bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the TROPOMI tropospheric NO2 product based on recurrent airborne campaigns
Authors: Tack Frederik , Merlaud Alexis , Ruhtz Thomas , Ene Dragos , Calcan Andreea , Schuettemeyer Dirk , Van Roozendael Michel
Published: March 2022

Sentinel-5 precursor (S-5p), launched on 13 October 2017, is the first mission of the Copernicus Programme dedicated to the monitoring of air quality, climate, ozone and UV radiation. The S-5p characteristics, such as the fine spatial resolution, introduce many new opportunities and challenges, requiring to carefully assess the quality and validity of the generated data products by comparison with independent measurements and analyses.

While routine validation is performed within the ESA Mission Performance Center (MPC) based on a limited number of Fiducial Reference Measurements (FRM), additional validation activities including aerial and ground-based campaigns are conducted in research mode as part of the S-5p Validation Team (S5PVT). A series of decentralized campaign activities take place since 2021, which have been identified to address key priorities for S5-p validation as well as key S5-p products (see s5pcampaigns.aeronomie.be for an overview of all campaigns).

Here, we will focus on recurrent observations with the airborne hyperspectral imager SWING, developed by BIRA-IASB. A SWING instrument is regularly installed in the Cessna T207A from FUB, while another SWING instrument is permanently installed in a BN-2 from INCAS, alongside other instruments such as in-situ samplers.  Recurrent validation activities are performed over the cities of Berlin, Germany and Bucharest, Romania to map the horizontal distribution of tropospheric NO2 and its urban/industrial sources, in close coincidence with the overpass of the TROPOMI sensor. During each flight, approximately 5 to 15 TROPOMI pixels can be fully covered by airborne measurements. The recurrent nature of this type of campaigns, meaning that a flight can take place whenever weather conditions and air traffic control allow, will result in a large statistical set of reference data covering variable meteorological and geo-physical conditions (including autumn and winter conditions), as well as different satellite overpass configurations.

In this context, a general airborne data format, following the Climate and Forecast (CF) conventions, has been developed, as well as harmonized tools for the airborne L2 data processing and the TROPOPMI validation in order to obtain consistent results. First results of the assessment of the TROPOMI tropospheric NO2 level2 product based on observations from recurrent airborne campaigns will be discussed. The developed validation strategies and developed tools are suitable for other airborne imagers than SWING and will be suitable as well for validation of future atmospheric missions such as Sentinel-5 and Sentinel-4.
Effect of forest canopy density on water status and photosynthesis of 14 herbaceous species in temperate forest
Authors: Matoušková Marie , Vitásek Roman , Plichta Roman , Houšková Kateřina , Hédl Radim , Urban Josef
Published: March 2022

The density of forest canopy is affecting understory light conditions as well as soil water availability. Trees either suppress the herbaceous understory species by competition for resources or help them to cope with increased climatic warming by canopy shading. Nevertheless, little is known about the light × water interaction on herbaceous species performance. In shaded environments, such as in the forest understory, the energy needed for stomatal opening may not be entirely offset by the imminent carbon gain, which may give a partial advantage to anisohydric species. The combination of shade and additional drought might damage the light-harvesting part of the photosynthetic systems because of the strong competition between species for light, which may be specifically critical for the anisohydric species. In this study, we compare seasonal water status, photosynthetic and fluorescence performance of 14 forest understorey herb species in open and closed forest stands, including perennials, annuals and grasses under favourable and mild drought-stress conditions. 
We found midday and predawn water potentials are different between several different water-managing species which were divided into rather isohydric, rather anisohydric and neutral species. Most of the species were less drought-stressed during the midday in the closed forest compared to open forest. In contrast, all species under the sparse canopy kept the same or higher light-saturated photosynthetic yield than those growing in the closed forest. Few species growing under the open forest had lower values of intercellular CO2 concentration compared to those growing in the closed forest both under favourable and mild drought-stress conditions. We found that almost every individual species had a different seasonal variation in stomatal conductance values and led to differences in the photorespiration rates, which were mostly driven by light conditions.
We conclude that herbaceous species growing in the closed forest were less drought stress and the response of studied physiological traits to the combined effect of drought and light was found to be species-specific.
A Bayesian network approach to environmental risk assessment of pesticides: direct and indirect effects of climate change
Authors: Moe Janincke , Mentzel Sophie , Grung Merete , Holten Roger , Stenrød Marianne
Published: March 2022

Weather patterns of Northern Europe are projected to change with increased temperature and precipitation by 2050. These climatic changes can potentially affect the transport and degradation of pesticides in the environment. Moreover, pesticide application patterns are expected to be altered as plant disease and insect pests potentially increase. Other agricultural practices are also expected to change such as crop types and application rate. We have used a Bayesian network model to better integrate these potential direct and indirect climate change effects on pesticide exposure, in a probabilistic approach to pesticide risk assessment. The Bayesian network serves as a meta-model to incorporate the predictions from a pesticide fate and transport model (i.e. WISPE). In this study, we ran the exposure prediction model for specific environmental factors linked to a representative Norwegian study area such as soil and site parameters together with chemical properties, under different scenarios of climate model projections and pesticide application patterns. The Bayesian network links the pesticide exposure predictions derived for this study area to effect distributions derived from toxicity tests to predict the probability distribution of the risk quotient to surrounding aquatic ecosystemsThus, this approach takes into account both direct climate change impacts (on pesticides fate and transport) and indirect effects (on pesticide application). Compared to traditional (deterministic) risk assessment methods, this probabilistic approach can better account for uncertainty associated with climate projections,
How soil sodification and pH restrict microbially mediated organic carbon turnover and aggregate formation: An artificial soil microcosm study
Authors: Schweizer Steffen , Fiedler Janosch , Boehm Anne , Dannenmann Michael , Garcia-Franco Noelia , Han Jincheng , Poll Christian , Wong Vanessa , Bucka Franziska
Published: March 2022

Exchangeable sodium can have pronounced influences on physicochemical soil properties whereas the combined impact on microbial turnover of organic carbon (OC) remains elusive. In this work, we aimed to differentiate the effects of exchangeable sodium and soil pH on microbially mediated aggregate formation and turnover of cattle slurry. We incubated the soils under controlled laboratory conditions using artificial soil model minerals containing quartz grains, montmorillonite and goethite. The montmorillonite was pre-treated with NaCl solutions of sodium adsorption ratios (SAR) 0, 1 and 5 which resulted in exchangeable sodium percentages (ESP) of 1, 7 and 19 on average. The soil pH was adjusted within two treatments to 7.5 and 8.5 for each ESP at the start of the incubation. We incubated these six treatments with and without cattle slurry ground to < 200 µm after addition of a combined microbial inoculum, extracted from a Cambisol (pHH2O 7.5, Germany) and a Calcaric Solonchak (pHH2O 9.3, Spain) added to all samples. The microcosms were incubated with three replicates over a period of 30 days at constant pF of 2.2. The CO2 emission measurements of the microcosms with exchangeable sodium indicated a delayed respiration. The respiration under ESP 19 increased rapidly within the first days of incubation, whereas it was more delayed under ESP 7 until 15 days of incubation. The delayed CO2 respiration might be related to inhibited structural formation in treatments with higher exchangeable sodium. To test this, we are investigating the data on water-stable aggregation by wet sieving. The delayed CO2 respiration was reflected in lower microbial biomass, extracted after the incubation. The microbial biomass under ESP 19 and pH 8.5 was highest whereas the amount of leached C after two rainfall events (at day 7 and 15) was lowest, which could be related to a higher microbially mediated OC sequestration. The composition of exchangeable cations was monitored before and after the whole incubation which might help explaining the processes of microbially mediated aggregate formation and microbial carbon turnover under different levels of exchangeable sodium.
Experimental study of the adaptation of an alluvial fan to climate change
Authors: Metivier Francois , Delorme Pauline , Devauchelle Olivier
Published: March 2022

We study the effect of an increase in flow discharge on the shape and growth of an experimental alluvial fan using a small scale controlled experiment. The fan is built by a channel in which the flow is located near the threshold of sediment motion. Under these conditions, it is possible to define a simple criterion for the incision of a fan as a function of both the amplitude and  duration of the change in fluid discharge. Our results show the relevance of this criterion and enable us to discuss the conditions under which a climate perturbation may or may not leave an imprint on the fan morphology and discuss its application to natural systems.
Geochemical monitoring of the geothermal reservoirs using a high-temperature downhole sampler
Authors: Clark Deirdre , Kaldal Gunnar Skúlason , Gunnarsson Bjarni Steinar , Galeczka Iwona , Þorbjörnsson Ingólfur Örn , Nielsen Steinþór , Sigurðardóttir Ásgerður K.
Published: March 2022

The monitoring of a geothermal reservoir during its development and production stage is crucial for sustainable and long-lasting utilization. Production wells can cut through several feeding aquifers resulting in discharging of a mixture of fluids originating from these different zones. As such, a sample obtained from a well head during conventional sampling represents an average chemical composition of the subsurface fluids. In contrast, a downhole sampler can collect fluids at precise depths and therefore providing an information about fluid properties at individual feed zones. As it has been observed in high temperature geothermal fields, lack of such a knowledge can lead to a decreased production efficiency and high cost of utilization. For example, extreme corrosion rates of perforated liners have been observed at specific depths due to localized mixing of fluids characterized by distinct compositions. Such damages could be avoided by identifying of such mixing depths before well flow test and by casing off these mis-matching feed zones through cement plugs or tiebacks. Similarly, scaling induced by fluid mixing, could be reduced by assessing appropriate casing depth, and therefore preventing the inflow of problematic fluids into the well.

The aim of this study is to design the downhole sampler that is capable of collecting fluids from high temperature wells at up to 300-400 °C during every stage of the geothermal utilization. The chemical data obtained from fluids at different depths will not only help to select the most energy efficient discharge fluids for improved productivity of the well. It will also contribute to the conceptual models of the reservoirs, hence, to better understanding of hydrothermal reservoirs through their production lifetime.
Grassroot farming governance reform and the cooperative way of knowledge exchange in rural China
Authors: Wang Weikai , Naylor Larissa , Hallett Paul
Published: March 2022

Rural cooperatives in China have been flourishing and diversified, but their functions and roles in enhancing knowledge exchange and social learning is still unclear. This paper adopts an integrated framework for knowledge management to examine the intermediary role of cooperatives in knowledge networking. Three broader types of rural cooperatives, namely specialised cooperatives, land shareholding cooperatives and cooperative unions are investigated in terms of their governance structure, stakeholder relations, knowledge flows and the mechanisms used by cooperatives to span knowledge boundaries. The findings show that cooperatives play a role of knowledge broker in knowledge exchange between farmer and relevant actors, but the functions and knowledge management mechanisms are heterogenous depending on the governance structure. Cooperatives provide a range of service to members and perform as a mediator or broker between science, policy, market, and farming practice. However, agricultural cooperatives should enhance wider community engagement to promote the interdependency of stakeholders, based on which knowledge can be transformed and put into actions. 
CO2 evolution after straw incorporation in soil supplemented with nutrients based on C:N:P:S stoichiometry
Authors: Amin Nazish , Panthi Sharan , O'Rourke Sharon Mary
Published: March 2022

Evidence exists for a constant C, N, P, and S content in stabilized organic carbon in soils globally. This indicates that fresh-C inputs to soil with insufficient nutrients can limit the size of the soil C pool. This study conducted an experiment to test C:N:P:S stoichiometry as a mechanism to increase the rate of organic matter (OM) mineralization following straw incorporation in soil. The objectives were to (i) determine whether straw incorporated in soil with supplementary nutrients to balance the C:N:P:S stoichiometric input would increase the rate of OM mineralization and (ii) assess the rate of OM mineralization from straw with stoichiometric nutrient input that was either N, P or S limited. Straw was incorporated in soil at a rate of 8 t ha-1with or without supplementary nutrients to convert a target 30% fresh C-input to SOC. Five soils with increasing silt and clay content were included in the study and incubated in an environmentally controlled chamber for 16 weeks. CO2 was collected at one or more weekly intervals in a 1N sodium hydroxide (NaOH) trap, precipitated by BaCl2, and titrated with HCl to determine the CO2-C evolved. A repeated measure multivariate ANOVA is being used to determine if there were differences in CO2-C between nutrient treatments or nutrient treatments over time. Decomposition of straw was completed in 12 weeks. In three out of five soils the total CO2-C production for a straw with stoichiometrically balanced nutrients was significantly greater (P < 0.01) than the straw with no nutrient addition. In the soils that demonstrated a greater rate of OM mineralization with nutrient supplementation, the N, P, and S limited treatments all produced less CO2-C. Interestingly, all five soils collected for this study had a high P fertility status, yet lower CO2-C was produced in the P-limiting treatment indicating that the soil P was not immediately available during straw decomposition. In conclusion, higher rates of OM mineralization were achieved when C-input was stoichiometrically balanced. Nutrient inputs of N, P and S could maximize the soil C sequestration potential.
Climatological analysis on the North-Western Black Sea upwelling phenomena
Authors: Mihailov Maria Emanuela , Lazar Luminita , Chirosca Gianina , Popov Petrica , Pantea Elena Daniela , Vatu Nicolae , Andrescu Dumitru , Chirosca Alecsandru Vladimir
Published: March 2022

We used monthly means by Copernicus Marine Services for the Black Sea basin to calculate a series of metrics related to wind-driven upwelling dynamics (Upwelling Index) and examine the relationship with nutrient and plankton environment. We then use these to objectively describe upwelling signals in terms of their frequency, intensity and duration during summer months over 26 years (1993 - 2019). We found that an increase or a decrease in the sea surface temperature is associated with a reduction (or increase) in upwelling events, a decrease/increase in the intensity of upwelling, and a decrease/increase in the cumulative upwelling intensity, with differences between Romanian Black sea areas. Nitrate supply by coastal upwelling has been estimated by combining sea surface temperature and salinity for the in-situ data for the North-Western Black Sea shallow waters. The seasonal vertical transport induced by wind forcing was assessed by daily wind data retrieved from the Copernicus Marine Service data was used. 
Eddy-covariance measurements and surface energy balance in almond orchards. Results and challenges.
Authors: Sánchez Juan Manuel , Simón Llanos , Rodríguez Antonio , López-Urrea Ramón , González José , Doña Carolina , Galve Joan Miquel , Calera Alfonso
Published: March 2022

This work is based on the energy flux measurements in almond orchards conducted in the framework of a research project focused on the water status monitoring of this crop in semi-arid environments. An eddy-covariance system was installed in a central location of a 11 ha young almond orchard in 2017 and data of the components of the energy balance equation were collected for 3 years. In 2020 the tower was moved to a nearby plot, to monitor a 10 ha mature almond orchard in this case. Both sites are located in Albacete (southeast Spain), and datasets are available through the European Fluxes Database Cluster.

The complex structure of the trees and the small size of the fields are a challenge for the characterization of the surface energy balance in almond orchards. This work analyzes the footprint area contributing to the turbulent flux measurements, as well as the energy balance closure as a function of the canopy height and the instruments deployment. Also, registered CO2 flux data allows a discussion on the behavior of the almond trees as carbon sinks in these environments.

Flux databases in woody crops are quite scarce in global networks. The measurement site introduced in this work will contribute with valuable flux data to the study of these expanding crops in semi-arid areas.

 

 

 
Validation of Cloud Reduction Algorithms Over MODIS Snow Products on Andes Mountain
Authors: Saavedra Freddy , Hernandez Ana , Gonzalez Daniela , Aguirre Yael , Contreras Valentina , Caro Alexis , Romero Carlos
Published: March 2022

The Andes Mountains span a length of 7000 km and are important for sustaining regional water supplies in South America. Rivers flow from the west side of the Andes to the Pacific Ocean and are the main source of water supply for energy generation, irrigation, and drinking water. Snow variability across this region has not been studied in detail due to sparse and unevenly distributed instrumental climate data. The optical remote sensing approach has been developed as a great tool to avoid this limitation. However, cloud cover reduces the ability to use it in the northernmost and southernmost portions of the Andes and the winter and spring in the central part of the Andes. We tested the performance of temporal, spatial algorithms in consecutive and simultaneous steps over daily MODIS snow cover products (Aqua and Terra). We evaluated the cloud reduction (effectiveness) and accuracy using simulated experiments from MODIS data by selecting low cloud cover images (“truth”) and cover with artificial clouds, then we ran all the algorithms and tested them based on the “truth” dataset. On clear sky days, we include higher spatial remote sensing data (Landsat and Sentinel) and in-field data from UAV. The combination of Aqua and Terra reduced the cloud cover by 10-15% on a yearly scale. The temporal combination with previous and following days yielded a substantial improvement in cloud removal but is usually less effective for large-area cloud cover. Developing a new dataset with cloud reduction can help to increase the performance of the snowmelt runoff model and extend a large latitude range across the Andes Mountains to use optical remote sensing data for seasonal snow studies. The use of machine learning, fusion with other snow products (e.g. radar), and more intense use of UAVs point to the next research.
Impact of NOx in SOA and organonitrates production
Authors: Aruffo Eleonora , Wang Junfeng , Ye Jianhuai , Ohno Paul , Qin Yiming , Stewart Matthew , McKinney Karena , Di Carlo Piero , Martin Scot T.
Published: March 2022

The concentration of nitrogen oxides (NOx) and their reservoir species, the organonitrates (ON), impacts on the secondary organic aerosol (SOA) production. To estimate the effect of different NOx levels on SOA, we carried out a series of laboratory experiments at the Harvard Environmental Chamber (HEC) investigating the production and partitioning of total organonitrates from α-pinene photo-oxidation in a NOx range varying between 1 ppb and 24 ppb. We measured not only the aerosol mass concentration by using a Scanning Mobility Particle Sizer (SMPS) and composition by an on-line aerosol mass spectrometry (AMS), but also the gas phase and particle-phase organonitrates (gON and pON, respectively) by a thermal dissociation laser-induced fluorescence (TDLIF). In our experimental conditions, we found the presence of crossover point of 6 ppb of NOx between clean and polluted conditions that affect the SOA production: in fact, the SOA yield for 1 to 6 ppb NOx increased, and for >6 ppb NOx steadily dropped. The ON partitioning ratio (pON/(pON+gON)) has been estimated, identifying that also this ratio is strongly affected by the NOx concentrations; in fact, it decreased from 0.27 to 0.13 as the NOx increased from <1 to 24 ppb. 
Reducing Uncertainty in Upper Mantle Rheology, Lithospheric Thickness and Geothermal Heat Flow Using a Bayesian Inverse Framework to Calibrate Experimental Parameterisations of Anelasticity
Authors: Hazzard James , Richards Fred , Roberts Gareth , Goes Saskia
Published: March 2022

Uncertainty in present-day glacial isostatic adjustment (GIA) rates represent at least 44% of the total gravity-based ice mass balance signal over Antarctica. Meanwhile, physical couplings between solid Earth, sea level and ice dynamics enhance the dependency of the spatiotemporally varying GIA signal on 3D rheology. For example, the presence of low-viscosity mantle beneath melting marine-based ice sheet sectors such as the Amundsen Sea Embayment may delay or even prevent unstable grounding line retreat. Improved knowledge of upper mantle thermomechanical structure is therefore required to refine estimates of current and projected ice mass balance.

Here, we present a Bayesian inverse method for mapping shear wave velocities from high-resolution adjoint tomography into thermomechanical structure using a calibrated parameterisation of anelasticity at seismic frequency. We constrain the model using regional geophysical data sets containing information on upper mantle temperature, attenuation and viscosity structure. The Globally Adaptive Scaling Within Adaptive Metropolis (GASWAM) modification of the Metropolis-Hastings algorithm is utilised to allow efficient exploration of the multi-dimensional parameter space. Our treatment allows formal quantification of parameter covariances, and naturally permits us to propagate uncertainties in material parameters into uncertainty in thermomechanical structure.

We find that it is possible to improve agreement on steady state viscosity structure between tomographic models by approximately 30%, and reduce its uncertainty by an order of magnitude as compared to a forward-modelling approach. Direct access to temperature structure allows us to estimate lateral variations in lithospheric thickness, geothermal heat flow, and their associated uncertainties.

<img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gepj.f1afa46e45e164677142461/sdaolpUECMynit/22UGE&app=m&a=0&c=89177a2843888e6703a2bdcf58cb598d&ct=x&pn=gepj.elif&d=1" alt="" width="1047" height="610">
High-frequency observations reveal acute chloride pulses and chloride legacy effects in an urbanizing watershed impacted by road salting
Authors: Oswald Claire , Ross Cody , Moslenko Luke , Wellen Christopher
Published: March 2022

In watersheds impacted by urban growth and road salt usage, increasing stream chloride (Cl-) concentrations are well-documented. Peaks in stream Cl- concentrations that exceed chronic and/or acute water quality guidelines are typical in the winter salting season when Cl- (from Cl--based de-icers) is flushed from the landscape but are not easily measured with grab samples. In some cases, chronic Cl- conditions persist into the summer growing season due to a build-up of Cl- in the subsurface. Estimating the proportion of Cl- loads transported in the salting and non-salting seasons is of interest for tracking the relative role of subsurface Cl- pools to the annual load, as well as the influence of runoff events on loads across the two periods. In this study, we made use of a 6-year record of high-frequency stream Cl- concentrations from an urbanizing watershed in southern Ontario, Canada. High-frequency measurements revealed that the acute and chronic water quality guidelines for Cl- were exceeded for 7 and 97 % of the study period, respectively. Salting season Cl- loads were 2 to 5 times higher than in the non-salting season, but surprisingly, inter-event periods contributed 21 to 56 % of the annual load across years. The results of this study illustrate the utility of high-frequency sensors for identifying water quality extremes that negatively impact aquatic ecosystems, identifying Cl- transport pathways, and tracking the build-up of legacy Cl- in the subsurface.
A Numerical Modeling Approach to Capture Erosion around Coastal Protection Structures under Wave Impact
Authors: Bihs Hans , Wang Weizhi , Ehlers Ronja , Kamath Arun
Published: March 2022

Common structure to protect the coastline against wave impact and erosion are seawalls. Whereas seawalls are eﬀective at preventing coastal erosion during storm events, the wave energy is not dissipated. Waves are propagation on a sloping beach towards the seawall, where they interact with the vertical structure. Resulting from the incident and reﬂected waves, downward directed vertical velocity components cause a region of increased bed shear stress at the toe of the seawall, ultimately leading to local scour. Future climate change induced sea level rise and increased wave heights create a need for estimating possibly larger scour holes around seawalls which can threaten their structural stability. In this contribution, a solution strategy for the prediction of seawall scour scenarios for diﬀerent water levels and wave conditions is presented. The high-resolution NavierStokes solver of the open-source hydrodynamics framework REEF3D is used to calculate the waves impacting the seawall. The interface capturing level set method for the free surface makes it possible to resolve the complex wave pattern in front of the seawall including the breaking of individual waves. Based on the near-bed ﬂow conditions, the bed shear stress is calculated. Then bed load and suspended sediment transport formulations are numerically solved. Erosion and deposition of the sediment is calculated with Exner’s equation for the conservation of sediment mass. The morpho-hydrodynamic solver requires relatively large computational resources and is suitable for the near-ﬁeld solutions. In order to predict realistic wave conditions at a given coastline location, more eﬃcient large-scale wave models are required. A coupling strategy for a fully nonlinear potential ﬂow model to the Navier-Stokes solver is presented. The numerical modeling results are validated against measured wave and sediment data from laboratory experiments.
A new classification and terminology system towards the development and utilisation of Martian simulants
Authors: Stavrakakis Hector-Andreas , Argyrou Dimitra , Chatzitheodoridis Elias
Published: March 2022

Since the 90s, an ever-increasing number of missions to Mars have been conducted which offer a plethora of information about the red planet. This information also led to the rapid development and advancement of prominent scientific fields in space and planetary exploration, such as astrobiology and ISRU technologies. The experimentation and research requirements of those fields, as well as, the need for better vehicle and instrument testing for further development, so that they will better operate on Martian conditions and its surface, increase in significance. Currently, this is performed with the use of natural (Analogue) and synthetic (Simulant) Geomaterials. 

However, the accessibility and the analysis of analogue and simulant data requires a thorough literature review in order to  identify implications for future research. In our latest research work, we conducted this detailed review and we identified, grouped, and analysed a number of implications that pertain mostly to the synthesis procedures of simulants, but also extend to the in situ analytical data from Mars that are used as a reference. Furthermore, we identified an urgent need for improving the current state of simulant research, as it is currently very time consuming and has implications, in hope that systematic work on the topic will culminate in a general standardisation effort.

The current work was done by analysing data on all available simulant geomaterials in order to provide recommendations and suggestions for mitigation actions for their development and their use during research, as well as to advocate the needs for a unified standardisation system. These actions include: (a) the consolidation of existing literature into database formats with easy access, based on (b) the development of a new informational construct based on ontologies and semantics, (c) to propose a classification system for simulants that is missing from the literature, and (d) assist the simulant geomaterial selection process through a proposed step algorithm. The ontological and semantic mindset should be followed at every step, and it is incorporated into the classification system, thus enabling easy access and interpretation by both humans and machines. This set of tools and recommendations should be applicable on all simulant related facets of space exploration.

 
Orientation of anisotropic particles in stratified turbulent flows
Authors: Sozza Alessandro , Pumir Alain
Published: March 2022

Small-scale turbulence and density stratification are two major ingredients shaping the life of marine micro-organisms in the pycnocline. Such tiny particles are rarely spherical, ranging from flat disks to elongated rods. Particle orientation with respect to the flow or to density gradients plays a crucial role in many aspects of phytoplankton's life, e.g. light harvesting for photosynthesis, enhancement of nutrient uptake, optimal navigation and vertical migration. However, it's still unclear how anisotropic particles align in a turbulent pycnocline and how they are able to cope with density stratification.

In the present work, we aim to characterize the effects of stratification on the orientation of inertialess non-spherical particles. To achieve this purpose, we performed direct numerical simulations of a mixed Eulerian-Lagrangian model. The flow is described by the Boussinesq equations, which evolve fluid velocity and density fluctuations in a triply periodic cubic domain. The space is initially seeded with spheroidal particles of different shapes (from rods to disks) transported by the flow as passive tracers. Particle orientation evolves in response to velocity gradients according to Jeffery’s dynamics.

We have explored different configurations of the parameters' space by changing particle shape, density stratification and turbulence intensity. The statistical properties of orientation are then unveiled by characterizing the particles' distributions and their mean behavior. Moreover, we have inspected the alignment of particles with respect to the flow and to the iso-density surfaces. We have analyzed rotation rates of the particles and compared our results with the case of spherical particles and homogeneous isotropic turbulence. Such outcomes provide a clear picture of the influence of stratification on the orientational dynamics and on its transition from non-stratified to strongly stratified turbulence. Finally, we conclude by discussing the implications of our results for oceanic applications.
Progress On a New Interactive 3-Dimensional Data Viewer for the Enlil Solar Wind Model
Authors: Pankratz Christopher , Lucas Greg , Knuth Jenny , Odstrcil Dusan , Craft James , Berger Thomas
Published: March 2022

One of the critical models in space weather forecasting is the Enlil solar wind prediction model that can inform space weather forecasters the direction and speed of coronal mass ejections CMEs. The Enlil code calculates the propagation of the solar wind throughout the 3D heliosphere, but current visualization capabilities in the forecasting offices are restricted to 2D planes intersecting Earth. This limits forecasters to only be able to view CME properties that are traveling directly in the plane of the Earth.

 

Here, we present an update on a new visualization capability being developed to take advantage of the full Enlil 3D data volume and interactively visualize the CME expansion out of the plane of the Earth.  We have been collaborating closely with researchers and forecasters at the Met Office in the UK and the Space Weather Prediction Center (SWPC) in the USA to develop a tool to enable full view of the heliosphere in a manner that can be tailored to these different types of users. To accomplish this, we are deploying the Enlil solar wind model into a scalable Cloud-based model staging platform computing environment, which will allow the full 3D Enlil output to reside in-situ with the visualization engine.  We will discuss our progress in deploying and running the Enlil model in the Cloud-based testbed environment, the process of interacting directly with space weather forecasters to design a new interactive 3D visualization tool that meets their needs, and will demonstrate use of the actual visualization tool, which is deployed and running in the Amazon Web Services (AWS) Cloud environment.
Zeta Potential of Intact Carbonate Core Samples Saturated with Natural Aqueous Solutions with Varying Concentration of Negative Potential Determining Ions
Authors: Atiwurcha Nacha , Derksen Jos , Vega-Maza David , Vinogradov Jan
Published: March 2022

Zeta potential is an important petrophysical property that controls electrostatic interactions between mineral, water, and non-aqueous phase fluids. These interactions play an important role in defining the wetting state of reservoir rocks. The zeta potential can be interpreted from the streaming potential measurements, which are shown to be an efficient means for a broad range of applications including monitoring of single- and multi-phase flows in subsurface settings, characterization of fracture networks, efficiency of CO2 sequestration, hydrogen underground storage and enhanced oil recovery. It is widely agreed that the zeta potential in carbonate rocks is controlled by the concentration of potential determining ions (PDI), but the understanding of this is still poor and there are very limited experimental data on quantitative characterization of the dependence of the zeta potential on concentration of negative potential determining ions (PDI) such as SO42-, CO32-, HCO3-, especially when their concentration is high and exceeds that of the positive PDIs.

In this study, the streaming potential method is used to investigate the zeta potential of natural carbonate rock samples in contact with natural aqueous solutions of low-to-high ionic strength and with varying concentration of sulphate (SO42-) and carbon (C4) related (HCO3-, CO32-) ions. In each set of experiments the total ionic strength was kept constant to eliminate the impact of concentration on the zeta potential. The study probed the concentration of negative PDIs that has never been reported before, with their respective lowest concentration consistent with previously reported values, and the highest concentration equal to the maximum achievable by stripping the tested solutions of Cl-.

Our results demonstrate that zeta potentials strongly depend on concentration of the negative PDIs, thus providing explicit empiric relationship between the zeta potential and a broad range of PDI concentration. Our findings improve the current understanding of the complex physicochemical processes that take place at calcite-water interface and provide important experimental data for surface complexation modelling of carbonate-brine systems.
From sediment images to travel distances: an estimation of expected accuracy
Authors: Cattapan Alessandro , Paron Paolo , Franca Mário J.
Published: March 2022

In this study we introduce a new algorithm that allows the automatic segmentation of the contour of sediment particles collected directly in the field. The benefits of this method consist in better performance with respect to other available methods, especially in case of shadows around the sediment particle and in a more systematic and faster procedure with respect to manual segmentation. The method is compared with the one proposed by Roussillon et. al. 2009 and its performances are assessed using shapes having known morphometry descriptors. We moreover propose a way to assess the relative error one can expect in the estimates of particles travel distances using sediment morphometry as their proxy. The conclusions derived hold under the hypothesis of validity of a relationship between particles’ relative mass loss and circularity and on the empirical Sternberg’s law. The expected relative errors of travel distances result to depend on accuracy with which particles’ shape is identified and on the distance itself, therefore suggesting the existence of a window of “more accurate” estimation.
Improving sub-seasonal forecasts of high and low flows using a flow-dependent nonparametric model
Authors: Kavetski Dmitri , McInerney David , Thyer Mark , Laugesen Richard , Woldemeskel Fitsum , Tuteja Narendra , Kuczera George
Published: March 2022

Sub-seasonal streamflow forecasts are used in a wide range of water resource management and planning applications. Practical interest includes forecasts of high flows (e.g., for managing flood events) and low flows (e.g., for managing environmental flows). However, this work reveals that while probabilistic forecasts evaluated over the full flow range can appear statistically reliable, performance specifically for high/low flows can suffer from notable under/over-estimation of forecast uncertainty, respectively. To address this challenge we consider a flow-dependent (FD) nonparametric representation of hydrological forecasting errors, and employ this representation to enhance the existing Multi-Temporal Hydrological Residual Error (MuTHRE) forecasting model. In a case study with 11 Australian catchments, the new MuTHRE-FD model achieves practically significant improvements over the original MuTHRE model in the reliability of forecasted cumulative volumes for high flows out to 7 days, low flows out to 2 days, and mid flows for majority of lead times in the range of 1-30 days. The improved performance of the MuTHRE-FD model provides forecast users with increased confidence in using sub-seasonal streamflow forecasts for applications across a range of flow magnitudes and lead times.
The potential for enhancing soil carbon levels through the use of organic soil amendments in Queensland, Australia
Authors: Biala Johannes , Wilkinson Kevin , Henry Beverley , Singh Shweta , Bennett-Jones Joshua , De Rosa Daniele
Published: March 2022

Application of organic soil amendments such as manure or compost is commonly listed amongst strategies with potential to sequester carbon in agricultural soils, and Australian farmers are able to earn carbon credits for increasing soil organic carbon (SOC) stocks through the use of organic amendments under the Government’s Emission Reduction Fund. Despite their assumed contribution to enhancing SOC levels and inclusion into climate change mitigation strategies, there has been little qualitative or quantitative assessment of the effects of organic amendments on SOC stocks and dynamics. We evaluated this potential for Queensland (Australia) by collating and analysing information on organic amendments and by modelling soil organic carbon sequestration with the FullCAM model in three different cropping locations. An estimated 2.7 million tonnes dry matter (dm) of organic amendments, containing up to one million tonne (dm) of organic carbon was likely land applied in Queensland in 2015/16. Simulations predicted that, in favourable locations, high annual applications of raw manure and compost (10 t and 15 t ha-1 yr-1 fresh matter, respectively) could result in annual soil organic carbon increases of 0.9% and 0.55%, respectively, averaged over 20 years of continuous sorghum cropping. In less favourable conditions and with less frequent or lower applications, carbon stocks may continue to decline but more slowly than without organic amendments. The paucity of key data for more accurate assessments of carbon sequestration potentials led us to identify research priorities that support development of frameworks for use of organic amendments in agricultural soils for climate, food security and waste management benefits.
brGDGT and pollen-based Holocene temperature reconstruction from the Olgi Lake in the Tarvagatai Mountains (north-central Mongolia)
Authors: Behling Hermann , Barhoumi Chéïma , De Jonge Cindy , Unkelbach Julia
Published: March 2022

Understanding the complex mechanisms that govern the short and long-term development of Holocene ecosystems requires the multi-proxy study of lake sediment or peat archives, for example. Factors such as climate variability can thus be determined, but also other factors influencing these ecosystems such as vegetation, disturbances (fires, storms, insect pests), as well as human impact. The objective of this presentation is to show new reconstructed Holocene (9500 ka – present) temperatures in the North-central region of Mongolia, in the Tarvagatai mountains, using two independent methods: transfer functions from pollen grains and from brGDGTs ratios. We aim to compare the results of these climatic reconstructions with each other, but also to analyze them with regard to the reconstruction of vegetation, fire dynamics and environmental changes, carried out by Unkelbach et al. in 2021. The temperatures obtained from the analysis of brGDGTs (calculated from the calibration of De Jonge et al., 2014) show a warm start to the Holocene (4.1 - 5°C), between 9500 and 8600 cal. yr BP. After an abrupt decrease in temperatures of 3°C to 8500 cal. yr BP, temperature remain stable until the mid-Holocene, to 5500 cal. yr BP, where a warm period of 1000 years is observed. From 4500 to 500 cal. yr BP, a gradual and continuous decrease in temperatures (down to -2.7°C) took place. This agrees with the climatic indications given by the vegetation and the results obtained by the WAPLS transfer function from pollen grains. 
Nearshore and coastal impact of Hurricane Irma (2017) on Barbuda, eastern Caribbean
Authors: Jackson Derek , Guisado-Pintado Emilia , Dolphin Tony , Heal Richard
Published: March 2022

Hurricane Irma, after building to a category 5, struck the island of Barbuda in 2017, causing widespread devastation and dramatic coastal and nearshore alteration. Pre-and post-event airborne (terrestrial) LiDAR, along with satellite-derived bathymetry for the site provided detailed topographical quantification of the seabed and landform response to this extraordinary event, and presented a unique set of forcing conditions with which to observe Category 5 impacts on low lying island environments.

Using pre-hurricane bathymetry, Hurricane-generated waves were simulated across the nearshore using in situ and far field measurements of initial wave conditions. An initial SWAN simulation was conducted from the offshore using the WW3 wave climate as boundary conditions to develop the wave spectrum for nested, nearshore high-resolution (10m) grids focussed on the island. Water levels from the local tidal cycle were also accounted for using a set of non-stationary runs and local tide gauge information with an input grid of every 6 hours to simulate tides during the passage of the storm.

Significant bathymetric changes were noted throughout the nearshore zone as a result of the Hurricane event with distinctive erosion and accumulation patterns observed. We highlight direct wave forcing (bed shear stress) and its coincidence with these patterns of sediment dispersal. Terrestrial dune ridge topography was also dramatically altered with severe flattening of relief (and vegetation) during the Category 5 event.

Our study helps demonstrate the heterogeneous nature of the impact that hurricanes of this magnitude have on low lying island environments and shows the dramatic before and after changes they can have on the local coastal landscape.
Differential exhumation of cratonic and non-cratonic lithosphere revealed by apatite fission-track thermochronology along the edge of the São Francisco craton, eastern Brazil
Authors: Fonseca Ana Carolina , Cruz Simone , Novo Tiago , He Zhiyuan , De Grave Johan
Published: March 2022

Lithosphere of cratons and orogens generally reacts differently to tectonic events. Although these differences are mostly clear during the orogenic phases, understanding how they respond to tectonic reactivation is still challenging. Here, we report the first detailed apatite fission-track (AFT) study pinpointing the gradual transition between cratonic and orogenic lithosphere, using the case study of the São Francisco craton (SFC) and the adjacent Araçuaí-West Congo Orogen (AWCO), eastern Brazil. The collision that built the AWCO partially affected the inherited rift structures of the Paramirim Aulacogen, embedded in the São Francisco-Congo paleocontinent. Our data reveal a differential Phanerozoic exhumation between closely interspaced areas affected and not affected by the AWCO deformation. Samples from the SFC present slow and protracted basement cooling during the Phanerozoic, while samples from the orogen display rapid exhumation since the Eocene. An intermediate ~N-S zone of c.40 km shows lower magnitude basement cooling during the Cenozoic, possibly because the propagation of AWCO deformation decreases towards the craton interior. Within the orogen, the Rio Pardo salient is the main reactive structure and probably results from the deformation of a master fault, inherited from its precursor rift. Here, we show how the magnitude of Phanerozoic denudation may be deeply associated with previous events of lithosphere weakening.