bluuebunny/crossref_metadata_2025 huggingface dataset:
The age and sources of respired CO2 from soils of dominant land use types across Switzerland  
Authors: Minich Luisa , Moreno Duborgel Margaux , Geissbühler Dylan , Udke Annegret , McMackin Ciriaco , Wacker Lukas , Gautschi Philip , Egli Markus , Hagedorn Frank
Published: March 2024

Soil CO2 efflux is one of the largest C fluxes between terrestrial ecosystems and the atmosphere and originates from different sources such as rhizosphere respiration and the mineralization of various soil organic matter components. Alterations of soil respiration induced by environmental changes, such as climate and land use change, can thus affect atmospheric CO2 levels. Land use regulates soil CO2 fluxes and their source contributions through various factors such as vegetation type, root density, nutrient input, and management. Soil CO2 fluxes from different land use types are likely to vary in their susceptibility to climate change induced perturbations. However, a systematic comparison of the age and sources of the soil CO2 efflux between different land use types remains elusive. Isotopic techniques using radiocarbon (14C) and stable carbon (13C) represent a powerful approach to identify the sources of soil CO2 fluxes. In this study, we investigated how land use affects the age and sources of soil-respired CO2 across Switzerland and in different seasons by using radiocarbon and stable isotopic approaches.We measured in situ rates and isotopic signatures (14C, 13C) of soil-respired CO2 in summer and winter from 18 sites of six dominant land use types in Switzerland: forests, croplands, managed peatlands (original and covered with mineral soil), and grasslands (lowland and alpine). The sites vary in their physico-chemical soil properties and span a climatic as well as elevational gradient from 400 to 3000 m a.s.l. across Switzerland. We further disentangled source contribution (autotrophic vs. heterotrophic respiration) to total soil respiration for each site by separating 14C, and 13C signatures of CO2 derived from root and soil incubations.In summer, the age of in situ soil-respired CO2 increased from lowland grasslands towards alpine grasslands, forests, croplands, and peatlands. We attribute this pattern to an increase of the mean age of soil organic matter along this trajectory. Additionally, we assume a decreasing contribution of rhizosphere respiration from grasslands to forests and arable land. We found managed peatlands to be hotspots of old carbon release, with the respired CO2 being around 500 to 1500 years old. Grasslands released the most modern CO2, in the range of contemporary atmospheric 14CO2 levels. Within grassland sites, we observed an increased age of soil-respired CO2 with increasing elevation (lowland towards alpine) which we attribute to slower C turnover in alpine areas due to cooler climatic conditions. CO2 respired from forest soils originates from bomb-derived decadial old carbon, indicating a reduced turnover as compared to grasslands. Isotopic data of CO2 derived from soil and root incubations will provide insights into source contribution.
Seismic Precursor for the October 7th Terrorist Attack?
Authors: Inbal Asaf
Published: March 2024

Seismic waves excited by human activity frequently mask signals due to tectonic processes, and are therefore discarded as nuisance.  Seismic noise-field analysis is, however, a powerful tool for characterizing anthropogenic activities. Here, I apply this analysis to examine seismic precursors to the October 7 Hamas attack on Israel. The precursory activity in Gaza included massive mobilization which took place in the hours leading to the attack, and was  documented on multiple media outlets. Favourable conditions, which arise due to a temporary lack of anthropogenic activity in Israel, allow remote seismic stations to record signals due to Gaza vehicle traffic. I use these seismograms in order to identify anomalous ground-motions, associate them with pre-attack mobilization, and precisely determine their location. By applying array analysis to three seismic stations located tens-of-kilometers from the Gaza strip, I was able to obtain valuable information on the Hamas attack plans. This suggests that embedding seismic noise-field analysis into decision-making protocols could enhance preparedness, thus providing an opportunity to blunt terrorist attacks and reduce the number of casualties.
Accurate Inertial Earth Rotation Measurements
Authors: Schreiber Karl Ulrich , Kodet Jan
Published: March 2024

The complex interaction between the fluids of the Earth and the solid Earth results in small variations in the rotational velocity of the Earth at the level of ∆Ω ≈ 10e-8, which are not predictable. These signals are usually observed utilizing the GNSS constellation and the global IGS receiver network. Stability is provided by the VLBI technique. Inertial Earth rotation sensing, based on ring laser gyroscopes, is now capable of detecting these signals with high temporal resolution. Therefore it is important to closely examine the inherent accuracy of the utilized gyroscope technology. This presentation outlines the latest improvements in sensor operation, reviews some crucial sensor properties and puts them into perspective with the established techniques in space geodesy.
Early development of Argon-39 as a new geochronometer for geologic processes on short time scales
Authors: Neumann Franka , Arck Yannis , Gardner W. Payton , Schaefer Joerg , Singhateh Modou L. , Oberthaler Markus , Aeschbach Werner
Published: March 2024

Up until now, the cosmogenic radioisotope 39Ar has not been used for surface exposure or burial dating of minerals due to its low concentration in rocks and the large sample size requirements for its detection by low-level counting. The novel analytical method Atom Trap Trace Analysis (ATTA) – already well established for gas samples from groundwater, ocean water or ice cores – can measure the isotopic ratio of 39Ar to stable Ar in the range of 10-16 on just a few ml STP of argon and therefore opens up new possibilities for applying 39Ar.This talk will report on the initial steps taken towards using 39Ar as a geochronometer. Calculations of production rates of 39Ar in typical continental rocks, exposed to cosmic radiation at the Earth surface, show that sample sizes of the order of 100 g of rock should yield a sufficient number of 39Ar atoms (order 103 to 104) for detection by ATTA. However, the amount of 40Ar in such samples – and therefore the total extractable Ar amount - is much lower than what is typically extracted from ice and water samples, which contain atmosphere-derived Ar. The 40Ar content in rock stems from 40K-decay and depends on the rock formation age and the potassium content. Dilution with 39Ar-free Ar results in sufficient total argon volumes for the standard ATTA analysis.Gas extractions from heated rock samples indeed show 39Ar isotope abundances 2-3 orders of magnitude above the atmospheric ratio, well within the measurement range of ATTA after dilution. In order to check the feasibility of exposure dating of rocks, several samples were taken for comparison from boulders of glacier moraines, previously dated with 10Be, in the Jamtal valley in Austria. Additionally, 10Be-dated samples from other moraine sites are to be analysed for 39Ar for further validation of 39Ar as a tool for exposure dating. As of now it remains to be seen whether reliable agreement between the dating methods can be achieved. Due to its relatively short half-life of 268 years, 39Ar would be a useful addition in multi-tracer studies on geologic processes within the last two millennia.  
Terrestrial Carbon Flux Dynamics in the Southern American Temperate Region: Insights from Dynamic Global Vegetation Models and GOSAT XCO2 Measurements  
Authors: Vardag Sanam Noreen , Artelt Lukas , Metz Eva-Marie , Basu Sourish , Jung Martin , Butz André
Published: March 2024

Understanding terrestrial carbon fluxes is a prerequisite for accurately predicting the global biospheric uptake and release of CO2 under climate change and other environmental stressors. Terrestrial carbon fluxes in the southern hemisphere still exhibit quite large uncertainties due to limited measurements and a lack of comprehensive process understanding. This study focuses on the South American Temperate (SAT) region, employing various Dynamic Global Vegetation Model (DGVM) models (TRENDY v9) to investigate carbon flux dynamics. We find significant discrepancies between these DGVM models in terms of both phasing and magnitude. To address this, atmospheric XCO2 measurements from the Greenhouse Gases Observing Satellite (GOSAT) during the period 2009-2018 are incorporated into an atmospheric inversion using the model TM5-4DVar to obtain net CO2 fluxes. We identify DGVM models that match the inversion results, particularly showing the same phasing and similar magnitude of net ecosystem exchange (NEE) as the inversion results. The matching DGVMs show that the increase in NEE during the mid of the year is driven by an early increase in heterotrophic respiration whereas the autotrophic respiration remains in phase with the gross primary production (GPP) and is delayed with respect to heterotrophic respiration. The observed flux behavior is linked to the onset of rainfall in the semi-arid regions of SAT, resembling findings in Australia by Metz et al. (2023). We hypothesize that soil rewetting processes in semi-arid areas play an important role in constraining the global carbon budget and should be represented more accurately in global carbon cycle models to improve the estimation of the global carbon budget.   Metz, E.-M., Vardag, S.N., Basu, S., Jung, M., Ahrens, B., El-Madany, T., Sitch, S., Arora, V.  K., Briggs, P. R., Friedlingstein, P., Goll, D.S., Jain, A.K.,  Kato, E., Lombardozzi, D., Nabel,J .E. M. S., Poulter, B., Séférian, R., Tian, H., Wiltshire, A., Yuan, W., Yue, X., Zaehle, S.,  Deutscher, N.M.,  Griffith, D.W.T., Butz, A. Soil respiration–driven CO2 pulses dominate Australia’s flux variability. Science, 379, 1332-1335, https://doi.org/10.1126/science.add7833, 2023. 
Interplay between natural drivers and human activities in two Northern Adriatic lagoons
Authors: Piazza Angelica , Tognin Davide , Canesso Devis , Carniello Luca
Published: March 2024

Coastal wetlands are important transitional environments, providing several ecosystem services such as carbon sequestration, water filtration and habitat provision for diverse plant and animal species. At the same time, various human activities, such as fishing, aquaculture, tourism and industrial operations, are centred around coastal wetlands. Therefore, the morphological evolution of many coastal transitional systems is not only influenced by natural processes, namely tidal currents and wind waves, but also anthropogenic interventions have been playing a pivotal role in adapting the morphological features to meet the needs of human activities. For instance, extensive areas are usually confined by artificial levees for aquacultural activities, large channels are dredged and inlets are stabilized for navigation purposes. However, the long-term effects of these modifications on the morphological evolution of shallow tidal systems are still unclear and can potentially affect the ecosystem as a whole.The aim of this work is to investigate the consequences of natural and anthropogenic drivers on two back-barrier lagoons in the northern Adriatic Sea: the Venice Lagoon and Marano-Grado Lagoon. Despite sharing a similar microtidal regime and meteorological conditions, the morphology of these systems exhibits distinct characteristics. The Venice Lagoon is about 550 km2 and it is connected to the Adriatic Sea with three inlets. Its evolution has been strongly affected by human interventions, such as the construction of jetties at the inlets at the beginning of the 20th century, the excavation of navigable channels between 1930 and 1970 and, more recently, the installation of a storm-surge barrier system, named Mo.S.E., to prevent flooding of the city of Venice. Instead, the Marano-Grado Lagoon is smaller, covering an area of 160 km2, and it is relatively more pristine than the Venice Lagoon. It is connected to the Adriatic Sea with six inlets, of which only two were provided with jetties in the 20th century, and it experienced fewer modifications of channels for navigation purposes.We applied a 2D, finite-element model to describe the hydrodynamic flow field and the wind-wave generation and propagation in these two environments. The computational grids were built upon the most recent bathymetric survey available for each system, that is the 2017 survey for the Venice Lagoon and the 2011 survey for the Marano-Grado Lagoon. We then performed an extensive calibration of the model with water level and discharge data available. Results allowed us to investigate similarities and differences in the hydrodynamics of the two tidal systems, highlighting the effects of specific anthropogenic interventions on the ecosystems.
Exchangeable soil and sediment fractions compared
Authors: Sager Manfred
Published: March 2024

Soil to plant transfer depends on availability, plant needs and plant excretion. Readily soluble and exchangeable ions represent the minimum available fraction. Traditionally, different extracts have been standardized to monitor just one or two nutrients resp. trace elements. Whereas customers expect a “true value”, leachings with neutral salts lead to slightly different results. Some of the uncertainties are due to the low concentration levels, others due to resorption of reagent blanks at the solid matrix. Thus, the interpretation is of relevance, and not the numeric level.From the point of view of blanks and ICP-compatibility, ammonium salts or weak organic acids should be preferable extractants.Data from a ring test of 5 soils and 12 participants show widely overlapping data ranges of extracts obtained with ammonium acetate and ammonium nitrate, but a trend to lower release of Cd, Cu, Pb and Zn into nitrate versus acetate, contrary to Cr and Ni. This is expectable due to complexation capabilities of acetate.Also from sediments of the River Danube, 1M ammonium acetate released much more Pb, Zn, P, Ca, and Mn than 1M ammonium chloride at the same pH = 7. For Cr, Al, and As, however, this effect was rather reverse. The proportion of acetate versus chloride release did not significantly correlate with loss of ignition, nor with pedogenic of these samples. (The pedogenic oxides were calculated as the sum of Al+Fe+Mn released into oxalate buffer pH 3, and turned into their oxides).Is it possible, to substitute the fraction exchangeable with LiCl by much cleaner dilute acetic acid? The released amount into LiCl is quite low, and in non-contaminated samples, As, Be, Cd, Cr, Mn, Mo, Pb and V were below detection limits. There is resorption of Cr, Ni, Pb, Zn reagent blanks at the solid, and Li blanks at the ICP for subsequent determinations get reduced. In case of K, Mn, Ba, and B, a good correlation and for S and P a moderate one, had been achieved between concentrations extracted into LiCl and dilute acetic acid, but not for others.In order to optimum use of ICP-OES as a multi-element instrument, and to cope with decreasing manpower in the labs, the number of extractions should be minimized. Thus, it was tried to simulate the concentration of K and P by CAL extract, B by Baron-extract, and Mg by CaCl2-extract, by a simple (BCR-like) sequence of 0,16M acetic acid, with subsequent 0,1M oxalate buffer pH 3. This would widen the scope for acid exchangeable trace elements and S also. K, P and B could be very well simulated, and fitted to equal numeric values by partial correlation analysis with other parameters obtained, but for Ca-exchangeable Mg, this was difficult.
Shifting precipitation pattern during Indian summer monsoon
Authors: Sharma Akanksha , Dimri Ashok Priyadarshan
Published: March 2024

Precipitation has a significant degree of temporal and spatial variability over the Indian region. A small change in precipitation frequency and its distribution may affect agriculture and water resources and can lead to extreme events such as flood and drought. Number of precipitating days and their spatial distribution has significant impact on many aspects of the socio-economic environment. In present study, 91-days climatology is used to enhance robustness and to reduce uncertainty of the time series. Further, Mann Kendall trend test and Pettitt’s test for change point detection is used for analysis of the number of precipitating days and corresponding precipitation over India and its sub-regions. India Meteorological Department (IMD) gridded dataset and ERA5 reanalysis dataset having resolution 0.25° x 0.25° is used for the period 1902-2020 and 1940-2020 respectively. Our results show that there is a positive trend of number of precipitating days and precipitation over northwest and negative trend over central northeast and northeast India. Indicating a westward shift of precipitation during monsoon season. Change point analysis shows majority of these changes occur after 1970. Positive precipitation anomaly is observed in the month of September over India, with the exception of the hilly and central northeast showing extension of higher precipitation from month of July-August to July-August-September. This extension is probably due to the strengthening of wind during recent time (1971-2020) which brought more moisture to the Indian landmass. Furthermore, increased moisture transfer from the Bay of Bengal has also been seen compared to the early period (1940-1970). Overall, the results of this study will help in understanding the impact of climate change on Indian summer monsoon that will assist in policy making and adapting water management practices.
Interhemispheric teleconnections as drivers of Southern Hemisphere climate in simulations of spontaneous Dansgaard-Oeschger-type events
Authors: Trombini Irene , Weitzel Nils , Valdes Paul , Rehfeld Kira
Published: March 2024

Dansgaard-Oeschger (DO) events are a dominant mode of millennial-scale climate variability during the last glacial period. While the influences of DO events are most pronounced in the North Atlantic region, their impacts are detectable on the global scale. In Antarctica, their imprint primarily manifests as a muted and anti-phased response, which can be explained by the bipolar seesaw mechanism. However, the ice core record revealed an additional in-phase component, suggesting the presence of atmospheric teleconnections.Here, we study the propagation of DO-type signals from the North Atlantic to the Southern Hemisphere in a set of simulations with the general circulation model HadCM3, including an isotope-enabled run. The simulations show spontaneous DO-type oscillations under glacial boundary conditions, which allows studying the timing and interaction of atmospheric and oceanic processes under a continuously varying background state. Consistent with the ice core record, we find a muted and anti-phased temperature response over Antarctica that lags the North Atlantic by ~300 years, and global sea surface temperature patterns in agreement with the bipolar seesaw mechanism. Additionally, we identify a robust Southern Hemisphere mode in phase with the North Atlantic. This mode is associated with hydroclimate changes in the tropical Pacific, which modulate the Southern Hemisphere atmospheric circulation, and, thereby, impact Antarctic temperatures. Notably, the dominant millennial-scale circulation pattern exhibits zonal asymmetries that do not resemble the leading modes of inter-annual variability. Preliminary analyses indicate a good agreement of the simulated millennial-scale variability in oxygen isotopes with a global compilation of speleothem and ice core records.
Validation of an orographic source in a Lagrangian gravity wave parameterization
Authors: Jochum Felix , Achatz Ulrich , Chew Ray , Lott François
Published: March 2024

Many operational gravity wave parameterizations rely on the single column and steady state approximations, thus neglecting horizontal propagation and transience. Recent studies indicate that these assumptions can lead to faulty predictions, motivating the development of more complex models. MS-GWaM, a Lagrangian gravity wave parameterization that has been in development for about a decade, is one such model that is based on a multi-scale WKB theory allowing for both transience and horizontal propagation. So far, it has been validated mainly for non-orographic gravity waves, however, a simple orographic source has already been implemented in a test version of the model, which is coupled to a pseudo-incompressible flow solver (PincFlow). The present study investigates that source in an idealized setting. For this purpose, the model is adjusted to PincFlow's recently implemented terrain-following coordinate system. In addition, the orographic source is supplemented with a blocked flow drag and a wave amplitude reduction that accounts for blocked layer formation. These are derived from background flow tendencies and gravity wave momentum fluxes in highly idealized, wave-resolving simulations. The model is then tested against the latter, using both the transient configuration and a newly implemented steady state mode. The comparison shows that allowing for transience results in a more accurate forcing of the resolved mean flow, especially when the orographic source is changing in time.
Research on urban heat island effect based on concentric circle division of urban structure - Take the Beijing-Tianjin-Hebei and Shanghai metropolitan areas as examples
Authors: Zhang Xu , Roca Cladera Josep , Arellano Ramos Blanca
Published: March 2024

In 2015, Limin Jiao et al. used concentric circles and inverse S function curves to analyze the construction land density of 28 major cities in China and successfully divided the internal structure of urban areas. Based on this, this study takes  Beijing-Tianjin-Hebei core area (Beijing, Tianjin and Langfang) and  Shanghai metropolitan area (Yangtze River Delta region) as the research objects, analyze the changes in construction land structure and urban heat island effect from 2001 to 2020.It is feasible to use the Anselin local Moran I tool of Arcgis to analyze urban centers based on population density (Yingcheng Lia; Xingjian Liu, 2018). We established a fishing net analysis, and the grid with HH significant clustering (high population density surrounded by those of similar high densities) can be regarded as the center of the city. Then, concentric circles with a diameter of 1KM are established based on these center points, and the proportion of construction land in each circle is extracted. And use the inverse S function (Formula 1) to fit the extraction results. (1) The determination coefficient R2 of all fitting results is greater than 0.98, and the results are highly reliable. Then the fitted function is differentiated twice. The two extreme points correspond to the concentric radius of the inner city and the suburbs (R1, R2, and R1
Optimizing Water Storage in a Mediterranean Karst Aquifer: A Comprehensive Vadose and Phreatic Modeling Approach
Authors: Bresinsky Lysander , Kordilla Jannes , Livshitz Yakov , Sauter Martin
Published: March 2024

This study focuses on the role of karst aquifers in the Mediterranean Basin as a buffered storage of freshwater, especially considering the anticipated increase in drought periods due to climate change. Climate change underscores the need for innovative groundwater management approaches to maximize the storage capacity of these aquifers. This study emphasizes the importance of enhancing aquifer recharge during normal or high rainfall to mitigate the impacts of droughts. Notably, many karst aquifers in this region, which developed extensively during the lower base levels of the Messinian Salinity Crisis, exhibit a dual-domain flow pattern. This pattern consists of a slower flow through the rock matrix and a faster flow through conduits. Despite the rapid drainage of these mature karst systems, some, particularly those in the Mediterranean, are limited in their outflow to the sea by marine clay deposits, as highlighted by Bakalowicz (2015, Environmental Earth Sciences). These systems have shown a significant capacity for storage over several years.In our study, we applied dual-permeability flow modeling to evaluate the storage potential of the Western Mountain Aquifer in Israel and the West Bank. The model utilizes the volume-averaged Richards' equation and integrates a term to account for the characteristic preferential infiltration in karst aquifers, even under nearly dry conditions. The model includes phreatic and vadose zone flows to comprehensively assess the storage capacities of the aquifer comprehensively. The results indicate that despite its advanced karst development, the Western Mountain Aquifer possesses a notable long-term storage capability. This is attributed to its extensive vadose zone and the restricted outflow, which is constrained by surrounding and overlying low-permeability formations (such as the Talme-Yafe, Negba, Daliya, and Menuha Formations, composed mainly of chalk and marl). The study explores various infiltration sites for managed aquifer recharge and considers current and future climatic conditions based on the RCP4.5 climate change scenario.
Glacial-interglacial variability using a low-complexity, physically based model
Authors: Pérez-Montero Sergio , Alvarez-Solas Jorge , Montoya Marisa , Robinson Alexander
Published: March 2024

Pleistocene glacial-interglacial variability is still under debate, as the many hypotheses proposed are subject to the models used and assumptions made. The longer time scales involved in glacial cycles make it difficult to use comprehensive climate models because of its large computational cost. In this context, conceptual models are built to mimic complex processes in a simpler and more computationally efficient way. Here we present a conceptual climate-ice sheet model that aims to represent the state-of-the-art physical processes affecting glacial-interglacial variability. Our model was constructed using linear equations that explicitly represent ice-sheet modeling approaches. Preliminary results are consistent with Late Pleistocene variability and point to the existence of nonlinearities related to both ice dynamics and ice aging that determine the timing and shape of deglaciations.
Farmers’ preferences for reducing agricultural plastics: A discrete choice experiment among UK farmers.
Authors: Barrientos Manuel , Aftab Ashar , Scarpa Riccardo
Published: March 2024

Post-Brexit agricultural policy has generated an extensive range of new instruments to improve the sustainability of UK farming. However, none of these proposed policies deal with plastic pollution on UK farmlands. In this article, we use the UK's evolving policy context regarding farming payments to propose a monetary incentive whose environmental policy target is to change or reduce the use of -potentially harmful- agricultural plastics. We conducted a Discrete Choice Experiment among a sample of northern England farmers in which they considered two hypothetical Sustainable Farming Incentive (SFI) contract alternatives plus an opt-out alternative. The proposed SFI contracts include five attributes, including the contract length, the SFI payment, and three agricultural plastic-reducing actions: i) reduce the use of polymer-coated fertilizers, ii) reduce the use of plastic mulch film, and iii) reduce the use of silage films made only of virgin plastics. These actions can be accomplished at a lower, medium, and high level of compromise, and the payment varies with them. As agricultural plastics are essential for farm productivity, farmers are not asked to completely eliminate their use but replace them with more sustainable alternatives. Moreover, we used a within-farmers design to test the effect of a stringent enforcement strategy on their participation and willingness to accept SFI. We hypothesize relevant trade-offs between the contract's compromise level, the monetary payment offered, and farm and farmer-specific variables such as farm size, farming activities, and plastic and microplastic pollution awareness, among many others. Likewise, stringent enforcement may lead to a reduction in the stated participation and an increase in the monetary compensation needed to perform the indicated activities. This research may help develop incentive-compatible agricultural policies to reduce the usage of harmful agricultural plastics and improve our understanding of key factors explaining farmers’ adherence to new agri-environmental schemes in the UK.
High-resolution nested UA-ICON simulation compared to mesospheric observations of the NASA VortEx campaign at ALOMAR
Authors: Kunze Markus , Siddiqui Tarique , Zülicke Christoph , Stolle Claudia , Stephan Claudia , Strelnikova Irina , Baumgarten Gerd , Wing Robin , Gerding Michael , Borchert Sebastian
Published: March 2024

We carry out high-resolution nested simulations over Andøya (ALOMAR) with UA-ICON to compare and interpret observational data in the mesosphere collected during the NASA VortEx sounding rocket campaign in March 2023.We apply UA-ICON with 250 levels and a model top at 150 km at a global horizontal resolution of R2B7 (~20 km) with subsequent one-way nesting with nests at R2B8 (~10 km), R2B9 (~5 km), R2B10 (~2.5 km) and R2B11 (~1.25 km) horizontal resolution. For the global domain, the dynamic situation during the campaign is specified (specified dynamics, SD) by nudging to ECMWF operational analyses up to an altitude of 50 km. At the 1.25 km resolution, UA-ICON resolves a substantial fraction of the GW spectrum. Therefore, GW parameterizations are turned off at this resolution to isolate the effects of resolved GWs.The Rayleigh-Mie-Raman (RMR) lidars, operated by IAP in Kühlungsborn, Germany, and at ALOMAR on Andøya, Norway, support the VortEx campaign through observations of temperatures and winds up to about 80 km by providing detailed information about GW activity including vertical wavelengths.We present first comparison results between the high-resolution nested UA-ICON simulation and the RMR observations for the VortEx campaign in March 2023.The emphasis is on estimating the vertical energy spectra of resolved gravity waves for the different grid refinements, compared to vertical energy spectra from the lidar observations.
Variability and  trends of near-surface wind speed over the Tibetan Plateau: the role played by the westerly and Asian monsoon
Authors: Zhang Gangfeng , Azorin-Molina Cesar , A. Guijarro Jose , Minola Lorenzo , Ma Yaoyao
Published: March 2024

Near-surface wind speed over the Tibetan Plateau exerts profound impacts on many environmental issues, while long-term (> 50 years) trend and multidecadal variability in the wind speed and its underlying causes in the Tibetan Plateau remain largely unknown. Here, by examining homogenized wind speed data from 104 meteorological stations over the Tibetan Plateau for 1961-2020 and reanalysis datasets, we investigate the variability and long-term trend in the near-surface wind speed and reveal the role played by the westerly and Asian monsoon interaction. The results show that the homogenized wind speed declined ( -0.091 m s-1 decade-1, p < 0.05) annually, with the strongest trend in spring ( -0.131 m s-1 dec-1, p < 0.05), and the weakest trend in autumn (-0.071 m s-1 dec-1, p < 0.05). However, there is a distinct multidecadal variability of wind speed, which manifested in an abrupt increase in wind speed in 1961-1970, a sustained decrease in 1970-2002, and a consistent increase since 2002. The observed variations in NSWS over different studied periods are likely linked to interdecadal variations in atmospheric-ocean interactions, and the correlation analysis unveiled a more important role of background westerly and East Asian winter monsoon in modulating near-surface wind changes over the Tibetan Plateau when compared to East Asian summer monsoon and Indian summer monsoon. The potential physical processes associated with westerly and Asian monsoon changes are further examined, in terms of: (i) regional pressure gradient force (i.e., geostrophic wind speed); (ii) vertical thermal momentum transfer (i.e., atmospheric stratification thermal instability); (iii) vertical dynamic momentum transfer (i.e., vertical wind shear); and (iv) Tibet Plateau Vortices (TPVs). They all partly concord with wind change, which demonstrates, that to varying degrees, these processes are possible causes of near-surface wind speed changes over the Tibetan Plateau. 
Resilience Optimisation of Urban Water-Related Infrastructures under Multi-Risk Scenarios
Authors: Yang Zhuyu
Published: March 2024

Urban water management highly relies on a large number of related technical infrastructures. However, urban water management faces a severe challenge due to climate extremes' increased frequency and severity. Recent phenomena, such as droughts, heatwaves, storms, rising aquifers, or sea level rise, threaten the balance of water resources and cause potentially a functional degradation of water-related infrastructures. To understand how to act, more and more researchers suggest understanding the resilience mechanisms of these infrastructures. Unlike the concept of "vulnerability", which focuses on protecting infrastructure from hazards, "resilience" considers mainly the recovery of infrastructure functionality. It accepts hazards and transforms them into non-risk factors.Even though “resilience” today in the literature has a wide range of meanings, studies on the resilience of infrastructures aim to the development of more effective and sustainable actions for the cities under risk. The choice of possible actions for optimising resilience is varied and multidimensional. In applying a case study in Lyon, France, this study aims to identify potential actions for improving the resilience of urban water infrastructures under multi-risk scenarios. Among the related theories and methods, the “Behind the Barriers” model is chosen as the foundation of this study. This model is considered a theory that allows effective and comprehensive analysis of urban infrastructure resilience. In the model, urban systems are conceptualised as complex systems, and long-term impacts and connections with the external environment are considered to overcome the barriers of temporal, geographic, and dimensional limits. The results show that, under different risk scenarios, the resilience of water-related infrastructures could be optimised by improving cognitive, functional, correlative, and organisational capacities.
Residential green space and summer heat stress: a repeated cross-sectional study
Authors: Beele Eva , Aerts Raf , Reyniers Maarten , Somers Ben
Published: March 2024

Urbanization and global warming have led to the emergence of urban heat islands, profoundly impacting the liveability and long-term well-being of people living in cities. This study investigates the impact of urban green space composition and configuration on stress and sleep quality in Leuven, Belgium, during the summers of 2021 and 2022.Utilizing three validated stress questionnaires (PSS, PSQI, and HSSI), we assessed mental health, sleep quality and heat stress during 4 heat and 4 control events for 785 respondents. Concurrently, we recorded risk and vulnerability factors related to physical sensitivity, socio-economic sensitivity and personal living space for each respondent. Urban land cover data at 50m and 250m buffer scales were analysed using composition and configuration metrics. Structural equation models were employed to investigate the impact of urban green space on stress and sleep quality during both heat and non-heat control events. Models were adjusted for risk and vulnerability factors, and effectively dealt with spatial autocorrelation inherent in our data.During control events, mental health, sleep quality and heat stress were predominantly associated with risk and vulnerability factors. High physical sensitivity, elevated socio-economic sensitivity and suboptimal personal living spaces were associated with higher physiological stress, poor sleep quality, and higher heat stress. Conversely, during heat events, stress indicators were predominantly associated with the surrounding green space, while associations with risk and vulnerability factors were limited. Augmenting high green relative cover may mitigate heat stress, while increasing low green cover may alleviate both heat stress and enhance sleep quality. Stratified analyses for socio-economic status and distinct urban-rural regions revealed notable differences among subgroups.In conclusion, this study emphasizes the importance of incorporating both low and high green spaces to mitigate heat stress and improve sleep quality and therefore, human health, during heat events.
The shape of the active length vs streamflow relation in temporary streams
Authors: Durighetto Nicola , Botter Gianluca
Published: March 2024

River networks are not static entities, as they dynamically respond to the time-variant climatic conditions in the surrounding landscape. Over time, rivers change in both the streamflow Q, as the hydrograph continuously peaks and recedes, and active length L, as the temporary (i.e. non perennial) reaches wet up and dry down. As such, a correlation between L and Q has long been recognized in literature, starting with the first empirical studies dating back to 1968. More recently, a few conceptual frameworks have attempted to explain the physical processes that relate L with Q, showing how the shape of the L(Q) relation is determined by the spatial distribution of the subsurface transport capacity along the network (i.e. the maximum specific flow by unit contributing area delivered downstream in the hyporheic region). Knowing the functional form of the L(Q) relation can be useful in a number of ways, including the following: a) it creates a link between the temporal dynamics of L and Q, allowing one to exploit widely available streamflow datasets to study temporary streams; b) it gives information on invisible subsurface properties of the hyporheic zone; and c) it may provide more reliable predictions of the configuration of the active portion of the network during hydrological conditions that have not been observed yet.
In this contribution, we studied the shape of the L(Q) relation in 45 different catchments around the world, spanning a wide range of climates, geology, morphology, and catchment area. We found that L(Q) relations can be split in 3 main categories: a) generally increasing relations, b) relations showing a plateau for the higher values of Q due to the presence of a maximum potential network that can't be exceeded, and c) relations with a sigmoid shape, when the network length is constant for the driest hydrological conditions e.g. because it is fed by a local perennial source. We speculate that, in most cases, the presence of a plateau or sigmoid shape might not be visible in the data due to the limited number of observations for the relevant high and low flow conditions. For each catchment we also tested different functional forms for the L(Q) relation and selected 3 analytical forms that are best suited to fit the available data (exponential, gamma, power-law). The power law generally performed reasonably well, even though it overestimated L for the largest values of Q in those cases in which a maximum potential wet network is observed. In most cases, the exponential distribution described the plateau quite well but has a reduced performance for the lower flowrates. The gamma distribution, instead, shows the best performance in describing L(Q) relations in all categories. The proposed contribution aims at identifying new general patterns common to all temporary streams, creating new modelling tools that enable large scale studies and giving new tools for the effective monitoring of dynamic river networks.
Micro-porosity found in quartz shear bands from Ikaria, Greece: insights from Hyperspectral Cathodoluminescence and High-Resolution Electron Backscatter Diffraction
Authors: McGill Gina , Précigout Jacques , Prigent Cécile , Arbaret Laurent , Airaghi Laura , Wallis David
Published: March 2024

Extensive micro-porosity can be found in numerous examples of quartz-rich mylonites deformed in crustal shear zones, but whether or not deformation is involved in the production of such pores remains a matter of active debate. The occurrence of syn-kinematic micro-scale porosity could result in overall changes in rock strength, as well as potentially generating a deep permeability. This would have major implications for fluid-rock interactions, earthquake nucleation and ore deposits. In this study, we focus on micro-pores occurring in quartz-rich shear bands from mylonitic granitoids which outcrop in Ikaria (Cyclades, Greece). Related to the back-arc geodynamics of the Aegean domain during the Miocene, this granitic body intruded the Cycladic basement during active detachment faulting, which has led to heterogeneous deformation of the pluton. While the granite exhibits large-scale levels of strain, increasing with proximity to the detachment fault, quartz-rich shear bands develop as a result of viscous strain localisation, giving rise to S-C structures. Micro- (to nano-) pores occur in pure quartz aggregates of these shear bands, where micro-structural features indicate dominant crystal plasticity, mostly recovering by subgrain rotation.Based on five samples collected at different distances from the detachment fault, we performed microprobe-based hyperspectral cathodoluminescence and electron backscatter diffraction (EBSD) to characterise the micro-pores in pure quartz aggregates. In cathodoluminescence maps, parent and recrystallized quartz grains produce blue (420 nm wavelength) and yellow (650 nm wavelength) signals respectively. Furthermore, both parent and recrystallised grains exhibit a distinct increase in luminescence at 650 nm, which appear visually as very bright yellow rims/halos at their grain boundaries and, to a minor extent, at their subgrain boundaries. Using high-resolution and standard EBSD, we highlight high (to very high) geometrically necessary dislocation densities that partly coincide with such rims/halos, particularly where micro-pores are described. Most of the dislocations that may contribute to these high densities are related to the main dislocation slip system of quartz (prism ), as deduced from from lattice preferred orientation and subgrain analyses. Our findings, therefore, suggest that highly luminescent "yellow" boundaries of quartz grains result from dislocation accumulation, and hence, from crystal plasticity, which can be linked to the production of micro-porosity in these rocks. 
Tidal Dissipation in a Partially Molten Asthenosphere on Io
Authors: Hay Hamish , Katz Richard , Hewitt Ian
Published: March 2024

The rocky Jovian moon, Io, exhibits global volcanism that is driven by heat dissipated by tidal deformation. The large rate of heat exported by this volcanism, in conjunction with evidence in the form of magnetic induction, suggests that the mantle may contain a significant fraction of partial melt. This melt may be present in regions where both solid and liquid coexist at the macroscale. Nevertheless, existing models to investigate the location and magnitude of tidal heating consider an internal structure consisting of layers of pure solid or liquid. Such models are not appropriate for tidal deformation of partially molten materials. Building upon recent advancements in the theory of gravitational poroviscoelastic dynamics, we model tidal heating within Io, taking into account the effect of a two-phase, partially molten asthenosphere. The solid regions are modelled as a Maxwell viscoelastic material, and the top and bottom of the asthenosphere are treated as impermeable boundaries. We find that tidal dissipation within the fluid-filled pores depends on the ratio of the asthenosphere’s permeability to the melt’s viscosity. Thus, a low-viscosity melt and highly permeable pore-network favour enhanced tidal dissipation within the fluid. When this ratio, representing the Darcy drag, is large enough, fluid dissipation can exceed that within the solid grains when solid viscosity is high (> 1017 Pa s) or ultra-low (< 1011 Pa s). Tidal dissipation by the pore-hosted melt exhibits its own distinct tidal heating pattern, which always produces enhanced heating towards low latitudes.
An ADCP large-scale international intercomparaison: Sault-Brénaz 2023
Authors: Despax Aurélien , Calmel Blaise , Le Coz Jérôme , Hauet Alexandre , Mueller David
Published: March 2024

In the last decades, Acoustic Doppler Current Profilers (ADCP) has become the most widely used tool for measuring discharge of rivers and canals. Discharge is a key information for many risk studies, structures dimensioning and even impact assessments. These values must therefore be correctly estimated. Quality assurance and quality control (QA/QC) procedures have been established to ensure that hydrological services share the best practices. Also, to ensure that ADCP tools are working properly, services has to regularly check that the equipment is properly calibrated.The lack of references value most of the time makes the task difficult. To make sure that ADCP is properly calibrated, interlaboratory testing are frequently organized. Large-scale intercomparaisons are particularly interesting because of the diversity of models and practices but it also makes them more complicated to organize. The Sault-Brénaz intercomparaison was definitively a big one with more than 120 European participants with 16 RiverPro, 15 M9, 15 StreamPro and 12 RS5 for a total of 160 measurements with 1870 transects among 4 sessions. Due to hydrological conditions, the protocol had to be adapted. Measurements took place on small straight canal of the Rhone river with a discharge of around 2m3/s.Following QA/QC procedures, participant had to post-process their data with the QRevInt open-source software. QRevInt provides many quality filters and computes uncertainty following OURSIN method. Then, to compute interlaboratory results, the QRame software has been used. This open-source software has been developed to apply QRevInt with default settings to a set of ADCP discharge measurements and to retrieve post-processed discharge and uncertainty results. When the dataset is actually an ADCP interlaboratory experiment, the empirical discharge uncertainty, for a given number of transects taken in the average, can be computed by application of the standard interlaboratory method.Results show that discharge varied slightly over time, particularly between sessions. To exploit further all the discharge results, different approaches to homogenizing data were tested. This issue of varying discharge over time is a common issue for interlaboratory experiments. A generalizable solution would enable experiments in extended conditions. Also, interlaboratory experiments permit to validate uncertainty computations. The greater the number of intercomparisons and the wider the measurement conditions, the more robust uncertainty models will be.