020).Here, we examine and test particle formation rate schemes and the sensitivity of the ESM EC-Earth3 applied in the work by Sporre et al. 2020. We have replaced the formation rate scheme based on Riccobono et al. (2014), derived exclusively from the relationship between organics vapors and sulfuric acid (H2SO4), with a more detailed molecular-model-based formation rate look-up table approach. This new scheme was created utilizing the Atmospheric Cluster Dynamics Code (ACDC) and currently applies tables of NPF from H2SO4 and ammonia. The tables include the effects of atmospheric H2SO4 and ammonia concentrations, temperature, ion-pair production, and cluster scavenging sink in the NPF process. We compare our model simulation results with ambient spring-time measurements of aerosol formation. We focus on boreal conditions and compare the performance of the new scheme to the previous model configuration to assess the simulations of local NPF events. For benchmarking, we also couple M7 with a one-dimensional high-resolution trajectory model ADCHEM with a more complex representation of aerosol chemistry. This enables us to compare observations of aerosol size distribution data from SMEAR II, a boreal measurement station in Finland (61.85°N, 24.28°E) with our ESM model results and with the detailed ADCHEM model results.Keywords: global modeling, new particle formation, aerosols, clouds, radiative effects, EC-Earth. Sporre, M. K., …, R., & Berntsen, T. K. (2020). Large difference in aerosol radiative effects from BVOC-SOA treatment in three Earth system models, Atmos. Chem. Phys., 20, 8953–8973. https://doi.org/10.5194/acp-20-8953-2020.Riccobono F., Schobesberger S., Scott C. E., et al. (2014) Oxidation products of biogenic emissions contribute to nucleation of atmospheric particles. Science. 344, 717–721, doi:10.1126/science.1243527.Session: AS3.2Consent: The presenting author is acting on behalf and with the consent of all authors of this contribution.
Human-caused increases in phosphorus burials in global lake sediments during the Holocene
Authors: Tu Luyao , Moyle Madeleine , Boyle John , Zander Paul , Huang Tao , Meng Lize , Huang Changchun , Grosjean Martin , Zhou Xin
Published: February 2023

Human activities have contributed to significant disruptions of the phosphorus (P) cycle on Earth’s surface.  Yet, there is little information about when and how humans started to influence the global P cycle in the past. In this study, we reconstruct lake-wide P burial rates during the Holocene based on sediment-P data of 108 lakes across the globe. The results indicate the first distinct increases in lake P burial rates after the mid-late Holocene (at around 4000 years before present BP) at global scales and in Europe. Yet, different land-use histories have caused different timings of the first increases in lake P records in other regions, with ~2000 BP in China and ~550 BP in North America. We further show that global lake P-sequestration rate from ~4000 BP to 1850 Common Era (CE) has doubled compared with that in the period before 4000 BP. Since 1850 CE, the value increased ~six-fold compared with the period before 4000 BP. These findings indicate that anthropogenic activities have been affecting the global P cycle over a pre-industrial background for millennia.