bluuebunny/crossref_metadata_2025 huggingface dataset:
Mapping forest temperature buffering from LiDAR
Authors: Senf Cornelius , Vandewiele Michiel
Published: February 2023

Ecological research on the responses of biotic systems to climate change is largely based on coarse-gridded climate data, derived from standardized meteorological weather stations. These stations measure temperatures in open areas at 1.2 to 2 m above ground covered by short grass, thus measuring macroclimatic conditions. Those macroclimate conditions are, however, not representative for the microclimates most organisms experience. In closed canopy forests, for instance, hot and cold temperature extremes are buffered by several degrees and forests thus provide microclimatic shelters for many forest-dwelling species under climate change. Yet, with increasing forest disturbances opening up forest canopies globally, the future buffering capacity of forests remains uncertain. We aim at closing this knowledge gap by modelling the temperature buffering capacity of forests from remote sensing data. Models were based on boosted regression trees and a set of forest structural and topographic predictors derived from an airborne LiDAR acquisition. Buffering capacity was estimated from in situ microclimatic loggers across 150 plots and a network of meteorological weather stations in the Berchtesgaden National Park – a 20,000 ha landscape located in southern Germany. Spatial models of temperature buffering yielded high predictive accuracies, ranging from R2=0.62 to R2=0.74 depending on the month of observation. Forest structure was consistently more important than topography in explaining temperature buffering. Spatial predictions of temperature buffering revealed a clear elevational gradient, with less buffering in higher-elevation forests (open canopy structures) compared to low-elevation forests (mostly closed canopies). We also found strong variation in temperature buffering over the successional trajectory, with no or even inverted buffering in disturbed sites and a recovery of the buffering capacity within 30 years after disturbance on most sites. Our results will help better understanding the impacts of climate change on forest dwelling species by improving species distribution models and other models of key life history traits. Our approach further provides the ability to be expanded to other regions.
Trace element- and Pb isotope fingerprints of natural vs. anthropogenically induced geochemical changes in tropical lake catchments: A case study from lake Naivasha, Kenya
Authors: Rosca Carolina , Junginger Annett , Kübler Simon , Schoenberg Ronny
Published: February 2023

Continuous lake sediment archives integrate valuable information of geodynamic transformations, climatic fluctuations and anthropogenic environmental forcing through time. In many parts of the world, such as sub-Saharan Africa, lake ecosystems are important pillars of biodiversity and wildlife preservation and evolution, as well as political and economic stability, especially with regard to the rapid population growth and increasing food and water demand.Located in the central part of the rift valley region, lake Naivasha is the second largest freshwater lake in Kenya, covers a catchment area of ca. 3400 km2 and is considered a “wetland of international importance” (RAMSAR convention, 2011). Previous studies and real-time observations documented a rapid intensification of agricultural activities ranging from subsidy economy (upper catchment) to industrial-sized horticulture practices (lower catchment) from the second half of the 20th century towards the present. These were suggested to have significantly influenced the drainage systems of the catchment and hydrochemistry of the lake, with potentially negative effects on the entire ecosystem. In addition, potential anthropogenic metal influx from other modern, diffuse sources (such as fossil fuel combustion) due to the increasing anthropogenic density and activities in the immediate vicinity of the lake remain poorly constrained.We analysed major- and trace elements and Pb isotope compositions of lake sediments covering the past ca. 150 years, as well as the surrounding lithologies in order to reconstruct the pathway(s) and source(s) of elemental influx and accumulation into the lake. The characterization of the geological background in this tectonically and volcanologically active region was primarily set on the northern part of the catchment where, the two main lake-feeding rivers Malewa and Gilgil discharge into the lake. Element correlation indices point to i) a strong influence of the local geological background and, ii) a relatively stable catchment for this time-period as seen from sub-parallel REE+Y patterns along the monolith. Lead isotope compositions, on the other hand, show more radiogenic values in the sediment deposited before the 1900’s (206Pb/204Pb: 19.502 – 19.546) and a significant shift towards less radiogenic isotopic ratios from the second half of the 20th century (206Pb/204Pb: 19.228 – 19.304), which persists towards the top of the core. We combine our extended geochemical data with geospatial projections of the land use to build a time-integrated cause-and-effect assessment of metals into lake Naivasha and disentangle the cause for the change in the Pb isotope composition.
A new satellite-based product for studying land-atmosphere interactions
Authors: Peng Jian , García-García Almudena
Published: February 2023

Information about the energy and water exchanges between the land surface and the lower atmosphere (i.e. land-atmosphere interactions) is necessary for example to improve our understanding of the effect of land-atmosphere interactions on the exacerbation of temperature and precipitation extremes. Observations of energy and water fluxes at the land surface usually rely on the eddy covariance method. There is a wide network of these measurements providing data over all continents but with large spatial gaps in Africa, Asia, South America and Oceania. Additionally, other problems are associated with these observational methods such as the energy and water balance non-closure. To improve the spatial coverage of land-atmosphere interactions data considering the energy and water balance closure, we explore the combination of remote sensing data and a physical-based model. The High resOlution Land Atmosphere Parameters from Space (HOLAPS) framework is a one dimensional modelling framework that solves the energy and water balance at the land surface using remote sensing data and reanalysis products as forcings. Preliminary results from the evaluation ofHOLAPS outputs over Europe at 5 km resolution show an improvement in the simulation of latent heat flux when using remote sensing data in comparison with results using only reanalysis data as forcing. Additionally, we see a moderate improvement in HOLAPS latent heat flux estimates against energy-balance corrected eddy covariance measurements in comparison with other products that solve the energy and water balance equations, such as the ERA5Land product. The new HOLAPS product is available at hourly resolution for the period 2001 to 2016 and these estimates can be useful for agriculture and forest management activities and to evaluate the representation of land-atmosphere feedbacks in weather and climate models.
A multi‐source remote sensing technical framework for wide-area landslide detection
Authors: Li Zhenhong , Zhang Chenglong , Chen Bo , Du Jiantao , Ding Mingtao , Zhu Wu , Song Chuang , Yu Chen , Zhan Jiewei , Peng Jianbing
Published: February 2023

Landslides pose a destructive geohazard to people and infrastructure that results in hundreds of deaths and billions of dollars in damages every year. China is one of the countries worst affected by landslides in the world, and great efforts have been made to detect potential landslides over wide regions. However, a recent government work report shows that 80% of the newly formed landslides occurred outside the areas labelled as potential landslides, and 80% of them occurred in remote rural areas with limited capability of disaster prevention and mitigation. In this presentation, a multi‐source remote sensing technical framework is demonstrated to detect potential landslides over wide regions.
Subseasonal fire forecast in the Amazon using week-2 precipitation forecast combined with a vegetation health indicator
Authors: Fernandes Katia , Bell Michael , Muñoz Ángel
Published: February 2023

Numerical predictions for a lead time of 2 to 4 weeks, a timescale known as subseasonal, has only in recent years begun transitioning from research to operational settings. One experiment dedicated to that effort is the Subseasonal Experiment (SubX). In here, SubX multi-model ensemble (MME) mean precipitation forecast (2017-2021) for days 8 to 14 (week-2 forecast) is used as a covariate in logistic regression models to predict fire risk in the Amazon. The hybrid (dynamical and statistical) modelling approach describes the NextGen methodology aimed at improving forecast outcomes at the seasonal and subseasonal time scales. In a complementary experiment, a vegetation health index (VHI) is added to SubX precipitation forecasts as a predictor to fires. The findings show that fire risk can be skillfully assessed in most of the Amazon where fires occur regularly. In some sectors, SubX week-2 precipitation alone is a reliable predictor of fire risk, but the addition of VHI results both in (i) a larger portion of the Amazon domain with skillful forecasts and; (ii) higher skill in some sectors. The added information provided by VHI as a predictor is most relevant where the mosaic of land covers includes savannas and grassland, whereas SubX precipitation can be used as the sole predictor for week-2 fire risk forecast where the mosaic of land cover is dominated by forests. The operationalization of the methods presented in this study could allow for better preparedness and fire risk reduction in the Amazon with a lead time greater than a week.
Last ca 2500 Yr history of the harmful algal blooms in the South China reconstructed based on the sediment record of the organic-walled dinoflagellate cysts
Authors: Anastasia Poliakova
Published: February 2023

Harmful algal bloom (HAB) is a known negative phenomenon that can result in a series of deleterious effects, such as beach fouling, paralytic shellﬁsh poisoning, mass mortality of marine species and a threat to human health, especially if toxins pollute drinking water or occur near by the public resorts. In the South China the problem of HABs has an ultimately important meaning. For this study, we used a 1.5 m sediment core LX-2018-2 collected from the Zhanjiang Mangrove National Nature Reserve (109°03´E, 20°30´N), Guangdong Province, South China. High-resolution coastal environment reconstruction with a specific focus on the HABs history during the last ca 2500 yrs was attempted. Age control was performed with the five radiocarbon dates obtained from benthic foraminifera. A total number of 71 dinoflagellate cyst types was registered. The most common types found consistently throughout the sediment sequence were autotrophic Spiniferites spp., Spiniferites hyperacanthus and S. mirabilis, S. ramosus, Operculodinium centrocarpum sensu Wall and Dale 1966, Polysphaeridium zoharyi, and heterotrophic Brigantedinium ssp., cyst of Gymnodinium catenatum and cysts mixture of Protoperidinium. Three local dinoflagellate zones LX-1 to LX-3 were established based on the results of the constrained cluster analysis and data ordination; additionally, the middle zone LX-2 was derived into two subzones, LX-2a and LX-2b, based on the dynamics of toxic and heterotrophic cysts as well as on the significant changes (probability, P=0.89) in percentages of eutrophic indicators. The total cyst count varied from 106 to 410 cysts per slide with 177 cyst types on average. Dinocyst assemblages were characterized by the high values of the post-depositional degradation index (kt) that varies between 3.6 and 7.6 (averaging 5.4) which is relatively high and typical for the areas with selective dinoflagellate cyst preservation that is related to bottom-water oxygen concentrations.
Structural architecture of the western Greater Caucasus pro-wedge: A case study from the Rioni foreland fold-and-thrust belt
Authors: Giorgadze Anzor , Alania Victor , Busch Benjamin , Enukidze Onise , Quandt Dennis , Pace Paolo , Razmadze Alexander , Shikhashvili Tamar
Published: February 2023

The Rioni foreland fold-and-thrust belt which is part of the western Greater Caucasus pro-wedge is located between the Lesser Caucasus and the Greater Caucasus orogens and is one of the most important examples of the collision-driven far-field deformation of the Arabia-Eurasia convergence zone (Alania et al., 2022). The Rioni foreland fold-and-thrust belt sedimentary infill consists of pre-and syn-orogenic sequences. Moreover, recent GPS and earthquake data indicate that the Rioni foreland fold-and-thrust belt is still tectonically active and the earthquakes’ focal mechanisms are mainly thrust faults (e.g., Tibaldi et al., 2017; Tsereteli et al., 2016).Fault-related folding and wedge thrust folding theories were used to interpret 2D depth-migrated seismic reflection profiles and to construct the regional balanced and restored cross-sections across Rioni foreland fold-and-thrust belt. The balanced cross-section is approximately parallel to the trust transport direction and has a total length of 64 km. On the other hand, the amount of shortening obtained for this part of the regional balanced cross-section is 40% (-42.78km).The main style of the deformation within the thin-skinned Rioni foreland fold-and-thrust belt is represented by a set of growth fault-propagation folds, duplexes, triangle zone, and a series of thrust-top basins. The evolution of the trust-top basins was mainly controlled by the kinematics of thrust sequences and competing growth fault-propagation folds and building compressional structures of the Rioni foreland fold-and-thrust belt was governed by the Greater Caucasus basement crustal-scale duplexes propagation along detachment horizons within the cover-generating thin-skinned structures.Acknowledgment: This work was supported by Shota Rustaveli National Science Foundation (SRNSF) [Structural model of the Rioni foreland fold-and-thrust belt and the Southern Slope of the Greater Caucasus (The Tekhuri river gorge area) Grant #: PHDF-21-087]References:Alania, V., et al. (2022). Deformation structural style of the Rioni foreland fold-and-thrust belt, western Greater Caucasus: Insight from the balanced cross-section. Frontiers in Earth Science, 10:968386.Tibaldi, A., et al. (2017). Active inversion tectonics, simple shear folding and back-thrusting at Rioni Basin, Georgia. Journal of Structural Geology 96, 35-53.Tsereteli, N., et al. (2016). Active tectonics of central-western Caucasus, Georgia. Tectonophysics 691, 328-344.
Update on the Interstellar Mapping and Acceleration Probe (IMAP) Mission
Authors: McComas David
Published: February 2023

This talk provides an overview of the Interstellar Mapping and Acceleration Probe (IMAP), what we hope and expect to learn from it, and where we are in the development of the mission. IMAP is currently in Phase C and is slated to launch in early 2025. IMAP simultaneously investigates two of the most important and intimately coupled research areas in Heliophysics today: 1) the acceleration of energetic particles and 2) the interaction of the solar wind with the local interstellar medium. IMAP’s ten instruments provide a complete set of observations to simultaneously examine the particle injection and acceleration processes at 1 AU while remotely dissecting the global heliospheric interaction and its response to particle populations generated through these processes. For more information about IMAP, see McComas, D.J. et al., Interstellar mapping and acceleration Probe (IMAP): A New NASA Mission, Space Science Review, 214:116, doi:10.1007/s11214-018-0550-1, 2018.
Scaling of Free Subduction on a Sphere
Authors: Ribe Neil , Chamolly Alexander , Gerardi Gianluca , Chaillat Stephanie , Li Zhong-hai
Published: February 2023

Because Earth's tectonic plates are doubly curved shells, their mechanical behavior during subduction can differ significantly from that of flat plates. We use the boundary-element method (BEM) to study free (gravity-driven) subduction in axisymmetric and 3-D geometry, with a focus on determining the dimensionless parameters that control the dynamics. The axisymmetric model comprises a shell with thickness h and viscosity η1 subducting in an isoviscous planet with radius R0 and viscosity η2. The angular radius of the trench is θt. Scaling analysis based on thin-shell theory reveals two key dimensionless parameters: a `flexural stiffness' St = (η1/η2)(h/lb)3 that is also relevant for flat plates, and a new `dynamical sphericity number' ΣD = (lb/R0)cotθt that is unique to spherical geometry. Here lb is the `bending length', or the sum of the lengths of the slab and of the seaward flexural bulge. The definition of ΣD implies that the dynamical effect of sphericity is greater for small plates than for large ones; we call this the `sphericity paradox'. By contrast, the purely geometric effect of sphericity is opposite, i.e. greater for large plates than for small ones. The dynamical and geometrical effects together imply that sphericity significantly influences subduction at all length scales. We confirm the scaling analysis using BEM numerical solutions, which show that the influence of sphericity on the slab sinking speed (up to a few tens of percent) and on the hoop stress (up to a factor of 2-3) is largest for small plates such as the Juan de Fuca, Cocos and Philippine Sea plates. We next study a 3-D model comprising a plate bounded by a ridge and a semicircular trench subducting in a three-layer earth consisting of an upper mantle, a lower mantle and an inviscid core. We examine the linear stability of the shell to longitudinal perturbations corresponding to buckling, and determine a scaling law for the most unstable wavelength that we compare with the observed shapes of northern/western Pacific trenches. 
Cenozoic inversion of the Lower Jurassic Beni Bassia Basin in the Eastern High Atlas (Morocco): effect of the right lateral transpression along the South Atlas Fault Zone (SAFZ)
Authors: Es-sabbar Ismail , Amrouch Khalid , Soulaimani Abderrahmane , Skikra Hamza
Published: February 2023

The intracontinental High Atlas Mountains are the result of multiple tectonic events, from Late Permian-Early Mesozoic Pangea breakup to Cenozoic Africa-Eurasia convergence. Prior to the Cenozoic inversion event, the South Atlas Fault Zone (SAFZ), which surrounded the High Atlas from the south, witnessed for the growth of multiple basins during the Liassic rifting in the eastern segment of the belt. The present work aims to shed light on the development of the Beni Bassia Liassic basin through two faults components of the SAFZ, the E-W J. Amalou faulted anticline (ridge) and Garn Talou fault from the South. Preliminary investigations based on the combination of field data and satellite images reveal significant results regarding the evolution of the basin. In the Beni Bassia Basin, the Ouchbis-Pleinsbachian Formation is an alternating layer of conglomerate limestones and marls, containing olistoliths over 10 meters in length, resulting from the destruction of the underlying platform of the Idikel-Sinemurian Formation. This huge breccia developed at the foot of steep faults on the southern margin of the basin, during the acceleration of the Liassic rifting. During the Cenozoic deformation and uplift of the Eastern High Atlas, bedding directions of Jurassic formations denote progressive changes from E-W in the northwestern to approximately NW-SE to N-S in the southeastern part of the basin. Similarly, the dip direction changes from dipping towards the south to dipping southwest to westward, indicating a dextral movement due to NNW-SSE regional shortening driven by the plates convergence. Other smaller-scale structures confirm dextral transpression kinematics at several places east of the High Atlas, including easterly detachments recorded in Lower Jurassic carbonates. Further investigations are planned to quantify the stress, strain and mechanisms involved in the configuration of the Liassic basin and the subsequent Cenozoic transpression.Keywords: Eastern High Atlas, South Atlas Fault Zone, Beni Bassia Basin, Jurassic, Inversion, Transpression.
SODAR observations and model simulations of the wind field structure in the atmospheric boundary layer at Severnaya Zemlya (Siberia) during YOPP
Authors: Heinemann Günther , Drüe Clemens , Makshtas Alexander
Published: February 2023

Measurements of the atmospheric boundary layer (ABL) structure were performed for three years (October 2017–August 2020) at the Russian observatory “Ice Base Cape Baranova” (79.280° N, 101.620° E) using SODAR (Sound Detection And Ranging). These measurements were part of the YOPP (Year of Polar Prediction) project “Boundary layer measurements in the high Arctic” (CATS_BL). ABL measurements and near-surface observations were used for verification of the regional climate model COSMO-CLM (CCLM) with a 5 km resolution for 2017–2020. The SODAR showed a topographical channeling effect for the wind field in the lowest 100 m. The verification of the CCLM with near-surface data of the observatory showed good agreement. The comparison with SODAR data showed a positive bias for the wind speed of about 1.0-1.5 m/s. The CCLM data showed the frequent presence of low-level jets (LLJs) associated with the topographic channeling. Although SODAR wind profiles are limited in range and have a lot of gaps, they represent a valuable data set for model verification. However, a full picture of the ABL structure and the climatology of channeling events could be obtained only with the model data. LLJs were detected in 37% of all profiles and most LLJs were associated with channeling, particularly LLJs with a jet speed ≥15 m/s (which were 29% of all LLJs). The analysis of the simulated 10m wind field showed that the 99%-tile of the wind speed reached 18 m/s and clearly showed a dipole structure of channeled wind at both exits of Shokalsky Strait. The climatology of channeling events showed that this dipole structure was caused by the frequent occurrence of channeling at both exits. Channeling events lasting at least 12 h occurred on about 62 days per year at both exits.
Flow differentiation in dykes and sills NOT limited by intrusion width
Authors: Koenders Curt , Petford Nick
Published: February 2023

Dispersive grain pressure (Bagnold, 1954) is commonly used to explain the observed axial concentrations of phenocrysts in dykes and sills via flow differentiation (Komar, 1972). The idea was formulated for particle fractions exceeding 0.13 by volume. A dispersive pressure is proposed that is greatest near the intrusion walls, forcing crystals to move inward, towards the centre of the magmatic flow where shear strains are low. However, Barriere (1979) argued that this phenomenological ‘Bagnold effect’ should be confined only to narrow (<<100 m) wide intrusions. His reasoning was that in larger channels, the wall effect driving the dispersive pressure diminishes swiftly, nullifying the dispersive pressure. This is true where the relevant length scale of the problem scales with the ratio W/d, where W is the full channel width and d is particle diameter.Here we show that for congested magma (0.5 > Φ > 0.8), with the rheology decomposed into scalar and vector components, particle fluctuations (in velocity) are dependent critically on the distance gap (h) between nearest neighbour that imparts a particle pressure. Thus, the critical ratio becomes d/h. It is fluctuations in the interparticle gap distance arising during shear in the flowing suspension that causes migration, irrespective of the channel width. We show that for a fixed particle size, d/h scales with crystal fraction (Φ) and the migration effect is enhanced as W/d increases.   We focus here on particle (crystal) migration as opposed to segregation or particle size sorting, although the latter are both amenable to analysis through modifications to our mathematical model.    Flow differentiation via particle migration is likely to be just as effective in wider channels (W >> 100m) than in narrow ones, eliminating the need to invoke other fluid dynamical or thermal explanations (convection, multiple intrusion, gravitational settling) to explain the central concentration of phenocrysts in dykes and sills exceeding several metres in width.  As the (multiphase) migration effect exerts a strong control on both magma rheology and composition, flowage differentiation as a mechanism for compositional variation during magma emplacement in large intrusions is open for re-evaluation.  ReferencesBagnold, RA, (1954). Experiments on gravity-free dispersion of large solid spheres in a Newtonian fluid under shear. Proc. Roy. Soc. London 225, 49-63.Barriere, M, (1976). Flowage differentiation: limitation of the Bagnold effect to the narrow intrusions. Contrib. Min. Pet. 55, 139-145. Komar, P, (1972). Mechanical interactions of phenocrysts and flow differentiation of igneous dykes and sills. Geol. Soc. Amer. Bull. 83, 973-988.
NAOseuM - NAO a bridge between past and future-Challenges in STEAM Education
Authors: Cossu Costantina , Falchi Simonetta
Published: February 2023

Agenda 2030 Obiettivo 4 : Istruzione equaNAOseuM - NAO a bridge between past and future- NAO Challenge 2022The Nao Challenge is an educational contest for high school students organized for the first time in Italy in 2015 by Scuola di Robotica (the School of Robotics) in collaboration with SoftBank Robotics and the Italian company CampuStore.The aim of the competition is to offer high school students the change to work and program a humanoid robot to be used in plausible and real-like situations.Scwe are convinced that education and culture in all the subjects, STEM and Arts, technoscience and humanities, are important to prepare future generations for the challenges that the current technological revolution. This challenge requires that students that the students employ all their skills, techno scientific, artistic, social:The competition  are divided into two categories for the semi-finals: those who own the robot Nao and those who do not. We have NAO, but it is possible use the NAO simulation software.The theme for this edition was the protection and promotion of cultural heritage.The project named "NAOseum", worked in close collaboration with the Archaeological Museum of Alghero "MUSA".The project participated in the NAO Challenge 22, passed all the preselections representing Sardinia in the national robotics competition, for the first time ever since its establishment.He also received thanks from the councilor for public education of the municipality of Alghero.The objectives are:Raise awareness among the youth population to discover the history of their territory by making them curious with the use of humanoid robotics;Increase the influx of the now disinterested population into museums thanks to the help of NAO;Develop a robot-human interaction that does not create a detachment between the two, but instead brings them closer;Highlight the gap between the ancient and the modern and demonstrate how they can instead be united to create something beautiful and useful for society;Intriguing the local population, and also those who come from outside, to the characteristics and curiosities that not all of them, they know about the unique Nuragic civilization of its kind.Website or Social Links https://linktr.ee/NAO_seumVideo https://youtu.be/28ubyZSujE
Global drought impact monitoring system based on online media mining and participative data collection
Authors: Bláhová Monika , Poděbradská Markéta , Janoušek Ondřej , Machátová Anna , Hlavinka Filip , Trnka Miroslav
Published: February 2023

Drought events are becoming one of the costliest phenomena under changing climate conditions, affecting almost every field of human activity and many ecosystems. Increasing severity and frequency of drought occurrence have led to the development of drought monitoring and predicting tools on both regional and global scales. Together with monitoring and analyzing drought risk and occurrence comes the necessity to monitor and evaluate single and multisectoral drought impacts. Aiming for early detection and a detailed description of drought impacts, we decided to design a system combining semi-automated online media scraping with a participative questionnaire accessible through Windy.com. Each week we perform an automatic search of media through automated scripts that are then read, evaluated, and sorted into impact categories and assigned geographic regions. The questionnaire allows users from around the world to describe drought impacts currently observed on the local scale. This method is unique in its combination of both regional impacts from media with direct inputs from volunteers worldwide, using a straightforward online questionnaire. The information from both sources is organized into seven impact categories (e.g., Agriculture, Wildfires, Business), and together they form an up-to-date global drought impact database that is visualized into drought impact maps. The spatiotemporal distribution of global drought impacts can then be compared with various drought indices and tools that characterize drought distribution and severity. After more than a year of active data collection in the system, we achieved a very good spatiotemporal match of reported impacts with drought events occurrence and severity (as observed by the SoilClim model). Compared to methods depending only on automated media analysis, our approach can get more detailed information from possibly underrepresented regions and create a comprehensive drought impact database.Acknowledgement: This study was conducted with support of SustES - Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797).
Greenspace, bluespace, and their interactive influence on urban thermal environments
Authors: Hu Leiqiu , Li Qi
Published: February 2023

Urbanization has continued growing dramatically in the past few decades, as more than half of the global population live in urban areas. The alternation of surface materials and morphologic characteristics in urban areas and anthropogenic emissions from daily activities have been evident with a considerable influence on a wide spectrum of local climate, hydrologic cycles, and ecologic patterns. Decades of research efforts have enlightened our physical understanding of the impacts of LULC on urban climates. In addition, such knowledge has provided a scientific basis for adaptation and mitigation strategies in cities to counteract the risks associated with adverse climate effects. Examples include the adoption of high albedo roofs and pavements to alleviate heat stress and harnessing the evapotranspirative cooling power of urban greenspace and blue space (water bodies, including lakes, rivers, etc.) to provide a more comfortable thermal environment. Building on multiple-year dense observations from the ground networks and high-resolution spaceborne thermal measurements, this presentation will discuss the heat mitigation capacity of nature-based cooling infrastructures, such as green space and blue space.   Specifically, we will compare the thermal benefits of different cooling infrastructures, and how their spatial organization, and coverage yield different diurnal effects at both the microclimate scale and the city scale. The study shed light on their individual and interactive effects under different meteorological conditions, which offers new insights into the cooling benefit of excising urban amenities under various synoptical conditions, including extreme heat events. The findings provide critical information support to invest in future natural-based cooling amenities in cities as the heat threats grow dramatically on a global scale. 
Comparison between numerical and parametrical uncertainty in the application of simplified water quality models
Authors: Postal Pasqualini Joana , Mainardi Fan Fernando
Published: February 2023

Simplified models based on the complete stirring tank reactor (CSTR) theory can be helpful in preliminary water quality assessments. The uncertainties of these tools should be considered for better decision-making. The research aimed to answer the following question: Is the uncertainty of the parameters or is the uncertainty of the numerical methods that generate the greatest range of possibilities for a simple water quality model? Two opposite hydrological conditions of lentic environments were investigated. Numerical uncertainty was estimated through an ensemble of six different numerical methods for solving the ordinary differential equation (ODE). Monte Carlo simulations were employed to quantify the parametric uncertainty. Uncertainty sources were compared based on the generated interquartile range for each case study. The numerical uncertainty was equivalent to the parametric uncertainty for low reservoir volumetric oscillation, whereas the numerical uncertainty prevailed over the parametric uncertainty for high volumetric ascension. The parametric uncertainty collaborated to consider the uncertainties in the definition of parameters that are not necessarily static. The results demonstrated that these considerations are relevant in situations of seasonal effects of water storage, which can be observed in drought scenarios, and even as an effect of climate change. Suggestion is in favor of the ensemble approach, as considering the variability of results through numerical and parametric uncertainties in simplified models could help build trust on the decision-making process concerning the preliminary assessment of water quality in lentic environments.
Bifurcations and Early-Warning Signs for SPDEs
Authors: Bernuzzi Paolo , Kuehn Christian
Published: February 2023

Bistability is a key property of many systems arising in the nonlinear sciences. For example, it appears in many partial differential equations (PDEs). For scalar bistable reaction-diffusions PDEs, the bistable case even has taken on different names within communities such as Allee, Allen-Cahn, Chafee-Infante, Nagumo, Ginzburg-Landau, Schlögl, Stommel, just to name a few structurally similar bistable model names. One key mechanism, how bistability arises under parameter variation is a pitchfork bifurcation. In particular, taking the pitchfork bifurcation normal form for reaction-diffusion PDEs is yet another variant within the family of PDEs mentioned above. More generally, the study of this PDE class considering steady states and stability, related to bifurcations due to a parameter is well-understood for the deterministic case. For the stochastic PDE (SPDE) case, the situation is less well-understood and has been studied recently. We generalize and unify several recent results for SPDE bifurcations. Our generalisation is motivated directly by applications as we introduce in the equation a spatially heterogeneous term and relax the assumptions on the covariance operator that defines the noise. For this spatially heterogeneous SPDE, we prove a finite-time Lyapunov exponent bifurcation result. Furthermore, we extend the theory of early warning signs in our context and we explain the role of universal exponents between covariance operator warning signs and the lack of finite-time Lyapunov uniformity. Our results are accompanied and cross-validated by numerical simulations.
Strong volcanic and climatic shocks on early modern wine production
Authors: Charpentier Ljungqvist Fredrik , Christiansen Bo , Schneider Lea , Thejll Peter
Published: February 2023

Wine is a particularly climate-sensitive crop for which long documentary series are available in much of Europe. Most studies of climate–wine growth relationships have hitherto utilised grape harvest date series. We instead investigate the climatic signature, and impact from volcanic forcing, on two long annual wine harvest quantity records from the Moselle Valley, in present-day Luxembourg, close to the latitudinal limit of commercial wine agriculture in Europe. A strong positive relationship between reconstructed temperature, especially summer temperature, and wine production quantities is found in our data that extend from the mid-fifteenth century until the end of the eighteenth century. Extremely cold or wet years show clear imprints on the wine harvest quantities. Large declines in the wine harvest – sometimes even total harvest failures – occurred after volcanic forcing events. The most significant decline in wine production quantities occurred during the first year after a volcanic forcing event. However, persistent wine production decline is evident over several consecutive years following larger volcanic forcing events. We compare the signature of Moselle Valley wine production declines following volcanic forcing events with corresponding tree-ring growth declines in different regions of Europe. It is evident that wine production shows a stronger and more distinct downturn following volcanic forcing events, even more minor ones, than tree-ring growth does in central Europe. Possible mechanisms for this behaviour are explored and discussed.
Modelling the impact of dams and exotic vegetation in New Zealand braided rivers
Authors: Stecca Guglielmo , Measures Richard , Hoyle Jo , Hicks D. Murray
Published: February 2023

River planform results from the complex interaction between flow, sediment transport and vegetation, and can evolve following a change in these controls. Disentangling this complex causation path as a preliminary measure to devising restoration measures is not straightforward. We propose a modelling approach that can be used as tool for analysis of observed trajectories and to forecast future behaviours in dam- and vegetation- impacted braided rivers.We focus two iconic braided river cases in New Zealand’s South Island: the Lower Waitaki River and the Waimakariri River. The Waitaki is impacted by the combined effects of exotic vegetation and a hydropower scheme that has altered the flow regime. As the Waitaki River is unable to clear vegetation efficiently, vegetation encroachment has promoted a shift towards a single-thread morphology. In contrast, the more active Waimakariri River, despite having been subjected to similar vegetation, retains a largely unvegetated channel due to its ability to naturally clear vegetation.A two-dimensional physics-based numerical model capable of accounting for the evolution of morphology and vegetation in braided reaches is constructed and applied to the two rivers.Calibration and validation of the vegetation parameter settings, which is critical to obtaining realistic planform styles, is carried out in applications to the two test cases by selecting the parameter values that allow the model to predict vegetation encroachment in the Waitaki and efficient vegetation clearing in the Waimakariri. The model responds sensibly to changes in parameters, showing that more aggressive vegetation types cause a sharper reduction of braiding.The calibrated model is applied to reconstruct planform changes in the Lower Waitaki under a reconstructed natural flow regime, showing that, even in the absence of the hydropower scheme, the river would have suffered from vegetation encroachment due to its naturally steady hydrology.Finally, summary metrics that represent vegetation presence in each model are computed and their dependence on the flood frequency is analysed. We find that vegetation presence across rivers and flow regimes can be explained as a function of the duration of periods of vegetation growth, intervening between floods that cause vegetation removal.
EroCA: a new tool for simulating constructed landform erosion
Authors: Yavari Shahla , McIntyre Neil , Shao Qi , Baumgartl Thomas
Published: February 2023

Extensive disturbances during the mining and rehabilitation process can include removal of vegetation, removal and storage of soils hence their modification, changes in topography, and planting of new vegetation. A main goal of mine rehabilitation is to produce a post-mining landscape that is resistant to geotechnical failure and to surface erosion processes. To achieve this, hydrology and erosion models are required to determine erosion rates under alternative landscape designs, including landscape form and cover options.
By critical review of the relevant literature, it was found that most previous erosion modelling studies have concentrated on surface hydrology in agricultural, forestry, and other natural systems, while disturbed ecosystems like mining regions have received little attention. Landscape evolution models have been developed for mined landform applications but modelling over long time-scales compromises the temporal and spatial resolution.
The main objectives of this research therefore were:

Extend an existing plot-scale hydrological model to plot-scale erosion model.
To improve knowledge of the errors and uncertainty in applying a high-resolution erosion model to mined landforms and to conclude on the potential applicability and limitations of EroCA.

The experimental data used in the research were from a 30 m × 30 m field plot on a mine waste rock dump in the wet tropical environment of the Ranger mine (north-east Australia) from the period 2009 to 2014. The new EroCA model is an extension to the RunCA model, which was developed to provide high resolution simulation of runoff and infiltration in constructed landforms. The extended model uses mass balance principles and established erosion and sediment transport models, covering both suspended and bedload, and solves the equations using the cellular automata approach. Code verification against analytical solutions of runoff and sediment illustrated small errors, which were partly due to approximations used in the analytical solutions. The EroCA model was then applied to the Ranger experimental plot data to assess the suspended and bedload erosion performance. EroCA was able to reasonably represent the observed flows and turbidity profiles. Although an arbitrary reduction in the erodibility parameter value of 20% per year was needed to simulate the bedload depletion.
Development of a Helium Resonance Lidar for the Upper Thermosphere
Authors: Geach Christopher , Kaifler Bernd , Büdenbender Hans Christian , Mezger Andreas , Rapp Markus
Published: February 2023

Resonance lidars targeting fluorescence lines of metallic layers in the mesosphere and lower thermosphere have long been used to measure profiles of wind and temperature [1], most recently achieving a maximum altitude of 300 km [2], but the rapidly decreasing densities of these metallic species prevents measurements at higher altitudes.
An alternative, first proposed in 1997 [3], is an extension of this technique to metastable helium, which would increase the possible range of resonance lidar measurements to 1000 km or higher. Last year, for the first time, a helium resonance lidar system was realized at the German Aerospace Center (DLR) in southern Germany [4]. The initial measurements by this instrument, made last year between January and March, captured the first profiles of metastable helium density, extending to an altitude of 700 km.              
We present an overview of this lidar system; we report an update on its status, including the results of the second measurement campaign; and we discuss the potential for wind and temperature measurements given anticipated improvements to system performance.
 
[1] Fricke, K. & von Zahn, U. (1985) Mesopause temperatures derived from probing the hyperfine structure of the D2 resonance line of sodium by lidar. J. Atmos. Terrestrial Phys. 47, 499–512.
[2] Jiao, J., Chu, X., Jin, H., Wang, Z., Xun, Y., Du, L., et al. (2022). First lidar profiling of meteoric Ca+ ion transport from ∼80 to 300 km in the midlatitude nighttime ionosphere. Geophysical Research Letters, 49, e2022GL100537. https://doi.org/10.1029/2022GL100537
[3] Gerrard, A. J., Kane, T. J., Meisel, D. D., Thayer, J. P. & Kerr, R. B. (1997) Investigation of a resonance lidar for measurement of thermospheric metastable helium. J. Atmos. Sol. Terrestrial Phys. 59, 2023–2035
[4] Kaifler, B., Geach, C., Büdenbender, H.C. et al. (2022) Measurements of metastable helium in Earth’s atmosphere by resonance lidar. Nat Commun 13, 6042 https://doi.org/10.1038/s41467-022-33751-6 
Predicting the unpredictable: Advances in Tracer-aided hydrologic modeling
Authors: Stadnyk Tricia
Published: February 2023

As global climate change alters hydroclimatic responses beyond the range of predictability based on historic hydrometeorological records, water resource practitioners are increasingly reliant on new methods of modelling continental and global hydrology. Though local scale heterogeneity and connectivity between hydrologic storages and fluxes tends to be averaged out across large domains, it is precisely these process scale changes that remain crucial as early indicators of climate change. A lack of data at continental scales, and particularly in high latitude regions, can therefore challenge accurate model calibration and evaluation. Efficient and accessible hydrologic prediction tools capable of diagnosing and interpreting continental scale changes in water balance components and overall water supply, ecosystem changes, and uncertainty methods for operational decision-making are needed.This presentation focuses on the recent advances in large-domain tracer-aided stable isotope modelling and the contributions isotope tracers make on improving hydrologic process representation across large-domains. The influence of process-based model outcomes will be highlighted using examples from cold regions domains, including the propagation of small historical differences into significantly different upper quantile flow predictions. Despite significant advances in tracer-aided modelling, the path forward must include building and supporting global operational monitoring networks, providing standard guidance for integration of tracer-aided approaches, and a focus on building model agnostic workflows and tools that efficiently leverage tracer-aided approaches.
Paleomagnetic study on Holocene sediments from Upper Toporowy Lake in Tatra Mts, Poland
Authors: Ucar Hakan , Kletetschka Gunther , Vondrak Daniel , Svecova Eva
Published: February 2023

Here we present paleomagnetic investigations on sediments from Upper Toporowy Lake (local name: Toporowy Staw Wyżni), an infilled lake located on the Polish side of the Tatra Mountains. The sampling was done using a peat corer. A total of 49 paleomagnetic samples were acquired in two parallel sediment cores (~50 cm each). Characteristic remanent magnetizations of the samples from the first core have shallower inclinations while the second have values near the expected geocentric axial dipole model. We note correlation of our inclination data with published records from Southern Europe records of an Early Holocene age sediment. Since a Holocene paleomagnetic master curve is absent for Central Europe, the data of this study represent a first step in constructing a master curve that will contribute to global magnetic models and dating of sediments.Acknowledgments: The research was supported by the Charles University Grant Agency (project no. 265321).