bluuebunny/crossref_metadata_2025 huggingface dataset:
A multiple streams analysis of drought policies in Ceará state, Brazil
Authors: Cavalcante Louise , Ribeiro Neto Germano , Dewulf Art , van Oel Pieter , Souza Filho Francisco
Published: March 2021

Interactions between society and water are complex, socio-hydrological systems are influenced by policies, which rarely are a simple linear response with the aim of providing the most efficient solution. In drought contexts, a new layer of complexity is added, considering the different uncertainties involved, related to the rainfall season, or the duration of multi-year drought events. We utilized the Multiple Streams Approach (MSA) theory to answer the following question: how do multi-year droughts function as focusing events? Focusing events may trigger greater attention to problems and solutions because they increase the likelihood that more organized interests, including some that are influential and powerful, could advocate policy change. MSA seeks to explain how policy changes. It assumes the policy change happens when three separate streams interact: (1) the problem stream, involving the emergence or recognition of a problem by society; (2) the policy stream, containing policy ideas and alternatives generated by specialists, researchers, politicians, and social actors; and (3) the politics stream, referring to the political, administrative, and legislative context favorable or unfavorable to developing certain actions to overcome the problem. The justification to apply the MSA lenses in this is study is to understand the influences of multi-year drought events as a focusing event that triggered the process of policy change considering the subnational context of Ceará state in Brazil. In this study, the following methodological procedures were used: (a) historical overview of drought occurrence and the policy responses in Ceará; (b) data processing of hydrologic records (rainfall). We found three main different policy approaches to drought impacts: reactive, proactive, and drought preparedness policies. We found in some cases that multi-year droughts served as focusing events that opened windows of opportunities, triggering policy response changes, such as, collaboration, new problem framing, and increased political attention. Our findings have implications for the socio-hydrology field, as there is still significant scope for increasing the understanding of the influences of public policies in the context of coupled-humans systems, especially in the context of drought. 
Geological CO2 contributions quantified by high-temporal resolution carbon stable isotope monitoring in a salt mine
Authors: Frank Alexander H. , van Geldern Robert , Myrttinen Anssi , Zimmer Martin , Barth Johannes A. C. , Strauch Bettina
Published: March 2021

CO2 emissions from geological sources have been recognized as an important input to the global carbon cycle. In regions without active volcanism, mines provide an extraordinary opportunity to observe dynamics of geogenic degassing close to its source.

High temporal resolution of stable carbon isotopes allows to outline temporal and interdependent dynamics of geogenic CO2 contributions. We present data from an active underground salt mine in central Germany that were collected on site with a field-deployed laser isotope spectrometer.

Throughout the 34-day measurement period, total CO2 concentrations varied between 805 ppmV (5th percentile) and 1370 ppmV (95th percentile). With a 400 ppm atmospheric background concentration, an isotope mixing model enabled the separation of geogenic (16–27 %) from highly dynamic contributions from anthropogenic CO2-sources (21–54 %). The geogenic fraction was inversely correlated to established CO2 concentrations that were driven by anthropogenic CO2 emissions within the mine. This indicates gradient-driven diffusion along microcracks.

Read more about this work in our open access publication in Scientific Reports at: http://rdcu.be/cblTz
Altitude dependence of geomagnetic external fields using Swarm and ground observatories data
Authors: Saturnino Diana , Pais M. Alexandra , Domingos João , Pinheiro Fernando J. G.
Published: March 2021

The separation of different sources  in the geomagnetic field signal measured at satellite altitude is still an open issue. One approach to tackle this problem may be non-parametric statistical methods, such as the Principal Component Analysis (PCA). Here, PCA is applied to Virtual Observatories (VO) geomagnetic time series, computed from an enlarged Swarm dataset  covering all local times and geomagnetic activity levels, from January 2014 to December 2019. For each 30-days time window, an Equivalent Source Dipole mathematical model is fitted to the data to reduce a cloud of satellite data points inside a cylinder to one single 'observation' at its axis and 500 km altitude. A VO mesh is constructed with 3394 VOs, with 2 degrees radius each and 3.5 degrees apart in latitude. We study the distribution of satellite data among the cylinders to test if any spatial or temporal sampling asymmetries can be present in the VO dataset and propagate to the PCA results. We also compare observed time series at ground level with VO time series at satellite altitude for the same latitude and longitude. After subtracting a main field model to both series, comparison of the residuals can give further insight on the dependence of external fields with altitude, with a 30-day time resolution.
Calibrating and validating an inundation model with and without crowdsourced water depths and velocities
Authors: Assumpção Thaine H. , Popescu Ioana , Jonoski Andreja , Solomatine Dimitri
Published: March 2021

Remote sensing and crowdsourcing data are new sensing methods that have the potential to improve significantly inundation modelling. That is especially true in data-scarce situations, for example when resources for acquiring sufficient traditional data are limited or when field conditions are not favourable. Crowdsourced water depths and velocities have been demonstrated to be useful for improving inundation models, ranging from the calibration of 1D models to data assimilation in 2D models. In this study, we aim to further evaluate how much the amount and type of crowdsourced data influence model calibration and validation, in comparison with data from traditional measurements. Further, we aim to assess the effects of combining both sources. For that, we developed a 2D inundation model of the Sontea-Fortuna area, a part of the Danube Delta in Romania. This is a wetland area, where data was collected during two 4-day field campaigns, using boat navigation together with the involved citizens. Citizens obtained thousands of images and videos that were converted into water depth and velocity data, while technicians collected ADCP data. We calibrated and validated the model using different combinations of data (e.g. all water depth data, half water depth and half water velocity). Results indicated that velocity data by themselves did not yield good calibration results, being better used in conjunction with water depths or by combining them into discharge. We also observed that calibration by crowdsourced water depths is comparable to the use of water depths from traditional measurements.
Impact of solutions on the identification of tectonic transients: A case study using the last decade of GNSS data in South America
Authors: Bedford Jonathan , Glaser Susanne , Männel Benjamin
Published: March 2021

GNSS derived displacement time series are used to track plate tectonics and the associated motions across major plate boundaries. With a growing number of continuous GNSS observations, it is becoming increasingly apparent that plate trajectories rarely conform to standard trajectory models. The deviations from these expected trajectories can be considered as transient motions, some being tectonically related, and others being related to geophysical fluid loading, local site effects, and artifacts of the GNSS processing. As we increasingly inspect the transient motions of GNSS displacement time series, we have to take care that the GNSS processing choices, such as the reference frame, are not introducing non-tectonically related artifacts into the eventual isolated tectonic signals.

Here we explore the effects that different solutions and processing strategies have on our eventual daily GNSS displacement time series - the aim being to explain how artifacts arise and to determine which strategies best mitigate these artifacts. We compare displacement time series made from both Precise Point Positioning and network (double-differenced) solutions that are provided in the latest official reference frame solution ITRF2014, and in JTRF2014 based on Kalman filtering.

In our analyses, we use approximately one hundred GNSS stations from South America, with a focus being to identify transient tectonic activity related to the subduction of the Nazca plate under Chile over the past decade.

 
Assessment of radiocarbon observations for constraining fossil fuel emissions in a comprehensive Carbon Cycle Fossil Fuel Data Assimilation System
Authors: Chen Hans W. , Scholze Marko , Kaminski Thomas , Vossbeck Michael , Rayner Peter , Karstens Ute
Published: March 2021

Estimation of greenhouse gas emissions from atmospheric measurement-based "top-down" methods is complicated by strong and uncertain fluxes from natural systems, for example carbon dioxide (CO2) sources and sinks from the terrestrial biosphere.  Additional tracers such as radiocarbon are promising for disentangling the different emission contributions from human activity and natural systems.  However, many open questions remain about how different uncertainties in the modeling and observation of these tracers influence the emission estimates.

Here we assess the potential benefits of using radiocarbon observations to constrain global fossil fuel emissions in a Carbon Cycle Fossil Fuel Data Assimilation System (CCFFDAS).  We performed sensitivity experiments to quantify how uncertainties in the observations and models affect the uncertainties in the derived emissions, including different prior assumptions about natural and anthropogenic CO2 fluxes and varying observation networks.  Further, we demonstrate how radiocarbon observations can complement the existing CO2 observation network.
Regionalization of seasonal precipitation over the Tibetan Plateau
Authors: Lai Hui-Wen , Chen Hans W. , Kukulies Julia , Ou Tinghai , Chen Deliang
Published: March 2021

The Tibetan Plateau (TP) is the “water tower” of Asia and is the origin of most major rivers that provide water resources supporting countries in Asia. Changes in precipitation over the plateau play an important role in the water management in those areas, but the spatiotemporal variations of the precipitation over the TP are not well understood mainly because of the sparsely distributed in-situ observation sites. This study takes advantage of the newly available high-resolution ERA5 reanalysis and the Global Precipitation Measurement satellite product IMERG together with in-situ observations to characterize the seasonality of precipitation over the TP using a self-organizing map algorithm fed with precipitation data from 2000 to 2019. Specifically, this study aims to (1) identify regions with distinct seasonality in precipitation, (2) determine the interannual variability in the classification and regional precipitation, and (3) explore the roles played by large-scale atmospheric circulations on the seasonality of regional precipitation. The classification reveals three major precipitation regimes in the TP centered at the western, southwestern, and eastern plateau. On a year-to-year basis, the western region is relatively robust, while the southwestern and eastern regions tend to shift mainly between the central and northern TP. A composite analysis shows that the western region experiences larger amounts of precipitation in winter and early spring when the westerly jet is anomalously strong to the north of the TP. Precipitation variations in the southwestern region are associated with intensity changes in the South Asian High and Indian summer monsoon. The precipitation in the eastern region is correlated with the Indian summer monsoon and anticyclonic circulation over the western North Pacific. Our findings provide a better understanding of the regional and interannual variations of precipitation regimes over the TP, and could help to interpret future changes in precipitation regimes due to climate change.
The record of the Eocene-Oligocene Transition and the “Grande Coupure”. Magnetostratigraphic constraints from the Ebro Basin revisited.
Authors: Garcés Miguel , Beamud Elisabet , López-Blanco Miguel , Gómez Manuel , Costa Elisenda , Sáez Alberto , Cabrera Luis
Published: March 2021

Magnetostratigraphy is the key to put disparate chronological pieces together in a consistent chronostratigraphic framework. Provided that a long continuous record of reversals can be obtained from the sedimentary record, a correlation with the GPTS may be established. Magnetostratigraphy provides added value to the chronology as long as it keeps certain independence from external age constraints, such as bioevents calibrated elsewhere or radiochronologic data.

An independent correlation is meant to not be anchored to a given chron on the basis of an external age constrain. Our experience recommends that external age constraints are best taken with flexibility, allowing for the searching of a best fit between the magnetic polarity sequence (in meters) and the GPTS (in million-years). This rationale relies on the fact that the Geological Time Scale is the tool that allows earth-scientist of many varied disciplines to understand and discuss about the dimension of time. But the time scale calibration is a task in continuous refinement. As the accuracy and precision of the dating tools increases, our ability to unravel lag times in geological processes increases too. As more refined data is produced, the calibration of the time scale reveals as an ongoing task rather than a final product.

Here we present the case of the Eocene-Oligocene Transition (EOT) as recorded in alluvial-lacustrine sediments of the eastern Ebro Basin. An earlier work provided a magnetostratigraphic correlation that was in agreement with small-mammals biostratigraphic data. A key constraint to this study was the Santpedor locality, which yielded a characteristic post-Grand Coupure small mammal assemblage, then attributed to the lowest Oligocene.

An extended record of the magnetostratigraphy has challenged the earlier correlation and puts forward an alternate scenario that reveals a misfit with earlier and recent biochronological interpretations of the fossil mammal record. The significance of this discrepancy in terms of heterochrony of biostratigraphic events, the punctuated character of faunal replacement across the EOT, and time lags between the marine and continental realms may need to be addressed.
Weathering zonation within cracks in desert boulders reveals piecemeal crack propagation over geologic timescales
Authors: Shaanan Uri , Mushkin Amit , Sagy Amir , Rasmussen Monica , Eppes Martha-Cary
Published: March 2021

Rock fracturing can be slow and steady, comprising physiochemical processes that involve the chemical breaking of bonds that are weakened in response to local stress loading. Whereas subaerial cracking of surface boulders is universally observed in desert environments, the rates and specific mechanisms that drive crack propagation in such conditions are yet to be completely understood.

Here, we present new field and petrographic observations from mode-1 (tensional) incipient (rocks are not yet split) fractures in alluvial boulders from the hyperarid southern Negev desert (Israel). Over 100 carbonate boulders embedded in a well-developed, 70 ka desert pavement that held visible fractures were forced apart along the incipient cracks. Doing so revealed a systematic recurring tri-zone pattern in crack morphology whose boundaries consistently paralleled the crack propagation front: Zone 1 – A weathered (as evidenced by incipient patina) zone proximal to the boulder surface; Zone 2 – A relatively fresh crack zone partly filled with aeolian particles and salts medial from the boulder up-facing surface;  Zone 3 – A chemically altered (as evidenced by petrographic analyses) zone of otherwise intact rock at the crack tip. The occurrence of such micro-morphological crack zonation suggests slow sub-critical crack propagation at sufficiently long geologic timescales that support development of differential weathering within the crack. The petrographic analyses of sections perpendicular to the plane of the crack indicate chemical alteration that precedes the crack propagation in both space and time (i.e., extends in front of the crack tip), also indicates slow piecemeal propagation of the crack. This linkage between chemical weathering processes at the crack tip and slow subcritical propagation of the crack into the boulder provides additional support for first-order control of environmental and climatic conditions on boulder cracking rates, regardless of the physical stress-loading mechanism.
Radiocarbon constraints on carbon cycling in plants and soils
Authors: Trumbore Susan , Sierra Carlos , Hoyt Alison , Hilman Boaz , Beem-Miller Jeffrey , Stoner Shane , von Fromm Sophie , Shi Zheng , Randerson James
Published: March 2021

Tracing ‘bomb’ radiocarbon produced by atmospheric testing of atomic weapons through vegetation and soils provides information of the dynamics of terrestrial carbon cycling on timescales of years to centuries. Processes operating on these timescales are of interest because they regulate key functions in long-lived plants and regulate the potential for increasing soil carbon storage.  However, the multiple pathways taken by carbon transiting ecosystems from photosynthesis to respiration and decomposition complicate the quantitative interpretation of radiocarbon observations.  In the 14Constraint project, we are exploring how to optimize measurements of radiocarbon as well as to improve their interpretation by providing constraints for comparison with models.   This talk will focus on efforts to synthesize global radiocarbon measurements of mean age and transit time, and suggest ways forward to improve process-level understanding.
Long-range transport of Icelandic dust towards Europe and Arctic 
Authors: Dagsson-Waldhauserova Pavla , Burdova Nathalie , Nickovic Slobodan , Cvetkovic Bojan , Arnalds Olafur , Moroni Beatrice , Djordjevic Dragana , Ceburnis Darius
Published: March 2021

High Latitude Dust (HLD) contributes 5% to the global dust budget and active HLD sources cover > 500,000 km2. In Iceland, desert areas cover about 44,000 km2, but the hyperactive dust hot spots of area < 1,000 km2 are the most dust productive sources. For example Hagavatn dust source of area about 10 km2 is captured on satellite images to produce visible dust plumes exceeding distance of > 700 km.

Recent studies have shown that Icelandic dust travelled about 2,000 km to Svalbard (Moroni et al., 2018) and about 3,500 km to Balkan Peninsula (Djordjevic et al., 2019). It estimated that about 7% of Icelandic dust can reach the high Arctic (N>80°). Previous study on Icelandic dust travelling about 1,300 km to Ireland (Ovadnevaite et al., 2009) serves as a case study to identify additional dust events arriving to Mace Head, Ireland in 2018-2020. In situ dust concentrations in Iceland, remote sensing and dust forecasts based on atmospheric-dust model DREAM (Dust REgional Atmospheric Model, https://sds-was.aemet.es/forecast-products/dust-forecasts/icelandic-dust-forecast) are used for this study.        

Reference:

Đorđević D., et al. 2019. Can Volcanic Dust Suspended From Surface Soil and Deserts of Iceland Be Transferred to Central Balkan Similarly to African Dust (Sahara)? Frontiers in Earth Sciences 7, 142-154.

Moroni B., et al. 2018. Mineralogical and chemical records of Icelandic dust sources upon Ny-Ålesund (Svalbard Islands). Frontiers in Earth Science  6, 187-219.

Ovadnevaite J., Ceburnis D., et al. 2009. Volcanic sulphate and arctic dust plumes over the North Atlantic Ocean. Atmospheric Environment 43, 4968-4974.

Additional studies on Icelandic dust: https://icedustblog.wordpress.com/publications/
Uncertainty estimation with LSTM based rainfall-runoff models
Authors: Klotz Daniel , Kratzert Frederik , Gauch Martin , K. Sampson Alden , Klambauer Günter , Brandstetter Johannes , Hochreiter Sepp , Nearing Grey
Published: March 2021

Uncertainty is a central part of hydrological inquiry. Deep Learning provides us with new tools for estimating these inherent uncertainties. The currently best performing rainfall-runoff models are based on Long Short-Term Memory (LSTM) networks. However, most LSTM-based modelling studies focus on point estimates.

Building on the success of LSTMs for estimating point predictions, this contribution explores different extensions to directly provide uncertainty estimations. We find that the resulting models provide excellent estimates in our benchmark for daily rainfall-runoff across hundreds basins. We provide an intuitive overview of these strong results, the benchmarking procedure, and the approaches used for obtaining them.

In short, we extend the LSTMs in two ways to obtain uncertainty estimations. First, we parametrize LSTMs so that they directly provide uncertainty estimates in the form of mixture densities. This is possible because it is a general function approximation approach. It requires minimal a-priori knowledge of the sampling distribution and provides us with an estimation technique for the aleatoric uncertainty of the given setup.  Second, we use Monte Carlo Dropout to randomly mask out random connections of the network. This enforces an implicit approximation to a Gaussian Process and therefore provides us with a tool to estimate a form of epistemic uncertainty. In the benchmark the mixture density based approaches provide better estimates, especially the ones that use Asymmetric Laplacians as components.
Real time interactions between soil microorganisms and microplastics at microscale
Authors: Mafla-Endara P. Micaela , Ohlsson Pelle , Hammer Edith
Published: March 2021

Terrestrial ecosystems are under threat due to the continuous accumulation of plastics in soils. Particularly, microplastics have been proven to negatively affect the performance of soil macrofauna such as earthworms, as well as soil mesofauna including springtails and nematodes. Unfortunately, two big groups remain largely unexplored: the soil microfauna and microflora.

Recent studies have shown that soil microbial community composition can significantly vary depending on the concentration and type of plastic, favouring some groups and disfavouring others. To have a better understanding of these relationships, it is necessary to study them at relevant scale: the microscale.

Considering that in situ observations are hard to achieve due to the opacity of soil and ever-changing soil architecture, we used transparent micro-engineered chips to study interactions between microplastics and soil microorganisms live. We hypothesized that different concentrations of microplastics interfere with a natural microbial community in terms of 1. Soil microbial colonization/succession of the chips and 2. Soil microbial growth inside the chips’ pore space.

We fabricated chips containing different microstructures that simulate soil pore spaces. The chips were bonded to a glass slide and one side was opened to allow microbial colonization. Each chip was filled with a mix of liquid nutrient medium and 1.0 µm polystyrene microbeads at microplastic concentrations of 0.0, 0.006, 0.001 and 0.0005 mg/ml. The chip´s opening was inoculated with 5 g of soil and incubated in the laboratory at room temperature for one month. We documented the presence/absence and abundance of different soil microbial groups changing over time by using an inverted microscope.

Our preliminary study reveals that larger microorganisms are sensitive to the presence of microbeads 1.0 µm size. We found that all major soil microbial groups (fungi, bacteria, and protists) and nematodes colonized the chips. However, their abundance was affected by the presence of microplastics, irrespective of the concentration. Particularly protists and nematodes were lower in number during the first days of the exposure. The beads were clearly visibly taken up into the cells of the protists or the digestive tract of the nematodes.

We are now investigating what consequences the lower abundance of certain soil microbial groups have for the soil food web. As seen here, micro-engineered chips are useful tools to provide visual access at the scale where most cell-to-cell interactions occur.
Towards a consistent quantification of ecosystem transpiration and its uncertainty from the SAPFLUXNET database
Authors: Poyatos Rafael , Granda Víctor , Flo Víctor , Mencuccini Maurizio , Martínez-Vilalta Jordi
Published: March 2021

Transpiration from forests and woodlands is the main component of terrestrial evapotranspiration. Ecosystem-scale transpiration estimates are needed to inform models and remote sensing products so that they can improve their quantification of the magnitudes, spatiotemporal patterns, and environmental sensitivity of transpiration at regional to global scales. Tree-level sap flow measurements can be used to estimate ecosystem transpiration in forests and woodlands and these data are now globally available in the SAPFLUXNET database (Poyatos et al. 2020). However, observational errors, sampling assumptions, and missing data propagate uncertainties in the upscaling process to the ecosystem level. Here we quantify ecosystem transpiration and its uncertainty, from hourly to annual scales, across SAPFLUXNET sites using two different approaches. In a first approach, we estimated hourly sap flow per unit basal area at the species level, which was then aggregated to the stand level using species-specific basal areas available in SAPFLUXNET metadata. In this approach, uncertainty was quantified from the observed variability in tree-level sap flow within a species. In a second approach, we used empirical relationships between tree diameter and sap flow to obtain stand-level transpiration and propagated the uncertainty in this relationship to the stand-level values. For both approaches, sap flow data obtained with uncalibrated heat dissipation probes were also adjusted using a recently published correction based on sap flow calibrations. The different upscaling methods, implemented in R code, will allow reproducible upscaling and uncertainty quantification from SAPFLUXNET datasets, paving the way towards a better understanding of ecosystem transpiration and its controls across the globe.

Poyatos, R., Granda, V., Flo, V., […], Steppe, K., Mencuccini, M., Martínez-Vilalta, J. (2020). Global transpiration data from sap flow measurements: the SAPFLUXNET database, Earth System Science Data Discussions, 1–57, .
Paleomagnetism of the ~860 Ma Manso dyke swarm, West Africa: implications for the assembly of Rodinia
Authors: Antonio Paul Yves Jean , Baratoux Lenka , Trindade Ricardo Ivan Ferreira , Rousse Sonia , Ayite Anani , Lana Cristiano , Macouin Mélina , Adu Emmanuel Williams Kobby , Sanchez Caroline , Silva Marco , Firmin Anne-Sophie , Martinez Dopico Carmen Irène , Proietti Arnaud , Amponsah Prince Ofori , Sakyi Patrick Asamoah
Published: March 2021

The West African Craton (WAC) is one of the major cratons in the Rodinia jigsaw puzzle (~1000–750 Ma). In the Rodinian models, the position of West Africa is mainly constrained by the assumption that it had been a partner of Amazonia since the Paleoproterozoic. Unfortunately, no paleomagnetic data are available for these cratons when the Rodina supercontinent is considered tectonically stable (~1000-750 Ma). Thus, every new reliable paleomagnetic pole for the West African Craton during the Neoproterozoic times is of paramount importance to constrain its position and testing the Rodinia models. In this study we present a combined paleomagnetic and geochronological investigation for the Manso dyke swarm in the Leo-Man Shield, southern West Africa (Ghana). The ~860 Ma emplacement age for the NNW-trending Manso dykes is thus well-constrained by two new U-Pb apatite ages of 857.2 ± 8.5 Ma and 855 ± 16 Ma, in agreement with baddeleyite data. Remanence of these coarse-to-fine grained dolerite dykes is carried by stable single to pseudo-single domain (SD-PSD) magnetite. A positive baked-contact test, associated to a positive reversal test (Class-C), support the primary remanence obtained for these dykes (13 sites). Moreover, our new paleomagnetic dataset satisfy all the seven R-criteria (R=7). The ~860 Ma Manso pole can thus be considered as the first key Tonian paleomagnetic pole for West Africa. We propose that the West Africa-Baltica-Amazonia-Congo-São Francisco were associated in a long-lived WABAMGO juxtaposition (~1100–800 Ma).

Keywords: West Africa, Neoproterozoic, Tonian, Rodinia, paleomagnetism.

 
Optimal design of experiments for effective modeling of atrazine degradation in soils
Authors: Chavez Rodriguez Luciana , González-Nicolás Ana , Ingalls Brian , Nowak Wolfgang , Streck Thilo , Xiao Sinan , Pagel Holger
Published: March 2021

The natural degradation pathways of the herbicide atrazine (AT) are highly complex. These pathways involve the metabolic activity of several bacterial guilds (that use AT as a source of carbon, nitrogen or both) and abiotic degradation mechanisms. The co-occurrence of multiple degradation pathways, combined with challenges in quantifying bacterial guilds and relevant intermediate metabolites, has led to the development of competing model formulations, which all represent valid descriptions of the fate of AT. A proper understanding of the fate of this complex compound is needed to develop effective management and mitigation strategies.

Here, we propose a model discrimination process in combination with prospective optimal design of experiments. We performed Monte-Carlo simulations using a first-order model that reflects a simple reaction chain of complete AT degradation and a set of Monod-based model variants that consider different bacterial consortia and degradation pathways. We used a Bayesian statistical analysis of these simulation ensembles to simulate virtual degradation experiments and chemical analysis strategies, thus obtaining predictions on the utility of experiments to deliver conclusive data for model discrimination. To do so, we defined different experimental protocols including a combination of: i) the metabolites to measure (AT, metabolites and CO2), ii) sampling frequency (sampling every day, every two days and every four days), iii) features difficult to quantify (specific bacterial guilds). As a statistical metric to measure the conclusiveness of these virtual experiments, we used the so-called energy distance.

Our results show that simulated AT degradation pathways following first-order reaction chains can be clearly distinguished from simulations using Monod-based models. Within the Monod-based models, we detected three clusters of models that differ in the number of bacterial guilds involved in AT degradation. Experimental designs considering main AT metabolites and sampling frequencies of once every two or four days at durations of 50 or 100 days provided the most informative data to discriminate models. Including measurements of bacterial guilds only slightly improved model discrimination. Our study highlights that environmental fate studies should prioritize measuring metabolites to elucidate active AT degradation pathways in soil and identify robust model formulations supporting risk assessment and mitigation strategies. 
Experiences on production - usage reasoned malfunctions & development of  X-ray tubes used in science and their effects on sediment measurements
Authors: Acar Dursun , Çagatay Namık , Genç Ş. Can , Eriş K. Kadir , Biltekin Demet , Yakupoğlu Nurettin
Published: March 2021

Surface fractures at the filament of X-ray tube increase more with metal fatique or wrong cooling  and heating processes. Fractured filament continue to work as repeating open circuit positions in random times with  turning fully conductive state in short time. We are explaining how open circuit flashes at the filament providing wrong measurement results. Their low voltage electric circuit conductive problems  repeat in milliseconds periods. At  the results, it gives the impression of healthy measurement values. Because that the measured sample absorbs photonic energy and direct it to neighbouring elements in continuous element  electron scattering  circulations , by the way that delayed secondary electron energy scatters hide all electron supply extinctions on the semi broken flament wire and indirect counts  continue by the detector from coming reflection energy. ( real counts are not from exact beam  target of sample surface during energy deprivations , and it is impossible to understand that the measurement is inaccurate because it causes similarity as discrete element counts in sedimentation layers ).  Filament voltage arcs do not warn machine with error reporting systems until to whole ruptured filament touch to anode walls or their far displaced edges of 2 broken filament positioning. Erroneous records take their place in the world of science if the lithology was not followed. We collected faulty measurement data from our experiences for indicate when and  how possible to facing such as events.

For eliminate  explained reasons at above , the tubes must be gently heated and  cooled. Excessive cooling or heating of the tubes or oxid placement and leakeage  at gasget contacts reduces the surface contact areas of the insilators with the corrosion by  condensing water around the rubber insulation gasgets , it causes cooling liquid leakage or increasing humidity at the tube housing block via following serial failures of HV unit such as increasing amounts of the broken tube events. During the replacement of insulating gasgets, enough care should be taken for gasket contact points as oiling  them with  silicone grease as a form of the thin film. High responsibility must be with continuous  result control  and reference correlations on the scientific sample. With this way we can eliminate possible  negative results by malfunctions on measurements.
Aerosol impacts for convective parameterizations: Recent changes to the Grell-Freitas Convective Parameterization
Authors: Barnes Hannah , Grell Georg , Freitas Saulo , Li Haiqin , Henderson Judy , Sun Shan
Published: March 2021

The Grell-Freitas (GF) cumulus parameterization is an aerosol-aware, scale-aware convective parameterization. This presentation will focus one of the several developmental activities ongoing in GF: the continued development of its aerosol-aware capabilities and the impact in global forecast models.

Previous versions of GF initialized aerosols based on an assumed value of aerosol-optical depth (AOD) that was applied uniformly across the entire globe. Observations of AOD indicate that AOD varies substantially across the globe. Recently, the constant AOD value assumed in GF has been replaced by global AOD data from NASA’s MERRA2 reanalysis. Thus, the distribution of aerosols at initialization more physically reasonable and geographically appropriate. This is important since the treatment of aerosols in GF should be most sensitive in regions with either very high or very low AOD. This method is extremely efficient, but can be adapted so that other aerosol and AOD products can be used in GF. Other products that could be used for initialization include the aerosol climatology used by the Thompson Aerosol-Aware Microphysical Parameterization or predicted aerosols using NOAA’s aerosol prediction model, which is currently one ensemble in the Global Ensemble Forecast System – Aerosols (GEFS-Aerosols).   

GF includes three aerosol related cloud processes: aerosol-influenced evaporation, aerosol-influenced auto-conversion of cloud water to rain water, and aerosol wet scavenging based on memory. As in Wang (2013) the treatment of wet scavenging has been modified so that the aerosol wet scavenging efficiency is proportional to precipitation efficiency. Additionally, aerosols in GF are now allowed to slowly return to their original concentrations during precipitation-free periods. These changes are important since they allow the aerosols in GF to evolve over time in a physically realistic manner.

The impact of these changes to GF will be shown in a version of NOAA’s operational global prediction model.   
Global Carbon Fluxes Induced by Agriculture-Related Land-Use and Land Cover Change Activities
Authors: Jain Atul , Xu Xiaoming , Shu Shijie
Published: March 2021

The aim of this study is to estimate the net carbon fluxes from agriculture-related land-use and land cover change (LULCC) activities, which are referred to as emissions from the land due to human activities. These include land use (LU, e.g., farmland for food and feed production, including management) and land cover changes (LCC, e.g., deforestation for and reforestation of agricultural land, and conversion of grasslands and pastureland to agriculture land or vice versa). Agriculture land-use practices could be a source of atmospheric CO2. However, the management of agricultural practices may reduce carbon emissions and increase soil carbon sequestration. Simultaneously, land-cover change activities clear existing ecosystems, their biomass and disturb the soil, generating carbon emissions. Previous earth system models usually have a simple or no representation of land agriculture practices, such as planting crops, fertilization, irrigation, harvesting grains for food and livestock-feed, recovering crop residue for feed and other usages, and grazing, livestock-feed, and manure cycle. This study uses a land surface model with spatially heterogeneous representations of such agricultural land use activities, in addition to land cover change, such as the change from forest to agricultural land. Our study shows the net agricultural land area increase of 0.11 million hectares/yr during 2007-2013, including 2.12 million hectares/yr of other land converted to agricultural land and 2.01 million hectares/yr of agricultural land converted to other lands. The results show that global net carbon flux due to agriculture-related LULCC is 2.26 Pg C/yr (net emission), consisting of 38% due to land-use activities and 62% due to land cover change. South America (22%), North America (19%), and South and Southeast Asia (13%) are the top contributing regions for net carbon flux induced by LULCC. South America has contributed the most flux from land cover change (18%), while North America has generated the most carbon flux due to land-use activities (12%) among all macro geopolitical regions.  By quantifying the carbon fluxes induced by different agriculture activities this study provides a complete estimate of the yearly carbon cycle in the agriculture system at the spatial scale, which may improve the representations of agriculture land use activities in Earth System Models.
No-regret adaptation to climate change through management of glacial lakes in the Santa River Basin in Peru
Authors: Celmi Gladis , Momblanch Andrea , Hess Tim , Fyffe Catriona L. , Potter Emily , Orr Andrew , Drenkhan Fabian , Walker-Crawford Noah , Loarte Edwin , Bustamante Maria Gracia , Pellicciotti Francesca
Published: March 2021

The vast majority (~70%) of tropical glaciers in the world are located in the Peruvian Andes. The Santa River Basin, in the Ancash region of Peru, is bound by two parallel mountain ranges; the Cordillera Blanca to the east and the Cordillera Negra to the west. The main water sources in the Cordillera Blanca are rivers and lakes originated from glacier melt, while the Cordillera Negra has no glaciers and depends on seasonal rainfall. In the last decades, water resources have decreased due to climate change, while demand has increased due to population growth and intensification of agricultural and industrial activities. Moreover, higher water levels in glacial lakes due to accelerated glacier melt has reduced their flood attenuation capacity that, along with other triggers of outburst floods, can have catastrophic consequences. One of the strategies adopted by the regional government is the construction of dams, floodgates and siphon drainage systems to reduce the risk of outburst floods. The lowering of lake water levels to provide flood attenuation conflicts with the need for increasing water regulation in the basin (to compensate glacier mass loss) and alters the natural downstream flow regime.

This study responds to the need for long-term planning of the major glacial lakes in the Santa River Basin to satisfy all water uses, including environmental ones, and contributing to flood reduction under alternative future climate change scenarios. We adopt a systems analysis approach with the support of the Water Evaluation and Planning system (WEAP) coupled with the hydro-glaciological model TOPographic Kinematic APproximation and Integration (TOPKAPI). They are driven by high-resolution climate projections from the Weather Research and Forecast (WRF) model for future emission scenarios and global climate models available in the CMIP5, for the period 2022-2050. The integration of these models allows representing the complex hydrology of the catchment, explicitly accounting for glacier mass change, and water resources management including the main lakes and water demands. A large spectrum of climate change and lake management scenarios are analysed with a no-regret approach using criteria related to the reliability of water supply for human demands and environmental flows, along with flood abatement and water scarcity. The results of this study that interface hydrology, water demands and infrastructures support local decision-making and exchange with stakeholders in the Santa River Basin, which will strengthen water security across water uses, fostering development and economic growth in the region.
Building bridges between disciplines: A generalized mathematical framework for climate change impact assessment
Authors: Guthke Anneli , Bakhshipour Amin E. , de Barros Felipe P.J. , Class Holger , Daniell James E. , Dittmer Ulrich , Friedrich Markus , Haas Jannik , Kropp Cordula , Merz Bruno , Oladyshkin Sergey , Schäfer Andreas , Sinsbeck Michael , Straub Daniel , Terheiden Kristina , Wieprecht Silke , Nowak Wolfgang
Published: March 2021

Climate change impact and risk assessment is per definition a highly interdisciplinary task. Collaboration across disciplines is, unfortunately, often complicated by different perspectives, approaches, and terminology. To help building bridges, we propose a generalized mathematical framework for impact and risk assessment.

In an unprecedented community effort, we have derived a generally applicable risk equation for spatially-distributed and dynamic systems. We start off with a general framing and then refine individual parts of the equation as much as needed. We will show how the individual terms of our unified risk equation explicitly relate to concepts of frequency, intensity, duration, exposure, vulnerability and asset worth. The rigorous mathematical treatment allows investigating the importance of risk factors and serves as a basis for risk management and reduction. Yet, the actual quantification of risk is not our primary goal – rather, the proposed framework forces us to be very precise in definitions and terminology. Thereby, it effectively improves communication and collaboration across disciplines. Indeed, we even learn greatly in cases where we identify limitations that seem to spoil such a mathematically rigorous treatment.

We have successfully applied the framework to various disciplines of civil and environmental engineering, such as flood risk assessment, seismic risk assessment and reliability analysis of critical infrastructure. Users of the equation praise the structured common ground for discussion and highly recommend at least hypothetically applying this framework to gain a more unified understanding of the problem at hand. In this presentation, we discuss the potential of our proposed framework for risk assessment under climate change. Our transparent and rigorous approach is ideally suited to inform stakeholders and policymakers. Further, we are confident that our approach will serve as a catalyst for interdisciplinary advances toward effective adaptation and mitigation strategies.
Interactive Stratospheric Aerosol models response to different sulfur injection amount and altitude distribution during volcanic eruption
Authors: Quaglia Ilaria , Brühl Christoph , Dhomse Sandip , Franke Henning , Laakso Anton , Mann Graham , Mills Micheal , Niemeier Ulrike , Pitari Giovanni , Sukhodolov Timofei , Timmreck Claudia , Tuccella Paolo , Visioni Daniele
Published: March 2021

Large magnitude tropical volcanic eruptions emit sulphur dioxide and other gases directly into the stratosphere, creating a long-lived volcanic aerosol cloud which scatter incoming solar radiation, absorbs outgoing terrestrial radiation, and can strongly affect the composition of the stratosphere.

Such major volcanic enhancements of the stratospheric aerosol layer have strong “direct effects” on climate via these influences on radiative transfer, primarily surface cooling via the reduced insolation, but also have a range of indirect effects, due to the volcanic aerosol cloud’s effects on stratospheric circulation, dynamics and chemistry.

In this study, we investigate the 3 largest volcanic enhancements to the stratospheric aerosol layer in the last 100 years (Mt Agung 1963; Mt El Chichón 1982; Mt Pinatubo 1991), comparing co-ordinated simulations within the so-called HErSEA experiments (Historical Eruptions SO2 Emission Assessment) several national climate modelling centres carried out for the model intercomparison project ISA-MIP.

The HErSEA experiment saw participating models performing interactive stratospheric aerosol simulations of each of the volcanic aerosol clouds with common upper-, mid- and lower-estimate amounts and injection heights of sulfur dioxide, in order to better understand known differences among modelling studies for which initial emission gives best agreement with observations. 

First, we compare results of several models HErSEA simulations with a range of observations, with the aim to find where there is agreement between the models and where there are differences, at the different initial sulfur injection amount and altitude distribution.

In this way, we could understand the differences and limitations in the mechanisms that controls the dynamical, microphysical and chemical processes of stratospheric aerosol layer.