bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolic rate and the vulnerability of mollusks to hyperthermal-driven extinction events
Authors: Gavirneni Siddharth , Ivany Linda , Reddin Carl
Published: February 2023

Climate change can be a major driving mechanism behind mass extinctions. The combined multistressor effects of rapid global warming, ocean acidification, and hypoxia are devastating to marine faunas. Such episodes in Earth’s history, dubbed ‘hyperthermals’, serve as natural experiments that can provide insight into the effects of climate warming on marine ecosystems in the past as well as today. As water temperatures rise and oxygen solubility decreases, metabolic rates, and, consequently, the oxygen demands of organisms increase. This suggests that organisms with higher metabolic rates, already requiring more oxygen overall, should be more vulnerable to deoxygenation associated with rapid climate warming. However, more active organisms generally have physiologies less vulnerable to hypercapnia resulting from CO2 buildup in the oceans during hyperthermal conditions. Previous work on activity levels of fossil taxa disagree whether more active organisms are selected for (i.e., less vulnerable) or selected against during major hyperthermal-driven extinction events.Here, we explore the effects of resting metabolic rate, body size, and temperature preference on extinction vulnerability in gastropods and bivalves during post-Paleozoic hyperthermals. We estimate metabolic rates with a general model of metabolic rate originally derived by Gillooly et al. (2001), using published biomass estimates and location-specific sea surface temperatures from published climate models. Following Reddin et al. (2020), we then calculate relative hyperthermal vulnerability (RHV), the difference between the risk of extinction at intervals associated with hyperthermal conditions versus baseline conditions, in order to determine how an organism’s metabolism may affect patterns of taxonomic extinction and survival across hyperthermal-driven extinction events. RHV can be preferable to more direct comparisons of extinction selectivity in that it allows for comparisons among groups with very disparate basal turnover rates. Preliminary results for bivalves indicate that a higher metabolic rate is associated with a reduced risk of extinction during hyperthermal conditions. These results also seem to suggest that the driving force behind this pattern of selectivity is the B0 standard metabolic rate coefficient, estimated using experimental data on respiration rates in modern bivalve and gastropod clades. Future work will focus on whether the range of variation in the experimental data underlying the B0 estimates lines up with what is expected of fossil taxa, and ultimately, whether these data can be used to evaluate how metabolic rate can affect species vulnerability to stress or extinction risk.
Investigating the interactions of alpha particles in collisionless oblique heliospheric shocks
Authors: Ofman Leon , Wilson Lynn B , Nieves-Chinchilla Teresa , Jian Lan , Szabo Adam
Published: February 2023

Heliospheric shocks associated with interplanetary coronal mass ejections (ICMEs) were observed by Wind, and DSCOVR at L1, STEREO spacecraft at ~1AU, and recently by the Parker Solar Probe in the inner heliosphere. The magnetic structure and the downstream magnetic oscillations were detected by Wind with 10.9 samples/s and DSCOVR with 50 samples/s. However, the velocity distributions of the protons are available at much lower cadence, and the potentially important interaction between  the alpha particles and  the heliospheric shocks are difficult to obtain directly from present data. Since the alpha particles in the solar wind are the second most abundant ion that can carry significant energy, momentum and mass flux of the solar wind, the alphas can significantly affect the propagation of these shocks. Recently, using hybrid-(PIC) models we studied the effects of alpha particles on the structure and magnetic oscillations of oblique high Mach number heliospheric shocks, and found that the magnetic and density structures of these shocks are significantly affected by the alpha particles with typical solar wind relative abundances. Here, we extend the study and report the results of new hybrid models of oblique shocks guided by observations. We investigate the typical observed relative solar wind abundances of alphas, Mach numbers, and shock normal directions, and compare the results for the various shock parameters. We model the effects of alpha particles properties on the shock ramp, wake, and downstream oscillations and study the properties of proton and alpha particle velocity distribution functions (VDFs) and the kinetic waves downstream of the shocks in the inner heliosphere. We expand the model and study for the first time the effects of relative streaming of proton-alpha ion populations as well as the ion anisotropies on the shock propagation. We investigate the effects of the ion kinetic properties on the heliospheric shock structures and discuss how the modeling results can improve the interpretation of spacecraft observations of these shocks. 
Mineralogical control of fracturing and micro-flaking due to thermal fatigue
Authors: Rüsch Ottaviano , Patzek Markus
Published: February 2023

Thermal fatigue driven by diurnal temperature variations can lead to the physical modifications of rocks and boulders that populate airless surfaces [1-2]. These modifications affect regolith evolution, e.g., particle size, porosity and roughness, and thus influence reflected and emitted radiation observed by spacecraft, Earth- and space-based telescopes. In order to study in detail how this process affects rocks of different mineralogy and under different environments (temperature, vacuum) we use a custom-made thermal cycling chamber operating in high vacuum and at cryogenic temperatures. The investigation on achondrite meteorite samples demonstrated moderate cracking after thermal cycling relative to chondritic samples and revealed a new phenomenon, i.e., formation and detachment of micro-flakes for lunar anorthositic samples [3]. The investigation of chondritic samples subjected to thermal cycling revealed i) formation and extension of cracking due to thermal fatigue for Jbilet Winselwan (CM2), Murchison (CM2) and Tagish Lake (C2ung); ii) absence of newly formed cracks for El Hammami (H5) and Allende (CV3), iii) absence of micro-flaking for all the above-mentioned samples. In addition, we find that in CM chondrites, cracking is often associated with hydrous fine-grained rims that surround chondrules and, in some cases, cracks diverging radially from the chondrules through the rim into the clastic matrix. These results illustrate how the mineralogy and texture, in particular the spatial context with minerals of different coefficient of thermal expansion (hydrous phyllosilicates and olivine/pyroxene), play an important role in crack formation and/or extension.References : [1] Delbo M. et al. (2014) Nature, 508(7495), 233-236, doi:10.1038/nature13153. [2] Molaro J. L. et al. (2015) JGR: Planets, 120(2), 255-277, doi:10.1002/2014JE004729. [3] Patzek M. and Rüsch O. (2022) JGR: Planets 127.10. doi:10.1029/2022JE0073
Projected Future Changes in Equatorial Wave Spectrum in CMIP
Authors: Bartana Hagar , Garfinkel Chaim , Shamir Ofer , Rao Jian
Published: February 2023

Changes of tropical wave-modes due to climate change will impact the predictability of the tropical atmosphere, and may impact extratropical weather as well. The simulations of convectively coupled equatorial waves and the Madden-Julian Oscillation (MJO) are considered in 13 state-of-the-art models from phase 6 of the Coupled Model Intercomparison Project (CMIP6).  We look at the wave-modes using frequency-wavenumber power spectra of the models and observations for Outgoing Longwave Radiation and zonal winds at 250 hPa. We analyze the spectra of the historical simulations and end of 21st century projections for the SSP245 and SSP585 scenarios.  The models simulate a spectrum quantitatively resembling that observed, though systematic biases exist. Most models project a future increase in power spectra for the MJO, while nearly all project a robust increase for Kelvin waves (KW) and weaker power values for most other wavenumber-frequency combinations. Models with a more realistic MJO in their control climate tend to simulate a stronger future intensification. In addition to strengthening, KW also shift toward higher phase speeds. The net effect is a more organized tropical circulation on intraseasonal timescales, which may contribute to higher intrinsic predictability in the tropics and to stronger teleconnections in the extratropics. In addition, those projected changes might be due to extratropical forcings, and more specifically due to changes in the North Pacific subtropical jet.
Microplastics transport during Managed Aquifer Recharge – A potential cause of groundwater contamination?
Authors: la Cecilia Daniele , Moeck Christian , Kägi Ralf , Philipp Matthias , Schirmer Mario
Published: February 2023

Managed Aquifer Recharge (MAR) belong to the nature-based engineering approaches poised to play an increasingly positive role in climate change adaptation. In fact, the increased groundwater availability thank to MAR can buffer future temporal water shortages driven by forecast longer droughts. However, one concern of MAR regards the quality of the infiltrating water as it affects groundwater quality.There is growing concern about groundwater contamination by microplastics (MP) delivered by the infiltrated surface water. Indeed, MPs have been found in rivers globally. Groundwater contamination by MPs could then have direct detrimental consequences on groundwater management and availability for human uses.In this study, we measured MPs larger than 20 µm in the different important stages of a major MAR-water supply system in Switzerland. The MAR system has been diverting an average of 95,000 m3/day of Rhine water through channels and ponds since 1958. Samples of filtered water were taken in triplicates from the Rhine River near Basel, the treatment stages before the managed infiltration outlets, the pumped groundwater, before and after the activated carbon filters. The methodology involved the analysis of the filters by means of micro-Fourier Transform InfraRed (FTIR) spectroscopy and MPs identification by means of the machine-learning model developed by the Purency company. The possible contamination by MPs smaller than 20 µm could not be assessed due to practical challenges for water filtration in the field and quantification (reliable micro-FTIR measurements down to 20 µm). Before analyses, we added surrogate particles of polyethylene with an average size of 60 µm for quality assurance and quality control.The measurements revealed satisfactory MPs reduction along the MAR system. While the number of MPs in the raw Rhine River had to be quantified still, MPs average concentration decreased from about 9.75 particles/l in the treatment stage to about 1.3 particle/l after the activated carbon filter. MPs average concentration increased to 7 particles/l between the pumped groundwater and the activated carbon filters. The increase was driven by a high count of polypropilene MPs in one of the triplicates. Our study could not exclude a possible MPs contamination by construction materials used in the facility. The measured concentrations referred to a randomised scan of about 50% of the area of the filters encompassing the centre and the edges of the filters. Most of the surrogate particles accumulated along the edges. Yet, we only considered particles with a value of the Relevance and Similarity metrics greater than 0.3.Acknowledgements: We thank our colleague Reto Britt who supported with the sampling campaign and laboratory measurements and the drinking water supplier for allowing us to carry out the study within their premises.
Conservation Agriculture to Rebuilt Soil Fertility in Northern Tunisia
Authors: Annabi Mohamed , Bahri Haithem , Cheikh M'hamed Hatem , Barbouchi Meriem , Toukebri Wael
Published: February 2023

Tunisia is an agriculture country. Such as many other Mediterranean countries precipitations  remains a decisive factor not only for the different agricultural uses of lands (rainfed or irrigated system) but also for the soils erosion. The latter  is accentuated by agricultural practices (tillage, pesticide inputs, low crop residue restitution…) which are often productive but do not protect natural resources. All these factors have led to the development of conservation agriculture based on no-tillage as a mean to combat soil erosion. In fact, in Tunisia, no-tillage areas increased from 52 ha in 1999 to 17000 ha in 2020. Based a set of 20 plots covering 6 soils types and located in the semi-arid area of the country, a periodic monotoing of a set of soil parameters were done during three years, which include soil sensitivity to erosion according Le Bissonnais method, soil organic matter content and soil microbial respiration. For each plot, a half  of the surface was no-tilled and the other half was conducted according the conventional method based on soil returning. The results show a rapid effect of no-tillage on soil erosion, since an improvement of 18%, 42% and 39% of soil resistance to erosion, respectively after the first, second and third year of switching to no-tillage system. The soil microbial activity response was also significative, whit a progressive increase of soil respiration in the no-tilled treatments compared to tilled treatments. The microbial respiration was higher in non-hydromorphic soils and particularity in the red Mediterranean soils, calcic-magnesic soils and isohumic soils were moisture conditions was the most favorable for a development of soil microorganisms. For soil organic matter content, the evolution trend was not detectable in relation to the slow evolution of this soil parameter. However, the evolution of particulate organic matter content (a part visible of soil organic matter, with a size larger than 2mm) shown an increase in no-tilled treatments comparative to the tilled treatments. The increase of the particulate organic matter content was more important in vertisols, podzol, calcic-magnesic soils and isohumic soils in relation with their higher wheat production compared to other studier soil types.  
Three Dimensional Wind and Rain Aircraft-Based Observations within the Hurricane Inner Core
Authors: Jelenak Zorana , Sapp Joe , Chang Paul , Bjorland Clayton , Carslwell James , Guimond Stephen
Published: February 2023

The three dimensional observations of wind and rain within the inner core of major hurricanes in the Atlantic basin were collected utilizing the Imaging Wind and Rain Profiler (IWRAP) on board a National Oceanographic Atmospheric Administration (NOAA) P-3 aircraft during the 2020-2022 hurricane seasons. With 30 m vertical and 150 m horizontal resolution, these measurements represent the highest resolution hurricane boundary layer (HBL) observations collected to date with a remote sensing instrument. State of the art IWRAP radar control and data acquisition system collects both in-phase (I) and quadrature (Q) signals for the entire observational profile. This allows for the full spectrum to be derived by utilizing a series of Fast Fourier Transforms (FFTs) on every single range gate resulting in the availability of the observations within lowest 500 m of the HBL. Previously, these observations were only possible from drop sondes. High resolution reflectivity profiles are processed into both three dimensional wind and rain products utilizing Ku- and C-band microwave observations. Over the course of three hurricane seasons, observations of 9 major hurricanes were collected and processed.            With its unprecidented resolution these measurements are providing insights into turbulant processes within HBL of the major hurricanes and can possibly lead into new HBL parametarization of the hurricane models. Validation of measurements were carried out with flight level aircraft measurements, Step Frequency Microwave Radiometer surface wind measurements and Tail Doppler Radar 3d Wind and Reflectivity data.            The measurement technique, collected data, validation results and data availability will be discussed and presented.
Physical properties of 3D printed materials and their applicability as proxies for heterogeneous geomaterials
Authors: Adamus Filip , Stanton-Yonge Ashley , Mitchell Tom , Healy Dave , Meredith Phil
Published: February 2023

3D printing is a rapidly evolving technology that has proven useful for a wide variety of disciplines and industries. However, knowledge of its applicability to the fields of rock and soil physics remains limited. 3D printing allows the design of samples with any desired microstructural composition, enabling independent control of properties such as pore space fabric, size, and density; a feat impossible to accomplish with naturally occurring geomaterials. The use of 3D printed samples is therefore highly attractive for relating the effective properties of heterogeneous materials to their microstructural arrangement, a key subject in the fields of rock and soil physics.This study aims to characterize the physical properties of 3D printed materials (i.e., elasticity parameters, porosity, permeability) and evaluate whether they are suitable to be used as proxies for heterogeneous geomaterials. Two distinct 3D printing technologies were employed for this purpose: the Fused Deposition Modelling (FDM), and Stereolithography (SLA) methods. The FDM method constructs 3D objects by superposing layers of polymer-based filament through a heated nozzle, whereas the SLA method, also known as resin 3D printing, uses a laser light source to cure liquid resin into hardened plastic.Samples with a variety of pore shapes (sphere, needle, penny shaped), sizes, and pore densities were designed and printed as cylindrical samples of 25 mm diameter and 62.5 mm height. Samples were then subjected to uniaxial compression to measure their effective elastic parameters (elasticity modulus and Poisson’s ratio), and these measurements were compared with theoretical predictions. Preliminary results indicate that the FDM printing method is inadequate for representing a heterogeneous solid composed of an isotropic matrix and void space, due to the intrinsically anisotropic fabric resulting from the layer-by-layer printing method. Additionally, samples with a porous microstructure appear to be effectively stiffer than the intact material, which is attributed to enhanced material sintering surrounding the edges of the void spaces. On the other hand, SLA printing appears to hold more promise and be able to represent a composite material composed of an isotropic matrix with a heterogeneous void space. Further measurements need to be made to confirm these preliminary findings, and this work is currently in progress. 
Clumped isotope evolution during aragonite diagenesis
Authors: Pederson Chelsea , Kluge Tobias , Mavromatis Vasileios , Immenhasuer Adrian
Published: February 2023

The clumped isotope (Δ47) proxy provides specific information on formation conditions of carbonate minerals, for example the related fluid temperature. Although the clumped isotope paleothermometer often allows the direct temperature reconstruction due to the measurements being relatively free of vital effects or mineral-specific fractionation, clumped isotope geochemistry during the diagenesis and recrystallization of sedimentary rocks is understudied. This work evaluates clumped isotope data during the alteration of bivalve shells to better understand how the proxy develops under varying diagenetic conditions. Aragonitic bivalves were experimentally altered in closed vessels with variations in durations (0-16 weeks), fluid chemistry (burial and meteoric fluids) and temperature (130 to 200°C).Results generally show increasing calculated temperatures (lower measured Δ47 values) with increasing experimental temperature and duration. Different fluid chemistries (burial versus meteoric fluids) also resulted in a constant offset of values for modern samples following alteration. Fossil carbonates seem to be more resistant to alteration of Δ47 values, indicating a reduced alteration potential compared to modern samples. Lastly, fast re-equilibration during the alteration experiments seem to follow a relatively simple model, similar to the proposed solid-state isotope re-ordering model of Passey and Henkes (2012) and others, but at much higher rate constants and starting at lower temperatures.
Determination of carbon bound non-exchangeable (CBNE) hydrogen isotope ratios in starch by Microwave Assisted Hydrolysis (MAH) and GC-CrAg/HTC-IRMS
Authors: Abrahim Aiman , Kelly Simon
Published: February 2023

Polysaccharides, e.g. starch, are the most abundant biopolymers on earth. They are long chain monosaccharides linked by glycosidic bonds and are playing different important roles in plants such as energy storage (e.g. starch and glycogen) structure and growth (e.g. cellulose and pectin).The determination of carbon bound non-exchangeable (CBNE) hydrogen isotope ratios in polysaccharides are of great interest in a broad range of research areas, as they contain intrinsic information about the metabolic pathway and geographical origin of the plant, derived from water incorporated during photosynthesis. Measuring non-exchangeable hydrogen isotope ratios in starch is challenging using methods such as the dual water-equilibration technique, which are labour intensive and open to a certain degree of contention of over equilibration times, temperatures, proportions of exchangeable hydrogen and fractionation factors. We report on a new approach, to determine non-exchangeable hydrogen isotopes in starch, after hydrolysis of the biopolymer into monosaccharides followed by conversion into volatile trifluoroacetamide (TFA) derivatives and analysis by GC-CrAg/HTC-IRMS.This new methodology (Figure.01) is rapid and simple compared to current available methods and should allow CBNE hydrogen isotope analysis to be more easily and widely used. 
Recent trends on the Bayesian approach for simultaneous recognition of contaminant sources in groundwater resources
Authors: Mahlknecht Jürgen , Torres-Martinez Juan Antonio , Mora Abrahan
Published: February 2023

Understanding diffusive pollution plays a key role in providing an appropriate management plan for protecting water resources. Controlling the diffusive contamination in water is hindered by a wide range of source-mixing processes. Accurate source apportionment is required for controlling harmful pollutants in water. Environmental tracers can be used for the source apportionment of pollutants. They inevitably exhibit diverse uncertainties stemming from measurement errors, spatiotemporal variability of sources, biochemical transformation, and dynamic mixing. To reflect the uncertainties involved in source apportionment, a statistical approach, the Bayesian mixing model has been actively adopted. Our contribution presents different recent cases regarding the application of the Bayesian mixing approach to track pollution sources and transformations in agricultural, urban and coastal aquifer environments using multiple isotope approaches (nitrate, sulfate and boron isotopes). The results demonstrate that current Bayesian mixing model studies are mostly limited to understanding the spatiotemporal diversity of water contamination, which is similar to previous deterministic calculations. Considering the nature of these models, which is capable of printing estimation uncertainty, the course of future research should focus on improving the precision of the current designs of source apportionment analysis.
Dawn-Dusk Asymmetry of the Kelvin-Helmholtz Waves at Earth's Magnetopause: One Solar cycle data
Authors: Kavosi Shiva , Nykyri Katariina
Published: February 2023

Kelvin–Helmholtz instability (KHI) plays a crucial role in solar wind plasma entry into the magnetosphere during the period of northward interplanetary magnetic field (IMF). Several studies have revealed the existence of dawn-dusk asymmetry of KHI along the Earth's magnetopause. However, the causes for such asymmetry are still speculative. Here we survey 11 years of in situ data from the NASA THEMIS (Time History of Events and Macro scale Interactions during Substorms) and MMS (Magnetospheric Multiscale) missions. We found that Kelvin–Helmholtz waves (KHWs) occurrence rates and locations exhibit a semiannual variation; the rate maximizes at the equinoxes and minimizes at the solstice. The rate varies for different IMF By polarities; it is maximum around the fall equinox for negative IMF By, while it is maximum around the spring equinox for positive IMF By. It is shown that the dawn-dusk and north-south asymmetry can be attributed to both the dipole tilt angle and the polarity of Interplanetary magnetic fields (IMF) By; KHI in the northern hemisphere favors the dawn sector for positive dipole tilt and the dusk sector for negative dipole tilt and vice versa in the southern hemisphere. This phase of dawn-dusk asymmetry is dependent on the IMF By polarities.
Assessing the role of ice-shelf damage on a three-dimensional ice-sheet model
Authors: Blasco Javier , Li Yanjun , Pattyn Frank
Published: February 2023

As stated in the latest IPCC report, sea level will continue to rise at the end of this century and most likely well beyond, depending on future emission pathways. The Antarctic ice sheet plays an important role, as it is the largest ice sheet and thus the largest source of water storage on Earth. However, projections for Antarctica from ice-sheet models yield very mixed results due to ice-sheet-related processes that are difficult to assess. One of the main sources of uncertainty is the stability of floating ice shelves. Although ice shelves do not directly contribute to sea-level rise, they have been shown to play an important role, as they modulate the grounded ice flow via their buttressing effect. Therefore, it is necessary to assess the stability of ice shelves in a warmer climate to make more accurate predictions and define safe trajectory scenarios. Satellite images show the formation of crevasse in regions with a high deformation rate. These crevasses weaken the stability of the ice shelf, as damage enhances inland ice acceleration and promotes further shearing and retreat. However, most continental-scale ice-sheet models do not account for ice shelf damage and its consequent potential feedback mechanisms. Part of this statement is due to the fact that ice shelves at coarse resolutions show low stability to damage implementation even in simple domains. Here we force a three-dimensional ice-sheet-shelf model with various damage formulations from the literature. Given the high uncertainty in damage formation and propagation, several parameters affecting the stability of the ice shelf are evaluated. Experiments are performed in different domains to test their influence in simple and symmetric cases, such as MISMIP+, as well as in the Amundsen-Sea Embayment. Our results highlight the importance of further research on ice damage, as it has strong implications for projections but is poorly accounted for in ice-sheet models.
Role of Quasi-resonant Planetary Wave Dynamics in Winter Precipitation Extremes over India’s High Mountain Region
Authors: Sharma Nischal , Attada Raju , Hunt Kieran M.R.
Published: February 2023

AbstractExtreme precipitation during winter over the western Himalayas (WH) is associated with western disturbances embedded in sub-tropical westerly jet streams, which are potentially linked to planetary wave dynamics. In this study, we explore a possible connection of quasi-resonant amplification (QRA) to precipitation extremes observed over WH using the global high-resolution reanalysis ERA5 during the period 1979-2019. Precipitation extremes have been identified using percentile approach (peak over threshold) where daily precipitation amount from the entire time series of precipitation exceeds the 95th percentile threshold at a particular grid point. Our analysis suggests that substantially magnified, quasi stationary mid-latitude planetary waves with zonal wavenumbers 6 to 8 accompany these extremes, highlighting the influence of QRA phenomenon. Furthermore, we also identified a fingerprint for QRA occurrence in terms of the zonally averaged surface temperature field. Lastly, we classified extreme precipitation intensities and various related key variables using k-means clustering and analyzed the wavenumbers associated with different categories. Our results underpin the significant role of the QRA mechanism in amplification of planetary waves, in turn, favoring western Himalayan precipitation extremes. Detailed results will be discussed.Keywords: Quasi-resonant amplification, zonal wavenumber, precipitation extremes, western Himalayas*E-mail of corresponding author: rajuattada@iisermohali.ac.in
Supervised versus semi-supervised urban functional area prediction: uncertainty, robustness and sensitivity
Authors: Deng Rui , Guan Yanning , Cai Danlu , Yang Tao , Fraedrich Klaus , Zhang Chunyan , Tang Jiakui , Liao Zhouwei , Wei Zhishou , Guo Shan
Published: February 2023

To characterize a community-scale urban functional area using geo-tagged data and available land-use information, several supervised and semi-supervised classification models are presented and evaluated in Hong Kong for comparing their uncertainty, robustness and sensitivity. The following results are noted: (i) As the training set size grows, models’ accuracies are improved, particularly for multi-layer perceptron (MLP) or random forest (RF). The graph convolutional network (GCN) (MLP or RF) model reveals top accuracy when the proportion of training samples is less (greater) than 10% of the total number of functional areas; (ii) With a large amount of training samples, MLP shows the highest prediction accuracy and good performances in cross-validation, but less stability on same training sets; (iii) With a small amount of training samples, GCN provides viable results, by incorporating the auxiliary information provided by the proposed semantic linkages, which is meaningful in real-world predictions; (iv) When the training samples are less than 10%, one should be cautious using MLP to test the optimal epoch for obtaining the best accuracy, due to its model overfitting problem. The above insights could support efficient and scalable urban functional area mapping, even with insufficient land-use information (e.g., covering only ~20% of Beijing in the case study).
Multimodal surface waves during energetic typhoons
Authors: Feng Xuping , Chen Xiaofei
Published: February 2023

Ambient noise tomography is a revolutionary technique in past twenty years, and has many far-reaching applications from exploration, regional and continental to global scales. Recently, surface wave overtones have been efficiently extracted from ambient noise cross-correlations by the frequency-Bessel (F-J) transform method. The excitations of overtones from noise cross-correlations, however, have not be investigated well. Here we collect 16-day continuous seismic data recorded by a seismic array installed in Mongolia during two super typhoons in 2011. Utilizing the F-J transform, we extract daily multimodal dispersion curves with high signal-to-noise ratios from vertical-vertical (Z-Z) component cross-correlations and transverse-transverse (T-T) component cross-correlations. For both the fundamental mode and overtones, our results show that the cross-coefficients between the wind speeds and the Z-Z dispersion amplitudes over 0.1Hz are over 0.6 in typhoon track regions, which suggests that these two typhoons excite Rayleigh waves over 0.1Hz.  For T-T surface waves, however, typhoons only excite the fundament mode over 0.1Hz, and overtones do not relate to typhoons. Our results indicate that energetic typhoons can efficiently excite multimodal Rayleigh waves while Love waves during this period may not come from the microseisms excited by typhoons, which may help us to deepen our understanding of the coupling system among the atmosphere, oceans and the solid earth.
Exploring a subglacial channel beneath Kamb Ice Stream with Icefin
Authors: Schmidt Britney , Washam Peter , Lawrence Justin , Horgan Huw , Stevens Craig , Stewart Craig , Dunbar Gavin , Balfoort Linda , Hulbe Christina , Hurwitz Benjamin , Mullen Andrew , Quartini Enrica , Dichek Daniel , Hegelein Veronica , Bryson Francis , Mandeno Darcy
Published: February 2023

Kamb Ice Stream (KIS) is one of the largest tributaries to the Ross Ice Shelf, grounded near the southermost edge of the massive ice shelf.  Stagnant for some 150 years, the rerouting of subglacial water beneath the ice stream and others in the region is likely critical to the stagnation of the ice stream, as well as present and future dynamics.  As part of the Antarctic New Zealand-led Antarctic Science Platform, our NSF- and NASA- funded team was able to participate in two field seasons accessing below KIS.  In Austral summer 2021-2022,  a hot water drilled borehole was made through the ice and into the major subglaciall channel upstream of the grounding line that carries subglacial water in to the ocean.  The access hole allowed for ice, ocean, sediment, and environemental observations inside the channel.  We deployed the Icefin ROV, which is a novel platform that provides hydrographic, imaging, and sonar exploration in situ below the ice.  Here, we report the first Icefin observations from within the channel.  We report channel geometry, ice-ocean interactions at the top and side walls of the channel, and sonar and imaging data of the sediment along a 500m mission extending upstream of the borehole.  In particular, we report bathymetric observations of the bed of the channel, which varied by 10s of me in width over the mission, and into which a small, meandering ~4m deep channel was incised into the sediments.  We discuss observations of boulder and sediment drape and suspended particulates in the water colum, and discuss implications for hydrological activity within the channel.
Flood rapid mapping for immediate response: from semi-automatized delineation to AI-derived estimations
Authors: Delbour Sébastien , Fatras Christophe , Gastal Vera
Published: February 2023

In the frame of the Copernicus Emergency Management Service - Rapid Mapping, reliable flood maps must be delivered to users within six hours from the availability of remote sensing data. This data can be of different types, either from optical or SAR datasets, which all present different properties (wavelengths, band availability, resolution, etc.). This production is currently performed using semi-automatic methods and processes, to avoid misclassification and provide flood maps as accurate as possible. In order to improve service delivery performances including for covering very large areas, there is a need of an accurate automatically produced first guess, to eventually be modified manually. This is the main reason why the use of AI to learn and detect flooded areas is explored here for both optical and SAR data. The FloodML project used a random forest approach mixed with an in-house learning database to assess flood maps from both optical and SAR datasets. It showed good results, and can cover automatically a 10,000 km² area in a few minutes only. The success of this first approach led to both FloodDAM and FloodDAM-DT projects. These follow-ons now focus on the detection of water height level irregularities in local river gauges, to then produce flood maps if needed, to potentially lead to a modelling of the flood event evolution through data assimilation.
Projection of Extreme Precipitation in East Asian Spring and Mei-yu Seasons in the Warmer Climate
Authors: Chen ChaoAn , Hsu Huang-Hsiung , Liang Hsin-Chien , Chiu Ping-Gin , Tu Chia-Ying
Published: February 2023

Changes in extreme precipitation in East Asia during the spring and Mei-yu seasons under global warming are evaluated based on two sets of high-resolution simulations with various warming pattern of sea surface temperature changes (SST' spa). In the spring season, extreme precipitation exhibits larger enhancements over the northern flank of the prevailing rainy region in conjunction with a shifting tendency of more frequent extreme precipitation events and northward enhancement in the probability distribution, indicating a northward extension of future spring rainband. Enhanced precipitation intensity in conjunction with less rainfall occurrence and prolonged consecutive dry days lead to a minor change in mean precipitation, implying a more difficult water resource management in the warmer climate. The projected enhancement in precipitation intensity is robust compared with the internal variability related to initial conditions and the uncertainty caused by SST'spa. In the Mei-yu season, extreme precipitation is intensified with a distribution of more frequent and more intense extreme events over the prevailing rainband region. The thermodynamic component of moisture flux predominantly contributes to changes in the spring season while both the thermodynamic and dynamic components of moisture flux contribute to the enhanced moisture transport furnishing the intensification of Mei-yu extreme precipitation from southern China to northeast Asia. Projecting future Mei-yu precipitation change is more difficult because of its higher uncertainty associated with 1) the larger variability embedded in the projection of extreme precipitation and 2) the model mean state that determines the spatial distribution of precipitation enhancement. 
Carbon storage in soil parent materials - a source, a sink, or both?
Authors: Evans Daniel , Blattmann Thomas
Published: February 2023

 

Soils are an important component of the global carbon cycle. Ensuring and maintaining the ability of soils to sequester and store carbon is crucial for mitigating climate change. A large proportion of research to date has focused on carbon storage in the uppermost horizons of a soil profile. Meanwhile, the sequestration and storage of carbon in subsoils and underlying soil parent materials is an area that is only recently being studied. This presentation will evaluate the role of soil parent materials as long-term sinks for organic carbon, using recent empirical research across a range of ecosystems and lithologies. However, some soil parent materials could also represent important sources of petrogenic (i.e., rock-derived) organic carbon. Research currently being carried out on carbon-rich bedrock exposed by retreating glaciers in Switzerland will be used to highlight how petrogenic organic carbon, once mobilized into the soil profile during soil formation, could threaten net zero carbon targets. The presentation will conclude with a synthesis of the research gaps that require further attention by a multidisciplinary geoscience community.
Coastal adaptation dynamics under future shoreline changes
Authors: Tierolf Lars , Haer Toon , Botzen Wouter , Aerts Jeroen
Published: February 2023

Coastal adaptation dynamics under future shoreline changesCurrently 24% of the worlds sandy beaches are eroding with rates exceeding 0.5m/ year, and future climate conditions of increased storm wave action and sea level rise (SLR) are likely to increase the rate of shoreline recession in a large part of the world. The loss of sandy beaches affects coastal communities by degrading natural flood protection and coastal amenities. People experiencing these changes may choose to adapt by implementing flood protection measures, or by migrating towards safer areas. To maintain beach width, a growing number of coastal managers is investing in beach renourishment projects. Beach renourishment restores coastal amenity value and flood protection, allowing further coastal development. Current assessments of coastal adaptation in face of SLR often do not account for the interactions of household adaptation and coastal management decisions on coastal flood risk. In this study we aim provide a better representation of coastal adaptation dynamics by simulating the interactions between coastal management decisions and household adaptation behavior under sea level rise. Therefor we develop an agent-based model grounded in expected utility theory, that simulates household and government agents adapting to shoreline change and increasing coastal flood risk. The model is calibrated using empirical survey data on household adaptation and household characteristics are derived from local census data. We then apply the model in France to simulate coastal adaptation dynamics for 2020-2080 under different Shared Socioeconomic Pathways (SSP) and climate change scenarios. By explicitly simulating coastal adaptation decisions and we provide a more realistic model of coastal adaptation dynamics under future development.
Assessing Flow Functionality in Hydropeaking Rivers
Authors: Yarnell Sarah
Published: February 2023

The global demand for renewable energy has placed added pressure on communities to increase hydropower development in rivers. While hydropower provides the opportunity for sustainable electricity generation, it is not without environmental impacts and adverse effects to river processes.  Increased understanding of the characteristics of hydropeaking flow regimes and the associated interactions and impacts on stream functions and native biota will help to facilitate improved mitigation measures downstream of hydropower facilities. This presentation provides an overview of several studies that quantify the characteristics of hydropeaks, assess hydropeak attenuation, and evaluate impacts of hydropeaking regimes on benthic communities and native riverine biota.  Building on these studies and examples of hydropeaking impacts on native aquatic species in California, USA, the presentation concludes with recommendations for improved hydropeaking flow management via a Functional Flows approach.
Study of tectonic fault transition from aseismic to seismic slip due to fluid injection
Authors: Turuntaev Sergey , Riga Vasily
Published: February 2023

The conditions for the transition from slow slip to seismic generation motion along a tectonic fault as a result of fluid injection through a well located near the fault are studied.Movements along the fault caused by fluid injection can occur in the form of slow slips or lead to earthquakes. The implementation of a particular type of movement is dependent on the injection parameters and the fault friction and stress conditions. Numerical calculations were performed in which the consequences of fluid injection lasting from 1.5 months to 6 years were modeled. The calculations varied the total volume of the injected fluid, the flow rate during injection, the rate-state friction law properties of the fault, tangential stresses on the fault. It was found that under certain combinations of fault parameters and fluid flow, seismic generations occur. The transition to such a mode within the framework of the considered model occurs abruptly, a further increase in the injection rate does not lead to an increase in the rate of seismic movement, reaching values of 0.1-1 m/sec, depending on tectonic tangential stresses.With fixed parameters of the rate-state friction law, the magnitude of the maximum displacement velocity depends on the rate of the pressure perturbation on the fault. Until the sliding velocity reaches a value of the order of 10-6 m/sec, the dependence of the logarithm of the sliding velocity on the rate of the pressure perturbation is linear or close to it, then there is a significant more dramatic increase in sliding velocity depending on the rate of the perturbation growth. The influence of the rate-state friction law parameters on the movements along the fault is not so unambiguous. However, it can be said that the sliding is determined by a combination of the following parameters: the critical length at which the stiffness of the fault section reaches the value of critical stiffness, and the characteristic response time determined by the parameters of the friction law.
Correlating Seismic Wave Velocities with the Physicomechanical Properties of Carbonate Rocks
Authors: Sahu Anamika , Singh Sandeep , Kumar Samadhiya Narendra , Joshi Anand
Published: February 2023

Seismic wave velocities (both P and S waves) measurements have been carried out for carbonate rock samples collected from Lesser Himalayan deposits exposed along Alaknanda valley between Rudraprayag to Helang village in Uttarakhand, India. This study has been carried out to evaluate the effect of the petrophysical and the mechanical properties of rocks on seismic wave velocities. On the core samples, petrophysical and mechanical measurements were performed where porosity, density, water absorption, and seismic wave velocities were first determined, followed by measuring the uniaxial compressive strength (UCS), and Brazilian tensile strength (BTS). Thin sections were prepared to measure the petrographic parameters (textural properties and mineralogical composition). This study focuses mainly on grain size and mineral composition. Petrographic investigation and X-ray diffraction (XRD) analysis were done to identify their mineralogy. Both petrographic and XRD analysis revealed that the main constituting minerals are dolomite, and in minor amounts, calcite, quartz, and opaque minerals are present. Interrelationships between seismic wave velocities and porosity, density, mineral constituents, grain size, uniaxial compressive strength, and Brazilian tensile strength were obtained using regression analysis. It has been concluded that there are significant positive correlations between compressional wave velocity and uniaxial compressive strength (r2 = 0.82), Brazilian tensile strength (r2 = 0.67). Similarly, strong to moderate correlations were found between shear wave velocity and uniaxial compressive strength (r2 = 0.73), Brazilian tensile strength (r2 = 0.68). Weak to moderate negative correlations were found between seismic wave velocities and porosity. Moderate positive correlations have been found between seismic wave velocities and dry density. There is moderate negative correlation has been found between uniaxial compressive strength and grain size. Furthermore, it has also been concluded that the influence of grain size on rock strength was more important than mineral content.
Deep learning insights into suspended sediment concentrations across the conterminous United States: Strengths and limitations
Authors: Song Yalan , Chaemchuen Piyaphat , Rahmani Farshid , Zhi Wei , Li Li , Liu Xiaofeng , Boyer Elizabeth , Bindas Tadd , Lawson Kathryn , Shen Chaopeng
Published: February 2023

Suspended sediment concentration (SSC) is a crucial indicator for aquatic ecosystems and reservoir management but is challenging to predict at large scales. This study seeks to test the feasibility of deep-network-based models to predict SSC at basin outlets given basin-averaged forcings and basin-physiographic attributes as inputs and extract insights by interpreting the spatially-varying model performances. We trained long short-term memory (LSTM) deep networks either separately for each of the 371 sites across the conterminous United States (local models), or on all the sites collectively (Whole-CONUS). The local and Whole-CONUS models presented median Nash-Sutcliffe Efficiency (NSE) values of 0.72 and 0.57, respectively, which are state-of-the-art results. However, this comparison disagrees with our previous “data synergy” conclusion for LSTM models and suggests there are still important yet unavailable sediment-related attributes. Both local and Whole-CONUS models tended to be more successful where SSC-streamflow correlations (Rs-q) were high - typically in the humid Eastern US - and with lower SSC. Low Rs-q basins were often found in the arid Southwest with higher SSC. The highly-nonlinear SSC-streamflow relationship is arguably due to heterogeneity in land cover and rainfall or limitations in sediment supply, suggesting these basins need to be simulated at higher spatial resolution. The local models mostly outperformed the Whole-CONUS one due to the latter lacking critical attributes, but the latter can be competitive in high-SSC regions with enough flow events. Moreover, the Whole-CONUS model also performed well for basins not included in the training dataset (median NSE=0.55), supporting large-scale modeling.