bluuebunny/crossref_metadata_2025 huggingface dataset:
Stromboli volcano monitoring with airborne SAR systems
Authors: Lanari Riccardo , Esposito Carmen , Berardino Paolo , Natale Antonio , Palmese Gianfranco , Perna Stefano
Published: February 2023

Synthetic Aperture Radar (SAR) is an active sensor that can be mounted onboard satellite or airborne platforms for observing of Earth’s surface in any weather condition and even during night [1]. In the last years, it has been shown that the interferometric SAR (InSAR) technique allows [2] generating high quality Digital Elevation Models (DEMs) [1] from spaceborne [3] and airborne [4–7] SAR data.Airborne SAR systems, unlike satellite SAR ones, are particularly suitable for environmental monitoring in case of emergencies due to their capability to maintain very tight revisit times and to acquire data practically without orbital constraints. The contribution of this work fits very nicely within this context. Indeed, in this work, we show the results obtained from the data collected during the acquisition campaigns carried out with the AXIS [5] and MIPS [8] airborne X-band interferometric SAR systems over the Stromboli island (Italy). In particular, starting from multiple single-pass interferometric SAR surveys we present the differences of the generated DEMs with the aim of measuring the topographic changes induced by the eruptive activity over the whole island during the July 2019 – October 2022 time interval. The work is supported by an agreement between IREA-CNR and the Civil Protection Department of Italy. References1. Franceschetti, G.; Lanari, R. Synthetic aperture radar processing; 1999;2. Moreira, A.; Prats-Iraola, P.; Younis, M.; Krieger, G.; Hajnsek, I.; Papathanassiou, K.P. A tutorial on synthetic aperture radar. IEEE Geosci. Remote Sens. Mag. 2013.3. Rabus, B.; Eineder, M.; Roth, A.; Bamler, R. The shuttle radar topography mission - A new class of digital elevation models acquired by spaceborne radar. ISPRS J. Photogramm. Remote Sens. 2003.4. Perna, S.; Esposito, C.; Amaral, T.; Berardino, P.; Jackson, G.; Moreira, J.; Pauciullo, A.; Junior, E.V.; Wimmer, C.; Lanari, R. The InSAeS4 airborne X-band interferometric SAR system: A first assessment on its imaging and topographic mapping capabilities. Remote Sens. 2016, 8.5. Esposito, C.; Natale, A.; Palmese, G.; Berardino, P.; Lanari, R.; Perna, S. On the Capabilities of the Italian Airborne FMCW AXIS InSAR System. Remote Sens. 2020, 12.6. Pinheiro, M.; Reigber, A.; Scheiber, R.; Prats-Iraola, P.; Moreira, A. Generation of highly accurate DEMs over flat areas by means of dual-frequency and dual-baseline airborne SAR interferometry. IEEE Trans. Geosci. Remote Sens. 2018.7. Wimmer, C.; Siegmund, R.; Schwäbisch, M.; Moreira, J. Generation of high precision DEMs of the Wadden Sea with airborne interferometric SAR. IEEE Trans. Geosci. Remote Sens. 2000.8. Natale, A.; Berardino, P.; Esposito, C.; Palmese, G.; Lanari, R.; Perna, S. The New Italian Airborne Multiband Interferometric and Polarimetric SAR (MIPS) System: First Flight Test Results. Int. Geosci. Remote Sens. Symp. 2022, 2022-July, 4506–4509.
From the last interglacial to the future – new insights into climate change from the PalMod Earth System modelling framework
Authors: Fieg Kerstin , Latif Mojib , Ilyina Tatjana , Schulz Michael
Published: February 2023

The PalMod project funded by the German Federal Ministry of Education and Research (BMBF) aims at filling gaps in our understanding of the dynamics and variability of the Earth system during the last glacial-interglacial cycle. Major goals are to enhance Earth system models (ESMs), to identify potential tipping points that could become important in a warming world, and to perform long-term projections with the advanced the ESMs. In PalMod Phases I and II, we focussed on three key epochs, the last glacial inception, MIS3, and the last deglaciation. In PalMod Phase III, we will use the new insights from the first two phases to perform more advanced climate projections into the next millennia. Special focus areas are rapid climate transitions, permafrost melting, and ice-sheet instability and sea level rise.  
Using Machine Learning to Reveal the Relationships Between Plant Functional Traits and Flux Regimes at Eddy-Covariance Towers
Authors: Cranko Page Jon , Abramowitz Gab , De Kauwe Martin G. , Pitman Andy J.
Published: February 2023

The current-generation of land surface models (LSMs) are powerful tools used in predictions of the future global climate and carbon cycle. Many of these LSMs are parametrised using plant functional types (PFTs), often of a coarse nature with only relatively few possible groups. In turn, extensive use of eddy-covariance data is utilised when calibrating these LSMs, with the model PFT matched to the classification reported by the site owners. Importantly, the PFT group is one of the few site characteristics that is consistently supplied across FLUXNET sites. However, there are issues with this method of LSM calibration. It is well-known that many PFT classification schemes cannot be predicted from climate, and that traits may vary more within species or sites than between them.
Here we present our results assessing the suitability of PFTs for capturing site flux regimes using a suite of machine learning techniques. We explore natural groupings of sites based on the measurements used for LSM calibration and identify potential site characteristics and traits that might allow these natural groupings to be predicted. Our results identify driving characteristics of site flux regime differences, and can be used to direct LSM development and highlight priority locations for future eddy-covariance flux towers.
Cloud Identification and Classification from Ground Based and Satellite Sensors on the Antarctic Plateau
Authors: Martinazzo Michele , Volonnino Viviana , Maestri Tiziano , Masin Fabrizio , Di Natale Gianluca , Bianchini Giovanni , Del Guasta Massimo , Palchetti Luca
Published: February 2023

Cloud identification from satellites is considerably challenging in polar environments due to the similar radiative properties of surface and ice clouds, making it difficult to detect and distinguish cloud features. CIC (Cloud Identification and Classification) is a machine learning algorithm adopted as the official software in the ESA Far-infrared Outgoing Radiation Understanding and Monitoring (FORUM) (Palchetti et al., 2020) End2End simulator (FE2ES). CIC is based on Principal Component Analysis and performs cloud detection and multi-scene classification. It is adaptable to every type of sensor and is particularly suitable when a small number of elements are available for the Training Set. Assessment studies have already been conducted to evaluate the performances of the algorithm in multiple conditions. In Maestri et al. (2019), CIC was applied to simulated radiance all over the globe, while Magurno et al. (2020) used the algorithm to analyze airborne interferometric spectra. Finally, in Cossich et al. (2021) the algorithm was tested on downwelling radiances collected at Dome-C in Antarctica. In this work, CIC is applied to high spectrally resolved data taken from ground and, for the first time, from satellites. Ground-based data are collected by the REFIR-PAD sensor (Di Natale et al., 2020), covering the far and mid-infrared part of the spectrum. Collocated satellite data are measured by IASI (Infrared Atmospheric Sounding Interferometer) which collects upwelling radiance between 3.4 and 15.5 μm. The period under study spans from 2012 to 2022. CIC results applied to ground-measured spectra are compared to IASI’s L2 classification products. Large discrepancies between the two classifications are observed, indicating an overestimation of the cloud occurrence in case of IASI. A verification is obtained using collocated ground-based LIDAR measurements, which are available for subsets of the collocated radiances. Finally, the CIC algorithm is trained with a subset of IASI data collocated with REFIR-PAD and LIDAR measurements. The training set is defined also with the help of the Advanced Very High Resolution Radiometer (AVHRR) on board of MetOp satellites. The AVHRR has 1 km resolution (at the nadir) and its collocated measurements are used to evaluate the scene homogeneity in the satellite field of view. Statistical analyses are then performed on IASI spectra using the CIC classification. Results indicate a much better agreement with ground-based data, improving the cloud occurrence provided in IASI L2 products.
The impacts of regional Arctic lake change on remotely sensed methane emission hotspots in Alaska, USA
Authors: Elder Clayton D. , Thompson David R. , Baskaran Latha , Nitze Ingmar , Grosse Guido , Hasson Nicholas , Walter Anthony Katey M. , Miller Charles E.
Published: February 2023

Arctic and boreal wetlands and lakes are experiencing complex ecological changes as a result of warming. The potential for rapidly thawing permafrost to promote large increases in methane (CH4) emissions via ground subsidence and ponding (thermokarst), and permafrost carbon mineralization is of particular concern for accelerating the permafrost carbon feedback (PCF) [Turetsky et al. 2020]. However, complex hydrological dynamics produce large uncertainties regarding the sign and magnitude of carbon loss in modeling and forecasting efforts. Determining CH4’s current and future contributions to the PCF is challenging due to sparse observations, high spatiotemporal variability, and heterogeneous Arctic landscapes. As a result, top-down (observation-based) and bottom-up (model/inventory-based) evaluations of annual Arctic and boreal CH4 emissions disagree by 50-200% [McGuire et al. 2012; Peltola et al. 2019]. Constraining the current budget and forecast uncertainty in future Arctic emissions will require scale-bridging approaches that reconcile fine spatiotemporal variability and regional to continental scale coverage. To this end, we compiled multiple large remote sensing datasets to study relationships between Arctic lake and thermokarst landscape morphology trends with remotely-sensed (AVIRIS-NG) CH­4 emission hotspot detections. Preliminary analyses from a lake-and-wetland-rich 1,750 km2 study area of the Yukon Kuskokwim Delta, AK, USA reveal discrete correlations between recently wetted areas and CH4 hotspot detections. However, in an analysis of over 1,200 lakes > 1 ha, hotspots were detected in greater abundance surrounding lakes that have shrunk in area since 1999 (p < 0.05) (Fig. 2). Our preliminary results imply a complex response of CH4 emissions surrounding dynamic permafrost environments. Ongoing analyses seek to further elucidate patterns related to waterbody size, permafrost ice and carbon contents, and relationships between terrestrial and limnetic hotspot detections. 
Dynamics of heated (or cooled) vortices in the stratosphere
Authors: Legras Bernard , Podglajen Aurélien , Duchamp Clair , Sellitto Pasquale , Limare Angela , Niu Zhaodong , Billant Paul , Zeitlin Vladimir , Lapeyre Guillaume , Plougonven Riwal
Published: February 2023

Recent extreme events associated with forest fires and large volcanic eruptions have demonstrated that dense aerosol clouds in the stratosphere often wraps up as persistent compact structures which rotate as anticyclones and also move vertically. One of these vortices has been observed over 3 months and experienced a 20 km rise. Such observations were made after the 2020 Australian wildfires, the 2017 British Columbia fire and more recently after the 2022 Tonga eruption and a few other cases. For all these events, the link was made with anomalous warming or cooling due to the composition of the clouds. This presentation will summarize the observed events and demonstrate the general characters of the stratospheric aerosol vortices. It will also discuss how they are detected by the weather assimilation systems through their signature in temperature, the conditions of their stability and how they can be reproduced experimentally with simple experimental models. Their impact on the transport of long-lived species will be discussed.Such structures seem so far proper to the Earth stratosphere and have found analogies nowhere else.Ref: DOIs: 10.1038/s43247-020-00022-5, 10.5194/acp-21-7113-2021, 10.5194/acp-22-14957-2022
A monazite- and REE-rich apatite-bearing mantle xenolith from Pleiku, central Vietnam
Authors: Hauzenberger Christoph , Konzett Jürgen , Joachim-Mrosko Bastian , Nguyen Hoang
Published: February 2023

Primitive mantle rocks usually contain rare earth elements (REE) in very low concentrations. Here we report an occurrence of monazite associated with REE-rich apatites in a carbonate-bearing wehrlite xenolith from Pleiku, central Vietnam. The sampled xenolith displays an equigranular matrix of rounded olivine grains. Texturally primary orthopyroxene, clinopyroxene and spinel are notably absent. Scattered within the olivine matrix two types of domains are present: domain-I contains numerous blocky clinopyroxene grains within a matrix of quenched silicate melt and is associated with a second generation of olivine, small euhedral spinel and rare grains of carbonates. Both apatite and monazite may be present. Domain-II typically contains abundant irregularly shaped patches of carbonate associated with quenched silicate melt, secondary olivine, spinel, and clinopyroxene. No phosphate phases are observed within type-II domains. Monazite occurs in different generations: monazite I is found as very small rounded to elongate grains included in primary olivine, partly crosscut by fine melt veinlets, monazite II as large grains up to 300 x 200 µm in size with embayed grain boundaries and monazite III as very small euhedral and needle-like crystals in silicate melt pools. For apatite two textural types occur: apatite I forms lath-shaped to rounded crystals up to 200 x 50 µm in size, apatite II is present within silicate melt pools of type-I domains where it forms euhedral needle-like to equant grains. Some of the apatite II crystals may have cores of monazite III. Monazites show compositional variation mainly with respect to ∑REE2O3 (63-69 wt%) and ThO2 (1.1-5.3 wt%) and only minor variations in P2O5 (29-32 wt%) SiO2 (<0.05-0.4 wt%) and CaO (0.2-0.4 wt%) Apatites are characterized by strongly variable and high REE2O3 and SiO2 contents (4-27 wt% ∑REE2O3,0.6-6.8 wt% SiO2) as well as with significant Na2O (0.3-1.5 wt%), FeO (0.1-1.8 wt%), MgO (0.2-0.6 wt%) and SrO (0.2-0.9 wt%) contents. F and Cl contents are in the range 1.9-3.0 wt% and 0.2-0.8 wt%, respectively. Based on textural evidence and chemical composition of the metasomatized mineral phases an initial stage of metasomatism is proposed which was triggered by a P-REE-CO2-rich agent with low aH2O resulting in the co-precipitation of carbonates as patches and along micro-veins and of phosphates in a peridotite assemblage. A subsequent second stage is characterized by pervasive infiltration of an alkali-rich basaltic melt into the carbonate + phosphate-bearing assemblage. The presence of monazite prior to silicate melt infiltration is indicated by narrow melt veins crosscutting monazite I grains. Reactions of the silicate melt with the pre-existing phases led to the formation of domains-I and -II and changed the composition of the infiltrating melt towards phonolitic-trachytic composition. The second stage led to partial breakdown and recrystallization of monazite and apatite.
The Development of the Northern San Andreas Plate Boundary Fault System - Importance of Lower-crustal Ductile Shear in Producing Primary Plate Boundary Structure
Authors: Furlong Kevin P.
Published: February 2023

The northward migration of the Mendocino Triple Junction (MTJ) drives a fundamental plate boundary transformation from convergence to translation; producing a series of strike-slip faults, that become the San Andreas plate boundary. How and why these faults develop where they do is enigmatic. We find that the 3-D structure of the Pacific plate lithosphere in the vicinity of the MTJ controls the location of San Andreas plate boundary formation. Recently developed, high-resolution seismic-tomographic imagery of northern California indicates that (1) the Pioneer Fragment, and extension of the Pacific plate beneath the western margin of North America occupies the western half of the slab window, immediately south of the MTJ; (2) the eastern edge of the Pioneer Fragment lies beneath the newly forming Maacama Fault system, which develops to become the locus for the primary plate boundary structure after approximately 6-10 Ma (eg. the present-day East Bay faults in the SF Bay region); and (3) the placement of the translating Pioneer Fragment adjacent to the asthenosphere of the slab window, and its coupling to the overlying North American crust generate a shear zone within and below the crust that develops into the  plate boundary faults. This plate boundary configuration has been operable since the initial formation of the transform plate boundary. As a result, the San Andreas plate boundary forms within the western margin of North America, approximately 100 km inboard of the western edge of North America, rather than at its western edge. One additional result of this is that blocks of North America lithosphere are detached and become terranes (such as the Salinian and Nacimiento (Franciscan) blocks) that are captured by and translate with the Pacific plate, producing the complex crustal architecture of coastal California.
Modelling of seismic anisotropy in the lowermost mantle with rheologically constrained geodynamic setup
Authors: Roy Poulami , Steinberger Bernhard
Published: February 2023

Seismic anisotropy is an observation that is believed to yield information on the flow pattern in the mantle. There are many studies of anisotropy in the upper mantle; however, the lower mantle is still underexplored, due to problems in seismic imaging and complexities of modelling of flow laws ofdifferent minerals. In this study, we modelled the radially anisotropic behavior of two different geodynamic setups, one is the rising of a mantle plume from the core-mantle boundary to the surface, and another is subduction of a slab reaching the lowermost mantle. We use ASPECT for modelling large scale mantle flow and ECOMAN to simulate the development of lattice preferred orientation of mantle fabric. We use the slip system of Bridgmanite following the previous experimental study by Mainprice et al. (2008). We then couple the results from ASPECT to ECOMAN for modelling the radial anisotropy and maximum shear wave splitting direction. We show that in the part of the lowermost mantle surrounding the plume horizontally polarized shear waves (Vsh ) are faster than the vertically polarized ones (Vsv ) while the inside of the plume tail shows opposite signature. However, Vsh becomes greater than Vsv when the plume flattens out at the surface. We also find that the maximum splitting direction is horizontal outside the base of the plume and it becomes vertical inside the plume tail and again becomes horizontal at the surface. This result corroborates previous seismic observations (Wolf et al., 2019) of the Iceland plume at the core-mantle boundary. Moreover, our result for the slab setup reveals that as the slab reaches the lowermost mantle, Vsh becomes higher than Vsv and maximum splitting is horizontal at the base of the slab. ReferencesWolf, J., Creasy, N., Pisconti, A., Long, M.D., Thomas, C., 2019. An investigation of seismic anisotropy in the lowermost mantle beneath Iceland. Geophys. J. Int. 219, S152–S166.Mainprice, D., Tommasi, A., Ferré, D., Carrez, P., Cordier, P., 2008. Predicted glide system and crystal preferred orientations of polycrystalline silicate Mg-perovskite at high-pressure: implicaitons for the seismic anisotropy in the lower mantle. Earth Planet. Sci. Lett. 271, 135–144.
Utility of Multisite Stochastic Simulations to Characterize and Model the Seasonal and Spatial Variability of Short-Duration Precipitation
Authors: Mascaro Giuseppe , Papalexiou Simon , Wright Daniel
Published: February 2023

The knowledge of the statistical variability of precipitation (P) at short durations (≤24 h) is necessary to support engineering applications and hydrologic modeling. In this talk, we provide novel insights into the seasonal and spatial variability of two statistical properties of short-duration P that have received less attention, including the spatiotemporal correlation structure (STCS) and the marginal distribution. To this end, we design a framework based on multisite Monte Carlo simulations with the Complete Stochastic Modeling Solution (CoSMoS) which we test using a dense network of 223 high-resolution (30 min) rain gages with more than 20 years of observations in central Arizona. We first show that an analytical model and a three-parameter probability distribution capture the empirical STCS and marginal distribution of P, respectively, across Δt’s from 0.5 to 24 h and the summer and winter seasons. We then conduct Monte Carlo multisite stochastic simulations of P time series with CoSMoS, which reveal that the statistical properties of short-duration P exhibit significant seasonal differences, especially at low Δt. In summer, the STCS of P is weaker and the distributions are heavy-tailed because of the dominance of localized convective thunderstorms. Winter P has instead stronger STCS and lighter tails of the distributions as a result of more widespread and longer frontal systems. The Monte Carlo experiments also demonstrate that, in most cases, P is characterized by a homogeneous and isotropic STCS across the region, and by parameters of the marginal distribution that are constant for the shape and dependent on elevation for scale and P occurrence. The only exception is winter P at Δt ≥ 3 h, where anisotropy could be introduced by the motion of frontal storms, and additional factors are required to explain the variability of the scale parameter. The findings of this work are useful for improving stochastic P models and validating convection-permitting atmospheric models.
The growth-stimulating bacteria (PGPB-group) in the increasing of the plant-microbial interaction potential in the winter wheat agrocenosis
Authors: Boroday Vera , Yakovenko Dmytro
Published: February 2023

The growth-stimulating bacteria (PGPB-group) in the increasing of the plant-microbial interaction potential in the winter wheat agrocenosis  Boroday V.V.1, 2,Doctor of Agriculture Science,Yakovenko D.O.1,1 Institute of Agroecology and Environmental Management, Metrologichna str., 12, Kyiv, 03143, Ukraine2National University of Life and Environmental Sciences of Ukraine, HeroivOborony str.15, building 3, of. 207, Kyiv, 03041, Ukraine The use of microorganisms of the PGPB group will contribute to the activation of nitrogen fixation and phosphate mobilization in the soil, and increase the potential of plant-microbial interaction. The purpose of our research was to find out the effect of biological preparations Groundfix® and Azotofit-r® (“BTU-Center”) on the main physiological groups of soil microorganisms during the cultivation of wheat plants of the Bohdana variety in the conditions of the Western Forest-Steppe of Ukraine. The biological preparation Groundfix® includes Bacillus subtilis, B. megaterium var. phosphaticum, Azotobacter chroococcum, Enterobacter spp., Paenibacillus polymyxa. Azotofit-r® contains nitrogen-fixing bacteria A. chroococcum and its biologically active products.It is established that in the agrocenosis of winter wheat, biological preparations Groundfix® and Azotofit-r® affect the ratio of ecological and trophic groups of microorganisms, in particular nitrogen-fixing, oligotrophic and microorganisms involved in the mineralization of humic substances, and the direction of mobilization processes in the soil. The complex application of biological preparations in different phases of plant development contributed to the slowing down of mineralization processes, the preservation of soil nitrogen in a more accessible form to plants during the period of active growth.The coefficient of oligotrophicity for the soil with the use of biological preparations in the spring weeding phase was low (<1). This indicates a high supply of soil microbiota with easily digestible organic substances and the formation of optimal conditions for the functioning of the soil microbial complex.The use of Azotofit and Groundfix (3 l/ha) for pre-sowing cultivation contributed to the abundance of saprotrophic species in these variants within 88.9-90.0% of the total abundance of micromycetes.Thus, the use of biological preparations Azotofit and Groundfix contributed to reducing the infectious potential of the soil and  increasing its microbiological activity in the agrocenosis of winter wheat.
 
Vredefort impact site modelling through inhomogeneous depth weighted inversion.
Authors: Vitale Andrea , Fedi Maurizio
Published: February 2023

We are showing an application of the 3D self-constrained depth weighted inversion of the inhomogeneous gravity field (Vitale and Fedi, 2020) of the Vredefort impact site.This method is based on two steps, the first being the search in the 3D domain of the homogenous degree of the field, and the second being the inversion of the data using a power-law weighting function with a 3D variable exponent. It does not involve directly data at different altitudes, but it is heavily conditioned by a multiscale search of the homogeneity degree.The main difference between this inversion approach and the one proposed by Li and Oldenburg algorithm (1996) and Cella and Fedi (2012) is therefore about the depth weighting function, whose exponent is a constant through the whole space in the original Li and Oldenburg and Cella and Fedi approaches, while it is a 3D function in the method which we will discuss here.The model volume of the area reaches 20 km in depth, while along x and y its extension is respectively 41 by 63 km. The trend at low and middle altitudes of the estimated β related to the main structures is fitting the expectations because the results relate to two main structures, which are geometrically different: the core is like a spheroid body (β ≈ 3) and the distal rings are like horizontal pipes or dykes (1 < β < 2).With a homogeneous depth weighting function, we recover a smooth solution and both the main sources, the main core and the rings of the impact, are still visible at the bottom of the model (20 km). This is not in agreement with the result by Henkel and Reimold (1996, 1998), which, based on gravity and magnetic inversion supported by seismic data, proposed a model where the bottom of the rings is around 10 km and the density contrast effect due to the core structure loses its effectiveness around 15 km.Instead, using an inhomogeneous depth weighting function (figure 28) we can retrieve information regarding the position at depth of both core and distal ring structures that better fits the above model. In fact, the bottom of the distal ring structure, that should be around 10 km according to Henkel and Reimold (1996, 1998), is recovered very well using an inhomogeneous depth weighting function, while in the homogeneous case we saw that the interpreted structure was still visible at large depths.In addition, also the core structure is shallower compared to the homogeneous approach and seems more reliable if we compare it with the model of Henkel and Reimold (1996, 1998).Instead, the inhomogeneous approach presented in this paper leads naturally us to a better solution because it takes into account during the same inversion process of the inhomogeneous nature of the structural index within the entire domain.
Cassini Bistatic Radar Observations of Titan's Seas: Results about Dielectric Properties and Capillary Waves Detection
Authors: Brighi Giancorrado , Poggiali Valerio , Tortora Paolo , Zannoni Marco , Hayes Alexander , Lalich Daniel , Bonnefoy Lea , MacKenzie Shannon , D Nicholson Phil , Oudrhiri Kamal , D Lorenz Ralph , M Soderblom Jason
Published: February 2023

Between 2006 and 2016, the Cassini spacecraft carried out 13 bistatic radar observations of the surface of Saturn's largest moon, Titan. Unmodulated right circularly polarized radio signals were transmitted by the spacecraft to the moon’s surface. Cassini’s high gain antenna was pointed so that specular reflections from Titan’s surface were received on Earth. Proper processing of right (RCP) and left circularly polarized (LCP) echoes from the moon can provide information about surface roughness and near-surface relative dielectric constant (ɛr) of the illuminated terrains.During Titan flybys T101, T102, T106, and T124, the track of the bistatic observations crossed the main stable liquid bodies of the north pole of Titan: Ligeia, Kraken, Punga Mare, and their estuaries. Strong and narrowband X-band (λ=3.6 cm) echoes were successfully detected from the seas at the Deep Space Network 70-meter station in Canberra.Reflected spectra feature Dirac-like shapes, with a spectral broadening around 1 Hz and lower bounded by the processing time resolution. Compared to bistatic observations of other planets, this implies unprecedentedly low RMS slope values for Titan’s seas on an effective length-scale of a few meters. Profiles of reflected LCP and RCP power are in general consistent with purely coherent reflections from the Fresnel area around the moving specular point, indicating a very flat surface.In addition, from the circular polarization power ratio, the surface dielectric constant can be derived. This can enrich our current understanding of the chemistry of Titan’s liquid hydrocarbon seas, further constraining their methane-ethane mixing ratio. From Cassini RADAR, VIMS, and ISS, Titan’s seas are expected to be ternary mixtures of methane, ethane and nitrogen (ɛr ≈ 1.6-1.9). From bistatic radar data, significant relative variations in liquid hydrocarbon composition are seen, and an unexpected correlation between the dielectric constant and incidence angle of observation seems to arise. The absolute values of permittivity are somewhat lower than expected.From the computed dielectric constant values, physical optics models are used to constrain the RMS height of the surface. This analysis provides meaningful insights into the presence of small capillary waves in the order of millimeters over the liquid surfaces of Titan, as already detected by Cassini monostatic RADAR.
Large-scale physics of hydrodynamic transport in random fracture networks
Authors: Dentz Marco , Hyman Jeffrey D.
Published: February 2023

We study flow and hydrodynamic transport in spatially random fracture networks.The flow and transport behavior is characterized by first passagetimes and displacement statistics, which show heavy tailsand anomalous dispersion with a strong dependence on the injectioncondition. The origin of these behaviors is investigatedin terms of Lagrangian velocities sampled equidistantly along particletrajectories, unlike classical sampling strategies at a constant rate. Thefluctuating velocity series is analyzed by its copula density, thejoint distribution of the velocity unit scores, which reveals a simple correlationstructure that can be described by a Gaussian copula. This insightleads to the formulation of stochastic particle motion in terms of aKlein-Kramers equation for the joint density of particle position andvelocity. The upscaled model captures the heavy-tailed first passagetime distribution and anomalous dispersion, and their dependence on theinjection conditions in terms of the velocity point statistics andaverage fracture length. The first passage times and displacementmoments are dominated by extremes occurring at the first step.The developed approach integrates the complex interaction of flow and structureinto a predictive model for large scale transport in random fracture networks.    
Three-dimensional modeling of barium cloud's expansion in the E and F regions: Applying for BROR mission.
Authors: Yokoyama Yoshihiro , Sergienko Tima
Published: February 2023

The chemical release at an ionospheric altitude allows us to investigate the plasma processes in the ionosphere-magnetosphere system. The numerical models of the expansion of the artificial plasma clouds produced by the chemical release have been developed. Previous works revealed that, for a barium release with no directional velocity in the uniform background, the neutral barium cloud expands radially, while the ionized barium (Ba+) cloud produced by photoionization of the neutral cloud expands into an elliptic structure along the direction of the magnetic field. And they also revealed that the background ionospheric and initial release conditions primarily affect the cloud’s behavior. Barium Release Optical and Radio rocket (BROR) mission plans to conduct several barium releases at different ionospheric altitudes between 120 and 180 km, which are much lower than past experiments, aiming to study small-scale processes and structure in the auroral ionosphere by means of an active modification of the ionosphere. Since the atmospheric composition of ion and neutral spices and their parameters vary significantly around the BROR target region, i.e., from the E region to the bottom of the F region, we took into these altitudinal differences in our model. We revealed that the altitudinal difference contributes significantly to the Ba+ cloud’s expansion, especially with no background and release velocity, producing a teardrop shape. We also found that the Ba+ cloud at lower altitudes expands slowly, confining to a relatively small area due to the higher collision frequency. In comparison, the Ba+ cloud at a higher altitude stretches faster along the magnetic field and ends up with larger radii due to the lower collision frequency and higher diffusion rate. In this presentation, we show numerical results for the different release conditions at several altitudes in the E and F region and discuss the effects of different release conditions at various altitudes.
Normalizing functional diversity metrics across heterogeneous data streams: from field to satellite data
Authors: Pacheco-Labrador Javier , de Bello Francesco , Migliavacca Mirco , Ma Xuanlong , Carvalhais Nuno , Wirth Christian , Duveiller Gregory
Published: February 2023

Fighting the current biodiversity crisis requires monitoring systems able to determine ecosystems’ biodiversity at the global scale systematically. Resource-demanding field surveys are fundamental, but they are unable to provide continuous coverage in space and time. Recent studies have shown that remote sensing theoretically has the potential to overcome this limitation and is thus becoming a promising tool for biodiversity monitoring.The present and upcoming fleet of Earth observation satellites offer wide variability of resolutions and spectral information that could be jointly exploited to map plant functional diversity robustly. However, this heterogeneity hampers the comparability of functional diversity metrics inferred from different sensors because their values depend on the trait-space dimensionality (e.g., the number of spectral bands). This problem is also inherent to comparing metrics computed from satellite imagery and field data or field surveys sampling different traits. Such dependency hides the actual information contained in the metrics and may mislead interpretation. Here we present a global normalization approach that removes the effect of dimensionality from functional diversity metrics such as Rao’s quadratic entropy index (Rao Q), allowing the computation of its equivalent number from independently processed imagery.The method outperforms image-based normalization and set metrics computed from the heterogeneous field and remote sensing datasets at the same scale. This enhanced comparability reveals the differences in diversity information related to trait selection and spatial resolution between the different data streams. We expect this new method to become broadly used in remote sensing, facilitating the integration of multiple missions and the validation of functional diversity products with field data.
Copernicus DEM vs. LiDAR: assessment of landform accuracy representation at regional scale
Authors: Niculita Mihai
Published: February 2023

Copernicus DEM is the new global dataset with the desired coverage and resolution to become the standard elevation dataset to replace SRTM. SRTM represents the Earth’s terrain at the level of February 2000, with a spatial resolution of 1’ and a feature resolution that can cover medium-scale landform features. The GLO-30 Copernicus DEM is based on the WorldDEM topographic data, which has an original resolution of 0.4”, obtained from TerraSAR-X and TanDEM-X SAR interferometry data. The WorldDEM sources were acquired between December 2010 and January 2015, and every surface was acquired twice. GLO-30 dataset is resampled from 0.4” to 1”. The global validation against ICEsat data revealed a RMSE of 1.68 m, a standard deviation of 1.68 m, and an absolute vertical accuracy linear error at 90% confidence interval of 2.17 m.In the present approach, LiDAR data at 0.5 and 1 m spatial resolution covering two regions over Eastern and Western Romania were used to evaluate the accuracy in landform representation of the GLO-30 Copernicus DEM. The results show that the deformations due to the RADAR acquisition (shortening and layover) are lower than for the SRTM dataset, but the number of voids is bigger, especially in the mountainous areas. The resolution of the geomorphic landforms is superior to SRTM data, with river channels, gullies, and landslides features being very often recognizable in non-forested areas.In conclusion, GLO-30 Copernicus DEM outperforms SRTM and can be used as a new source of global elevation data, but care is needed when certain types of landforms are targeted by the analysis, especially in forested areas. The most affected by the inconsistencies due to the RADAR acquisition technology is the hydrological features, especially in mountainous areas with forest cover.
The Ethics and Role of Geoscientists in Existential Risk Studies
Authors: Futerman Gideon
Published: February 2023

Existential and Global Catastrophic Risk, defined by Beard et al 2020 as risk that may result in the very worst catastrophes “encompassing human extinction, civilizational collapse and any major catastrophe commonly associated with these things.” As such, it has been the topic of work by many philosophers as we move into a world where humans have more and more power over the world around us.However, geoscientists have typically neglected the study of these risks, and have in turn been neglected in the field of existential risk studies. I will discuss the ethical importance of reducing existential risk from a variety of different ethical frameworks, and how this links to the concepts in geoethics. I will then discuss some of the opportunities for geoscientists to contribute to the reduction of these risks, including some of the work that has been done by geoscientists to identify and reduce existential risk and increase civilisational resilience, as well as how methodological expertise of different geoscience disciplines can contribute to the growing corpus of theoretical work around existential risk.
The net ecosystem productivity penalty of high vapor pressure deficit at a subalpine coniferous forest in Switzerland
Authors: Hörtnagl Lukas , Gharun Mana , Eugster Werner , Burri Susanne , Merbold Lutz , Shekhar Ankit , Meier Philip , Baur Thomas , Staudinger Markus , Etzold Sophia , Zweifel Roman , Buchmann Nina
Published: February 2023

During one week in June 2019, a subalpine coniferous forest in the European Alps experienced record-high vapor pressure deficits and air temperatures. During these extreme conditions, the forest abruptly changed from a strong net carbon sink to a carbon source. We quantified the immediate impact of these extreme conditions on measured net ecosystem CO2 fluxes (NEP) by calculating the NEP penalty, a measure describing the amount of CO2 sink lost compared to less extreme conditions.

26 years of eddy covariance measurements revealed that the NEP penalty increased with VPD and that only a few hours of high VPD per year were enough to reduce the potential annual carbon budget of the forest by up to 22%. Rising air temperatures and an increasing frequency of extreme VPD conditions might have increasingly adverse effects on the CO2 sequestration potential of this Picea abies forest, autochthonous vegetation at this elevation.
The MANCOGA Project - co-designing NbS using mangroves against coastal hazards in Ghana
Authors: Brix Holger , Mahu Edem , Kaiser David , Eschenbach Christiane , Atiglo Donatus Yaw , Staneva Joanna
Published: February 2023

Coastal hazards such as erosion, flooding and pollution are major problems globally, exacerbated by increasing frequency and severity of hydro-meteorological extremes amidst inadequate technology and adaptive capacity. The Ghanaian coast is an example of a region impacted by such problems. Factors hampering the management and improvement of these issues include the lack of data, insufficient communication structures between stakeholders and missing pathways to informed decisions with sustained impact.In this context, the MANCOGA project stands out by employing a co-design approach to develop a robust and participatory Nature-based Solution (NbS) to coastal hazards. The co-design pilot phase has drawn the focus onto steps for restoring wetlands, mangroves in particular, to provide sustainable livelihoods by protecting and reinvigorating coastal systems and environmental health.In the implementation phase, MANCOGA will evaluate mangrove ecosystem services for their potential as NbS to a number of pressing local issues. A Digital Twin will use What-If scenarios to predict the role of mangroves as NbS for flood mitigation and erosion prevention. Being a dominant Blue Carbon ecosystem, mangroves will also contribute to climate change adaptation strategies as well as provide socio-economic value (e.g., through carbon credits). The wider effects on water quality, through the reduction of eutrophication, is critical for local economics, including fisheries. We employ aerial photography and remote sensing to identify possible nature-based solution areas.The comprehensive community involvement of stakeholders from all societal and administrative levels facilitates frameworks to understand and evaluate effectiveness of NbS applications. The relationships and collaborative approach developed during the co-design phase will guarantee continued involvement of stakeholders. MANCOGA will provide a digital toolbox of intuitive, interactive tools to analyze and disseminate archived and new observational data, which will enable ecosystem service quantification before and after the application of NbS, and lead to knowledge-based decision-making.We envision MANCOGA as the start of sustained collaboration, knowledge transfer and capacity building. Therefore, we warmly invite researchers and stakeholders, from Africa and elsewhere, to connect to MANCOGA and share experiences and efforts.
Testing Spatial Out-of-Sample Area of Influence for Grain Forecasting Models: How does out of Spatial Out-of-Sample AoI Change through the Season?
Authors: Davenport Frank , Shukla Shrad , Lee Donghoon , Anderson Patrese , Husak Greg , Funk Chris
Published: February 2023

The potential for predictive models based on earth observations (EO) and survey data to assist in famine early warning and other development applications is rapidly growing. However, while the spatial-temporal extent of EO data is complete, high quality survey data is generally limited in spatial and temporal scope. The perennial question in all predictive analysis, and especially when trying to move from research to operational application in the developing world is: If we create a forecast model from region A (based on observed outcomes) can we apply the same model in region B, where we do not observe or have limited observations of those outcomes? Prior research has proposed examining the Area of Influence (AoI) based on structurally similar characteristics in the EO predictors. We expand on and evaluate this approach in the context of grain yield forecasting in Sub-Saharan Africa (SSA). Specifically, we evaluate an AoI methodology established for generating raster surfaces and apply it to vector supported grain data.  We ask the following questions: What are the key characteristics that make a forecast fit for one country work in another country? Can pooling models across multiple countries provide more accurate out-of-sample estimates than a model fit to one country or district? Does AoI change through the season? Does a model fit for in early season have the same AoI as a model fit late in the season. 
Establishing the structure of the Cretaceous Neotethyan Orhaneli ophiolite, NW Turkey
Authors: Paksoy Yunus Can , Paksoy Nefise , Topuz Gültekin
Published: February 2023

Orhaneli ophiolite is a Late Cretaceous ophiolitic suite, obducted over the Late Cretaceous high-pressure rocks of the Tavşanlı Zone that represents the subducted part of the southern passive continental margin. It is part of the Neotethyan ophiolites related to the Izmir-Ankara-Erzincan Suture. The present work aims to decipher the inner structure of the Orhaneli ophiolite. This implies constructing the geometrical relationships between structural elements and to evaluate their original positions relative to the paleo-horizontal and paleo-ridge axis.The Orhaneli ophiolite comprises three tectonic domains separated from each other by N-S trending east-vergent thrusts. The middle domain comprises mantle harzburgite, dunite, pyroxenite, and crustal layered gabbro and cumulate peridotite. The Moho transition zone is represented by a 1 km thick, highly sheared zone that consists of serpentinite and mylonitic gabbro. Mylonitic gabbro has a layered-laminated structure and is very well lineated. Mantle structures (compositional layerings and foliations) are dominantly sub-vertically dipping with the N-S trend. While the layered gabbros are dipping to the east with 65° near the Moho, the dip direction progressively changes to the west stratigraphically upward. The eastern domain is the tectonic repetition of the mantle section of the middle domain. Foliations and compositional layerings strike N-S and sub-vertical dips. The western domain corresponds to relatively lower parts of the mantle which consists of harzburgite and dunite. The absence of pyroxenites distinguishes the mantle rocks of this domain from the others.It is observed that (1) there is a low-angle relationship between the mantle structures and the lower parts of the layered gabbro, (2) layered gabbros are progressively steepening stratigraphically upward, (3) the boundary between the lithospheric mantle and the crust is strongly sheared.