bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal History of Miocene – Pliocene strata in the Well LKB, Kutei Basin, Indonesia
Authors: Jamaluddin Jamaluddin , Wagreich Michael , Mohamed Sayed Mostafa
Published: March 2022

Temperature is the most important parameter in hydrocarbon generation. Well LKB was drilled to test a section in the Sanga Sanga area of the Neogene Kutei Basin in East Kalimantan. The Sanga Sanga Block contains four large to giant hydrocarbon fields in mid- to upper Miocene deltaic sandstones of the Mahakam Delta, Eastern Kalimantan (Indonesia). Well LKB was drilled to a total depth of 2286 m within a Miocene deltaic sequence. Following the measurement of vitrinite reflectance, the samples are scanned in fluorescence and white light modes to obtain sample descriptions. The mean maximum vitrinite reflectance data provide a basis for inferring some aspects of the thermal history of the sedimentary sequence in well LKB. The well intersected with a small portion of the oil mature level. The conventionally defined principal zone of oil generation (oil window) probably lies in the section from about 1066 to 3962 m. The measured maximum formation temperature at 2286 m is 93,9 °C. Assuming a surface temperature of 26 °C, the bottom hole temperature (BHT) corresponds to a geothermal gradient of 34,55 °C/km. Temperature measurements at intermediate levels give a range of geothermal gradients. The highest temperature gradient results from a single mesurement at depth of about 225 m which would indicate a geothermal gradient of 158,1 °C/km. This value is more than three times higher than the gradients obtained from any other measurements downsection. The causes of this extremely high thermal gradient is unknown. Although the presence of faults, overpressured zones, and flux of hot formation water that expelled from deeper parts of the section are possible mechanism, such an extreme geothermal gradient may also be a product of measurement errors that may be related to older reworking and hence it would be more matured. The average geothermal gradient calculated from the other five measurements is more normal by 38,5 °C/km.  Modelling the measured levels of maturation using the logging run temperatures gives maturity levels different from those observed. A compromise model that approximately simulates the observed maturity levels can be obtained by assuming a cover loss of about 914 m of sediments since Pliocene, and geothermal gradients respectively of 38 °C/km and 30 °C/km for pre- and post- Pliocene times, respectively.
The ALBACORE oceanographic cruise: tectonic and sedimentary processes at distinct temporal and spatial scales in the Alboran Sea
Authors: Lafuerza Sara , d'Acremont Elia , Rabaute Alain , Gorini Christian , Leroy Sylvie , Alonso Belen , Le Roy Pascal , Frigola Jaime , Ketzer Marcelo , Praeg Daniel , Lopez-Gonzalez Nieves ,   ALBACORE Scientific Party
Published: March 2022

The Alboran Sea (Western Mediterranean) is a relatively small ocean basin connected with the Atlantic that provides a rich archive of tectonic and sedimentary processes at distinct temporal and spatial scales during the Quaternary. Since the collisional boundary of the Eurasia-Nubia plates crosses the Alboran Sea, this basin is also the locus of active geohazards: the constant seismic activity, concentrated mostly along the Al Idrissi strike-slip fault system and submarine landslides, that can cause tsunami hazards affecting the entire Alboran coasts and damages to submarine cables and infrastructures. Previous understanding of the Alboran Sea has been based on seafloor and subsurface geophysical data of differing resolution and scale, combined with very short sediment coring and IODP and industrial boreholes. In order to obtain new constrains on the geology of the Alboran Sea, the ALBACORE cruise was held in October and November 2021 onboard the R/V Pourquoi Pas? In addition to sites in the northern Alboran Sea targeting contourites, several sites in the southern Alboran Sea were selected as key study areas: the Al-Idrissi active fault zone, the Al-Hoceima shelf, the Xauen/Tofiño and the Francesc Pages banks.

The scientific work of the ALBACORE campaign included the acquisition of Calypso cores (up to 28m long), sampling of consolidated strata with Cnexoville, in situ geotechnical measurements (Penfeld) with a seabed cone penetration test device (up to 50m long), heat flow measurements (up to 6m long), swath bathymetric imaging of the seafloor and water column, and sub-bottom profiling. The total length of sediments recovered reached 734m. Results from the ALBACORE cruise address the following scientific objectives:

To understand better the causal relationships between the present-day morpho-structural pattern and date Quaternary tectonic pulse and associated sedimentary systems

To determine the Late Pleistocene-Holocene stratigraphic pattern and the paleo-oceanographic implications of contourites.

To explore the chronological evolution of cold-water coral mounds and their paleoceanographic and palaeoclimatic signature since the Middle Pleistocene.

To investigate the causal factors of slope instability processes and evaluate the geological hazard associated with tectonic pulses and fluid seepage.

To determine the recent high-resolution sequence stratigraphy of the Al-Hoceima shelf in order to decode the late Pleistocene and Holocene sea-level changes at millennial scale.
Anthroprogenic landscapes: assessing the geomorphological stability of tailings dams using a Landscape Evolution Model
Authors: Hancock Greg , Coulthard Tom
Published: March 2022

Tailings are a by-product of the processing of minerals at mine sites and are usually fine grained, contain water and processing chemical residues and are usually very erodible. Tailings are commonly stored in ‘tailings dams’ and these dams are a feature of many mine sites. These dams are in a geomorphic disequilibrium and have similar risk to that of water storage dams with geotechnical, seismic, hydrological (rainfall) and erosional induced failure concerns. These dams also pose a risk of release of polluted water and the accompanying chemicals and fines.  At the majority of mine sites tailings dams will be permanent geomorphological features which do not geomorphologically integrate with the surrounding landscape. A dam has a design life and it has been suggested that closure designs be considered for a 1000 year design life with other sites considered for 10 000 year scenarios. New methods are therefore needed for assessing long-term behaviour of anthropogenic structures such as tailings dams. Computer based Landscape Evolution Models (LEMs) are a new tool to assess tailings dam design.  These models provide information on type of erosion and erosion location as well as erosion rates. Models such as CAESAR-Lisflood can also provide information on water quality and stream sediment loads and models the transport of all size fractions. The model can therefore provide guidance on long-term behaviour, which allow designs to be tested and improved accordingly. The work uses CAESAR-Lisflood to examines a series of hypothetical tailings dams subject to a range of different possible rainfall scenarios. The findings demonstrate that without maintenance the dam wall will be breached at a time exceeding the dam life design for average conditions but may breach within decades for an extreme (yet possible) event. For both cases water quality will be reduced for centuries post breach and may never reach background (pre breach) levels representing a permanent change in water quality. The modelling here provides a method for the assessment of not just tailings dams but other anthropogenic structures and their geomorphological behaviour. The work here also raises questions about landscape stewardship for such altered systems.
Remote sensing of tropical vegetation properties in response to fire return time
Authors: Ningthoujam Ramesh K. , Prestes Nayane Cristina Candida dos Santos , Andrade Marcelo Feitosa de , Carniello Maria Antonia , Coetsee Corli Wigley , Harrison Mark E. , Kusin Kitso , Rasul Azad , Hoscilo Agata , Pellegrini Adam , Oliveras Imma , Feldpausch Ted R. , Page Susan , Bloomfield Keith J. , Harrison Sandy P. , Prentice Iain Colin
Published: March 2022

Fire modifies vegetation spectral reflectances in the optical, thermal and microwave domains due to the changes it induces in vegetation canopy components (leaves, needles, branches) and in soil properties. Freely available satellite-derived (Landsat) Vegetation Indices (VIs) and PALSAR Mosaic backscatter measurements (known to be sensitive to vegetation structure) were used to help understand vegetation properties (species richness, basal area) in relation to fire return time (FRT) across a range of tropical biomes (open savanna, savanna forest, evergreen forest, peat-swamp forest) in Mato Grosso (Brazil), Kruger National Park (South Africa) and Central Kalimantan (Indonesia).

For each site, we combined: (i) post-fire Landsat imagery (30 m) to derive VIs sensitive to vegetation diversity with (ii) PALSAR (25 m) backscatter that employes a longer wavelength (21 cm) and dual polarisation (Horizontal-Horizontal, Horizontal-Vertical) enabling the capture of strong backscattering of signal by branches and trunks.

Most of the Landsat VI values showed greater variability in forests compared to open savanna, reflecting the greater diversity in species’ composition and growth form. A strong positive relationship was found between VIs and FRT across biomes and especially in forests. The amount of vegetation burned per fire as recorded by the magnitude of changes in these VIs, was highest in annual burn regimes (FRT = 1 year). Green and red-edge bands provided better discrimination of vegetation species richness and basal area. A significant positive relationship to basal area in response to fire return time was also found using PALSAR data due to its deeper canopy penetration level and strong backscattering from woody components. The observed responses of VI- and PALSAR-inferred species’ richness and basal area in response to FRT in different tropical biomes suggest that the green and red-edge channels from optical and longer wavelength HV-backscatter are useful metrics to quantify post-fire tropical vegetation dynamics.
Ground cover retrieval with Hyper- and Multi- spectral data fusion for post-fire soil erosion modelling - The Castanheira de Pêra study site.
Authors: Lazzeri Giacomo , Vieira Diana C. S. , González-Pelayo Oscar , Frodella William , Keizer Jan Jacob , Moretti Sandro
Published: March 2022

The identification of the type and extent of the area damaged by natural hazards such as wildfires using Earth Observation data can contribute to a better understanding of the processes affecting the Man-Nature system and, thereby, Man’s capability for sustainable land management. Fire effects are not limited to vegetation and litter cover and composition but include topsoil properties, both of which contribute to the enhanced hydrological and geomorphological activity typically observed in recently burnt areas. The present study focusses on fire-induced changes in topsoil properties, vegetation and ground cover and how this latter parameter can be acquired via satellite multi- and hyperspectral analysis for the determination of soil erosion model ground cover inputs. This objective has been achieved via the comparison of field ground cover data with multi and hyperspectral satellite derived data. Hence, we applied both types of ground cover data – i.e. field and satellite-based to the same erosion model to assess how the different model input values affected the differences between predicted and observed soil erosion rates.
To this end, the present study applied the modified Morgan-Morgan-Finney (MMF) erosion model to a pine plantation that had recently been burnt by the dramatic, June-2017 Pedrógão wildfire in Central Portugal. The MMF model was calibrated against the observed plot-scale erosion rates and the seasonal patterns therein, operating on the effective hydrological depth, fire severity impact and ground cover. Furthermore, we tested satellite and field based burn severity assessments and compared both model predictions with the field erosion measurements at plot scale. Additionally, the MMF input parameters linked to vegetation cover were estimated from field observations as well as various remotely-sensed indexes derived from Sentinel-2 MSI (MultiSensing Instrument) and PRISMA (HyperSpectral Precursor of the Applicative Mission) hyperspectral data. The results showed that remote sensing data can provide valuable estimates of post-fire vegetation recovery for parameterization of the MMF model for the first post-fire year. An important condition, however, is that the spatio-temporal resolution of the satellite-based data match the spatial patterns in fire severity on the one hand, and, on the other, the changes in soil erosion processes with time-since-fire. Therefore, factors such as pre-fire fuel load, vegetation composition and topsoil properties will require careful consideration when extrapolating the current results to other burnt areas.
Towards spatio-temporal comparison of transient simulations and temperature reconstructions for the last deglaciation
Authors: Weitzel Nils , Andres Heather , Baudouin Jean-Philippe , Bothe Oliver , Dolman Andrew M. , Jonkers Lukas , Kapsch Marie , Kleinen Thomas , Mikolajewicz Uwe , Paul André , Rehfeld Kira
Published: March 2022

An increasing number of Earth System Models has been used to simulate the climatic transition from the Last Glacial Maximum to the Holocene. This creates a demand for benchmarking against environmental proxy records, which have been synthesized for the same time period. Comparing these two data sources in space and time over a period with changing background conditions requires new methods. We employ proxy system modeling for probabilistic quantification of the deviation between temperature reconstructions and transient simulations. Regional and global scores quantify the mismatch in the pattern and magnitude of orbital- as well as millennial-scale temperature variations.

In pseudo-proxy experiments, we test the ability of our algorithm to accurately rank an ensemble of simulations according to their deviation from a prescribed temperature history, dependent upon the amount of added non-climatic noise. To this purpose, noisy pseudo-proxies are constructed by perturbing a reference simulation. We show that the algorithm detects the main features separating the ensemble members. When scores are aggregated spatially, the algorithm ranks simulations robustly and accurately in the presence of uncertainties. In contrast, erroneous rankings occur more often if only a single location is assessed.

Having established the effectiveness of the algorithm in idealized experiments, we apply our method to quantify the deviation between data from the PalMod project: an ensemble of transient deglacial simulations and a global compilation of sea surface temperature reconstructions. No simulation performs consistently well across different regions and components of the temperature evolution which we attribute to the larger spatial heterogeneity in reconstructions. Our work provides a basis for a standardized model-data comparison workflow, which can be extended subsequently with additional proxy data, new simulations, and improved representations of uncertainties.
Development of a multimodal approach to monitoring of coastal waters
Authors: Galešić Divić Morena , Divić Vladimir , Kvesić Marija , Kišević Mak , Andričević Roko
Published: March 2022

The levels of monitoring quality and quantity for environmental factors present continuous challenges for engineers, scientists, and related decision-making bodies. This is particularly highlighted in complex ecosystems such as coastal areas and estuaries with the pronounced intersection of numerous natural gradients. On the other hand, constant technological advances of different measurement equipment, including the remotely operated vehicles and their modular design, are introducing vast opportunities for gathering various data. Furthermore, readily available open-source solutions for hardware and software domains present additional potential in developing the framework for multipurpose monitoring. We are developing a multimodal approach to monitoring coastal zones, particularly in estuarine waters, which comprises using commercially available measurement equipment (multisensory probes) and, more importantly, building task-oriented drifters with relevant sensors. Furthermore, we are implementing the usage of remotely operated vehicles, both areal and underwater, which present a suite of measurement devices for data amplification (metadata), collection, and verification, especially when coupled with satellite data. Moreover, the use of drones has additional value in reducing the disturbance of natural conditions and improving the safety of researchers. So far, the monitored data include conductivity, temperature, pressure, wave heights, water velocity, dissolved oxygen, chlorophyll, colored dissolved organic matter, turbidity, hyperspectral properties, and further research including thermal camera and LIDAR technology. Different measurement approaches also contain several issues such as temporal and spatial scale comparability and interoperability, while drone use implicates some concerns about privacy, noise, and the general social attitude. These issues are currently being investigated, generating some challenges for future progress. Through current multiple research projects, we are testing the presented multimodal approach on the case study of the river Jadro estuary near the city of Split (Croatia), aiming to develop a field laboratory with the potential to be replicated in any similar hydrological monitoring.
A comparison of multi-criteria and machine learning weighting for flood risk assessment in the Southern Ontario, Canada
Authors: Khalid Rahma , Khan Usman T
Published: March 2022

Floods, the most frequent and severe of natural disasters worldwide, inflict significant social, environmental and fiscal impacts, including: loss of human life, damage to natural habitats and damage to infrastructure. Flood risk mapping can be used to mitigate these impacts as it provides a holistic approach to identifying flood prone areas by simultaneously considering socioeconomic and environmental indicators. This research compares the performance of two multi-criteria decision making methods, and one Machine Learning (ML) method in the development of flood risk mapping. This approach was first developed and validated for the Don River watershed in the Greater Toronto Area and subsequently extended to several other watersheds across Southern Ontario. Remote sensing data such as Digital Elevation Models and landuse and lancover datasets were used to develop the environmental flood hazard extent, and combined together with socioeconomic indicators, flood risk maps were developed using subjective and objective weighting schemes in a GIS analysis. The subjective maps were produced using the Analytical Hierarchy Process (AHP), the objective maps were produced using the Shannon Entropy method and the ML maps were produced using Artificial Neural Networks. The accuracy of these maps was compared against the floodplain map of the Don River. For a range of flood risk severity, where 1 was very low risk and 5 was very high risk, the AHP maps were superior in identifying areas where flood risk severity was 4 or greater. Conversely, the Entropy maps were superior in identifying areas where flood hazard risk was 5, however the difference in accuracy for both scenarios was marginal between the two methods. The accuracy of the ML maps showed marginal superior performance under both scenarios in comparison to the multi-criteria maps. Additionally, the uncertainty in the combination of flood risk indicators was quantified through a sensitivity analysis focusing on the discretization of the number of classes in each indicator dataset. The outcome of this research provides an accurate and simplified alternative to using hydrological and hydraulic models, especially when insufficient data limits the use of hydrological and hydraulic models. Future research should focus on an optimisation approach to the discretization of classes in indicator datasets.
Swept Away: Flooding and landslides in Mexican poverty nodes
Authors: García Silvia , Aquino Raul , Mata Walter
Published: March 2022

Natural disasters should be examined within a risk-perspective framework where both natural threat and vulnerability are considered as intricate components of an extremely complex equation. The trend toward more frequent floods and landslides in Mexico in recent decades is not only the result of more intense rainfall, but also a consequence of increased vulnerability. As a multifactorial element, vulnerability is a low-frequency modulating factor of the risk dynamics to intense rainfall. It can be described in terms of physical, social, and economical factors. For instance, deforested or urbanized areas are the physical and social factors that lead to the deterioration of watersheds and an increased vulnerability to intense rains. Increased watershed vulnerability due to land-cover changes is the primary factor leading to more floods, particularly over pacific Mexico. ln some parts of the country, such as Colima, the increased frequency of intense rainfall (i.e., natural hazard) associated with high-intensity tropical cyclones and hurricanes is the leading cause of more frequent floods.

 

In this research an intelligent rain management-system is presented. The object is built to forecast and to simulate the components of risk, to stablish communication between rescue/aid teams and to help in preparedness activities (training). Detection, monitoring, analysis and forecasting of the hazards and scenarios that promote floods and landslides, is the main task. The developed methodology is based on a database that permits to relate heavy rainfall measurements with changes in land cover and use, terrain slope, basin compactness and communities’ resilience as key vulnerability factors. A neural procedure is used for the spatial definition of exposition and susceptibility (intrinsic and extrinsic parameters) and Machine Learning techniques are applied to find the If-Then relationships. The capability of the intelligent model for Colima, Mexico was tested by comparing the observed and modeled frequency of landslides and floods for ten years period. It was found that over most of the Mexican territory, more frequent floods are the result of a rapid deforestation process and that landslides and their impact on communities are directly related to the unauthorized growth of populations in high geo-risk areas (due to forced migration because of violence or extreme poverty) and the development of civil infrastructure (mainly roads) with a high impact on the natural environment. Consequently, the intelligent rain-management system offers the possibility to redesign and to plan the land use and the spatial distribution of poorest communities.
Wave Gradiometry and Continuous Wavelet Transform Thresholding
Authors: Bolarinwa Oluwaseyi , Langston Charles
Published: March 2022

A gradiometer array was deployed as part of the wavefields community experiment conducted by IRIS in the summer of 2016 near Enid, Oklahoma, USA. The gradiometer consisted of 7 levels of concentric square rings with each ring being four times the area of the immediate smaller ring; the largest ring spanned an 800X800 km2 area. Each ring was made up of 16 three-component, 4.5 Hz nodal instruments. In a bid to appraise the effectiveness of the gradiometer in characterizing seismic waves, we computed seismic wave attributes in the form of apparent slowness and signal azimuth from gradiometer records of a magnitude 4.2 event that occurred during the wavefields experiment and compared these attributes with those computed from a coincidental, 3-km aperture phased array by means of a new array analysis method based on the continuous wavelet transform (CWT). Just as in gradiometry, the phased array technique provides wave attributes for all time points, which allows a point-for-point comparison of the gradiometry attributes with those for the phased array method. Prior to analysis, we extracted body wave phases from the gradiometer and phased array data by means of scale-time gating in the CWT space. This step was necessary to reduce the effect of seismic phase interference that can negatively impact gradiometry results. Gradiometry analysis of the vertical component data revealed a P wave horizontal phase velocity of 6.17+-0.04 km/s, which only deviates by 0.03 km/s from the phase array result obtained over an identical time window. The corresponding azimuth computed using gradiometry is 2.2 degrees off the great circle path between the event’s epicenter and the gradiometer center. If the smallest gradiometer ring is labelled 1 and the rest progressively labelled based on their sizes up to 7, this optimal result was obtained using the gradiometer subarray that combines rings 1,3 and 5. Thus, the gradiometer with its relative portability may be preferred over a traditional phased array deployment in some geophysical campaigns.  Using CWT thresholding techniques finds those areas of the wavelet transform plane that contain high SNR for useful processing using beam forming or gradiometry.
A laboratory study of turbulent magnetoconvection: Could thermoelectricity induce asymmetry in geomagnetic secular variation?
Authors: Xu Yufan , Horn Susanne , Aurnou Jonathan
Published: March 2022

It has been proposed that thermoelectric (TE) currents may be important in the vicinity of planetary core boundaries (Stevenson 1987, EPSL; Giampieri & Balogh 2002, P&SS). However, TE-induced core dynamics remain largely unstudied. To address this, we have conducted a series of laboratory experiments of turbulent Rayleigh-Bénard convection with a vertical magnetic field in a cylindrical cell filled with liquid gallium. Thermal measurements are taken at a fixed buoyancy forcing with varying Lorentz force. When buoyant inertia dominates, a large-scale overturning circulation cell develops, which imposes strong lateral temperature gradients onto the tank's top and bottom boundaries. In experiments equipped with electrically conducting boundaries, the large-scale circulation slowly precesses in azimuth when thermoelectrically induced Lorentz forces become comparable to buoyant inertial forces. Moreover, TE introduces an asymmetry in the system: this novel magnetoprecessional mode reverses its traveling direction when the magnetic field polarity is reversed. Extrapolating our results to Earth's core, we estimate the required net Seebeck coefficient to generate TE dynamics at CMB conditions. Furthermore, because TE-driven flows reverse direction as the magnetic field reverses, we hypothesize that thermoelectricity can provide a natural symmetry breaker by driving CMB (or ICB) core flows in opposite directions between normal and reversed geomagnetic field polarities. To test our hypothesis, we need to better constrain the electrical, thermal conductivity, and Seebeck coefficient of the CMB (or ICB), and gather observational evidence of geomagnetic secular variation during field reversals. This study is reported in Xu et al. 2022, JFM
Realistic and Fast Modeling of Spatial Extremes over Large Geographical Domains
Authors: Huser Raphael , Hazra Arnab , Bolin David
Published: March 2022

Various natural phenomena, such as precipitation, generally exhibit spatial extremal dependence at short distances only, while the dependence usually fades away as the distance between sites increases arbitrarily. However, the available models proposed in the literature for spatial extremes, which are based on max-stable or Pareto processes or comparatively less computationally demanding "sub-asymptotic" models based on Gaussian location and/or scale mixtures, generally assume that spatial extremal dependence persists across the entire spatial domain. This is a clear limitation when modeling extremes over large geographical domains, but surprisingly, it has been mostly overlooked in the literature. In this paper, we develop a more realistic Bayesian framework based on a novel Gaussian scale mixture model, where the Gaussian process component is defined by a stochastic partial differential equation that yields a sparse precision matrix, and the random scale component is modeled as a low-rank Pareto-tailed or Weibull-tailed spatial process determined by compactly supported basis functions. We show that our proposed model is approximately tail-stationary despite its non-stationary construction in terms of basis functions, and we demonstrate that it can capture a wide range of extremal dependence structures as a function of distance. Furthermore, the inherently sparse structure of our spatial model allows fast Bayesian computations, even in high spatial dimensions, based on a customized Markov chain Monte Carlo algorithm, which prioritize calibration in the tail. In our application, we fit our model to analyze heavy monsoon rainfall data in Bangladesh. Our study indicates that the proposed model outperforms some natural alternatives, and that the model fits precipitation extremes satisfactorily well. Finally, we use the fitted model to draw inferences on long-term return levels for marginal precipitation at each site, and for spatial aggregates.
Analysis of Turbulence Energy Transfer at an Interplanetary Shock Observed by MMS
Authors: Ngampoopun Nawin , Ruffolo David , Bandyopadhyay Riddhi , Matthaeus William
Published: March 2022

Turbulence near an interplanetary shock is of practical interest because turbulent magnetic fluctuations are key to the diffusive shock acceleration and transport of energetic particles, which can lead to significant space weather effects.  In this work, we examine burst-mode observations by the Magnetospheric Multiscale Mission (MMS) for an interplanetary shock passage at a distance of 25 Re­ on 8 January 2018.  The instrumental resolution offers an opportunity to examine the energy transfer rate of solar wind turbulence in both the upstream and downstream regions. We implement a Hampel filtering-based technique to mitigate the instrumental noise in plasma moment data. We use a Kolmogorov-Yaglom Law for the third-order structure function and a von Kármán-decay law to calculate the energy dissipation rates at the inertial scale and energy-containing scale, respectively. The results show that the region downstream of the shock has stronger and better developed turbulence and a higher energy transfer rate than the upstream region. N.N. has been supported by STFC studentship and UCL Doctoral School. This research has also been supported by grant RTA6280002 from Thailand Science Research and Innovation, by the MMS Theory and Modeling team grant 80NSSC19K0565, and the NASA LWS program grant 80NSSC20K0377 under NMC subcontract 655-001.
A Framework for Standardizing Electromagnetic Water Content Sensor Assessment using Granular Porous Media
Authors: Jones Scott B. , Chang Chieh-Yun , González-Teruel Juan D. , Robinson David A. , Friedman Shmulik P. , Szyplowska Agnieszka , Skierucha Wojciech
Published: March 2022

Electromagnetic (EM)-based sensors used for water content determination are now being widely used across the globe in research, environmental monitoring networks, weather stations, irrigation management, feed and grain quality control in addition to a host of other applications. The multi-million-dollar EM sensor market continues to expand and yet lacks test standards and is generally lacking in information about sensor quality and performance. Decades of past sensor assessments have presented mixed testing approaches and a commensurate measure of mixed results. Confusion regarding EM sensor-function, -failure rate and -value, stems from testing results that often use non-standard targets including inhomogeneous (variable density and water content) and complex materials (e.g., soils) that may not be widely available for subsequent testing and verification by others. Electromagnetic sensors employ time- or frequency-domain measurements to estimate real (and sometimes including imaginary) permittivity and electrical conductivity, with different sensors measuring at varied and often unknown frequencies. Sensor output is affected by environmental impacts on circuitry (temperature) combined with effects of porous medium temperature, electrical conductivity, interfacial polarization and dielectric relaxation, all of which often combine to alter the apparent permittivity and resulting water content. Although a few attempts have been made to standardize testing, more work and research is required before an international standard can be recognized and adopted. Here we point to standardizing 1) granular porous test media, 2) media packing approaches and 3) permittivity-water content calibration functions with examples and comparison of different EM sensors.  
The WATSON COST Action: Water isotopes in the critical zone from groundwater recharge to plant transpiration
Authors: Barbeta Adrià , Coenders-Gerrits Miriam , Geris Josie , Jakovljević Tamara , Llorens Pilar , Marttila Hannu , Nerantzis Kazakis , Orlowski Natalie , Öztürk Emel Zeray , Penna Daniele , Popp Andrea L. , Rothfuss Youri , Scandellari Francesca , Stockinger Michael , Stumpp Christine , van Meerveld Ilja , von Freyberg Jana , Vreča Polona , Žvab Rožič Petra
Published: March 2022

The WATSON COST Action (CA19120; https://watson-cost.eu/) started in September 2020. It aims to integrate and synthesize current interdisciplinary scientific knowledge on the use of the stable isotopes of water to understand the mixing and partitioning of water in the Earth’s Critical Zone. The network is organized into working groups that focus on a major scientific challenge: 1) groundwater recharge and soil water mixing processes; 2) vegetation water uptake and transpiration; and 3) catchment-scale residence time and travel times. A fourth working group organizes the network and dissemination activities.

WATSON aims at better connecting academia and stakeholders from industry, non-profit organizations, and government agencies. WATSON fosters the exchange of information and expertise among scientists and stakeholders, builds capacity in the use of the latest isotope approaches and translates scientific cutting-edge knowledge into tangible outputs and recommendations on how to use stable water isotopes to effectively address water management needs. 

Our poster describes the WATSON network, as well as its activities. These include the preparation of an open-access database of water isotope-based studies in the Critical Zone, the development of protocols for water sampling and stable isotope analysis, the organization of virtual and in-person meetings, seminars, training schools, and the exchange of students, researchers, and technicians via short term scientific missions.
CAMELS-spat: catchment data for spatially distributed large-sample hydrology
Authors: Knoben Wouter , Clark Martyn
Published: March 2022

The recent publication of large-sample datasets for hydrologic modeling and analysis has led to a revival of comparative hydrology. The “CAMELS” branch of these datasets currently provide catchment attributes and meteorological time series for basins located in the United States, Chile, Brazil, Australia and Great-Britain, with a dataset for France under development. A key characteristic of these datasets is that information is provided as catchment-averaged data; i.e. each catchment is treated as a lumped entity with no spatial variability. Some progress is being made to extend large-sample hydrology to include spatially distributed data, most notably by the recent LamaH dataset which covers part of Central Europe.

Here we present progress on developing a continental domain dataset for large-sample hydrology intended for spatially distributed modeling and analysis. Our domain covers the United States and Canada, expanding both geographically and climatically on the region covered by the LamaH dataset. We focus mostly on relatively undisturbed headwater catchments, because accurate data on water management policies and infrastructure can be difficult to obtain. Our aim is to provide the necessary data for process-based modeling and analysis at a sub-daily temporal resolution. 
Seasonal Change in the Deep Atmosphere of Uranus, 1981 to 2021
Authors: Akins Alex , Hofstadter Mark , Butler Bryan , Molter Edward , de Pater Imke
Published: March 2022

Our team is using radio observations of Uranus, collected with the Very Large Array (VLA) telescope, to track seasonal changes in the deep troposphere of Uranus between 1981 and the present. In Hofstadter, Akins, and Butler (https://doi.org/10.5194/egusphere-egu21-1374), we reviewed evidence for seasonal changes in Uranus’ atmosphere from a record of VLA observations between 1981 and 2012. We found that large scale latitude structure has remained essentially similar for the bulk of the record with the exception of the pole-equator contrast differences between mid-summer observations in 1985 and late summer observations in 1994. This record has been extended to the present (close to ½ a Uranian year) with VLA observations in 2015 (published in Molter et al. 2021 https://doi.org/10.3847/PSJ/abc48a) and in late 2021 (and early 2022). Here, we will discuss our analysis of data obtained between 2012 and the present. All observations during this period were made with the upgraded Jansky VLA receivers and thus obtain higher sensitivities than those obtained before this time. This sensitivity permits resolution of zonal banding in the deep atmosphere, with bands observed between 0 and 20 degrees with 2 K brightness temperature contrasts at depths between 1-10 bar. These variations are likely driven by small-scale circulation patterns and associated condensation effects similar to those associated with the large pole-to-equator variations. We will discuss the consistency of these datasets and inferred distribution of opacity sources (NH3 or H2S). As we approach winter solstice in 2030, it will be particularly important to monitor Uranus’ deep atmosphere to provide further evidence for near-solstice changes in the deep atmosphere structure or composition as a seasonal phenomenon. Confirmation would provide insight into how varying insolation due to Uranus’ obliquity drives atmospheric changes in a manner unlike other giant planets.
Directional Discontinuities in the Inner Heliosphere
Authors: Madár Ákos , Erdos Geza , Opitz Andrea , Nemeth Zoltan , Facsko Gabor , Timar Aniko , Biro Nikolett , Koban Gergely , Dalya Zsuzsa
Published: March 2022

The Parker Solar Probe and Solar Orbiter spacecraft make whole new spatial and time scales available in the inner Heliosphere. With these new data, we study directional discontinuities that are common structures in the solar wind in this region. Their radial distribution can provide insight into the physical processes of this virtually collisionless plasma. Applying a method (Erdős & Balogh, 2008) based on minimum variance analysis to select directional discontinuities in magnetic field data, we determine their number as a function of distance from the Sun. How the directional discontinuity occurrence rate depends on the solar wind speed is also part of our analysis.
Numerical investigation of the effects of chemical dissolution and mineral reaction on reservoir performances in CO2-plume geothermal systems 
Authors: Zhou Dejian , Tatomir Alexandru , Sauter Martin
Published: March 2022

The increasing emission of greenhouse gases and increasing demand for energy supply are reasons to investigate geothermal energy systems where scCO2 is the working fluid. However, the complex dissolution and reaction of minerals during the heat production processes affect the performance of geothermal reservoirs. Thus, a comprehensive numerical model that includes the Thermal-Hydraulic-Chemical (THC) coupled physical-chemical processes was implemented in the open-source simulator DuMuX, to model the phase displacement, chemical dissolution, heat transport, and mineral reactions. The aim is to investigate the influence of these parameters on the overall geothermal reservoir performance. More precisely, this study investigates the effects of salt precipitation, mineral reactions, injection rate, injection temperature, and geothermal reservoir size on heat production rate and scCO2 sequestration. The simulation results show that the scCO2- calcite reaction decreases the reservoir heat production rate but increase the sequestration of scCO2. Moreover, its effects are proportional to the scCO2 injection rate but inversely proportional to the geothermal reservoir size. On the other hand, the dissolution of scCO2 in brine has the same influence as the reaction between scCO2 and calcite, benefiting the CO2 sequestration but minimizing the heat production rate of the geothermal reservoirs. Furthermore, the sensitivity analysis presents that the influence of chemical dissolution and mineral reactions are only significant when the injection rate is large and the reservoir size is small.
A storm-track regime perspective on the connection between cold spells over North America and wet/windy extremes over Europe
Authors: Riboldi Jacopo
Published: March 2022

The occurrence of cold spells over North America leads, on average, to a zonalisation and intensification of the North Atlantic jet stream and results in an enhanced risk of extreme wind and precipitation events over Europe. Cold spells enhance low-level baroclinicity at the entrance of the North Atlantic storm track and enhance extratropical cyclogenesis next to the East coast of the United States. However, the mechanisms by which this impact propagates from the entrance to the exit of the storm track, where Europe is, remain unclear.

We investigate from a regime perspective the two-way relationship between the occurrence of cold spells over the eastern coast of North America and the North Atlantic storm track. We stratify the occurrence of cold spells over two different regime classifications of the state of the North Atlantic storm track: the first one based on more classical k-means clustering of 500hPa geopotential height, the other based on dynamical system theory. The regimes have been further characterized using diagnostics acquired from dynamical meteorology, as the E vector or the wave activity flux, and display very different patterns of Rossby wave propagation. The analysis will highlight whether the occurrence of cold spells is able to cause shifts in storm track regimes. On the other hand, if the state of the storm track remains unchanged, this would suggest that other factors rather than cold spells modulate the connection to European wind and temperature extremes.

 
Evaluating the vegetation-atmosphere coupling strength of ORCHIDEE land surface model
Authors: Zhang Yuan , Narayanappa Devaraju , Philippe Ciais , Li Wei , Goll Daniel , Vuichard Nicolas , De Kauwe Martin G. , Li Laurent
Published: March 2022

Plant transpiration plays a central role in regulating water cycle and land surface energy budget. Correctly representing the controls of such processes in Earth system models is thus critical to accurately project future climate. Transpiration is controlled by physiological processes of stomatal regulation in response to water and temperature stress, and by canopy structure through the aerodynamic transport of water vapor in the boundary layer from leaves to the atmosphere. The strength of the vegetation coupling to the atmosphere can be summarized by a decoupling coefficient Ω. A value of Ω of 0 implies a strong coupling, leaving a dominant role to stomatal conductance in regulating H2O and CO2 fluxes, while Ω of 1 implies a complete decoupling of leaves from the atmosphere, that is, the transfer of H2O and CO2 is limited by aerodynamic transport. In this study, we investigate how well the state-of-the-art land surface model, ORCHIDEE, simulates the decoupling of vegetation to atmosphere using observation-based empirical daily estimates of Ω at 106 FLUXNET sites. We also tested whether calibration of parameters controlling the dependence of the stomatal conductance to the water vapor deficit (VPD), or using observation based canopy height improves the simulated Ω. A set of random forest models were built to further investigate the impacts of different factors on Ω. Our results show that Ω is underestimated by ORCHIDEE (0.20) compared with the observation-based estimates (0.28), and that the calibration of stomatal conductance parameters improved the simulated Ω (0.24). Nevertheless, the bias of simulated Ω remains large in grasslands and croplands after the calibration. We also found that in observation vegetation tends to be more decoupled to atmosphere when there is low wind speed, high temperature, low VPD, large leaf area index (LAI) and in short vegetation. ORCHIDEE generally agrees with this pattern but underestimated the VPD impact when VPD is high, overestimated the contribution of LAI and did not correctly simulate the temperature dependence when temperature is high. Canopy height does not show strong direct impact on Ω. Our results highlight the importance of observational constraints on simulating the vegetation-atmosphere coupling strength, which can help improve the predictive accuracy of water fluxes in Earth system models.
An experimental study on effects of grain size distribution on debris flow deposition characteristics
Authors: Izumiyama Hiroaki , Yamakoshi Takao , Takahashi Yuya , Nishiguchi Yuki , Okuyama Ryosuke
Published: March 2022

Precise prediction of travel distance of debris flow is required to design countermeasure strategy against natural disaster. A lot of numerical simulation tools have been developed using a selected shear stress which has been modeled to express the characteristics of debris flow and a modeled entrainment ratio. However, the calculation results for past events often show underestimated travel distance. One of the possible causes of the fact may be that the effect of grain size distribution on the entrainment ratio. This is because most models have been modeled assuming debris flow is constituted by a single size particle. An entrainment ratio model involving the effect of particle size distribution may improve the calculation reproductivity. From an engineering point of view, it is desirable that the effect can be taken into account as simply as possible. In this study, we conducted an experiment to know the extent to which the entrainment ratio is affected by the grain size distribution. The experiments were undertaken in a rectangular flume the channel slope of which can be adjusted at two points in longitudinal direction. Two-size mixtures of spherical glass beads or gravels were set as debris flow material. For each mixture, travel distance of debris flow and fractions of each size of debris flow material deposited near the channel slope change point were measured using high-speed camera.