bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the implications of net-zero emissions at different global warming levels
Authors: Ziehn Tilo , King Andrew , Brown Josephine , Cassidy Liam , Borowiak Alexander
Published: February 2023

To stop global warming, humanity needs to achieve close to net-zero greenhouse gas emissions. Many countries are committed to reducing greenhouse gas emissions significantly over the next decade and to reaching net-zero emissions by 2050, in line with the Paris Agreement goal of limiting global warming well below 2°C above pre-industrial levels. This can only be achieved through deep decarbonization and removal of carbon dioxide from the atmosphere. However, many questions remain about the long-term implications of stabilising global temperatures at the Paris Agreement goals or missing this target but stabilising the climate at a higher global warming level.We have run bespoke millennium-length simulations with the Australian Earth System Model, ACCESS-ESM1.5, under net-zero emissions at different global warming levels ranging from about 1.5°C to 3°C. Here, we discuss these simulations and analyse the evolution of temperature, precipitation and carbon budgets. We will present results on the linearity of local climate changes under different stabilised global warming levels and how these compare with local changes in rapidly warming climates. We will also discuss the processes that cause these local non-linearities and raise opportunities for research that these simulations provide.We must gain a better understanding of potential future climates which evolve under near-zero greenhouse gas emissions. Policymaking is based on achieving net-zero emissions and we hope our work and similar analyses can increase understanding of a changing climate under net-zero scenarios.
Structural model of the two orogens convergence zone: A case study from western Kura foreland fold-and-thrust belt, Georgia
Authors: Enukidze Onise , Alania Victor , Beridze Tamar , Pace Paolo , Razmadze Alexandre , Merkviladze Demur , Shikhashvili Tamar
Published: February 2023

Collision and subsequent convergence of Arabia and Eurasian plates during the late Alpine time caused extensive intracontinental deformation in the Caucasus region. Inversion of back-arc basins, exhumation and crustal thickening took place in the far-field zone, forming two orogens, and leading to a convergence between the Lesser Caucasus (LC) and Greater Caucasus (GC). Continuous convergence between the LC and GC caused incremental deformation of the Rioni and Kura foreland basins. Recent GPS, earthquakes, and paleoseismic data indicate that the Kura foreland fold-and-thrust belt (KFFTB) is tectonically fairly active (e.g., Sokhadze et al., 2018; Tibaldi et al., 2020; Tsereteli et al., 2016; Stahl et al., 2022).In this study, we have integrated the post-stack depth-migrated 2D seismic proﬁles, borehole, and outcrop data to explore the structural geometry and kinematic features of the western KFFTB. Here we show the structural style of deformation of the convergence zone between the frontal part of the LC retro-wedge and the GC pro-wedge based on seismic reflection profiles. The seismic reflection profiles reveal the presence of a triangle zone and south-and north-vergent fault-related fold and south-vergent thrusts.In combination with surface geology and borehole data, we have analyzed along-strike variations of the south-vergent passive-back thrust and transition from the fault-propagation fold to wedge structure by using 2D seismic proﬁles in the western KFFTB.Based on the 2D seismic profiles and field data interpretations as well as our sequential kinematic modeling results, we have established the geometry and structural evolution of the LC-GC convergence zone in the western KFFTB since the Late Miocene.Acknowledgement: This research was supported by Shota Rustaveli National Science Foundation of Georgia (SRNSFG) [grant # YS-21-612. Geometry and kinematic evolution of frontal part of the Eastern Achara-Trialeti fold-and-thrust belt]
The Deep Network: curating and co-producing quality ocean-education information for adults.
Authors: Johansen Caroline
Published: February 2023

In order to successfully set the EU on the path to reach climate neutrality by 2050, it is essential to have communities on board and willing to make changes to act for a sustainable future. However, without courses focused on climate change on the core curriculum of most schools in Europe, many adults are under informed about the effects of climate change, and what can be done on an individual level to reach these goals. The impact of warming oceans are multifold and affect not only communities that directly boarder the sea, but all neighboring nations as well. The Deep Network project addresses the need for adults to become more aware of the problems regarding climate change and the ocean by curating an online ocean-education information hub. To accomplish this, a network will be built working in close partnership with researchers, ocean activists, industries, and professional adult educators to develop high quality, accessible educational material that covers a range of topics related to how human activities impact the ocean. Some of the topics covered in the Deep Network project include ocean pollution, rising sea levels, ocean warming/acidification, habitat destruction, fisheries, and tourism. Additionally, to engage communities to action and to maintain a sustained interest in marine science and conservation, “inspiring practices” will be promoted for each topic. These are examples of realistic actions or lifestyle changes that one can directly implement into one’s own life. Anthropogenic influences on the oceans directly affect us all in varying ways. The goal of The Deep Network project is to create a strong line of accessible communication, trust, and transparency between ocean research and the communities, to ensure that the responsibility of a sustainable future falls not on the scientists, activists, and industry partners alone. A well-informed community has the potential to make a difference in legislation and gives people the opportunity to make educated decisions to act for a sustainable future.
Implication of carbon allocation in plants for soil organic matter cycling.
Authors: Hulin Baptiste , Abiven Samuel
Published: February 2023

Plants allocate carbon to roots, shoots, respiration and rhizodeposition. The quantitative partitioning depends on genetic and environmental factors, as well as on the plant’s phenology. The first two or three pools represent most of the carbon input to the soil, depending on the ecosystem considered. Quantifying this partitioning is of major importance as roots, shoots, and rhizodeposition are constituted of several organic compounds differing in residence time. Moreover, besides being carbon inputs, these compounds modify in different ways their surroundings and might slow down or accelerate the cycling of carbon and nutrients.One frequently used method to quantify this partitioning is the 13C labelling of atmospheric CO2, which allows to trace organic carbon in the soil-plant system. 13C labelling of CO2 can be either continuous, or as single or multiple pulses. It can be combined with gas measurements that estimate the priming effect induced by the plant inputs. This poster aims at synthesizing the literature about experimental quantification of carbon allocation to different plant pools, and comparing the methods used. It allows to identify the plant traits that predict this allocation. Moreover, we show the preliminary results of a continuous 13C labelling experiment that compares plant traits with carbon content variations in soil columns.Whereas shoots and roots are relatively simple to quantify, rhizodeposition is not. It therefore represents a major incertitude when considering the carbon inputs to soil. Moreover, labile exudates represent an important part of rhizodeposition that induce an increase of older soil carbon mineralisation. Several experiments show that the loss of carbon induced by rhizodeposition priming effect is bigger than the input. These results are often associated to plants with high photosynthetic activity.A trade-off is to be found when considering 13C labelling. Continuous labelling allows a quantification of net rhizodeposition which is independent of the phenology and that integrates the whole plant growth. On the other side, pulse labelling is easier and less expensive. Regarding priming effect quantification, gas flux measurements are precise but do not integrate the whole plant growth. Mass quantification through carbon content change do, but it requires very accurate estimations of these changes.
Analysis of Transboundary Water-Food Nexus based on Physical-Virtual Water and Food Trade Network
Authors: Lee Sanghyun , Taniguchi Makoto , Masuhara Naoki , Yoo Seung-Hwan , Oh Yun-Gyeong
Published: February 2023

This study aimed to analyze the interaction among watershed, food-producing, and food-demanding areas through the connected system of physical-virtual water flows and local food networks in terms of the transboundary water-food nexus, even though they might not be geographically connected. Here, we analyzed the potential food network of local rice among 47 prefectures in Japan using the gravity model and estimated the physical-virtual water flows (PVWFs) by lining the physical water flow in food-producing areas and virtual water flow embedded in the food network. Through in-and out-degree centralities of the food network, we found that the results of degree centrality revealed which prefecture was more influenced by the changes in self-supply ratios (SSRs) of local rice. As all prefectures intended to increase consumption of local rice that was produced in their area, the scale of the food network was reduced, as shown by the decrease in in-and out-degree centralities. Based on the food network, we analyzed the dependency of food-demanding areas on each watershed based on a connected system of PVWFs. In a case study of the Kansai region, the northern watershed directly affected Hyogo, which was also indirectly influenced by Osaka in terms of PVWFs. In the food network with 20% SSR, the PVWF was estimated to be 189.17 x 106 m3·yr-1 from the northern watershed to Osaka in the food-producing area of the northern watershed, showing higher interaction of Osaka with the northern watershed than with other watersheds.
Primary versus secondary degassing during basaltic eruptions
Authors: Levillayer Nicolas , Sigmarsson Olgeir
Published: February 2023

Volcanic gases are a major concern, especially when eruptions take place in inhabited or touristic areas. Several studies have revealed that during basaltic eruptions, toxic metals such as Pb, Cd, As and Zn are efficiently outgassed, carried by the major gas species, mainly sulfur and halogens. However, part of the degassing occurs after the eruption, while the lava flow is solidifying, and the composition of this secondary gas is virtually unknown.After the primary (syn-eruptive) degassing, the lava is depleted in sulfur, leading to relative enrichment in halogens in secondary (post-eruptive) gas emission. This change in major species concentration could impact the volatility of metals and thus the toxicity of the gas emitted.To investigate this subject, we collected, using filter packs, gas samples of both the primary and the secondary gas phases of the Geldingadalir and Meradalir eruptions. The filters were then leached in diluted acid and the resulting solution analyzed for trace element composition.Results show syn-eruptive gas samples with very homogeneous trace volatile element composition and distinct from all the post-eruptive gas. Conversely, the secondary gas is more diverse, with distinct composition in samples collected around the main Geldingadalir crater and those collected on the lava flow.To compare our gas samples (having different air dilution factors), we normalized each element to Cu (well measured and moderately volatile). Overall, the lava flow post-eruptive gas appears enriched in Zn, Sb and Pb with respect to syn-eruptive (10-100 times higher normalized enrichment factor). These elements are known to form chloride species and could thus have an enhanced volatility due to higher Cl concentration in the secondary gas phase. The Sulfur-loving (chalcophile) element Te has, on the other hand, a 10 times lower normalized enrichment factor in the lava flow gas, which is consistent with a sulfur depletion.It thus seems that volcanic gas emission changes radically between primary and secondary degassing. Increase volatility of some metals such as Lead or Zinc might lead to higher toxicity, with important hazard for the local population and environment.
Multilayer soil scheme and interactive vegetation in regional climate models – A case study for Mainland Southeast Asia using REMO
Authors: Abel Daniel , Ziegler Katrin , Paeth Heiko
Published: February 2023

This study is part of the CLIENT II-project Drought-ADAPT which investigates droughts in Mainland Southeast Asia (MSEA) with a focus on the Central Highlands of Vietnam and under recent and future climate conditions. For these purposes, we use the regional climate model REMO (v2015). This version, as it is used in recent CORDEX-simulations like CORDEX-SEA and CORDEX-CORE, considers a single-layer soil and static vegetation scheme.Soil hydrology and vegetation play a key role for mass and energy fluxes between the land surface and the atmosphere. Thus, their adequate representation by schemes is very important to simulate the fluxes. Hence, we replace the single-layer soil scheme by a multilayer one which allows a vertical water movement in the soil. Its application in Central Europe led to improved land surface-atmosphere fluxes. Additionally, the static vegetation is replaced by an interactive vegetation module, called iMOVE, which solely was implemented in REMO2009. It allows the interaction of various plant characteristics with environmental conditions, like a decrease of LAI during dry conditions, while the former static version prescribes monthly static values independent of the prevailing conditions. We’ll show results of the effects both individual changes have on the mentioned fluxes and related variables in the study area of MSEA. Additionally, we’ll present first results of the promising combination of both individual schemes.
Quantifying controlling factors of ice segregation in alpine rocks
Authors: Mayer Till , Eppes Missy , Draebing Daniel
Published: February 2023

Rockwall erosion by rockfall processes proceed at rates between 0.05 ±0.03 to 14.4 mm a-1 (Draebing et al., 2022) and are key agents of alpine landscape evolution. Previous studies suggest that frost weathering is a major contributing process to alpine rockwall erosion (Draebing and Mayer, 2021). Frost weathering occurs primarily by frost cracking driven by ice segregation, but our current process understanding is based on studies focusing on high-porosity low-strength rocks. However, rock types forming alpine rockwalls are characterized by crack-dominated porosity and high rock strength, therefore, it is unclear how past findings from low-strength rocks apply in these settings. In this study, we will perform laboratory ice segregation tests on rock samples with different saturation levels and fracture density to quantify their influence on frost cracking efficacy.We used Wetterstein limestone rock samples in laboratory experiments and exposed rocks to realistic-rockwall freezing conditions while monitoring acoustic emissions as a proxy for cracking. To differentiate triggers of cracking, we modelled ice pressures and thermal stresses. We tested the influence of (i) saturation (low versus full initial saturation), (ii) crack density (0.4 versus 0.6 % rock porosity), and (iii) temperature range (-10 to 0°C) on the efficacy of ice segregation.(i)  Our data showed that the efficacy of ice segregation is not controlled by initial water content in alpine rocks. These results suggest that water available at depth within alpine rock masses can rapidly travel along fractures to form ice lenses near the rock surface. (ii) Crack density has a direct impact on the elastic properties of rocks, which shifts the stress threshold for crack propagation. A fractured rock with high crack density is less prone to ice segregation as its lower brittleness increases the critical fracture toughness.(iii) Our data revealed temperature patterns promoting ice segregation with highest rates of frost cracking at temperatures between -10 and -7 °C in high strength Wetterstein limestone.We conclude that frost cracking efficacy in high alpine environments is more impacted by temperatures than by initial rock moisture, which potentially results in more rockfall at colder north- than warmer south-facing rockwalls. Draebing, D., Mayer, T., Jacobs, B., and McColl, S. T.: Alpine rockwall erosion patterns follow elevation-dependent climate trajectories, Communications Earth & Environment, 3, 21, https://doi.org/10.1038/s43247-022-00348-2, 2022. Draebing, D., and Mayer, T.: Topographic and geologic controls on frost cracking in Alpine rockwalls, Journal of Geophysical Research: Earth Surface, 126, e2021JF006163, https://doi.org/10.1029/2021JF006163, 2021.
Integration of topographic and InSAR surveys for studying the long-term evolution of the land subsidence process in an urban area
Authors: Zuccarini Alessandro , Di Paola Gianluigi , Giacomelli Serena , Martini Alberto , Severi Paolo , Berti Matteo
Published: February 2023

Since the beginning of the 1960s, the urban area of Bologna has experienced land subsidence due to excessive groundwater withdrawals. Ground deformation reached its peak during the 70s of the last century when maximum displacement rates of about 10 cm/year were documented, and significant damage to structures and infrastructures occurred. This process has been intensively monitored over the years, and extensive ground displacement measurements were collected employing increasingly sophisticated techniques, ranging from topographic levelling to GNSS surveys and, since 1992, satellite interferometry. Satellite data, in particular, has given a substantial contribution to the reconstruction of the subsidence process in more recent times, with a progressively higher spatial and temporal resolution towards the newer surveys. The available interferometric data are the results of four consecutive SAR campaigns undertaken by local authorities: 1992 – 2000 (ERS), 2002 – 2006 (ENVISAT), 2006 – 2011 (RADARSAT), 2011 – 2016 (RADARSAT and COSMO-SkyMed), and a fifth survey performed by the UniBo spin-off “Fragile” from the free SENTINEL1 2014 – 2020 data. As long-term data are essential to comprehensively understand the ongoing subsidence process evolution, within this work, a methodology was developed to integrate ground-based and remotely sensed monitoring data collected over the years, and produce continuous cumulative ground displacement time series and maps, depicting the long-term temporal evolution and spatial distribution of the subsidence process, respectively. The results obtained through the adopted processing chain highlight that the long-term ground displacement field well agrees with the 3D geological model of the area and that the cumulative subsidence and displacement rates temporal evolution nicely matches the pluriannual trend of the piezometric and groundwater pumping time series.
Evaluating Erosion Risk on Agricultural Soils with the Modified Mini-JET Device
Authors: Vrana Michal , Zumr David , Krasa Josef , Dostal Tomas
Published: February 2023

The Jet Erosion Test (JET) is a method for determining the erodibility of incohesive agricultural soils by measuring the critical shear stress. The measurements were performed using a modified Mini-JET device, which is well-suited for field measurements as it is small, light, requires a relatively small amount of water, and can be operated by a single person. The Mini-JET device uses a water jet with a known kinetic energy to create an erosion crater in the soil, and then measures the rate at which the crater forms to determine the soil's erodibility and the critical shear stress. These parameters are needed for estimating the susceptibility of the soil to water erosion, and can help in the design of erosion control measures. The Mini-JET experiments were conducted on experimental plots in Risuty, central Czechia. Two soil with different properties were tested. In parallel with the experiments, a number of soil properties were monitored, including bulk density, soil texture, soil water content, aggregate stability, and total organic carbon. A total of 75 simulations were carried out as part of this study. The results of the Mini-JET experiments showed a large temporal and spatial variability in the soil erosion parameters. Despite this variability, the absolute values of the determined erodibility coefficients were comparable to those reported in previous studies. This indicates that the Mini-JET method is suitable for studying the erodibility of agricultural soils, although a sufficient number of replicates must be carried out to obtain representative values. The information obtained with the Mini-JET method can be used in physically based soil erosion models, which are used to predict the erosion of soil and the effectiveness of erosion control measures.  Research has been supported by project TUDI (European Union's Horizon 2020 research and innovation programme under grant agreement No 101000224) and LTA-USA 19019 (Ministry of Education of the Czech Rep.).
The interplay between tectonics and karst in the formation of the canyons in the Al-Hajar Mountains (Sultanate of Oman)
Authors: Pezzotta Andrea , Marinoni Alessia , Zucali Michele , Zerboni Andrea
Published: February 2023

The Al-Hajar Mountains (Northern Sultanate of Oman) characterise the north-eastern part of the Arabian Plate and exhibit a complex tectonic history. They formed during the overthrusting of the Semail Ophiolite and the slope-basin sedimentary sequences over autochthonous sedimentary cover and metamorphic units. The post-orogenic history is characterised by extension and subsequent shortening, forming a series of regional-wide anticlines. The Jebel Akhdar dome, in the central Al-Hajar Mountains, is one of these anticlines; it consists of a pre-Permian basement and Permian to Late Cretaceous carbonate platforms. Along the southern flank of the anticline, the Jebel Akhdar Mesozoic shallow-water limestone is deeply cut into a network of narrow and sometimes meandering canyons. The combination of remote sensing, morphometry, field survey and structural analysis is the multidisciplinary approach used to explore the evolution of canyons and understand the processes that oversaw their deep incision. We identified a group of joint and fault sets, morphostructural lineaments and inactive karst features (both in the epikarst and in the hypokarst) at various scales and evidence for canyons overdeepening respect to the present-day watershed basins. Our reconstruction suggests the ancestral action of karst dissolution along the many structural weaknesses available along the phreatic zone. This led to the formation of a complex network of conduits, later exhumed and occasionally reworked by fluvial processes and linear erosion, whose dynamic was tuned by pre-Quaternary and Quaternary climatic changes.
Successive Co-occurring IOD and ENSO Unprecedentedly Intensify Indian Ocean Westward Equatorial Undercurrent During the Summers of 1998 and 2
Authors: Huang Ke
Published: February 2023

Using mooring observations and reanalysis, we show that anomalously strong westward Equatorial Undercurrent (wEUC) developed in June–July in 2016 and 1998 in the Indian Ocean, which coincided with extreme Indian Ocean Dipole (IOD) and El Niño events. Simulations show that equatorial Kelvin and Rossby waves were excited by winds associated with El Niño and positive IOD events during 2015 and 1997, and their negative phases during 2016 and 1998. The constructive relationship between the delayed-time contributions of eastern-boundary-reflected-waves that excited by the easterlies in 2015 and 1997 and the direct contributions of wind-forced-waves that excited by the westerlies in 2016 and 1998 resulted in the intensified wEUC. Slow intermediate-order baroclinic-modes, rather than fast low-order baroclinic-modes, dominated the strong wEUC. The eastern-boundary-reflected-waves dominated in 1997–1998 and directly wind-forced-waves dominated in 2015–2016. Our results emphasize the importance of constructive interactions of the directly-wind-forced and boundary-reflected waves in driving the interannual variability of Indian Ocean wEUC.
Improving non-photochemical quenching, fluorescence emission and gross primary production of boreal evergreen needleleaf forests in a land surface model
Authors: Leverne Lucas , Abadie Camille , Bacour Cédric , Zhang Yhoan , Raoult Nina , Bastrikov Vladislav , Peylin Philippe , Krieger-Liszkay Anja , Maignan Fabienne
Published: February 2023

Climate change is caused by the ever-increasing anthropogenic CO2 emissions and the resulting accumulation of carbon dioxide in the atmosphere, whose effects are so far mitigated by the oceanic and continental CO2 uptakes. The terrestrial sink is the most uncertain component of the global carbon cycle mainly because the gross primary production (GPP), which is the quantity of atmospheric carbon absorbed by plants through photosynthesis, is highly variable in time and space, and because the involved processes are complex. As photosynthesis is not directly measurable at a scale larger than the leaf, land surface modelers have been looking for large-scale proxies of GPP. Solar-induced chlorophyll fluorescence (SIF) estimates from satellite instruments have emerged as a promising resource to inform on the space-time distribution of GPP, and have been increasingly used over the last decade. However, numerous challenges remain to be addressed to acutely understand the SIF signal, and its relationship with plant photosynthesis, to be able to correctly exploit space-borne SIF retrievals to constrain GPP simulated by land surface models (LSMs). Notably, we still lack knowledge on the non-photochemical quenching (NPQ), which represents the third deactivation pathway of the light energy absorbed by chlorophyll pigments, alongside photochemistry and fluorescence. In this study, we focused on boreal evergreen needleleaf forests (BorENF), which cover 29% of the world's total forest area, and whose GPP budget is still debated. We took advantage of both passive and active fluorescence measurements to improve the representation of NPQ, SIF and GPP in the ORCHIDEE LSM. We first used active measurements taken at the Hyytiälä BorENF site on Pinus sylvestris trees, to separately model the sustained and reversible NPQ components. Indeed, it was previously documented that during winter such evergreen trees suppress photosynthesis and sustain molecular modifications of the photosynthetic chain allowing the dissipation of the excess energy absorbed as heat (sustained NPQ). The reversible NPQ occurs during growth season in response to environmental stress (e.g., excessive light or droughts). In a second step, we optimised several ORCHIDEE parameters related to NPQ, SIF and GPP representations, using data assimilation techniques. We performed a multi-variables and multi-sites approach, simultaneously assimilating in situ GPP estimates at nine BorENF FLUXNET sites and collocated SIF estimates from the TROPOMI satellite instrument. The improvements brought to SIF and GPP were evaluated at those sites over independent years (i.e. not used in assimilation) with positive results, and at the regional scale against the FLUXCOM and FLUXSAT GPP products, as well as against TROPOMI SIF data.
Machine Learning Parameterization for Super-droplet Cloud Microphysics Scheme
Authors: Sharma Shivani , Greenberg David
Published: February 2023

Machine learning approaches have been widely used for improving the representation of subgrid scale parameterizations in Earth System Models. In our study we target the Cloud Microphysics parameterization, in particular the two-moment bulk scheme of the ICON (Icosahedral Non-hydrostatic) Model.  Cloud microphysics parameterization schemes suffer from an accuracy/speed tradeoff. The simplest schemes, often heavy with assumptions (such as the bulk moment schemes) are most common in operational weather prediction models. Conversely, the more complex schemes with fewer assumptions –e.g. Lagrangian schemes such as the super-droplet method (SDM)– are computationally expensive and used only within research and development. SDM allows easy representation of complex scenarios with multiple hydrometeors and can also be used for simulating cloud-aerosol interactions. To bridge this gap and to make the use of more complex microphysical schemes feasible within operational models, we use a data-driven approach.  Here we train a neural network to mimic the behavior of SDM simulations in a warm-rain scenario in a dimensionless control volume. The network behaves like a dynamical system that converts cloud droplets to rain droplets–represented as bulk moments–with only the current system state as the input. We use a multi-step training loss to stabilize the network over long integration periods, especially in cases with extremely low cloud water to start with. We find that the network is stable across various initial conditions and in many cases, emulates the SDM simulations better than the traditional bulk moment schemes. Our network also performs better than any previous ML-based attempts to learn from SDM. This opens the possibility of using the trained network as a proxy for imitating the computationally expensive SDM within operational weather prediction models with minimum computational overhead. 
Controls of Andean valley-floor width
Authors: Tofelde Stefanie , Clubb Fiona J.
Published: February 2023

River-valley cross sections range from deeply incised gorges with narrow or no floodplains to wide valley floors of kilometer wide, densely populated plains. The diversity of valley geometries is the product of the interplay between tectonic uplift and erosion by rivers. Rivers deepen valleys through vertical incision into underlying bedrock or sediment deposits and widen valley floors by lateral erosion of enclosing valley walls. While the rate of incision is thought to mainly compensate tectonic uplift, comparably little is known about processes and controls of valley widening and valley-floor width. Due to this knowledge gap, we are currently unable to reproduce the wide range of valley shapes that we observe in nature and fail to predict valley floor and floodplain evolution under changing environmental conditions.Field measurements of valley floors are sparse, but generally indicate that valleys are narrower at sites of enhanced uplift and grow wider with greater river discharge and in softer lithologies. However, order of magnitude scatter in those datasets suggest further, so far unknown controls on valley-floor width. Here, we systematically quantify valley-floor widths of 82 river valleys draining the Western Andes between 5°S and 38°S. At each site, we estimate potential control parameters on valley-floor width including river discharge, rock erodibility, uplift rates, total sediment discharge, and lateral sediment supply from valley walls. The respective influence of each of these parameters on valley-floor widths is investigated using a random-forest approach. A better understanding of controls on valley-floor evolution will both enhance future prediction of floodplain response to climate change and enable past climate and tectonic reconstructions from valley topography.
Low-frequency modes in internal variability of surface solar radiation
Authors: Chtirkova Boriana , Folini Doris , Ferreira Correa Lucas , Wild Martin
Published: February 2023

We investigate potential reasons for decadal-scale internal variability of surface solar radiation (SSR) using model data from the Coupled Model Intercomparison Project - Phase 6. We compare unforced coupled atmosphere-ocean (piControl) to atmosphere-only (piClim) simulations with prescribed climatological sea surface temperatures (SSTs) to access the relevance of SSTs for unforced SSR inter-annual variability. Further, the connection between SSTs and known climate modes of variability is exploited. We focus on coupled and ocean-only modes of variability such as El Niño–Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO). Using the climate indices which describe these modes, we relate the SST field to SSR trends in different regions and we find a relationship between periods with strongly changing SSTs and decadal SSR depending on the regions. Unforced clear-sky SSR trends appear to mimic the SST trend pattern, while all-sky trends show a complex spatial structure with trends opposite in sign in different regions. These results are based only on pre-industrial control simulations (CMIP6 piControl) and can be used to infer in which direction internal variability has affected SSR in the historical period and whether it has enhanced or suppressed the anthropogenic signal from aerosols.
Heat mortality during summer 2022 in Switzerland attributable to human-induced climate change
Authors: Vicedo Cabrera Ana Maria , De Schrijver Evan , Ragettli Martina S. , Shumacher Dominik , Fischer Erich , Seneviratne Sonia
Published: February 2023

Fuelled by our changing climate, the summer of 2022 was one of the warmest on record, with numerous heatwaves and other weather extremes occurring around the globe. However, there is limited quantitative evidence on the contribution of human-induced warming to the weather-related health impacts observed in recent extreme weather events. We present a health attribution analysis of heat-related mortality attributable to human-induced climate change in the past summer of 2022 in Switzerland. We combined state-of-the-art methods in climate science and epidemiology with high-resolution mortality and temperature data to estimate the number and fraction of all-cause deaths that could be attributed to heat between June and August 2022. We, thus, estimated that 623 [95% CI: 151 - 1,068] all-cause deaths can be attributed to heat between June and August 2022, representing 3.5% [95% CI: 0.9-6.1] of total all-cause mortality during the same period. In a second step, we modelled counterfactual daily temperatures representing summer 2022 in absence of anthropogenic climate change. Specifically, four counterfactual daily mean temperature series were derived by subtracting the anthropogenic signal from the observed series which ranged between 1.19 and 2.75 ºC. Then, we quantified the hypothetical heat mortality burden in absence of climate change, and finally, estimate the contribution of climate change by subtracting it from the observed heat mortality impacts. We estimated that, in absence of an anthropogenic signal, the heat-related burden would have amounted to 1.4% [95% CI: -0.2 - 3.4] of all-cause mortality, corresponding to 253 deaths [95% CI: -27;594]. Thus, 2.1% [95% CI: 0.8 - 3.7] of the all-cause mortality in summer 2022 would have been avoided in absence of anthropogenic warming. This corresponds to 370 [95% CI: 133-644] deaths and 60% of the observed heat-mortality burden between June-August 2022. Females and the oldest age group were the most affected. Specifically, 60% of heat-related deaths attributed to climate change were in females (220 [69 - 393] vs. 150 [62 - 250] in males), and 90% in older adults (330 [129-565] vs. 39 [-5 - 84]). Our findings confirm that climate change is already affecting the health of the population in Switzerland by amplifying the heat-related mortality burden, with a stronger impact on females and older adults.
Operational evaluation of an industrial differential quantum gravimeter
Authors: Janvier Camille , Merlet Sebastien , Rosenbusch Peter , Ménoret Vincent , Landragin Arnaud , Pereira dos Santos Franck , Desruelle Bruno
Published: February 2023

We report on the recent progress on exail’s Differential Quantum Gravimeter (DQG). Developed by exail quantum sensors (formerly known as muquans). The DQG  measures the acceleration due to gravity and the vertical gravity gradient simultaneously. It is an industry-grade demonstrator that has been operational for three years now and has achieved state-of-the-art sensitivity mainly limited by Quantum Projection Noise down to a noise floor at about 40E/sqrt(tau) and a long-term stability better than 1E [1]. For gravity measurements the performances are on par or better than exail’s AQG with a sensitivity of 600nm/s²/sqrt(tau) and a stability down to 5nm/s². Measuring the acceleration of the Earth gravity g and the gravity gradient simultaneously and at the same location promises enhanced information on the distribution of underground masses, especially at shallow depths [2].In addition to survey measurements, we report on the DQG evaluation at the the LNE-Trappes characterized gravimetry laboratory near Paris [3]. A comparison to the gravity reference value has shown good agreement. The vertical gravity gradient measurement also compared favorably to the determinations obtained using a spring relative gravimeter both in terms of performance and in terms of ease-of-use.Finally, we present on-going instrumental developments that will be key to the design of more compact instruments. Such instruments will be the basis for the Horizon Europe project FIQUgS which aims at realizing field compatible commercial gravimeters as well as data processing tools. [1] C. Janvier, et al., “A compact differential gravimeter at the quantum projection noise limit”, Phys. Rev. A 105, 022801 (2022)[2] G. Pajot, O. de Viron, M. M. Diament, M. F. Lequentrec-Lalancette, V. Mikhailov, Geo-Physics 73, 123 (2008).[3] S. Merlet, et al., “Micro-gravity investigations for the LNE watt balance project” Metrologia vol 45 265 (2008) 
The effect of CaO and CaO+MgO on the viscosity of a phonotephritic melt
Authors: Giuliani Gabriele , Di Fiore Fabrizio , Valdivia Pedro , Mollo Silvio , Romano Claudia , Di Genova Danilo , Vona Alessandro
Published: February 2023

The assimilation of carbonate rocks by magmas can dramatically change their chemistry and differentiation path, thereby affecting the rheological properties of the derived products. Here we present a set of viscosity measurements exploring the effect of variable degrees of carbonate assimilation on the melt viscosity (η) of a phonotephrite from Vesuvius (Italy). We doped the starting material with different amounts (0, 10, and 20 wt.%) of CaO and CaO+MgO, mimicking the effects of limestone and dolomite assimilation, respectively. Through this approach, we focused on the composition change liquid phase, regardless of the effect of CO2 bubbles produced by the decarbonation on the rheological properties.The high and low temperature liquid viscosity of the decarbonated melts were measured by concentric cylinder viscometry (CC) and differential scanning calorimetry (DSC), respectively. Viscosity data show non-Arrhenian trends, well described by both Vogel-Fulcher-Tammann (VFT) and Mauro-Yue-Ellison-Gupta-Allan (MYEGA) equations. Trends obtained at high-T, low-η differ from those at low-T, high-η conditions. In the high-T regime, all decarbonated melts show lower viscosity than the pristine melt, the effect being more pronounced when only CaO is added. The opposite trend is observed in the low-T-regime, due to different fragility of the investigated melt.,The most recent predictive viscosity models well reproduce the high-T, low-η regime, whereas modeled data are less accurate in the low-T, high-η regime. This discrepancy is apparently caused by the lack of decarbonated melt (i.e., Si poor, Ca-Mg-rich compositions) in the calibration dataset of viscosity models.
Effects of Spacing Distance between Cylindrical Obstacles on Granular Shock Interactions in Gravity-Driven Experimental Flows
Authors: Wang Jian , Chen Zheng , Wang Dongpo
Published: February 2023

Gravity-driven geophysical granular flows, such as rock avalanches, landslides, debris flows, etc., interact with obstacles (e.g. bridge piers and buildings) as they flow down the slope, causing rapid changes in flow velocity and height in the vicinity to form a granular shock wave in front of the object. The interaction between shock waves will affect the granular-flow field near the obstacles. However, the complex physical processes make some challenges in understanding how the granular material behaves in the influencing area of shock-shock interaction.In this study, systematic chute experiments were performed with glass particles to investigate the dynamic interaction between granular flow and two circular cylinders with variable spacing distances. The pressure sensors were used to measure the impact pressure of the granular flow on the upstream cylindrical surfaces and a plate equipped flush with the chute bed. The accelerometers were mounted at the bottom of the plate to record seismic signals generated by the granular flow impacting on the bed as well as the cylinders. Flow velocities and depths were determined using an image processing method. The discrete element method (DEM) was utilized to construct a virtual model of the chute system and particles and to simulate the dynamic processes of granular flow interacting with the cylinders. The experimental and the DEM simulated results showed that bow shock waves were generated just upstream of the two cylinders and a granular vacuum zone was formed on the lee side of each cylinder, with the incoming flow velocity being significantly reduced in the granular-shock influencing area. As the spacing decreases, the two shock waves change from being independent to mutual interference. In addition, the effects of spacing distances on the shapes of the granular vacuum and bow shock waves were investigated by experiments and compared to the DEM results, showing a strong interaction between granular shocks. The pinch-off distance which is determined by the length of the granular vacuum also showed a dependence on the spacing distance of the cylinders, indicating a decreasing pinch-off distance with decreasing value of spacing. The impact pressures and acoustic signals generated by granular flow impacting on the chute bed and the surfaces of the cylinders in the shock influencing area for varying Froude numbers were also analyzed.In summary, the DEM simulations and the recorded signals are helpful to analyze the interaction between granular shock waves. The finding in present study may contribute to better understanding granular shock dynamics and may eventually in improving the design of the protective structure in hazard-prone area.
How much does Antarctic landfast ice affect coastal polynyas?
Authors: Pirlet Noé , Fichefet Thierry , Vancoppenolle Martin , Rousset Clément , de Lavergne Casimir , Mathiot Pierre
Published: February 2023

The coastal polynyas of the Southern Ocean play a crucial role in the formation of dense water and have an impact on the stability of ice shelves. Therefore, it is important to accurately simulate them in climate models. To achieve this goal, the relationship between grounded icebergs, landfast ice, and polynyas appears to be central. Indeed, grounded icebergs and landfast ice are the main drivers of coastal polynyas. However, we do not fully understand how much Antarctic landfast ice impacts coastal polynyas in the model. Moreover, at a circumpolar scale, there are no observations of grounded icebergs available. To address these gaps in knowledge, we conducted a study using the global ocean--sea ice model NEMO4.2-SI³ at a 1° resolution. We ran two simulations for the period 2001-2018, with the only difference being the inclusion or exclusion of landfast ice information based on observations. All other factors, including initial conditions, resolution, and atmospheric forcings, were kept the same. We then compared the results of these simulations with observations from the Advanced Microwave Scanning Radiometer (AMSR) to evaluate the performance of the new simulation. Our analysis allowed us to determine the extent to which prescribing the distribution of landfast ice and setting the sea ice velocity to zero on landfast ice regions influenced various aspects of the sea ice, such as polynyas, landfast ice, and sea ice distribution in the model. In the future, we plan to refine this technique by using higher resolution (1/4 degree) and testing more complex methods, such as assimilating icebergs and physical parameterization.
Internal architecture of the frontal part of subduction accretionary prism: the role of folding in brittle diffuse deformation
Authors: Remitti Francesca , Festa Andrea , Nirta Giuseppe , Barbero Edoardo , Mittempergher Silvia
Published: February 2023

Studies of the shallow part (Tmax< 150°C) of ancient and active prisms documents that ductile (e.g., folds), brittle and localized (e.g., faults) deformation, and diffuse deformation (e.g. scaly fabric), likely contemporaneous at the scale of geological time, may occur in the same outcrop. Moreover, the source areas of precisely located shallow slow earthquakes (downdip locating the transition from brittle to ductile deformation) span a range of depths from <1 to ~15 km below the seafloor, overlapping the temperature range of megathrust earthquake rupture in some convergent margins (e.g. Nankai and Japan Trench), and propagating up to the seafloor in other ones (e.g. Costa Rica). This implies that the shallow part of the accretionary prisms cannot be uniquely defined as characterized by ductile/brittle behavior or as prone to localization or de-localization of deformation.To better understand how deformation affects the frontal part of accretionary prisms, the general architecture and internal structure of the frontal part of accretionary prisms need to be considered.  Field evidence of the deformational structures occurring in the frontal part of active and ancient accretionary prisms from the mesoscale to the regional scale suggests that recumbent and isoclinal folding are frequent in the shallow part of accretionary prisms, developing in pre-lithification to poorly metamorphosed rocks. In this framework, diffuse scaly fabric and pervasive boudinage, traditionally considered as evidence of shear delocalization, could be alternatively seen as the result of the progressive deformation envisioned in literature for the formation of recumbent folds i.e.: buckling with the development of an overturned fold limb and subsequent kinematic amplification by coaxial strain components with vertical maximum shortening. However, the plethora of brittle structures accommodating the change in shape on the hinge and limbs of the folds, have a different distribution in space and accommodate a different strain than brittle fracture associated with faults and/or thick shear zone. Therefore, this interpretation has implications in terms of the distribution in space of brittle structures and in the distribution of shear strain in the frontal part of subduction zones.