bluuebunny/crossref_metadata_2025 huggingface dataset:
A Bayesian hierarchical spatio-temporal ratio-estimator approach to model phosphorus loading in six Ohio watersheds: the importance of accounting for inter-annual and inter-basin variabilities
Authors: Alameddine Ibrahim , Sawma Jessica , Khalife Hassan
Published: March 2022

Surface water bodies serve a critical role in preserving ecological systems and maintaining biodiversity. Anthropogenic eutrophication of fresh water ecosystems is one of the main causes of surface water quality degradation. Excessive nutrient loading to freshwater bodies is a driving cause of water quality impairments worldwide. Accurately estimating riverine nutrient loads remains an imperative step towards mitigating and managing impairments. Yet, load estimation is often hindered by the sporadic and infrequent monitoring of nutrient concentrations. Several modelling approaches have been proposed and implemented over the years to estimate pollutant loads; yet most suffer from biases and/or from their capabilities to transparently quantify uncertainties. In this work, we propose a spatio-temporal Bayesian hierarchical ratio-estimator model to predict the annual total phosphorus loads between 2005 and 2020 for six intensively monitored watersheds discharging in Lake Erie and the Ohio River-USA. The integration of higher-level Land-Use-Land-Cover predictors proved successful in capturing inter-station variabilities in phosphorus loading. Meanwhile, accounting for annual climatic variability partially helped explain temporal changes in the flow-weighted nutrient concentrations across the six watersheds. The performance of the model was tested against different levels of data censorship. Results showed that under a weekly sampling program, the load estimates from the proposed Bayesian Hierarchical spatio-temporal model were within -19 and 31 % (mean difference of 0.3% across stations and years) from the true loads calculated for years with uninterrupted concentration measurements. Predictions from traditional load estimation methods were found to vary between -56% and 73% from the true loads. Meanwhile, failing to account for the spatio-temporal hierarchical structure of the proposed model, either by adopting a completely pooled or an unpooled model, resulted in a significant drop in the accuracy of the predicted loads and inflated the associated uncertainties.
Snow avalanche activity in the Țarcu Mountains, Southern Carpathians. Comparative analysis based on tree ring studies.
Authors: Feher Renata , Chiroiu Patrick , Voiculescu Mircea
Published: March 2022

Information regarding the Spatio-temporal behavior of extreme natural phenomena, such as avalanches, has become necessary due to the increase in human casualties and property damage in recent decades. Thus, the prevention of geomorphological risks associated with high mountain areas requires knowledge of the characteristics of geomorphological processes that occur here. Avalanches occupy a central place among these phenomena with the greatest destructive capacity (Voiculescu, 2000).

The aim of this study is to 1) reconstruct the past activity of snow avalanches in the Tarcu Mountains and to fill a gap in knowledge due to the lack of such studies in the studied area and 2) to point out the synchronicity of major events with those reconstructed in other mountain areas in the Southern Carpathians: Bucegi, Făgăraş, Piatra Craiului, Parâng Mountains. The morphology of the investigated area determines the formation of constrained avalanches. For events reconstruction, we used semi-quantitative Shored index (Shroeder, 1980). We identified 51 events in a 101-year chronology in Picea abies: 12 events with It  between 10-20% and 6 events with It  between 20-40%. The relatively young age of the trees is a good indicator of the disturbances caused by past events. We based our reconstruction on dating growth disturbances such as reaction wood, traumatic resin ducts, and scars. Reaction wood, very present in our case, highlighted the intensity of avalanche activity and the expansion of events. Resin ducts and scars are a good indicator of avalanches that brought us important information in the dating of events and helped us to delimit the affected areas (the 2005 synchronous event with other 9 couloirs). The return period values are higher than those obtained by Corona et al. (2010) in the French Alps (2.5-12 years), smaller than those obtained by Corona et al. (2007) in the Swiss Alps (slightly over 20 years) and similar to those obtained by Decaulne et al. (2012) in Northern Iceland (15-20 years). 11 events synchronous with events of another 11 couloir (1985, 1987, 1988, 1998, 2000, 2005, 2006, 2007, 2008, 2010, 2016).

In the future we want to highlight the type of avalanche by relating the activity of avalanches to cold season temperatures by using the Standardized Winter Index (IIS) (Micu, 2009; Voiculescu, Onaca, 2014) and climate scenarios, cf. Germain et al. (2009). Our study can be the basis for the elaboration of hazard and risk maps, in the perspective of tourist investments in the Tarcu Mountains or in the development of tourist activities in safe conditions.
Spasmodic deformation in the Southwest of the Gondwana boundary, Upper Paleozoic of Ventana ranges in Argentina
Authors: Tomezzoli Renata N. , Arzadún Guadalupe , Fortunatti Natalia , Cesaretti Nora N. , Febbo María B. , Calvagno Juan M. , Choque Giselle
Published: March 2022

At the east of the Ventana Ranges, Buenos Aires, Argentina, outcrops the Carboniferous-Permian Pillahuincó Group (Sauce Grande, Piedra Azul, Bonete and Tunas Formation). We carried out an Anisotropy of Magnetic Susceptibility (AMS) study on Sauce Grande, Piedra Azul and Bonete Formation that displays ellipsoids with constant Kmax axes trending NW-SE, parallel to the fold axes. The Kmin axes are orientated in the NE-SW quadrants, oscillating from horizontal (base of the sequence-western) to vertical (top of the sequence-eastern) positions, showing a change from tectonic to almost sedimentary fabric. This is in concordance with the type and direction of foliation measured in petrographic thin sections which is continuous and penetrative to the base and spaced and less developed to the top. We integrated this study with previous Tunas Formation results (Permian). Similar changes in the AMS pattern (tectonic to sedimentary fabric), as well as other characteristics such as the paleo-environmental and sharp curvature in the apparent polar wander path of Gondwana marks a new threshold in the evolution of the basin. Those changes along the Pillahuincó deposition indicate two different spasms in the tectonic deformation that according to the ages of the rocks are 300-290 Ma (Sauce Grande to Bonete Formation deposition) and 290-276 Ma (Tunas Formation deposition). This Carboniferous-Permian deformation is locally assigned to the San Rafael (Hercinian) orogenic phase, interpreted as the result of rearrangements of the microplates that collided previously with Gondwana, and latitudinal movements of Gondwana toward north and Laurentia toward south to reach the Triassic Pangea.  
Simulation of climate change due to reducing emission of each anthropogenic aerosol component by region using a coupled atmosphere-ocean model
Authors: Takemura Toshihiko , Sudo Kengo , Goto Daisuke , Suzuki Kentaroh
Published: March 2022

The Summary for Policymakers of the Working Group I of the 6th assessment report of the Intergovernmental Panel for Climate Change (IPCC) contained a diagram of the contribution of the global mean change in surface air temperature from the preindustrial to the present climate by the composition of the short-lived climate forces (SLCFs) including aerosols. However, it was estimated by a two-layer energy budget emulator with effective radiative forcing obtained from a model inter comparison project, AerChemMIP. Although the effects of total anthropogenic aerosols have been included in the past, present, and future simulations by climate models, it is essential to estimate and analyze climate change by composition of SLCFs using coupled atmosphere-ocean models in the next step. For example, the amount of temperature change varies significantly with CO2 concentration even when the reduced amount of anthropogenic SO2 emissions and then the instantaneous radiative forcing are the same (Takemura, 2020, doi:10.1038/s41598-020-78805-1). In this study, sensitivity experiments to reduce anthropogenic emissions of SO2, organic matter, and black carbon to zero for each of the 12 regions of the world are simulated using a coupled atmosphere-ocean aerosol model MIROC-SPRINTARS and the results are analyzed in comparison with the experiment under standard emissions. Similar experiments are conducted for biomass burning aerosols from several regions. In the simulations, well-mixed greenhouse gas concentrations are set in two patterns, 2015 and 2060 for SSP3-7.0. The same set of simulations using an atmospheric general circulation model with prescribed sea surface temperature and sea ice are conducted for calculating the effective radiative forcing and rapid adjustment due to each anthropogenic aerosol. This set of experiments also aims to generate scientific knowledge to explore the optimal path for emission reductions of SLCFs and use it in policy making. The project S-20 of the Ministry of the Environment of Japan is also conducting experiments to reduce emissions of SLCFs other than aerosols, as well as experiments to reduce SLCFs emissions using a global cloud-resolving model NICAM. Conducting similar experiments with other climate models and comparing them will enable us to better understand the climate impact of SLCFs with uncertainty.
Molecular Clock Dates for Bacterial Origins are consistent with Impact Bottleneck Scenarios
Authors: Fournier Greg , Rangel L. Thiberio , Moore Kelsey , Payette Jack , Momper Lily , Bosak Tanja
Published: March 2022

The Late Heavy Bombardment (LHB) and other late accretion impactor scenarios are often invoked as habitability constraints on the Hadean/Eoarchean Earth. These hypotheses either describe an “impact frustration” where life would not arise until high impact fluxes abated, or “impact bottlenecks” with Bacteria and Archaea representing surviving lineages that subsequently diversified. Phylogenomics studies using relaxed molecular clocks have frequently used these early impact fluxes, especially the LHB, as older-bound constraints on extant life’s early diversification. However, the intensity, timing, and sterilization potential of these scenarios is poorly constrained, and lacks consensus. We propose inverting this hypothesis testing, evaluating late accretion impact hypotheses using molecular clocks that do not presuppose impact frustration or bottlenecks as constraints. However, in the absence of these constraints, previous studies lack the precision to discriminate between these hypotheses. Our recently developed molecular clock approach, using horizontal gene transfers as “cross cutting events” between lineages, overcomes this limitation, and provides sufficient precision to test the proposed biological impact of specific planetary hypotheses such as the LHB.   Using this methodology, we show that major bacterial groups likely diversified between 3.75 and 3.55 Ga, with the last common ancestor of extant Bacteria likely existing shortly after 3.8 Ga.  These ages are consistent with the LHB impact bottleneck hypothesis, wherein bacteria and archaea represent survivors of early Archean cataclysms that extinguished most primordial biodiversity ~3.9 Ga. Future work extending this methodology to Archaea can potentially provide an independent test of the impact bottleneck hypothesis.
A thirst for snowmelt? Tree water use in spring
Authors: Nehemy Magali F. , Maillet Jason , Perron Nia , Pappas Christoforos , Sonnentag Oliver , Baltzer Jennifer L. , Laroque Colin P. , McDonnell Jeffrey J.
Published: March 2022

Describing the water sources for tree transpiration and how sources vary in time and space is fundamental to understand how vegetation impacts the hydrological cycle. While many tree water source partitioning studies have focused on the growing season, little is known about transpiration sources before, during, and after snowmelt when trees rehydrate and recommence to transpire in spring. Here we investigate spring snowmelt and the onset of tree rehydration and transpiration in two sites within the boreal forest of Saskatchewan, Canada. Specifically, we investigate the source of transpiration during the first days and weeks after transpiration onset relative to snowmelt timing. We document the source of transpiration of three boreal forest tree species— jack pine (Pinus banksiana), black spruce (Picea mariana), and larch (Larix laricina)—by combining observations of weekly stable isotope values of xylem, soil water, rainfall, and snowmelt with physical measurements of soil moisture dynamics, snow depth and high-temporal resolution measurements of tree stem radius and sap flow. We show that the onset of rehydration and transpiration overlaps snowmelt and that trees use snowmelt water during stem rehydration and the onset of transpiration. Soil water showed a rapid shift to isotopically depleted-snowmelt water values during the end of the snowmelt period. But our data showed a delay in the shift in xylem isotope signatures from pre-melt to the clear snowmelt-depleted water signatures that dominate thereafter. This appears to be controlled by tree water transit time that was in the order of 9 to 18 days. Our study shows that snowmelt is an important source for stem rehydration and the onset of transpiration in the boreal forest during spring onset. Our data also highlights the importance of monitoring phenological and physiological responses during tree water source investigations. In a warmer world, the timing of snowmelt and vegetation phenology are likely to continue to change, as well as the decline in water availability via snowmelt in northern ecosystems. Therefore, understanding tree water use dynamics during spring onset is important to identify the impact of climate change on the evolution of forest composition and groundwater recharge.  
Rocks and Rivers that Remember:  Using Smartrocks To Constrain Bedload Transport Statistics and Evolving Thresholds of Motion in Natural Mountain Rivers
Authors: Johnson Joel , Pretzlav Kealie , Olinde Lindsay , Bradley D. Nathan , Masteller Claire
Published: March 2022

Instrumented “smartrock” tracer clasts hold the potential to quantify unique and useful sediment transport statistics from the point of view of each grain--a Lagrangian reference frame.  In this presentation we synthesize lessons learned based on two successful smartrock field deployments in natural mountain rivers during snowmelt floods. Our sensors contain accelerometers, data loggers and batteries.  We have primarily used smartrock data to simply measure the exact timing of grain rests and motions, although future analyses and additional sensors could be used to measure many more aspects of transport.  In addition to methodological suggestions and challenges, we show how smartrock data can be used to measure (a) rest and hop time scaling over a range of timescales, and (b) changes in thresholds of motion through time as a function of discharge.  In data from Halfmoon Creek, Colorado, USA, and Reynolds Creek, Idaho, USA, rest duration scaling is heavy-tailed and varies systematically with both timescale and shear stress.  The shear stress dependence suggests that bedload clast dispersal becomes less superdiffusive as flood size becomes larger. We identify several likely diffusion regimes, and hypothesize how timescales of flow variability from turbulence to daily discharge cyclicity may cause scaling breaks over minutes to hours.  In addition, thresholds of motion tend to increase with cumulative flow (reducing transport rates over time), but also decrease with increases in discharge (increasing transport rates until grains restabilize at the higher flow). The threshold data are used to calibrate and partially validate a new model for discharge-dependent threshold evolution. Finally, we brainstorm ways in which smartrocks could be used to explore sediment transport questions in other Earth surface environments.
Using X-ray imaging to find the magnetopause location
Authors: Samsonov Andrey , Sembay Steven , Carter Jennifer , Branduardi-Raymont Graziella , Read Andrew
Published: March 2022

The process of charge exchange between solar wind highly charged heavy ions and exospheric neutrals produces soft X-rays in geospace. The regions with the strongest emissivity are the magnetosheath and cusps. The Soft X-ray Imager (SXI) on board the forthcoming SMILE mission will measure X-ray emissivity integrated along the line-of-sight. By analyzing 2-D maps of X-ray counts from the SXI, we can extract information about magnetopause shape and position. It has been suggested that the maximum of integrated emissivity is tangent to the magnetopause. We check this assumption using the results of MHD simulations for different points along the SMILE trajectory. We show that this method can be used for finding the magnetopause location if some corrections are applied. We present methods of determining the location of the maximum of integrated emissivity using SXI counts maps for a moderately and strongly compressed magnetosphere.
Impact-based Forecast and Warning Services Capacity Development
Authors: Kucera Paul , Page Elizabeth
Published: March 2022

The COMET program has been supporting impact-based forecast and warning services (IBFWS) capacity development.  An IBFWS system has been implemented at the Barbados Meteorological Service (BMS) as part of the US National Weather Service (NWS) Weather Ready Nations (WRNs) initiative.  COMET collaborated with local partners and stakeholders including BMS, Barbados Department of Emergency Management, (DEM), and the Caribbean Institute of Meteorology and Hydrology (CIMH) in the implementation of the IBFWS framework.  The IBFWS system was implemented in six phases that included 1) identifying the hazards, impacts, risks through stakeholder workshops; 2) developing new standard operating procedures; 3) adapting software tools that integrates the IBFWS framework; 4) training of stakeholders; 5) testing and evaluation of system; and 6) the development of documentation for public outreach.  Recently, IBFWS training resources have been developed following the guidance of WMO-No. 1150: WMO Guidelines on Multi-hazard Impact-based Forecast and Warning services.  The IBFWS course includes topics on the Process for Implementing Impact-based Forecast and Warning Services, Identifying Hazards and Constructing Impacts Tables, Using Multi-hazard, Impacts-based Forecast and Warning Services, and Communicating Risk.  These online training modules include engagement simulations related to the types of decisions that need to be made in developing impact-based forecasting programs. Future work is planned to develop a full curriculum related to impact-based forecasting. The presentation will provide an overview of the IBFWS system implementation in Barbados and the associated training resources that have been developed.
CO2 flow in supercritical geothermal systems
Authors: Parisio Francesco , Vilarrasa Victor
Published: March 2022

Technological advances have allowed to target geothermal systems at greater depth and higher temperature in the supercritical regime. Supercritical geothermal systems (SCGS) could potentially provide a drastic increase in power generation, with estimates up to 50 MW per well. A handful of wellbores worldwide have either (or have shown potential to) reached supercritical resources in magmatic provinces. As a common occurrence in volcanic area, the resident fluid is not pure and mixtures of water and CO2 are the norm. In this contribution, we will explore the flow conditions of H2O-CO2 mixtures at temperature and pressure conditions above the critical point of water. The multi-phase and multi-component problem of H2O-CO2 mixture flow is a non-trivial problem and few studies have been done in the past. We present finite element simulations with the open-source multi-physics framework MOOSE that explore the flow conditions of H2O-CO2 mixtures at high temperature and pressure. As a benchmark problem, we assume an injection of cold CO2 into a water filled reservoir. We analyse the pressure and temperature changes and the evolution of the injected CO2 in time. We show how gravity forces play a role in the long term and at relatively large distance from the injection. We discuss the potential of employing CO2 as a working fluid in SCGS.
The Global Geodetic Observing System (GGOS) - infrastructure for Science and Society -
Authors: Miyahara Basara , Sánchez Laura , Sehnal Martin , Craddock Allison
Published: March 2022

The Global Geodetic Observing System (GGOS) is a collaborative contribution of the global Geodesy community to the observation and monitoring of the Earth System. Geodesy is the science of determining the shape of the Earth, its gravity field, and its rotation as functions of time. Essential to reaching this goal are stable and consistent geodetic reference frames, which provide the fundamental layer for the determination of time-dependent coordinates of points or objects, and for describing the motion of the Earth in space. With modern instrumentation and analytical techniques, Geodesy is capable of detecting time variations ranging from large and secular scales to very small and transient deformations – all with increasing spatial and temporal resolution, high accuracy, and decreasing latency. The geodetic observational and analysis infrastructures as well as the high-quality geodetic products provide the foundation upon which advances in Earth and planetary system sciences and applications are built. In this way, GGOS endeavors to facilitate and enable production and sharing of the Earth observations needed to monitor, map, and understand changes in the Earth’s shape, rotation, and mass distribution. GGOS also advocates the global geodetic frame of reference as the fundamental backbone for measuring and consistently interpreting global change processes as well as the essential geospatial infrastructure to ensure a homogeneous and sustainable development worldwide.

GGOS closely works with its parent organization, the International Association of Geodesy (IAG), to keep these fundamental geodetic contributions sustainable. The IAG Services provide the infrastructure and products on which all contributions of GGOS are based, and the IAG Commissions and IAG Inter-Commission Committees provide expertise and support to address key scientific issues within GGOS. Additionally, GGOS supports the IAG by strengthening external and interdisciplinary relations and contributions to the broader geospatial information community, including relevant United Nations groups, in particular, the UN Committee of Experts on Global Geospatial Information Management (GGIM), its Subcommittee on Geodesy, and the new UN Global Geodetic Centre of Excellence (scheduled to commence operations in early 2022). The main contribution of GGOS in this regard is to support actions and initiatives to communicate the value of Geodesy to society as well as to help to understand and solve complex issues facing the global geodesy community. Towards this objective, GGOS is developing a comprehensive Geodesy portal (https://ggos.org/) including detailed descriptions of geodetic observations (https://ggos.org/obs/) and products (https://ggos.org/products/), and various outreach tools such as short videos to explain the roles and importance of Geodesy to non-geodesists.
Testing a (quasi-)free base for modelling core-mantle boundary topography
Authors: Rolf Tobias , Crameri Fabio , Heyn Björn H. , Thielmann Marcel
Published: March 2022

The core-mantle boundary (CMB) is the most prominent compositional boundary inside the Earth. Its topography provides insight on lower mantle flow and the thermochemical structure above the CMB. Yet, CMB topography remains challenging to observe and estimates from seismology vary substantially. Numerical models of mantle convection provide complementary means to estimate CMB topography. Classically, topography is determined from the normal stresses acting on the CMB. However, this is known to face severe complications when applied to the surface boundary of the mantle, leading to non-Earth-like topographic scales and a different style of subduction. A (quasi-)free surface yields more Earth-like predictions, but for the CMB this comparison has never been made.

Here, we compare CMB topography predicted from mantle convection modelling using different treatments of the CMB. Specifically, we test the role of a ‘sticky core’, a quasi-fluid approximation the core. We compare results predicted by different codes (with either sticky core or true free base) and compare to a simple analytical case. Also, we simulate the evolution of subduction and deep thermochemical provinces to compare the topography of the (quasi-)free CMB and the free-slip approach. Initial results indicate that the sticky core approach can reproduce CMB topography reasonably well, but has rather high computational cost (grid resolution, number of particles). In analogy to the sticky air at the surface, the viscosity contrast of the sticky core layer determines the quality of predicted topography, with larger contrasts (≥103) leading to acceptable levels of artificial CMB topography. In dynamic flow cases with vigorous mantle convection, entrainment by plumes further complicates application of the sticky core, but can be tackled with an unmixing procedure. A true free base tends to better accuracy than the sticky core approach and avoids the problem with entrainment, but it also comes with additional computational costs as various forces at the CMB have to be taken into account.
Observations of slope movements in mountain landforms using permanent in-situ GNSS instruments
Authors: Beutel Jan ,   PermaSense GNSS Team
Published: March 2022

Slope movements in mountain areas are abundant and diverse phenomena, with an extreme range in size and velocity, and constituted from different materials such as bedrock, debris, and ice. In the past two decades, many studies have observed accelerating trends in the surface velocities of these landforms, often attributed to global warming and its amplified impact on high mountains. Detailed data needed for quantitative analysis and modelling, however, remain scarce due to logistic and technical difficulties. In particular, state-of-the-art monitoring strategies of surface displacement in high-mountains rely either on geodetic terrestrial surveys or on remote sensing techniques. While these methods are beneficial for the establishment of long-term time series and distributed datasets of surface displacements, they lack high temporal resolution and are sensitive to data gaps. These characteristics limit their potential for underpinning detailed process understanding and natural hazard management procedures. By contrast, in-situ permanent instruments allow high temporal resolution without observation gaps, providing unprecedented information w.r.t. the processes at hand. Furthermore, continuous observations with short transmission delays are suitable for applications in real-time, essential for many aspects of natural hazard monitoring and early warning systems.

Here, we present a decadal dataset consisting of continuously acquired kinematic data obtained through in-situ global navigation satellite system (GNSS) instruments that have been designed and implemented in a large-scale multi field-site monitoring campaign across the Swiss Alps. The monitored landforms include rock glaciers, high-alpine steep bedrock as well as landslide sites, most of which are situated in permafrost areas. The dataset was acquired at 54 different stations between2304 and 4003 m a.s.l and comprises ~240’000 daily positions derived through double-difference GNSS post-processing. Apart from these, the dataset contains down-sampled and cleaned time series of weather station and inclinometer data as well as the full set of GNSS observables in RINEX format. Furthermore, the dataset is accompanied by tools for processing and data management in order to facilitate reuse, open alternative usage opportunities and support the life-long living data process with updates. To date, this dataset has seen numerous use cases in research as well as natural-hazard mitigation and adaptation measures. Some of those are presented in order to showcase the fidelity and versatility of the monitoring network.
Morphological response to climatic and anthropic pressures of the Vjosa river, a reference system for river management and restoration
Authors: Crivellaro Marta , Serrao Livia , Bertoldi Walter , Bizzi Simone , Vitti Alfonso , Zolezzi Guido
Published: March 2022

Besides their environmental values, near-natural rivers offer the opportunity to observe and investigate riverine processes as they would occur under limited anthropic pressures, representing fundamental references for river management and restoration. Even so, few large near-natural rivers can still be found in Europe and worldwide, and their knowledge is often scarce due to a lack of hydromorphological monitoring and baseline studies. Among them, the Vjosa/Aoos River (GR, AL) has been recently recognized as a key large fluvial corridor and a significant model ecosystem. We investigate the catchment-scale recent morphological trajectories of the Vjosa river and its tributaries, coupling the reconstruction of channel adjustments over the past 50 years from remote sensing images with the analysis of possible drivers of change at the catchment and reach scale. We considered eight reaches in the main course of the Vjosa river as well as in some major tributaries (Sarandaporo, Drinos, Shushica) with different morphologies and confinement degrees. Our results underline the sensitivity of the Vjosa system to both hydrological alterations and human pressures. Specifically, it is possible to observe a response  of the system passing from an intense period of high magnitude, frequency, and duration of flood events in the 1960s to a drier period in the following decades. To study the morphological response, three time periods are considered: 1968-1985, 1985-2000 and 2005-2020. In the first examined decades, river trajectories highlight the narrowing of the active channel as a primary response to the hydrological change in the majority of selected reaches, with a 20-50% active width reduction with respect to 1968. In the following time periods, the narrowing rate decreases at the catchment scale, while in the last phase the effect of human pressures in some reaches can be observed. Indeed, from the late 1980s, human pressures at different spatial and temporal scales can be identified, locally altering the natural trajectory of the affected reaches. Such pressures include sediment mining and extensive bank protection of the lowland reaches, together with flow regime alteration occurring in one headwater sub-catchment.  However, our analysis reveals primarily a high sensitivity of the Vjosa system to recent climatic variations, suggesting the importance of accounting for future projected changes in rainfall regime in shaping morphological trajectories. The baseline knowledge on the morphological sensitivity and recovery time developed in this work provides an important reference for the management of highly dynamic river corridors in temperate and Mediterranean climates.
Evidence for Multiple Ferrel-Like Cells on Jupiter
Authors: Duer Keren , Gavriel Nimrod , Galanti Eli , Kaspi Yohai , Fletcher Leigh , Guillot Tristan , Bolton Scott , Levin Steven , Atreya Sushil , Grassi Davide , Ingersoll Andrew , Li Cheng , Li Liming , Lunine Jonathan , Orton Glenn , Oyafuso Fabiano , Waite Hunter
Published: March 2022

Jupiter’s atmosphere is governed by multiple jet streams, which are strongly tied to its three-dimensional atmospheric circulation. Lacking a solid surface, several theories exist for how the meridional circulation extends into the interior. Here we show, collecting evidence from multiple instruments of the Juno mission, the existence of mid-latitudinal, turbulent driven, meridional circulation cells, similar to the Ferrel cells on Earth. Different than Earth, which contains only one such cell in each hemisphere, Jupiter can incorporate multiple cells due to its large size and fast spin. The cells form regions of upwelling and downwelling, which we show are clearly evident in Juno’s MWR data between latitudes 60S and 60N. The existence of these cells is confirmed by reproducing the ammonia observations using an advection-relaxation model. This study solves a long-standing puzzle regarding the nature of Jupiter’s sub-cloud dynamics and provides evidence for 8 cells in each Jovian hemisphere.
Diagnosing the effect of circulation trends on atmospheric temperature
Authors: Thomas Rhidian , Woollings Tim , Dunstone Nick
Published: March 2022

In studying recent climate, changes to atmospheric circulation are often understood as a response to temperature changes. This work instead quantifies the contribution to temperature trends from the atmospheric dynamics, by analysing trends in the ERA5 zonal-mean temperature budget over the satellite era. The results are consistent with several previously highlighted trends in the circulation. In the winter hemisphere, the region of subtropical descent and heating associated with the Hadley cell strengthens on its poleward side, and the deep diabatic heating in the ITCZ intensifies and shifts northward in the northern hemisphere (NH) winter. In keeping with other studies, we find a weakening of the transient eddy heating associated with the NH summer storm tracks. At high northern latitudes, the climatological eddy heating is weakened at low levels; this signal is strongest in NH winter, consistent with the reduced baroclinicity associated with arctic warming. Our work also points towards emerging trends in the transition seasons, SON and MAM, and underlines the importance of circulation changes in understanding trends in atmospheric temperature.
Potential of satellite surface soil moisture products for spatially calibrating distributed eco-hydrological models
Authors: Gomis-Cebolla José , Garcia-Arias Alicia , Perpinyà-Vallès Martí , Francés Félix
Published: March 2022

Calibration of distributed hydrological models needs to include spatial information of the hydrological processes in order to guarantee a robust spatial representation of the model state variables. Satellite remote sensing monitoring the Earth in a temporal and spatial comprehensive way stands out as a valuable resource of this kind of information. Surface soil moisture (SSM) plays a key role in the description of the hydrological cycle, especially in semi-arid areas. Nevertheless, the coarse resolution of available SSM products has restricted the use of SSM in the calibration of hydrological models to only the temporal approach. The current operational SSM estimates (1km) resulting from new sensor estimates or the application of downscaling methodologies pave the way for this spatial calibration approach. The present study explores the applicability of these spatially enhanced SSM estimates for distributed eco-hydrological modelling in Mediterranean forest basins. On one hand, it contributes to fill the existing research gap on the use of remote sensing SSM spatial patterns within the distributed hydrological modelling framework, in particular in medium/small basins. On the other hand, it serves as an indirect validation method for the spatial performance of satellite SSM products. TETIS eco-hydrological distributed model was implemented in three case studies, named Carraixet (eastern Spain), Hozgarganta (southern Spain), and Ceira (western Portugal), which were strategically selected to perform this research in the Mediterranean Region. The SSM estimates selected for evaluation were: Sentinel-1 SSM provided by the Copernicus Global Land Services (CGLS), SMAP SSM disaggregated using Sentinel-1 provided by the National Aeronautics and Space Administration (NASA), SMOS SSM provided by the Barcelona Expert Center (BEC), and SMOS and SMAP SSM disaggregated using the Dispatch algorithm provided by Lobelia Earth. The methodology employed involved a multi-objective and multi-variable calibration using the considering remote sensing SSM spatial patterns and in-situ streamflow, using the Spatial Efficiency Metric (SPAEF) and the Nash-Sutcliffe efficiency index (NSE) respectively. In spite of the spatial and temporal differences amongst products, the multi-objective calibration approach proposed increased the robustness of the hydrological modelling. Spatial and temporal agreement depends on the selection of the SSM product. The disaggregating methodology determined the spatial agreement to a greater degree than the sensor itself.
Space-time modeling of rainfall-induced shallow landslides in South Tyrol, Italy
Authors: Moreno Mateo , Steger Stefan , Lombardo Luigi , Crespi Alice , Zellner Peter James , Pittore Massimiliano , Mair Volkmar , van Westen Cees
Published: March 2022

Shallow landslides of the slide-type movement represent potentially damaging events in mountain areas all over the world. These geomorphic processes are caused by a combination of predisposing factors (e.g., hillslope material), preparatory conditions (e.g., prolonged snow-melt), and triggers (e.g., heavy rainfall). Data-driven methods have been used to model shallow landslides at regional scales. Traditional approaches are mainly focused on the spatial dimension, whereas the space-time component remains a challenge.

This contribution is built upon data on past landslide occurrence from 2000 to 2020 events in the province of South Tyrol, Italy (7400 km²). The inventoried information systematically relates to damage-causing and infrastructure-threatening events. The methodical procedure included an initial delineation of slope units that were subsequently replicated in time (2000 to 2020) and randomly subsampled to generate balanced distributions of landslide presence/absence observations across space and time. Different spatial static factors and cumulative daily precipitation time windows were aggregated into the mapping units. A Generalized Additive Mixed Model (GAMM) was implemented to derive statistical relationships between the different static and dynamic factors and the occurrence in space-time of shallow landslides. The resulting predictions were validated from multiple perspectives and transferred into space for different combinations of dynamic factors (e.g., triggering and preparatory precipitation, seasonal effects).

The first results are promising. The exploratory analysis has revealed that from a temporal viewpoint, the best-performing model consists of a combination of preparatory and triggering factors while additionally accounting for seasonal effects. The further inclusion of the spatial static factors improved the modeling results. The developed approach shows the potential to integrate static and dynamic landslide factors for large areas by also accounting for the underlying data structure (e.g., repeated observations nested in space) and data limitations (e.g., accounting for spatial data incompleteness). The proposed method is expected to enhance the predictability of shallow landslides at multiple spatial and temporal scales and provide a better understanding of the role of the environmental processes. This study is framed within the PROSLIDE project, that has received funding from the research program Research Südtirol/Alto Adige 2019 of the Autonomous Province of Bozen/Bolzano – Südtirol/Alto Adige.
Catchment scale variation of contaminants in glacial sediments from the Cordillera Blanca, Peru
Authors: Beard Dylan Bodhi , Clason Caroline , Rangecroft Sally , Rodríguez Wilmer Sánchez , Blake William
Published: March 2022

Historically, glaciers have been seen as pristine environments. However, research has shown that glaciers can accumulate and store contaminants through processes such as atmospheric deposition, mass movements, and anthropogenic activities. Numerous anthropogenically and naturally-derived contaminants have been found within glacial sediments, including fallout radionuclides, potentially toxic elements, and heavy metals. The introduction of these contaminants often come from human activities such as the use of agricultural fertilisers, carbon based industries, vehicular use, and nuclear power plants. However, these contaminants can also originate from natural sources such as erosion of metal-rich rock and forest fires. Through mechanisms of secondary release, these often legacy contaminants are remobilized, finding their way into glacial riverine systems and downstream environments. This can then pose potential threats to human and ecosystem health, as well as impacting food quality, water resources, livelihoods, and social justice.

When assessing potential downstream risk from glacial contaminants, it is crucial to know what types of contaminants may be released in meltwaters and in what quantity. Here we identify contaminants in cryoconite – a sediment found on the surface of glaciers – in Peru’s Cordillera Blanca, from which meltwater feeds into the Rio Santa. Previous studies have shown that glaciers in similar environments (i.e. high mountain glacier catchments) have been found to contain differing types and concentrations of contaminants within cryoconite. However, until now this had not been reported for cryoconite on glaciers in Peru. This research investigates the variation in contaminant load in cryoconite from four different glaciers (Pastoruri, Shallap, Vallunaraju, and Yanapacca) within the Cordillera Blanca. Key contaminants in cryoconite from this region have been analysed using X-ray fluorescence, gamma spectrometry, and ICP-MS. These results contribute to an improved understanding of the extent to which glaciers may act as a secondary source of contaminants to the Rio Santa catchment. This is an important first step towards assessing the risk of contaminant release from glaciers in this region.
Observing iceberg size distributions and implications for calving processes
Authors: Shiggins Connor , Lea James , Harcourt William , Shankar Siddharth , Brough Stephen , Fahrner Dominik
Published: March 2022

Icebergs are a key component of the ice-ocean interface, and provide the opportunity to gain insight into calving processes, and freshwater budgets in fjords and oceans amongst others. Iceberg area and volume distributions have been characterised for a handful of sites across the Greenland Ice Sheet, though a greater spatial and temporal range of data are required to understand how iceberg dynamics vary between different glaciers. Here we present iceberg area and volume distributions from 141 ArcticDEM scenes from 2010-2017 for 19 marine-terminating glaciers in Greenland, with 588,856 icebergs automatically detected.

The data show emerging evidence for more positive power law slope values (i.e. glaciers with larger icebergs) at glaciers with mean terminus depths exceeding 230 meters. However, the range of these values are generally consistent once a depth of 230 metres is exceeded. Glaciers with shallower depths can generate similar iceberg distributions, though typically these provide more negative exponents (i.e. are dominated by smaller icebergs).

Our results allow a characteristic range of iceberg size distributions to be defined for glaciers with mean terminus depths greater than 230 metres, which is likely controlled by a change in dominant calving processes at/near these depths. While shallower glaciers can in some cases provide similar distributions, most observations show distributions dominated by smaller icebergs. Together these suggest that mean terminus depth exerts a fundamental control on calving processes and the resulting iceberg size distributions.

Having the capability to constrain expected iceberg distributions from these data will be useful for understanding controls on calving processes, how fjord freshwater fluxes may evolve, and characterising how the size of icebergs that are exported from fjords will change as Greenland’s marine-terminating glaciers continue to retreat.
A high-accuracy Total Air Content setup: System performance and first results from Skytrain Ice Rise, Antarctica
Authors: Nehrbass-Ahles Christoph , King Amy , Hoffmann Helene , Grieman Mackenzie , Rowell Isobel , Humby Jack , Miller Shaun , Thomas Elizabeth , Bauska Thomas , Schmitt Jochen , Mulvaney Robert , Wolff Eric
Published: March 2022

Some modelling studies and sea level reconstructions suggest the loss of the West Antarctic Ice Sheet (WAIS) during the Last Interglacial (LIG) about ~120’000 ago, but direct evidence for a collapse of the WAIS is lacking. The WArm Climate Stability of the West Antarctic ice sheet in the last INterglacial (WACSWAIN) project aims at providing direct evidence allowing for a comprehensive assessment of whether or not the WAIS collapsed during the LIG. One of the expected consequences of such massive ice mass loss is the change of the elevation of land masses in close proximity of the WAIS due to isostatic adjustments. This process, together with changes in ice sheet thickness, may have altered the elevation of Skytrain Ice Rise above sea level on the order of 200 m. Such major changes in the elevation should be imprinted in the Total Air Content (TAC) based on simple barometric considerations. Here we present a new experimental setup of a high-accuracy, high-precision TAC measurement system constructed at the British Antarctic Survey. This setup is dedicated to and optimised for the measurement of TAC and is based on a vacuum extraction principle. The air is extracted from the ice by melting the sample by thermal radiation and the released air is dried and directly expanded into a 30-litre expansion chamber. State-of-the-art pressure gauges and thorough temperature control allow for an accuracy of 0.2% with a real ice reproducibility of 0.2% to 0.4% for 100 g and 30 g samples, respectively. Here, we discuss the performance of this new TAC system and present first TAC data from the Holocene section of the Skytrain Ice Core, Antarctica.
Water dynamics in an infiltration trench in an urban centre in Brazil
Authors: Coutinho Artur Paiva , Lopes Bezerra Paulo Henrique , Lassabatere Laurent , Neto Severino Martins dos Santos , Melo Tassia dos Anjos Tenório , Antonino Antonio Celso Dantas , Angulo-Jaramillo Rafael , Montenegro Suzana Maria Gico Lima
Published: March 2022

Infiltration trenches are compensatory techniques that have been settled up for decades. These aim to store the stormwater previously collected and infiltrate water into its banks. The objectives of the proposed study consist of modeling the water dynamics in an infiltration trench in order to evaluate its hydraulic performance. The studied trench is installed in the city of Recife (Pernambuco-Brazil, Brazil). We analyzed the response time of the infiltration system, the percentage of the infiltrated volume, and the dynamics of water storage processes for an extensive series of several rainfall events. We used the PULS method to model the events and quantify the contributions of each compartment to the water budget (infiltration, evaporation, etc.). Both observations and modeling demonstrated that the infiltration trench had a positive effect, with high performance, allowing the infiltrating of a large part of the drained volume. The infiltration trench achieved its objective of decreasing the volume drained on the surface. In this research, we also question the changes in the soil characteristics with time (in particular clogging of the banks) and the potential occurrence of preferential flow.