bluuebunny/crossref_metadata_2025 huggingface dataset:
Using geodynamic modeling to test plate tectonic scenarios of the Mediterranean-Alpine area
Authors: Kaus Boris , Le Breton Eline , Reuber Georg , Schuler Christian
Published: March 2020

Using geological and geophysical data, it is possible to reconstruct the past motion of tectonic plates involved in the Alpine orogeny and propose possible scenarios for their geological evolution. However, those scenarios have not yet been tested for geodynamic consistency.

Here, we perform 3D thermomechanical geodynamic simulations of the Mediterranean-Alpine area starting with a plate tectonic reconstruction at 20 Ma based on the work of Le Breton et al. (2017). The models include viscoelastoplastic rheologies and a free surface, and thus simulate the spontaneous occurrence of shear zones as well as the development of topography. Whereas some aspects of the tectonic reconstruction are well constrained (i.e. past position of the plates and subduction-collision fronts), many details such as the dip and length of the subducted plates, their thermal structure as well as their rheology, are unknown. The models are run forward in time to see to which extent they are consistent with the kinematic reconstructions. Perhaps unsurprisingly, our initial modelling attempts show a wide variety of behavior, including slab break off events and slab rollbacks in the wrong directions. Yet, in all cases tested so far, the model evolution does not reproduce the present-day geological setting, with Adria frequently moving too far towards the east and breaking apart internally, frequently no Alpine chain forming and in some cases new subduction zones developing within the Western Mediterranean that swallow Sardinia and Corsica.

Reproducing geological scenarios with thermomechanical geodynamic modelling thus requires substantial additional work, both from the modelling side (testing the effect of uncertain parameters on the behaviour of plates and subduction zones), as well as from the plate reconstruction side (assessing which parameters are well constrained and need to be reproduced).  Nevertheless, interesting insights can already be obtained from our models, and in our presentation, we will highlight some of the links between interacting subducting plates and plate motion.

Le Breton E, Handy MR, Molli G, Ustaszewski K (2017) Post-20 Ma Motion of the Adriatic Plate: New Constraints From Surrounding Orogens and Implications for Crust-Mantle Decoupling. Tectonics 36:3135–3154. doi: 10.1002/2016TC004443

 
Estimating wave-induced bottom shear stresses in the Gulf of Bothnia
Authors: Tuomi Laura , Kotilainen Aarno , Kanarik Hedi , Virtasalo Joonas , Vähä-Piikkiö Olga , Pettersson Heidi
Published: March 2020

Sea floor erosion can be induced by waves, bottom currents and ice. Although the Gulf of Bothnia in the Baltic Sea is a relatively small basin, the record value of significant wave height is 8.1 m with highest individual wave of 15 m. In the present climate the seasonal ice cover limits the wave growth during winter time, but in the future climate it is estimated that ice extent will reduce which can lead to more severe wave climate. Thus, the effect of waves on the bottom sediment erosion is expected to increase. We used wave model WAVEWATCH III to do a 30-year high-resolution hindcast for the Gulf of Bothnia. The hindcast wave parameters were validated against wave buoy and altimeter wave measurements to ensure good quality of the wave hindcast. The hindcast near-bottom orbital velocities and amplitudes were used to estimate wave-induced bottom shear stress. These calculations are based on the wave spectra, taking into account the effect of different wave heights and wave lengths. The results were used to evaluate the extent of areas that experience significant wave-induced bottom stress under the present climate. Furthermore, the results show how often and for how long periods the wave-induced stress exceeds the critical values for sediment resuspension to take place. The estimates of the critical values for resuspension are calculated utilising the seabed sediment data available for the Gulf of Bothnia. The adequacy of the results is evaluated by comparing the known erosional seafloor areas to the ones estmated based on the hindcast values. This study is part of the SmartSea project of the Strategic Research Council of the Academy of Finland (grant no. 292 985).
On the relationship between offshore geodetic coverage and slip model uncertainty
Authors: Kosari Ehsan , Rosenau Matthias , Bedford Jonathan , Rudolf Michael , Oncken Onno
Published: March 2020

Characterizing the time-dependent slip evolution along subduction megathrusts during seismic cycles is a key step to unfold the recurrence patterns of and hazard imposed by great earthquakes. However, having adequate geodetic observations in the appropriate locations is essential for reliably modelling both interseismic coupling and coseismic slip. The 2011 Tohoku-oki earthquake as a well-known trench breaking and tsunamigenic megathrust seismic event clearly demonstrated the limitations of the distributed slip models using land-limited geodetic instruments. In this study, we have set up a scaled analogue megathrust model to produce analogue earthquakes while Digital Image Correlation (DIC) and the Analogue Geodetic Slip Inversion Technique (AGSIT) have been applied to retrieve the model surface velocities (incremental displacement) and model coseismic slip distribution, respectively. We generated more than 20 slip models for a series of events by sequentially disregarding trenchward rows of virtual GPS stations (vGPSs) for slip modelling thereby systematically reducing simulated offshore coverage. The analogue earthquakes have been categorized to two different sets as non-trench-breaking and trench-breaking ruptures. Here we show how slip models of analogue earthquakes change as a function of offshore coverage quantitatively and qualitatively. The sensitivities with respect to a potential bimodality of slip distribution and up-dip limit of the slip distribution model have also been assessed.

 
Simulation of river pollution by heavy metals under different scenarios of anthropogenic load on watershed and climate changes
Authors: Motovilov Yuri , Fashchevskaia Tatiana
Published: March 2020

The distributed physically-based model ECOMAG-HM was applied to simulate cycling of water and heavy metals (HM) (copper, zinc, manganese) on the surface, in soil, groundwater and river water of the Nizhnekamskoe Reservoir (NKR) watershed under various scenarios of economic activity and climate changes*. The NKR watershed is located in the South Ural region of Russia and has an area of 186000 km2. This watershed is characterized by high background concentrations of HM due to wide occurrence of ore deposits and considerable concentration of ore-parent elements in rocks. The main purpose of the study was to quantify the contribution of point (wastewater) and diffuse sources to pollution of water bodies, which is necessary for planning measures to reduce HM pollution in the watershed. The first objective of the study was to assess the ECOMAG-HM model potential for large scale modelling water quality parameters at the different hydrological and hydrochemical monitoring stations by comparing simulated and observed the hydrological and hydrochemical regimes in the historical period on the main river and its tributaries. The local areas of the catchment were identified, which were not covered by hydrochemical observations, with significant levels of river water HM contamination. The maps of simulated spatial fields of genetic components of runoff and HM washoff to the river network were designed. The contribution of anthropogenic sources to the HM runoff formation was estimated and it has been established that with the current level of anthropogenic load, the contribution of wastewater point discharges does not exceed 4%. Scenarios and consequences of increasing the amount of HM discharged as part of wastewater are considered. The time scale of the catchment self-purification from HM was evaluated. The results showed that in the absence of external impacts on the catchment area, a decrease of HM content in river waters over a 400-year period will not be exceed 10%. Climate change impact assessment on water quantity and quality was simulated for future period on the level 2050 for copper. The results are (a) the average annual river flow will increase by 11%, (b) the average annual flow of copper - by 18%, (c) the increase in copper runoff was mainly due to an increase in river runoff, (d) the change in average annual concentrations of copper in river runoff is insignificant (+7%). 
Acknowledgements. The work was ﬁnancially supported by the Russian Science Foundation (grant no. 17-7730006).

*Motovilov, Yu.G., Fashchevskaya, T.B. Simulation of spatially-distributed copper pollution in a large river basin using the ECOMAG-HM model // Hydro. Sci. J., 2019, V. 64, Is. 6, pp. 739–756.
Conflicting drivers of land carbon uptake variability reconciled by land-atmosphere coupling
Authors: Humphrey Vincent , Berg Alexis , Ciais Philippe , Frankenberg Christian , Gentine Pierre , Jung Martin , Reichstein Markus , Sonia I. Seneviratne
Published: March 2020

Obtaining reliable estimates of the sensitivity of carbon fluxes to water availability, temperature and vapor pressure deficit is essential for constraining climate-carbon feedbacks in Earth system models. However, these variables often co-vary because of soil moisture – atmosphere feedbacks, especially in situations where they are most susceptible to strongly impact ecosystems (e.g. during droughts and heatwaves), leading to potentially conflicting results when sensitivities are assessed independently. In particular, there is conflicting evidence on the role of temperature versus water availability in explaining these variations at the global scale.

Here, we show that accounting for the effect of soil moisture – atmosphere coupling resolves much of this controversy. Using idealized climate model experiments, we find that variability in soil moisture accounts for 90% of the inter-annual variability in land carbon uptake, mainly through its impact on photosynthesis. Without SM variability, the inter-annual variability (IAV) of land carbon uptake is almost eliminated. We show that the effects of soil moisture can be decomposed into 1) a direct ecosystem response to soil water stress and 2) a dominant indirect response to extreme temperature and vapor pressure deficit triggered by land-atmosphere coupling and controlled by anomalous soil moisture conditions.  Importantly, these two mechanisms do not necessarily have the same spatial extent, and some regions can be more sensitive to indirect effects than to direct effects.

These two pathways explain why results from coupled climate models suggest a dominant role of soil moisture, while uncoupled simulations diagnose a strong temperature effect. These findings have strong implications for offline model sensitivity analyses as well as field scale manipulation experiments (i.e. rainfall exclusion studies) where the impact of drought on carbon exchange and vegetation activity is often studied by intervening solely on soil moisture content with little consideration of the physical feedbacks on temperature and air humidity occurring in natural conditions.
Detecting Transient Creep Events on the Ismetpasa Segment of the North Anatolian Fault with Continous GNSS Time Series
Authors: Özdemir Alpay , Doğan Uğur , Jara Jorge , Çakır Ziyadin , Jolivet Romain , Ergintav Semih , Özarpacı Seda , Benoit Angélique
Published: March 2020

Twenty six years after the Mw 7.3 Gerede Earthquake in1944, Ambraseys (1970) first recognized, in the offset of a manmade wall, the signature of slow aseismic slip along the central segment of the North Anatolian Fault (NAF). Following this discovery, many studies characterized the behavior of aseismic slip with land-and space-based geodetic techniques, including creepmeters. It is now well recognized that the aseismic slip rate decreases logarithmically from more than 3 cm/yr in the years following the Gerede Earthquake to approximately 6±2 mm/yr today. In the last two decades, InSAR allowed deriving maps of ground velocities suggesting that aseismic slip extends along a 100-km-long section of the fault. Furthermore, aseismic slip rate varies in space along strike, reaching its peak value approximately 15-24 km east of the city of Ismetpasa. Furthermore, creepmeter measurements and InSAR time series indicate that aseismic slip in the region of Ismetpasa behaves episodically rather than continuously, alternating quiescent periods and transient episodes of relatively rapid aseismic slip. These observations raise questions about how slip accommodates tectonic stress along the fault with significant implications in terms of hazard along the seismogenic zone.

 

In order to monitore spatial and temporal variations in the aseismic slip rate and to detect slow slip events along the fault, we have established ISMENET -Ismetpasa Continuous GNSS Network- in July 2016. ISMENET stations are distributed over approximately 120 km along strike. In order to explore the shallow, fine spatio-temporal behavior of aseismic slip, stations are located within 200 m to 10 km of the fault. We process GNSS data with the Bernese (V5.2) and GAMIT/GLOBK (V10.7) GNSS software. We analyze the GNSS time series to extract the signature of aseismic slip using a principal component analysis to reduce the influence of non-tectonic noises.

 

Keywords: Ismetpasa, Aseismic slip, GNSS, PCA, Time Series Analysis, NAFZ
The use of interdisciplinary storylines to ensure the inclusiveness of marginalized stakeholders in participatory sociohydrological modelling: A case study in Tz’olöj Ya’, Mayan Guatemala
Authors: Bou Nassar Jessica , Malard Julien , Adamowski Jan , Ramírez Ramírez Marco , Tuy Héctor
Published: March 2020

New and unconventional sources of data that enhance our understanding of internal interactions between socio-economic and hydrological processes is central to sociohydrological modelling. Participatory modelling (PM) departs from conventional modelling tools by informing and conceptualizing sociohydrological models through stakeholder engagement. However, the implementation of most PM processes remains biased, particularly in regions where marginalized communities are present. Most PM processes are not cognizant of differentiation and diversity within a society and tend to treat communities as homogeneous units with similar capabilities, needs, and interests. This undifferentiation leads to the exclusion of key actors, many of whom are associated with marginalized communities. In this study, a participatory model-building framework (PMBF), aiming to ensure the inclusiveness of marginalized stakeholders - who (1) have low literacy, (2) are comparatively powerless, and/or (3) are associated with a minoritized language - in participatory sociohydrological modelling is proposed. The adopted approach employs interdisciplinary storylines to inform and conceptualize system dynamics-based sociohydrological models.The suggested method is underpinned by the Multi-level Perspective (MLP) framework, which was developed by Geels et al. (2002) to conceptualize socio-technical transitions and modified in this study to accommodate the development of interdisciplinary storylines. A case study was conducted in Atitlán Basin, Guatemala, to understand the relationships that govern the lake’s cultural eutrophication problem. This research integrated key stakeholders from the indigenous Mayan community, associated with diverse literacy ranges, and emerging from three different minoritized linguistic backgrounds (Kaqchikel, Tz’utujil, and K’iche’), in the PM activity. The generated model serves as a decision support system for managing nutrient discharge into Lake Atitlán, allowing stakeholders to investigate trends of different policy and management scenarios. The participatory model-building activity helped eliminate the impact of power imbalances in water resources management and empower community-based decision-making.
Meter-scale retrieval of industrial methane emission using GHGSat’s satellite constellation
Authors: Strupler Mathias , Jervis Dylan , McKeever Jason , Varon Daniel , Gains David , Tarrant Ewan , Maasakkers Joannes D. , Pandey Sudhanshu , Houweling Sander , Aben Ilse , Scarpelli tia , Jacob Daniel J. , Germain Stephane
Published: March 2020

To reduce green house gases emissions, it is crucial to be able to give actionable feedback to industrial facility operators on their emissions. For this purpose GHGSat is building a constellation of satellites capable of monitoring and quantifying emissions from individual sites.

In 2016, GHGSat launched a demonstration satellite called GHGSat-D. It is the first and only satellite able to retrieve the methane column with a spatial resolution of less than 50 meters. We will present examples of detection and quantification of methane leaks in Central Asia using GHGSat-D. The retrieved methane column density shows plumes originating from known source locations and aligned with the local wind direction.  The largest and most persistent of those sources was estimated to have an emission rate of 10-42 tons.h-1, a magnitude comparable to the Aliso Canyon and Ohio blowouts. The complementarity of GHGSat's observations with other satellites observations will be highlighted using a comparison of GHGSat-D and Sentinel-5P in the same Central Asia region.

We will provide an update of GHGSat's constellation, with news from GHGSat-C1 (launch March 2020) and GHGSat-C2 (launch summer 2020). Lessons learned and improvements to the new satellites will be discussed. The anticipated vertical column density precision of GHGSat-C1 and C2 are 2% and 1% of background methane concentration respectively, compared to 13% for GHGSat-D. We will also introduce  the data calibration and validation plans for the new satellites.
Mantle flow in planets: lessons from sugar syrup, hair gel, milk skin and marble cake.
Authors: Davaille Anne
Published: March 2020

Even in the eon of supercomputers, I would claim that laboratory experiments remain an invaluable tool to investigate new phenomena and old problems, for at least 6 reasons:  (1) Since they let nature solve the equations, they can explore new phenomena for which such equations do not yet exist. (2) You usually can turn around them and have a good look at their three-dimensional structure. (3) You can observe their evolution through time. (4) you can simplify the system until you understand something ! (5) On the other hand, experiments can explore ranges of parameters, or geometries, where the equations are too challenging to be solved analytically or even numerically. (6) They are at the same time fun and thought-provoking. So yes, laboratory experiments are crucial for exploring new physics, testing theories and computer codes, and show your students, colleagues and family « how it works ». 
Mantle dynamics, and thermal convection, is a good example.  The emergence of mantle convection models was dictated by the failure of static, conductive, and/or radiative thermal history models to account for the mantle temperature regime, the Earth’s energy budget, and the Earth’s lateral surface motions. Convection, which transports heat by material flow, is the only other physical mechanism capable of explaining these observations. The force driving flow is gravity, whereby material lighter than its environment rises, while denser material sinks. Such density anomalies can be produced by differences in composition and/or temperature. Then, the flow patterns produced by convection also strongly depend on the way the material deforms when submitted to a force: cold surface rocks break (typical of a solid) on short time scale and distances, while hot mantle rocks creep (typical of a liquid !) on geological time scales. This dual nature of a solid and a liquid is the main source of complexity, and debate, in mantle dynamics. Modern physics calls these solid-liquid materials « soft matter », and we use plenty of them in the everyday life and in the kitchen. I will show how differently mantle plumes and lithospheric plates form in honey syrup, hair gel, milk and cake. And how marble cake can help us understand mantle mixing.
Tectonic structure and metallogeny of the Western Chukotka: insights from comprehensive geophysical dataset interpretation.
Authors: Antashchuk Kseniia , Atakov Alexey , Mazurkevich Kirill , Petrov Oleg
Published: March 2020

Geological structure of western part of the Chukotka fold belt has been studied basing on the results of joint interpretation of geophysical data. The potential-field data, seismic and magnetotelluric data along two regional profile crossed the area and the off-shore seismic data obtained on the East Siberian sea were used in this study. The NE and NW oriented fault systems which control the mineragenous zones location were first detected and delineated. Joint interpretation of seismic and MT data along regional profiles allowed us to study: the deep structure of NW directed thrusts; the intrusion bodies morphology; the structural features of the Paleozoic and Mesozoic formations and the structure of volcanic deposits. The models of geological structure along regional profiles were used as a reference for potential field interpretation. Architecture of crystalline basement of the area was studied and several “steps” were detected. The depth of crystalline basement increases from north to south and reaches the largest depth under the volcanic deposits of Ochotsk-Chukotsk Volcanic Belt (OCVB).
Centennial scale environmental change at key arctic observational sites
Authors: Christensen Torben Røjle , Rasmussen Kerstin , Abermann Jakob , Raundrup Katrine , Christoffersen Kirsten , Hansen Birger Ulf , Arndal Marie Frost
Published: March 2020

The Arctic is changing in response to ongoing warming. Multiple effects have been documented in terms of sea-ice distribution, land-ice volume and ecosystems both in the marine and terrestrial realm, which are clear responses to the overall global warming. Targeted efforts documenting individual components of the arctic system build the base-line for quantification of these effects.

Comprehensive ecosystem observational programs covering both glacial, terrestrial and marine components are rare in the Arctic but one such, the Greenland Ecosystem Monitoring (GEM) program, has now been operational for nearly 25 years at three main sites in Greenland. Zackenberg valley and Young Sund in NE Greenland is representing the high-arctic environment, Disko Island on the central west coast of Greenland at the border between the high and the low-arctic and Nuuk-Kobbefjord in SW Greenland the low-arctic.

The GEM program at all three sites cover inter-annual variation in ecosystem dynamics of glacial, terrestrial and marine ecosystems with data gathered from more than 2000 parameters some of which being automatically recorded at very high frequencies (up  to 20 Hz for micro-meteorological measurements). This present-day detailed, comprehensive and high-frequency monitoring of ecosystem dynamics calls for the question: Which historical sources may be used in order to anchor the environmental status of the monitored areas back in time?

For the composite landscape dynamics including glacier, terrestrial and near-coastal environments it is of great value to study visual, mainly photographic evidences that are available from different parts of the portfolio of arctic exploration during the 19th and 20th centuries. We will in this presentation review available historical archival data (early photographs, paintings, drawings) from the GEM monitoring locations and their immediate surroundings.

The different historical setting over the centennial timescale is briefly discussed and particular illustrative records from the individual sites are shown. The evidence of change hereby shown at the centennial time scale is evaluated in the perspective of results from decadal scale present day monitoring.
The intra-annual variability as a potential driver for the mean deep circulation in the tropical oceans
Authors: Delpech Audrey , Ménesguen Claire , Marin Frédéric , Cravatte Sophie , Morel Yves
Published: March 2020

The deep tropical ocean circulation is dominated by systems of vertically and meridionally alternating zonal jets, known as the Equatorial Deep Jets (EDJs) and Extra-Equatorial Jets (EEJs) respectively. The energy sources and physical mechanisms responsible for this circulation are still poorly understood. Recent studies have suggested the importance of intra-annual equatorial waves to transfer their energy to the EDJs.

In this study, we use idealized numerical simulations forced with a wave-like surface momentum flux to investigate how intra-annual variability can be relevant to the formation of the EEJs. It is shown that the amplitude of the jets, their meridional scales and their vertical and latitudinal extensions are sensitive to the period and wavelength of the forced wave. Short intra-annual waves with periods around ~70 days and wavelength ~300 km are found to reproduce the observed circulation most realistically. Focusing on the dominant barotropic mode, the underlying physical processes are detailed. A spectral analysis reveals that the energy transfer between the forced waves and the jet-structured circulation is compatible with a decay instability occurring in waves triadic interactions.

In parallel, a statistical analysis is performed on observations of the 1000m-velocities inferred from Lagrangian Argo floats drifts to document the amplitude and scales of the deep intra-annual variability in the tropical Pacific and Atlantic oceans. It gives evidence for the presence of short intra-annual waves that share common properties with the most unstable waves found for the EEJ generation.
Hydraulic modelling of brown trout habitat in a hydropower-impacted Alpine braided stream
Authors: Ni Yufang , Lane Stuart N.
Published: March 2020

Braided rivers have complex and dynamic bed morphologies. In Alpine streams, they may be impacted upon by natural flow variability (e.g. snow and ice melt) that can lead to the lateral displacement of suitable habitat. To date, this process has been investigated in two-dimensional models due to the difficulty of applying fully three-dimensional computational fluid dynamics at the scale of river reaches. This is problematic because lateral and vertical variations in kinetic energy and vorticity and their change through time are crucial determinants of where good habitat is found and where it migrates to as river discharge changes. Here we attempt a reach-scale three-dimensional model of stream habitat using the open-source toolbox OpenFoam, with turbulence resolved by Delayed Detached Eddy Simulation (DDES), to model the flow structures in a braided reach of the Turtmanna, a tributary of the Rhône river, Switzerland. The results show that locations deemed suitable in a 2D solution are not when looked at in 3D, and vice versa. This result has important implications for the use of hydraulic habitat modelling for the design of environmental flows in human impacted Alpine streams.
Impact of oily wastewater for public health in rural area: a case study of Kazakhstan
Authors: Radelyuk Ivan , Tussupova Kamshat , Zhapargazinova Kulshat
Published: March 2020

Oil refinery industry historically has been related with groundwater pollution. According to WHO, contaminants may reach groundwater most easily as a result of discharge to the ground surface and subsequent infiltration through the soils, or releases from the ponds. Environmental Performance Review for Kazakhstan from UNECE states that oil refinery factories in Kazakhstan are one of the biggest sources of groundwater contamination despite of existing governmental and industry environmental monitoring systems. Recent studies showed that more than 50% of the people in rural Kazakhstan use groundwater for domestic purposes, consequently, many people potentially drink unsafe water. Despite this, oil refineries in Kazakhstan continue to discharge wastewater with high concentrations of different pollutants and these contaminants reach the groundwater very easily. The aim of this paper is to analyse and interpret a dataset obtained during a 6-year (2014–2019) monitoring program of the control of groundwater quality surrounding recipient of poorly treated wastewater discharges in one of the Kazakhstani industrial clusters. Multivariate statistical techniques and Heckman selection model were used for assessment of loading of natural and anthropogenic contribution to contamination, including separated evaluation of the impact of toxic substances.

The results show that PCAs have high loading of anthropogenic contamination to groundwater from the oil refinery industry coupled with natural geochemical processes. High concentrations of several parameters, such as total petroleum hydrocarbons, phenols, sodium, chlorides, sulphates, total dissolved solids and total hardness were identified. Water containing such exceeding concentrations of substances affects human body significantly and normally is considered to be rejected by consumers. By means of cluster analysis, the examined wells were combined in three groups according to the concentrations of chemicals and their locations. The results enable a prediction of the groundwater flow in the region studied as well as an estimation of which sites would be most severely affected by contamination. According to obtained data from Heckman analysis, focus of further research should be paid to the distribution of toxic contaminants. The industry is continuing to pollute the environment, which means that assessment of existent and future hazards is needed through improved monitoring system. Thus, the next step of the research considers contamination transport modelling for definite identification of groundwater flow and potentially affected rural areas.
eWaterCycle: Fully open en transparant hydrological data and modelling platform facilitates FAIR policy making.
Authors: Hut Rolf , Hall Caitlyn , Drost Niels , van de Giesen Nick
Published: March 2020

In Spring 2019, eScience Center Netherlands and Delft University of Technology facilitated a workshop to develop a FAIR – Findable, Accessible, Interoperable, Reusable – multi-application platform that hydrological experts and non-experts can use to guide their decision-making. Many hydrologists believe that there are too many models in the field. Each new research generation strives to improve current methods with increasing complexity and developing individual models to fit specific situations - and to what end? If other experts struggle to adapt a model, it’s unreasonable to expect a non-expert to gain meaningful insight to address challenges impacting a community or guide policy.

 A community-driven platform (eWatercycle) has been developed by an international multi-disciplinary team of hydrologists, research software engineers, tinkerers, science policy advisors, and more. The diverse and inclusive team membership is critical to ensure that the best possible tool is developed to address multi-faceted questions and benefit a wide-reaching community. eWatercycle incorporates many popular hydrological models (e.g., SUMMA, PCRGLOB-WB, WFLOW, and HYPE). We have incorporated the massive ERA5 climate reanalysis dataset, as well as global stream gauge data, such that users can analyze a system for any region. 

Considering the potential complexity from eWatercycle’s inclusion of several model types, the team continues to develope this model framework in close cooperation with potential end-users. We envision end-users may include a government scientist working to inform policy decisions on water management or city officials developing risk management strategies for extreme weather events. Users of eWatercycle will not be required to learn new programming languages or overcome significant technical barriers to begin using the framework. As a result, users will be able to use eWatercycle to work towards solving region-specific problems with confidence by considering the outcomes of different hydrological models and access to potential uncertainty in the available data and modeling techniques.

We will demonstrate the latest version of the eWatercycle platform, it's models, data and analyses capabilities. 
The impact of global warming on the upwellings and primary productivity at the southern limb of the California Current, Baja California, Mexico
Authors: Carriquiry Jose , Treinen-Crespo Christina , Villaescusa Julio , Pearson Ann , Barbara Loic
Published: March 2020

Although most simulation models published have concluded that coastal upwelling will intensify in three of the most productive marine ecosystems of the world, the results seem contradictory for the California Current System (CCS). These contradictory results may be due to the fact that instrumental records are too short to yield reliable predictions. Because of this, we opted to test this hypothesis by studying the sedimentary record of Soledad basin, in Baja California, Mexico, using geochemical proxies to reconstruct at ultra-high resolution the history of productivity and sea surface temperature during the last two millennia, with particular emphasis on the Anthropocene. Our results indicate that SST (alkenones and TEX-86) do not show a cooling trend during the Anthropocene, but rather multidecadal cycles related to PDO. Likewise, primary productivity organic biomarkers [i.e., alkenone concentration (C37 Total) as a proxy for phytoplankton productivity, etc] show an increasing trend that started 2000 years ago with prominent multidecadal cycles, but without any observable trend taking place during the Anthropocene. An interesting feature of the organic matter record is the increasing amplitude of the cycles towards the present, starting 2000 years ago. Primary productivity is probably controlled by large scale mesoscale eddies developing at the southern Baja California margin.
How does drought affect the δ18O cellulose record? A Biosphere 2 experiment.
Authors: Bailey Kinzie , Hu Jia , Warner Christiane , Ladd Nemiah , Meredith Laura , van Haren Joost , Beyer Matthias , Lehman Marco , Prohaska Neill
Published: March 2020

Wood cellulose records environmental conditions via its isotopic composition, which can be used to reconstruct different environmental events or patterns. However, it has been suggested that there can be a decoupling of the δ18O of cellulose and environmental conditions due to a lag from post-carboxylation processes. Thus, studying the dynamics of intra-seasonal tree growth provides a unique way to examine how the δ18O of cellulose responds to environmental and ecophysiological processes. There are two main factors that contribute to the δ18O signature of cellulose: the isotopic content of the source water and the leaf evaporative enrichment effect, both of which can vary under natural settings. Thus, separating the source water signal from the atmospheric humidity signal in the δ18O of cellulose can be difficult. In this study, we took advantage of a highly controlled ecosystem scale study at the University of Arizona Biosphere 2 tropical forest biome, where a drought treatment was implemented with a deep re-wetting component followed by a shallow re-wetting component. Continuous measurements of δ18O of atmospheric water vapor, soil water and xylem water as well as targeted gas exchange measurements of stomatal conductance and transpiration were made throughout the study. We also collected the δ18O of phloem sugars and cellulose to address how well the Roden et. al. (2001) cellulose model estimated observed δ18O values. One main objective was to examine how the fraction of carbonyl oxygen atoms that exchange at the cambium during cellulose biosynthesis, or Pex, is altered, since recent studies suggest that Pex can very among species, across aridity gradients, and throughout the growing season. Thus, this highly instrumented experiment allows us to look at variations in Pex at a high temporal scale. By examining potential shifts in Pex throughout the formation of a tree ring, we can increase the robustness of reconstructions by targeting specific woody anatomy to capitalize on the different signals of source water and the evaporative effect laid down in wood cellulose.
Assessing the potential groundwater recharge from precipitation in the Pyrenees in the global change context
Authors: Caballero Yvan , Lanini Sandra , Hevin Guillaume , Le Cointe Pierre , Pinson Stéphanie , Desprats Jean-François , Le Coent Philippe , Dewandel Benoît
Published: March 2020

The Pyrenees range is a transboundary region shared by Spain, France and Andorre whose water resources are diverse (snowmelt and rainfall runoff in a topographically variable context, groundwater in complex and heterogeneous aquifers) and poorly known. As many other mountain regions, this territory is particularly vulnerable to the impacts of climate change. In the framework of the PIRAGUA project, funded by FEDER through the EU POCTEFA Program, the potential groundwater recharge from precipitation was estimated over the last 30 years at the scale of the Pyrenean range.

 

Using the meteorological forcing data provided at high spatial resolution in the framework of the PIRAGUA Project, the effective rainfall was computed at the daily time step using three different simple water balance methods, including land use effect on evapotranspiration (crop coefficients method) over the 1981-2010 period. Resulting effective precipitation ranges from 50 to more than 2000 mm/year on average and shows strong differences between the east and west sides of the Pyrenean chain.

 

Potential groundwater recharge from precipitation was then estimated using an effective precipitation infiltration ratio derived from the comparison of the IDPR geomorphological index to the baseflow index extracted from selected river discharge time series over the Pyrenees. The resulting potential recharge was finally averaged at the groundwater bodies’ scale of the Pyrenean chain.

 

Corresponding potential groundwater resources were finally compared to groundwater uses estimated at the Pyrenean scale in order to 1) assess their respective importance in relation to water uses and 2) identify the sectors of the territory for which situations of tension on groundwater resources could already be observed, tensions which are likely to increase in the context of climate change.

 
Biological sources and molecular composition of iron oxides bound organic carbon in agricultural soils
Authors: Huang Qiaoyun , Chen Wenli , Liu Yurong
Published: March 2020

A strong link exists between iron oxides and soil organic carbon (SOC). However, the role of iron oxides in the preservation of SOC in agricultural soil remains poorly understood. In this study we comprehensively examined the concentration, molecular composition and biological sources of iron oxide-bound organic carbon (Fe-bound OC) in arable soils collected from 12 sites in central and east China. The effect of elevated temperatures on Fe-bound OC in two contrasting soils was also investigated. The results indicated that 6.2 ~ 31.2% of the SOC was bound to iron oxides in agricultural soil, and that the binding mechanisms varied from adsorption in most soils to coprecipitation in those with a large content of organic carbon. The distribution of Fe-bound OC showed no clear variation in relation to site, but Fe-bound OC reached a peak in soils with an annual mean temperature of 16.4°C. Correlation analysis demonstrated that TOC might be the main determinant for the amount of Fe-bound OC, and that the binding mechanism is influenced by both TOC and the active Fe ratio. Analysis of C/N, 13C isotope, and synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectroscopy showed that iron oxides selectively protected plant-derived aliphatic compounds and polysaccharides in agricultural soil. Warming decreased the content of Fe-bound OC from 3.46 g kg−1 to 1.99 g kg−1 in Ultisol, while enhanced that from 4.04 g kg−1 to 5.12 g kg−1 in Histosol. NMR results suggested that warming could alter the composition of soil organic matter by accelerating O-alkyl C degradation and increasing the sequestration of recalcitrant alkyl C and carboxyl C. It is supposed that warming promoted the association of iron oxides with microbial-derived polysaccharides and aliphatic compounds. This study revealed the quantitative characterization, biological sources and molecular composition of Fe-bound OC in arable soils, which provides useful information for evaluating and managing the global C cycle under the framework of climate change.
Recent and near future climate change in the Antarctic Peninsula
Authors: Bozkurt Deniz , Bromwich David H. , Rondanelli Roberto
Published: March 2020

This study assesses the recent (1990-2015) and near future (2020-2045) climate change in the Antarctic Peninsula. For the recent period, we make the use of available observations, ECMWF’s ERA5 and its predecessor ERA-Interim, as well as regional climate model simulations. Given the different climate characteristics at each side of the mountain barrier, we principally assess the results considering the windward and leeward sides. We use hindcast simulations performed with Polar-WRF over the Antarctic Peninsula on a nested domain configuration at 45 km (PWRF-45) and 15 km (PWRF-15) spatial resolutions for the period 1990-2015. In addition, we include hindcast simulations of KNMI-RACMO21P obtained from the CORDEX-Antarctica domain (~ 50 km) for further comparisons. For the near future climate change evaluation, we principally use historical simulations and climate change projections (until 2050s, RCP85) performed with PWRF (forced with NCAR-CESM1) on the same domain configuration of the hindcast simulations. Recent observed trends show contrasts between summer and autumn. Annual warming (cooling) trend is notable on the windward (leeward) coasts of the peninsula. Unlike the reanalysis, numerical simulations indicate a clear pattern of windward warming and leeward cooling at annual time-scale. These temperature changes are accompanied by a decreasing and increasing trend in sea ice on the windward and leeward coasts, respectively. An increasing trend of precipitation is notable on the central and northern peninsula. High resolution climate change projections (PWRF-15, RCP85) indicate that the recent warming trend on the windward coasts tends to continue in the near future (2020-2045) and the projections exhibit an increase in temperature by ~ 1.5°C and 0.5°C on the windward and leeward coasts, respectively. In the same period, the projections show an increase in precipitation over the peninsula (5% to 10%). The more notable warming projected on the windward side causes more increases in surface melting (~ +20% to +80%) and more sea ice loss (-4% to -20%) on this side. Results show that the windward coasts of central and northern Antarctic Peninsula can be considered as "hotspots" with notable increases in temperature, surface melting and sea ice loss.
Scaling behavior of lidar-derived snow depth across the semi-arid Chilean Andes
Authors: Mendoza Pablo , Shaw Thomas , Pinto Fabiola , Lagos Miguel , Revuelto Jesús , Musselman Keith , MacDonell Shelley , McPhee James
Published: March 2020

The seasonal melt of mountain snow-cover provides a vital source of freshwater for downstream systems, sustaining multiple productive uses, population needs, and unique ecosystems. In the semi-arid Andes Cordillera, the snowpack acts as a natural water reservoir, releasing spring snowmelt runoff that accounts for more than 60 % of the total annual streamflow. Hence, understanding and characterizing the spatial variability of snow over this large domain is critical for accurate hydrological predictions. We examine the probability density functions and the geostatistical structure of snow depth through variogram analysis, using terrestrial lidar scans acquired during two seasons (2018 and 2019). First, we compare the spatial patterns of snow depth near maximum accumulation at three experimental sites: (i) the Tascadero catchment (-31.26°N, 3270-3790 m a.s.l.), (ii) the Las Bayas experimental catchment (-33.31°N, 3218-4022 m a.s.l.); and (iii) the Valle Hermoso catchment (-36.91°N, 1449-2563 m a.s.l.). Second, we analyze the inter- and intra-annual variability of snow depth patterns in the Las Bayas catchment, where seven scans were acquired during seasons 2018 and 2019. 

The comparison across sites reveals snow depth fractal behavior until a first omnidirectional scale break in the range 15-22 m for unvegetated areas, and a short-range fractal dimension spanning 2.5-2.65. In the woodland of Valle Hermoso, a much shorter (5 m) scale break and a larger short-range fractal dimension (2.73) are found. Secondary scale ranges and breaks spanning 62-125 m are found in all sites but Tascadero, where snow depth follows a bimodal distribution across the domain. In the Las Bayas domain, inter-annual consistency is found in snow scaling patterns, with two distinct regions separated by a short scale break ~6 m early in the winter, increasing to larger break lengths (15-18 m) in July and August. These results help to inform about the appropriate spatial configuration for snowpack modeling across the Andes. Efforts to better understand the modulation of topography (slope and wind exposure) and vegetation on snow depth distribution patterns, as well as impacts of dominant wind directions on anisotropies in fractal parameters, are ongoing.
Analytical upscaling of fill-and-spill hydrology
Authors: Craig James , Taheri Mahkameh , Ranjram Mark
Published: March 2020

Fill-and-spill hydrology, where landscape storage features such as bogs, lakes, prairie sloughs, or surface depressions impound and then dynamically release water after a deficit is filled, has received increased attention in recent years. In systems dominated by fill-and-spill, the contributing runoff area is a function of both local storage deficit and the degree and nature of connectivity between storage features. Here, a closed-form analytical upscaled probabilistic event model of runoff response from thousands of bog cascades in a wetland complex is developed and demonstrated. The efficient mathematical model represents the individual wetland contributing area, runoff coefficient, and pre-event deficit of each bog as probability distributions that may be estimated via a combination of spatial analysis and field observation.

The model is here used to explore the impacts of cascade depth, network branching ratio, local contributing area, and deficit distribution on runoff response. The upscaling results provide insight into the critical runoff characteristics and emergent behaviour of watersheds typified by fill-and-spill hydrology and clarify the role of ‘gatekeeper’ storage features at large scales and for systems with shallow cascade depth. The mathematical solution is found to be a generalization of the well-known PDM (Probability Distributed Model) and Xinanxiang probabilistic runoff models for the specific case where network depth is one and contributing area of each storage feature is zero, and therefore can be readily generalized to support simulation of classical rainfall-runoff responses in heterogeneous landscapes. The results of the model enable exploration of scaling and distribution effects upon catchment runoff in basins influenced by fill-and-spill hydrology.