bluuebunny/crossref_metadata_2025 huggingface dataset:
The forgotten salt basin: Sivas Basin, Turkey
Authors: Callot Jean-Paul , Ringenbach Jean-Claude , Ribes Charlotte , Kergaravat Charlie , legeay Etienne , pichat Alexandre
Published: March 2022

Located in the center of the Anatolian Plateau in Turkey, the Tertiary Sivas Basin was built after the closure of the northern Neotethys oceanic domain from Upper Cretaceous to Pliocene times. It developed over an ophiolitic basement obducted from the north during the Late Cretaceous, initially separating the Kirshehir continental block from the Taurus microplate. During the Paleogene, the onset of the Tauride compression resulted in the development of a foreland basin within the Sivas domain, affected by north-verging thrusts reworking the foreland sequence and ophiolitic sheets. The flexural deepening of the basin resulted in the accumulation of a thick marine turbiditic succession in the foredeep area, followed by a rapid shallowing and the deposition of a thick evaporitic sequence during the late Eocene. This very special episode allowed for a second youth of the basin. Although studied for a quite long time, the Sivas Basin was indeed recently revisited as being likely the world’s finest open-air museum of salt tectonic structures. Despite huge difference with respect to known salt provinces, the Sivas basin provides outstanding outcrops of the classic geometries associated to the development of diapirs, i.e. halokinetic sequences along diapir walls, and associated stratal deformations, and more exotic structures such as bubble shaped minibasins, megaflaps and evaporites allochtonous glaciers and canopy. We will here review some of the results obtained thanks to a 5 year long project, during which the basin was dissected at the metric scale by a team including four PhD students to handle (1) the detailed mapping of a 60x30 km2 domain, (2) the coupled tectono-sedimentary analysis of the central, salt-controlled area, (3) decipher the complex and recurrent story of evaporite reworking and redeposition, (4) incorporate some matrix scale observations, and eventually (5) integrate the Sivas story within the Tethyan domain evolution. More generally, this fairy tale was also an opportunity to critically review the processes of geologic knowledge acquisition, basically here the trial and error game of building a coherent story, even based on fantastic outcrops.
Sensitive parameters for hydrodynamic modelling of a multi-use case study
Authors: Santjer Rieke , Sieburgh Erik , Basnayake Vindhya , Ye Ni , El Serafy Ghada
Published: March 2022

The sector of aquaculture cultivation is rapidly growing, since aquaculture is a promising food and protein supply for the increasing human world population. However, aquaculture is adding to the competition of marine space, especially in European Seas. One possible solution for relaxation of spatial competition is an approach of marine multi-use such as the combination of food and renewable energy production. Implementation of offshore aquaculture cultivation systems creates challenges for offshore engineers with respect to risks and huge costs. Large-scale hydrodynamic models, which are able to represent large and small-scale impacts, can serve as a tool to ease such challenges during the planning and assessment phase. One of these models is the calibrated and validated Dutch Continental Shelf Model (DCSM), developed by Deltares. This hydrodynamic large-scale and three-dimensional model covers the North-Western European Shelf and is based on the D-FLOW FM software. However, due to the complexity and thus computational costs of the DCSM, the application of the DCSM for various inputs and scenarios to understand multi-use in practice is limited. In this work, the DCSM is used for a case study in the North Sea. To minimise the computational amount, the considered area is cut-out from the DCSM. This nested model is based on initial conditions and inputs of the DCSM and the FINO3 platform. This platform was chosen as it is part of the UNITED project. The UNITED project is 4-year Horizon2020 EU project led by Deltares with 26 partners. The present study uses this nested model to investigate the sensitivities of input parameters. The variables water temperature, salinity and current velocities are selected, since these are the most important variables for mussel and seaweed cultivation, which are covered by this model. It is important to have information on the impact by changing the model input. Therefore, the parameters will be ranked according to their sensitivity. Since the used model still is a large and complex model, several sensitivity analysis techniques will be used. The Morris method will give a pre-liminary ranking of parameters. However, this method only changes one input at a time (one-at-a-time) and does not consider correlations between parameters. Therefore, it is planned that the method will be extended by copulas for the model input. Furthermore, it is planned to also give information about the variances of outputs. The Sobol’ variance-based method will be applied on the most influential parameters as previously detected, because the number of model runs is dependent on the number of parameters. The final results can later be used for model optimisation to allow efficient spatial planning of marine multi-use configurations. 
Baffin Bay surface flux perspectives on autumn Greenland blocking
Authors: Ballinger Thomas , Topal Daniel , Ding Qinghua , Li Zhe , Boisvert Linette , Hanna Edward , Vihma Timo
Published: March 2022

The northwest Atlantic Arctic has been recently characterized by rapid environmental change. Examples in the last two-to-three decades include: accelerated retreat of eastern Canadian Arctic glaciers, melt over high-elevation and latitude areas of the Greenland Ice Sheet (GrIS), and shifts in Baffin Bay ice phenology. Many of these glaciological changes and associated extreme events are linked to atmospheric circulation anomalies over the North Atlantic and surrounding areas, including the frequent, intense, and/or persistent presence of Greenland blocking anticyclones. These mid-tropospheric (i.e., 500 hPa) high-pressure cells are often accompanied by invigorated temperature and moisture advection and cloud radiative processes that are known to provoke widespread melt of the region’s cryosphere, even during periods when melt tends to be uncommon. Blocking characteristics are often associated with melt processes, but how these processes and related air-sea exchanges feedback on this type of upper-level atmospheric pattern largely remain uncertain. Evaluating these processes and their uncertainties is especially relevant in the cold season, when upward surface fluxes persist along the ice edge and through thin sea ice cover. Such system-level interactions deserve attention for their multi-scalar effects on the local climate and cryosphere and impacts on the polar jet stream that influences North American and European weather regimes.

This study focuses on the autumn season (September-December) to evaluate interactions involving Baffin Bay’s ice cover and its turbulent and radiative fluxes, and regional atmospheric circulation and winds. Focus is directed on this season as net surface fluxes climatologically tend to intensify from one month to the next and have increased roughly in tandem with the strength and motion characteristics of the overlying circulation described by the Greenland Blocking Index (GBI), and Greenland Streamfunction Index (GSI), respectively. Using flux data from ERA5 reanalysis and the Atmospheric Infrared Sounder (AIRS), we utilize bi-and-multivariate techniques to examine how individual and collective surface flux terms relate to the autumn GBI/GSI variability and trends since 1979. We then take a process-scale view, and investigate such interactions between the Baffin Bay boundary conditions, associated surface fluxes, and the GBI/GSI patterns in months where extremes occur in the ice cover and GBI/GSI independently as well as in tandem for applicable cases. We further aim to model the interaction between autumn Baffin ice-ocean surface fluxes and upper-level patterns using CAM6 Prescribed SST AMIP Ensembles and wind-nudging CESM experiments to isolate the role of Baffin environmental change on the large-scale atmospheric circulation and vice versa.
Contact metamorphic reactions related to magmatic sill intrusion in the Guaymas basin
Authors: Cheviet Alban , Buatier Martine , Choulet Flavien , Galerne Christophe , Riboulleau Armelle , Aiello Ivano , Marsaglia Kathleen
Published: March 2022

Igneous sill intrusions into young organic-rich sedimentary basins have major impact on the carbon cycle but also on the transfer of major and trace element between deep and superficial geological reservoirs. The Guaymas Basin in the Gulf of California represents the nascent stage of an ocean characterized by siliceous organic-rich sediments (diatom ooze) deposited at high sedimentation rates. A very dense network of shallow sill intrusions recently invaded the basin. We focused on Site U1546 (Holes A and C) located at about ~51 km northwest of the axial graben of the northern Guaymas Basin spreading segment; this site recovered 540m of sediments and  an 80m-thick sill located at 350-430 meters below the seafloor (mbsf). The relatively high geothermal gradient (> 200 °C/km) induces measurable diagenetic transformations in sediments, involving sulfides, carbonates and silica (and clay minerals). Based on retrieved materials from IODP Expedition 385, we present here geochemical and mineralogical characterization of the sedimentary intervals at sill contacts. Our results indicate that sulfides and silica polymorphs are the main phases impacted by contact metamorphism. The transition between opal CT-quartz and pyrite-pyrrhotite is observed in the contact aureoles. In the upper aureole, authigenic quartz and disseminated 20-50 micron pyrrhotite partly fill secondary pores and detrital feldspars are partially dissolved. Patchy carbonate also fills primary interparticle sediment pores just above the contact. In the lower contact aureole, quartz and 200-micron-size euhedral crystals of pyrrhotite are also present. Additionally, a significant metasomatism is observed in the lower contact-aureole meta-sediments with authigenic plagioclase precipitated around detrital feldspars and locally euhedral pyroxenes included in patches of carbonate cement; this suggests precipitation by late to post magmatic fluids at T>300°C. The lower contact aureole is also more enriched in CaO, Na2O, Fe2O3 and trace elements (Cu, As, Zn…). Based on these petrological investigations a new conceptual model of magma sediment fluid interactions will be proposed.
Modelling of changes in hydrological balance in Gambia river basin using two lumped models
Authors: Ba Doudou , Máca Petr , Langhammer Jakub , Bodian Ansoumana
Published: March 2022

This study investigated the calibration performance of hydrological models applying a series of split-sample to crash-test potential combinations of calibration-validation periods under drought type (dry/wet) using lumped models: BILAN and GR2M. A sub-period focused on the drought was systematically selected for model calibration based on a particular climate characteristic (precipitation, temperature, runoff) and a 7-year moving window. This approach gives perception into calibrated parameters transferability overtime under similar or different climate conditions (drought). 

Both lumped models yielded similar results over a set of 6 catchments in a main West African river basin located in Senegal: the Gambia river basin. The Kling-Glupta Efficiency (KGE) was the objective function to assess models’ efficiency. A dependency was found between the model performance and the extent of input data. 

Results have shown that the calibration performance decreases within an extending simulation period width. A focus on the impact of drought type on calibration performance revealed models simulating better dry than wet years. The analysis on how model performance would be affected when calibrated in a climate condition different to the validation (e.g. calibrated in dry(wet) and validated into wet (dry) revealed that calibration over a wetter or dryer condition than the validation and vice-versa may lead to an over(under)estimation of the simulated runoff. 

The results also indicate a general performance loss due to the transfer of calibrated parameters to independent validation periods of −5 to −25%, on average. The shift of model parameters in time (validation) may generate a significant level of errors. The outcome of this study may lead to a master of the uncertainty associated with one hydrological model and a better assessment of runoff in a real-world application.

Keywords: Gambia river basin; calibration; crash test; rainfall-runoff model; BILAN; GR2M; lumped hydrological models;  
A regional data driven model for simulating phreatic ground water levels in Flanders
Authors: Wolfs Vincent , Franken Tim , Gullentops Cedric , Lermytte Johan , Corluy Jan
Published: March 2022

The summers of 2017 to 2020 were characterized by exceptional dry spells throughout Europe. Climate models show that such periods of drought could occur more frequently and become even more extreme in the future. The recent periods of intense droughts lead to significant ecological, economic and even societal damages in Flanders (Belgium). During these summers, receding groundwater levels were observed throughout Flanders that reached historical low levels. To monitor low ground water levels and to support a proactive drought management, the Flemish government developed an operational ground water indicator. This indicator gives an overview of the current phreatic ground water levels combined with a prediction for the next month for a selected number of phreatic wells. To increase the spatial resolution of the indicator, we developed a novel data driven regional ground water model for phreatic aquifers.

The ML model combines a gradient boosting decision tree model (CatBoost) with a Long Short Term Memory (LSTM) network. CatBoost is used to model the average ground water depth at each location. This value is passed to the LSTM network that predicts the temporal evolution of the groundwater at each location around its average. The training dataset for the CatBoost model contains the average groundwater depth of 5.673 wells spread across Flanders and a large set of explanatory variables related to soil texture, distance to a drainage, geology, topography, meteorology and land use. The model performance is evaluated using cross-validation which showed the model generalizes well with a mean absolute error of 69cm. The most important explanatory variables for the model are the thickness of the phreatic aquifer, the vertical distance to closest drain, the topographic index and the precipitation surplus.

The training dataset for the LSTM model contains 408 wells that have sufficiently long and reliable observations for training. The input data to the LSTM consists of rainfall and evapotranspiration up to 10 years prior to each observation, combined with the same explanatory variables as the CatBoost model. A single regional LSTM model is trained on all 408 wells simultaneously. The resulting model is accurate with a median RMSE of 20cm for the validation data, outperforming the currently used SWAP models [1]. The ML model is however less performant in simulating the higher ground water depths during summer and shows a consistent bias towards lower ground water depths during long dry spells.

[1] Kroes, J.G., J.C. van Dam, R.P. Bartholomeus, P. Groenendijk, M. Heinen, R.F.A. Hendriks, H.M. Mulder, I. Supit, P.E.V. van Walsum, 2017. SWAP version 4; Theory description and user manual. Wageningen, Wageningen Environmental Research, Report 2780
Floating solar interactions with water bodies under climate warming
Authors: Exley Giles , Page Trevor , Folkard Andrew M. , Thackeray Stephen J. , Hernandez Rebecca R. , Armstrong Alona
Published: March 2022

Floating solar photovoltaics (FPV) are deployed on aquatic systems worldwide as an alternative to ground- and roof-mounted installations. FPV installations represent a considerable water surface transformation, and the consequent threats and opportunities for hosting aquatic systems are poorly understood. Moreover, we must consider any impacts within the context of a changing climate, given FPV operational lifetimes.

Impacts on aquatic systems may be significant given that FPV can perturb two key drivers of water body function - wind shear stress and solar radiation intensity. The potential impacts of changes on water body function are wide-ranging. For example, FPV may beneficially reduce the occurrence of nuisance algal blooms or could detrimentally lead to anoxic conditions, leading to the release of heavy metals from bed sediments. However, impacts are likely to be highly water body-specific, dependent on deployment configuration and be contingent on future climate conditions.

To better understand FPV effects on aquatic ecosystem processes, which underpin ecosystem services, we extended an existing lake model to simulate FPV installations under future climate scenarios on a UK reservoir. We examined plausible changes to a range of meteorological variables, water temperatures, reservoir inflow and depth. We found that FPV alters key water quality properties, including water temperature and phytoplankton community composition. Depending on the conditions, the implications are positive or negative. Our analysis shows that FPV can partially mitigate the impacts of climate change by reducing water temperature. The extended lake model will help inform policymakers and practitioners on best practices for deploying FPV, minimising detrimental impacts and maximising co-benefits.
35S-labeled methionine dynamics in a 62-year agricultural post-mining soil chronosequence
Authors: Wang Qiqi , Jones Davey , Chadwick David , Wang Deying , Zhao Yi , Bauke Sara , Tietema Albert , Bol Roland
Published: March 2022

Global industrial sulphur (S) dioxide emissions between 1900 to 1980 led to excessive S deposition and associated soil acidification.  However, since introducing effective mitigation strategies, industrial S emissions have been significantly reduced, with concurrent reductions in S deposition. This has resulted in S deficiency in many croplands which now require supplementary S applications via fertilisers. We examined if such past differential atmospheric S inputs (‘legacy’) influence organic (or inorganic) S dynamics in current agricultural soils. We used a 62-year chronosequence of the reclaimed agricultural field after brown-coal mining (Inden, Germany) to sample topsoil (0-30 cm) from seven sites (representing the years 1956, 1971, 1985, 1995, 2005, 2011, and 2018). The dynamics of sulphur transformation were determined by adding 35S labelled methionine (Met) at 6, 24 and 48 h in an incubation experiment. The 35S-Met and 35S-SO4derived from labelled Metwere determined by measuring CaCl2-extractable 35S with or without BaCl2, the difference between the total added 35S-Met and the CaCl2-extractable 35S was recognized as the 35S immobilised in the microbial biomass. Results showed that soil S concentrations declined in a curvilinear pattern over the full chronosequence, from 0.27 (in 1956) to 0.11 g S kg-1 soil (in 2018). In contrast, soil C peaked in 1995 at 16 g C kg-1 soil, with the lowest values in 1956 at 10 g C kg-1 soil. For the site recultivated in 1985, transformation and S dynamics obviously differed from others. Here, compared with other sites, the 35S-SO4(inorganic S) concentrations (as % of the total 35S-Met added) peaked at 12, 29, 38% respectively, and 35S-Met (organic S) was the lowest at 35, 23, and 16%, respectively (at sampling times, 6, 24, and 48 h). The microbial biomass immobilized 53% of 35S-Met added to the soils in less than 6 h, and gradually released it as 35S-SO4 as incubation time increased. We conclude that organic S transformation in the soils was driven by the C rather S content, possible through differences in microbial C biomass, As such the effect of the S legacy in the soils could not be confirmed. 
A simple sedimentological model demystifying the complexity of fossil bearing cave deposits in the Cradle of Humankind, South Africa.
Authors: Edwards Tara , Pickering Robyn
Published: March 2022

The caves and palaeocaves from the Cradle of Humankind (Cradle), South Africa preserve a rich fossil record of early hominin evolution representing at least three genera: (Australopithecus, Paranthropus, early Homo) and have consequently been the subject of much research. Direct dating of the South African caves had long been hampered by the perception the sedimentary fills are not amenable to direct radiometric dating. The last decade has, however, seen major advances in the ability to reliably date the fossil sites. While some dating methods have been applied directly to fossils and their encasing sediments, the most precise and consistent results come from uranium lead (U-Pb) dating of cave carbonates, known as flowstones and a relatively large dataset places the cave deposits and fossils between 3 and 1.5 Ma. Coupled with the dating issues, there is a second, long held view that the stratigraphy of these sites is too complex and, in many cases, unresolvable. However, coupled with the advances in direct dating the flowstones, there has been a considerable change in understanding of the depositional setting and stratigraphy of these ancient caves. Here we present a model to demystify the stratigraphy and sedimentology of the cave deposits and offer a set of facies which can be applied, in modified site-by-site basis, at all the fossil localities throughout the Cradle. Sedimentary facies vary laterally, depending on the distance from the cave entrance, with entrance facies characterised by coarse-grained material, even piles of boulders. Hydrodynamic sorting winnows finer material and bone into the deeper reaches of the cave resulting in red-brown layered or massive sediments. These clastic sediments are almost all externally derived, and in our model are correlated to times during which the cave entrances are more open; we argue these time windows correlate to a drier external hydroclimate. The stacked occurrence of flowstones and these clastic sediments point to these conditions, both how open the caves are and the general climate state, have oscillated repeatedly in the past. The U-Pb flowstone chronology pins the flowstones and their deposition to specific time windows and investigations into the bigger climatic picture are ongoing. This has the potential to provide a detailed palaeoenvironmental context for the rich early human fossil record, as well as provide otherwise rare southern hemisphere terrestrial records of hydroclimate variability.
Radionuclide transport through fractured chalk under abrupt variations in ionic strength
Authors: Roded Sari , Klein-BenDavid Ofra , Turkeltaub Tuvia , Tran Emily L. , Geller Yehonatan , Gerara Yarden , Teutsch Nadya , Weisbrod Noam
Published: March 2022

Radionuclide migration through saturated fractured chalk was studied in the context of predicting potential risks to groundwater in the vicinity of nuclear repositories. The aim of the present study was to examine the effect of salinity changes which might result from a sudden rainstorm leading to freshwater infiltration on the mobility of radionuclides in fractured carbonate rocks. A tracer mixture, simulating radioactive contaminants related to spent fuel (SF), including U, Sr, Ce (simulant for redox active actinides) and Re (simulant for Tc) was injected into a naturally fractured chalk rock in the laboratory. Uranine, a fluorescent dye, served as a conservative tracer. Two sets of experiments were carried out in which tracers were added to solutions of different ionic strength (IS) represented by total dissolved solid (TDS) values (Cl- and HCO3- as major anions): (1) low IS artificial rainwater (TDS of ca. 102 mg/L,); and (2) high IS artificial groundwater (TDS of ca. 104 mg/L). In both sets of experiments, the tracer mixture was introduced into a fractured chalk core, followed by the injection of tracer-free solution at the same IS. Next, the opposite (low/high IS) tracer free solution was introduced into the core to induce salinity variation. The behavior of the simulants was investigated under swift changes in background (BG) solution salinity. In all cases, Re breakthrough curves (BTCs) were unaffected by the change in BG solution and exhibit conservative behavior in comparison to that of the Uranine. Cerium was transported as intrinsic colloidal carbonate complexes, in agreement with previous studies, and remained unaffected by the abrupt change in BG solution. Uranium and Strontium BTCs were influenced by the abrupt change in IS, as their recovery significantly increased when high IS solution was injected into the core and reduced when low IS solution is introduced, regardless of the injection order. This indicates that U and Sr sorption to fractured surfaces is enhanced at low salinity, a phenomenon attributed to the replacement of Sr and U ions by Ca and Na at the adsorption sites at elevated IS conditions. The variable mobility of radionuclides found in this study should be considered in the design of natural and engineered barriers for SF disposal, especially in regions where seasonal rains or flooding may cause abrupt changes to groundwater ionic strength.
Towards a process-oriented, diagnostic framework for understanding multi-scale variability among tropical cyclogenesis events
Authors: Martinez Jonathan , Davis Christopher , Rios-Berrios Rosimar
Published: March 2022

Societal vulnerability to tropical cyclone (TC) hazards continues to grow among expanding coastal communities. Additionally, climate projections indicate that TCs will likely attain higher intensities, produce greater amounts of rainfall, and contribute to enhanced storm-surge inundation amid a warmer climate. Despite accumulating confidence among the climate projections for TCs, a vital element to the compounding nature of TC hazards remains highly uncertain: how might the frequency of TCs change amid a warmer climate?

We posit that the frequency of TCs is inextricably connected to variability among the multi-scale processes that constitute tropical cyclogenesis. Therefore, TC frequency projections should be substantiated with multi-scale assessments that account for convective processes, the evolution of mesoscale precursor disturbances, and large-scale environmental forcing. As a first step towards understanding variability among cyclogenesis events in the context of the Earth’s warming climate system, we present intercomparisons between simulations of cyclogenesis by varying the horizontal grid spacing in an idealized, aquaplanet modeling framework using the Model for Prediction Across Scales-Atmosphere (MPAS-A). Four simulations are constructed—three with quasi-uniform horizontal grid spacings of 60 km, 30 km, and 15 km, and a high-resolution simulation with 3-km horizontal grid spacing in the tropics that smoothly transitions to 15-km grid spacing in the extratropics. Tropical precursor disturbances to cyclogenesis are identified and objectively tracked with the TRACK algorithm.

Probability density functions are created for each 6-h time step along the disturbance trajectories to characterize and compare the composite environmental conditions accompanying cyclogenesis as a function of the model grid spacing. Intercomparisons between simulations are further investigated with phase diagrams that depict the composite area- and volume-averaged evolution of thermodynamic and dynamic processes throughout cyclogenesis. Furthermore, shear-relative composite-mean analyses are created to assess structural differences between precursor disturbances to cyclogenesis in the simulations. Collectively, the analyses provide an extensible framework and systematic method to assess multi-scale variability during the cyclogenesis process. We will discuss the implications of our findings in the context of the Earth’s warming climate system and proffer a path towards elucidating TC frequency projections through process-oriented diagnostics that characterize the multi-scale variability inherent to tropical cyclogenesis.
Assessing the physical controls of simulated drain flow dynamics 
Authors: Mahmood Hafsa , Schneider Raphael , Frederiksen Rasmus , Christiansen Anders , Stisen Simon
Published: March 2022

Almost 50% of the agricultural land in Denmark is tile drained, and it includes a wide range of hydrogeological and topographical settings. These drains in the shallow groundwater system influence the hydrology and nutrient transport in subsurface and surface waters significantly. Therefore, it is critical to understand the share of drainage with respect to the recharge in shallow groundwater systems to get a holistic picture of drain flow dynamics in varied topographical and hydrogeological settings. To address these issues, multiple tile-drain catchments (28 sites, with measured drain flow timeseries) across Denmark are used to test the response of tile drains in varied topographical and hydrogeological settings on field scale. Using the national hydrological model of Denmark (DK-model) in MIKE-SHE as a basis, 10m resolution groundwater flow models for all the drain catchments are established. Combined calibration for all drain catchments is conducted by evaluating percent bias (PBIAS) and Kling-Gupta Efficiency (KGE) of simulated and observed discharge data using the Pareto Archived Dynamically Dimensioned Search (PADDS) of the OSTRICH optimization tool. Principal component analysis (PCA) on independent physical explanatory variables (and indexes) representing topography and hydrogeology is used to reduce all collected variables to significant variables only. Linear polynomial ridge regression is used to study whether independent explanatory variables are sufficient to represent drain flow distribution or whether additional information derived from the groundwater flow models is needed. In this presentation, we will show if the independent topographical and geological variables can predict drain flow fraction and among all explanatory variables, which variables play the most significant role. Moreover, the resulting groundwater flow model of Denmark will serve to produce a training dataset of drain flow fraction that can be used further with machine learning approaches to predict drain flow dynamics for all of Denmark. The results of the study will contribute to improved drain flow predictions across all of Denmark by improving the understanding of controls on drain flow behaviour.
Impacts of climate change on European minimum flows under global warming of 1.5, 2, and 3 °C
Authors: García-Valdecasas Ojeda Matilde , Di Sante Fabio , Coppola Erika
Published: March 2022

Drought is a recurring hazard in Europe, affecting various sectors and causing a wide range of socioeconomic and environmental consequences. Global warming is very likely to significantly alter the water cycle across Europe, with serious implications for terrestrial hydrology. As a result, hydrological droughts are expected to become more frequent and severe in this region. In this framework, this preliminary study assesses the impact of climate change on extreme river droughts for the entire European region using a large ensemble based on 44 EURO-CORDEX simulations under the business-as-usual emision scenario (RCP8.5). For this, long-term (1976-2100) daily runoff from EURO-CORDEX simulations is used to feed a river routing model derived from the CETEMPS Hydrological Model (CHyM), obtaining thus the simulated daily discharge.

To investigate how climate change may affect the magnitude of minimum flows, a block minima method is here applied using 7-day simulated minimum yearly flows for each river point during nonfrost seasons. First, minimum flows for a reference period (1995-2014) are fitted to different extreme values statistical distributions to determine which is best for adjusting the yearly minimum discharge. Then, the minimum flows at various recurrence intervals obtained from the best distribution's adjustment are used to analyze changes at +1.5, 2, and 3 °C global warming above preindustrial levels. Therefore, the purpose of this preliminary work is twofold: (1), to elucidate what is the best probability distribution to fit the annual 7-day minimum discharge in Europe and (2) to project the minimum river flow to analyze the impact of climate change on extreme river drought.

The findings of this study will provide valuable information to plan suitable adaptation and strategies to climate change from a hydrological perspective.

Keywords: Hydrological drought, EURO-CORDEX, CHyM, minimum river flow

Acknowledgments:  first author is supported at present by OGS and CINECA under HPC-TRES program award number 2020-02
Comparing gravity waves in a kilometer scale run of the IFS to AIRS satellite observations
Authors: Lear Emily , Wright Corwin , Hindley Neil , Polichtchouk Inna
Published: March 2022

Gravity waves impact the large scale circulation, and increasing our understanding of them is important to improve weather and climate models. This presentation focusses on atmospheric gravity waves in the stratosphere using data from the ECMWF ERA5 reanalysis, AIRS (Atmospheric Infrared Sounder) on NASA’s Aqua satellite and a high resolution run of the IFS operated at a km-scale spatial resolution. Data was examined during the first 2 weeks of November, as the high resolution model was initialized on the 1st of this month. Asia and surrounding regions are investigated, because preliminary studies of AIRS data suggested strong gravity wave activity in this region during this time period. Waves can also be seen in the ERA5 data at the same times and locations. The high resolution model also shows significant gravity wave activity in similar areas to where it is seen in the AIRS data, particularly over Russia. The 2D+1 S-Transform was used to find wave amplitudes, horizontal and vertical wavelengths and momentum flux for all three datasets. Weather models are advancing rapidly and km scales such as the experimental IFS run could become operational in next decade. At these grid scales, gravity waves must be resolved instead of parameterized so the models need to be tested to see if they do this correctly. This work provides information on how a cutting edge model resolves gravity waves compared to observations.
CO2Image: a next generation imaging spectrometer for CO2 point source quantification
Authors: Butz Andre , Scheidweiler Leon , Baumgartner Andreas , Feist Dietrich G. , Gottschaldt Klaus-Dirk , Jöckel Patrick , Kern Bastian , Köhler Claas , Krutz David , Lichtenberg Günter , Marshall Julia , Paproth Carsten , Slijkhuis Sander , Sebastian Ilse , Strandgren Johan , Wilzewski Jonas S. , Roiger Anke
Published: March 2022

CO2Image is a satellite demonstration mission, now in phase B, to be launched by the German Aerospace Center (DLR ) in 2026. The satellite will carry a next generation imaging spectrometer for measuring atmospheric column concentrations of carbon dioxide (CO2). The instrument concept reconciles compact design with fine ground resolution (50-100 m) with decent spectral resolution (1.0-1.3 nm) in the shortwave infrared spectral range (2,000 nm). Thus, CO2Image will enable quantification of point sources with CO2 emission rates of less than 1 MtCO2/a. This will complement global monitoring missions such as CO2M, which are less sensitive to point sources due to their coarser ground resolution, and hyperspectral imagers, which suffer from spectroscopic interference errors that limit the quantification of small sources due to their coarser spectral resolution. Further, CO2Image is sufficiently compact to envision, after successful demonstration, a fleet of sensors operated by public bodies to support and evaluate greenhouse gas emission reduction strategies on community-scales.

Here, we will focus on the design choices and performance analyses carried out for building the mission. We have developed an end-to-end simulator that starts out with realistic atmospheric CO2 concentration fields simulated by large-eddy-simulations of CO2 plumes emitted by various point-sources in a 50x50 km2 tile. The latter represents a typical individual target which CO2Image will sample in less than 100 ms in a pushbroom configuration using forward motion compensation. The simulated concentration fields will be used to create synthetic measurements from instrument parameters. These measurements will then be fed into our retrieval and we will use mass balance methods to estimate the compatible emission rates. We evaluate various performance parameters and hypothetical error sources such as calibration errors in terms of their impact on the emission estimates. 
A screening model for quantifying PFAS leaching in the vadose zone and mass discharge to groundwater
Authors: Guo Bo , Zeng Jicai , Brusseau Mark , Zhang Yonggen
Published: March 2022

A growing body of site investigations have demonstrated that vadose zones serve as significant long-term sources of PFAS to groundwater. Quantifying PFAS leaching in the vadose zone and mass discharge to groundwater is therefore critical for characterizing, managing, and mitigating long-term contamination risks. Recently, mathematical models representing the PFAS-specific transport and retention processes, including surfactant-induced flow, and rate-limited, nonlinear adsorption at solid-water and air-water interfaces, have been developed. While these advanced models provide fundamental insights into the primary processes controlling the long-term retention of PFAS, they are less suitable for screening-type applications due to significant computational cost and the requirement for detailed input parameters. To address this knowledge gap, we develop a simplified model by assuming steady-state infiltration and linear solid-phase and air-water interfacial adsorption; a two-domain model is used to represent kinetic solid-phase adsorption. We derive novel analytical solutions for the simplified model allowing for arbitrary initial conditions. The newly derived analytical solutions are then validated by application to miscible-displacement experiments under a wide range of conditions and by comparisons to a state-of-the-art comprehensive model under both experimental and field conditions applicable to PFAS-contamination sites. Overall, the simplified analytical model provides an efficient and accurate screening-type tool for quantifying long-term PFAS leaching in the vadose zone.
El Niño forecasting by climate networks: comparison of the forecasting performance in observational data and in historical and controls runs of CMIP5 and CMIP6
Authors: Ludescher Josef , Bunde Armin , Schellnhuber Hans Joachim
Published: March 2022

The El Niño Southern Oscillation (ENSO) is the most important driver of interannual global climate variability and affects weather and climate in large parts of the world. Recently, we have developed a dynamical network approach for predicting the onset of El Niño events well before the spring predictability barrier. In the regarded climate network, the nodes are grid points in the Pacific, and the strengths of the links (teleconnections) between them are characterized by the cross-correlations of the atmospheric surface temperatures at the grid points. In the year before an El Niño event, the links between the eastern equatorial Pacific and the rest of the Pacific tend to strengthen such that the average link strength exceeds a certain threshold. This feature can be used to predict the onset of an El Niño with 73% probability and its absence with 90% probability. The p-value of the hindcasting and forecasting phase (1981-2021) for this performance based on random guessing with the climatological average is 4.6*10-5.

To assess whether this predictive feature is also present in coupled general circulation models, we apply our algorithm to historical and control runs of CMIP5 and CMIP6. We find that the predictive performance present in observational data is absent or very low in GCMs. The lack of this feature may explain the difficulties of GCMs to overcome the spring barrier.
Implementation of a FAIR Compliant Automated Workflow for Infrastructures
Authors: Bundke Ulrich , Kennert Marcel , Mahnke Christoph , Rohs Susanne , Petzold Andreas
Published: March 2022

The European infrastructure In-service Aircraft for a Global Observing System (IAGOS) (www.IAOGS.org) has implemented an automatic workflow for data management organizing the dataflow starting at the sensor towards the central data-portal located in Toulouse. The workflow is realized and documented using the web-based Django framework with a model-based approach using Python.

This workflow performs all necessary data processing and QA/QC tests to automated upload NRT processed data and serves the PI as basis for approval decisions. This includes repeated cycles for different stages of data maturity. The PI can monitor the status of all tasks by web-based reports produced by the Task Manager.  An automated reprocessing is possible by storing metadata on all steps as well as decisions of the PI. The implementation of the workflow is one big step to make IAGOS data handling compliant with the FAIR principles (findable, accessible, interoperable, reusable).

The workflow is easy adaptable to manage the workflow of other Infrastructures or research institutes. Thus, we will open the development under MIT license and invite other datacenters to contribute to the development.

Acknowledgments:

This work was supported by European Union's Horizon 2020 research and innovation programme under grant agreement No 824068 and by Helmholtz STSM Grant “DIGITAL EARTH”
Swarm-derived indices of geomagnetic activity
Authors: Papadimitriou Constantinos , Balasis Georgios , Boutsi Adamantia Zoe , Antonopoulou Alexandra , Moutsiana Georgia , Daglis Ioannis A. , Giannakis Omiros , Consolini Giuseppe , Gjerloev Jesper , Trenchi Lorenzo
Published: March 2022

Ground-based indices, such as the Dst, ap and AE, have been used for decades to describe the interplay of the terrestrial magnetosphere with the solar wind and provide quantifiable indications of the state of geomagnetic activity in general. These indices have been traditionally derived from ground-based observations from magnetometer stations all around the Earth. In the last 7 years though, the highly successful satellite mission Swarm has provided the scientific community with an abundance of high quality magnetic measurements at Low Earth Orbit (LEO), which can be used to produce the space-based counterparts of these indices, such the Swarm-Dst, Swarm-ap and Swarm-AE indices. In this work, we present the first results from this endeavour, with comparisons against traditionally used parameters. We postulate on the possible usefulness of these Swarm-based products for a more accurate monitoring of the dynamics of the magnetosphere and thus, for providing a better diagnosis of space weather conditions.
Convection-permitting ICON-LAM simulations as input to evaluate renewable energy potentials over southern Africa
Authors: Chen Shuying , Poll Stefan , Heinrichs Heidi , Hendricks-Franssen Harrie-Jan , Görgen Klaus
Published: March 2022

The largest part of the global population without reliable access to electricity lives in Africa. Here, renewable energy is a sustainable, cost efficient, and climate-friendly solution, especially given the large untapped renewable energy potential existing over the African continent. However, most renewable energy-related studies over Africa typically use input datasets at relatively coarse spatial resolutions (e.g., ERA5 at about 30km). Our objective is to produce a prototypical high-resolution dataset over southern Africa from dedicated atmospheric simulations. The data will be used with renewable energy assessment models, to eventually evaluate the renewables potentials. The hypothesis is that the high-resolution datasets provide more realistic and accurate renewable energy potential estimates. The ICOsahedral Nonhydrostatic (ICON) Numerical Weather Prediction (ICON-NWP) model is run as the operational forecast model at the German Weather Service (DWD); and we employ the same model in its Limited Area Mode (ICON-LAM) in this project. The study domain over southern Africa is chosen due to its high solar and wind energy potential. ICON-LAM dynamically downscales the global deterministic ICON-NWP forecasts dataset from a spatial grid spacing of 13km to a convection-permitting resolution of 3.3km, without convection parameterization. This southern Africa ICON-LAM implementation is novel and has not been run before. Simulations cover the time span from 2017 to 2019 with contrasting meteorological conditions. The high-resolution triangulated grid cells of the 3.3km domain are exactly inscribed in the 13km global grid cells, following the sub-triangle generation rule of the ICON model mesh. To keep the ICON-LAM close to the observed atmospheric state the model atmosphere is reinitialized every 5 days, with one day spinup. The land surface and subsurface are run transient. In a very initial evaluation step, simulated 10m wind speed, global solar radiation, 2m air temperature, and precipitation from the coarser driving model, the ERA5 reanalysis as well as our ICON-LAM setup are validated using satellite data and in situ observations from the two local meteorological networks (SASSCAL and TAHMO). Initial results point to an added value of the convection-permitting simulations.