bluuebunny/crossref_metadata_2025 huggingface dataset:
From stress drop mapping to earthquake nucleation conditions in the northern Chilean subduction zone
Authors: Folesky Jonas
Published: March 2024

The characteristic stress drop of an earthquake is indicative of its slip to fault dimension. Its value is affected by fault strength, fault topography, the presence of fluids, and other properties. By estimating stress drops throughout an entire subduction zone, namely for the seismically highly active northernmost part of Chile, and combining it with mapped b-values and their corresponding magnitude distribution, this work aims to better constrain the conditions under which earthquakes of different provenances may nucleate.Database is a recent seismicity catalog, containing over 180,000 events and covering 15 years of seismicity, for which more than 50,000 stress drop estimates were computed. Their class wise spatial average segments the subduction zone into different parts. This difference, however, is small compared to the natural scatter of stress drop values. By considering stress drop variations, b-value map, magnitude distribution, and thermal modeling, I describe a variety of mechanisms of earthquake nucleation which might explain the observed stress drop variation. This is done for 1) the plate interface in general; 2) local shallow interface features, i.e., asperities and creeping sections; 3) the highly active intermediate depth seismicity region. In all three cases, the combination of stress drop distribution and b-value mapping helps to better understand the differences in earthquake nucleation and to formulate hypotheses on the controlling factors of earthquake nucleation.
The Potential Impact of Floating Wind turbines on the deep water oxygen deficit in seasonally stratified shelf seas
Authors: Rippeth Tom P. , Lincoln Ben J. , Shen Sijing , Scannell Brian , Meng Xin , Hopkins Jo , Sharples Jonathan
Published: March 2024

Seasonally stratified shelf seas are amongst the most biologically productive on the planet. A consequence is that the deeper waters can become oxygen deficient in late summer in response to deep water remineralisation of sunken organic matter. Model simulations suggest that a warming climate will accelerate this deficiency due to strengthening stratification and the increased duration of stratification. In the next decades the seasonally stratified seas will host the massive expansion of off-shore wind farms, and in particular the new generation of floating wind turbines.  Here we integrate novel turbulence timeseries measurements with vertical profiles of water column properties from a seasonally stratified shelf sea to estimate oxygen and biogeochemical fluxes. These new results are used to investigate the role of vertical mixing in the development of the seasonal O2 deficit with particular reference to the potential impact of enhanced mixing associated with the wake of the floating wind turbines. 
Multitask Learning for Tornado Identification Using Doppler Radar Data
Authors: Xie Jinyang , Zhou Kanghui , Han Lei , Guan Liang , Wang Maoyu , Zheng Yongguang , Chen Hongjin , Mao Jiaqi
Published: March 2024

Tornadoes, as highly destructive small-scale weather events, demand accurate detection and identification for effective weather decision-making. While weather radar serves as a primary tool for tornado identification, traditional radar-based tornado identification algorithms, such as Tornado detect algorithm (TDA) and Tornado Vortex Signature algorithm (TVS), are susceptible to radar noise, with limited tornado feature extraction capability leading to high rates of false alarms and low probability of detection. In response to these challenges, this study introduces an innovative multi-task learning network based on spatial-temporal information (TS-MINet) to improve tornado identification. Leveraging continuous three-frame radar Level-II data as inputs, including reflectivity, radial velocity, and spectral width, TS-MINet adopts a multi-task learning structure, simultaneously performing tornado detection and number estimation tasks to comprehensively extract tornado-related information. TS-MINet integrates channel recalibration blocks, spatial construction module, and temporal construction module, constructing a robust tornado identification model that overcomes the limitations of traditional algorithms with single-frame radar data. The introduction of channel recalibration blocks refines local representations, capturing micro-scale features crucial for accurate tornado identification. Inspired by the transformer architecture, the spatial construction module enriches global spatial dependencies by assimilating information from different spatial regions. Simultaneously, the temporal construction module captures the time-relatedness of consecutive radar frames, providing a nuanced understanding of tornado evolution. Given the limited number of tornado samples, data augmentation techniques like random rotation and cropping are implemented during model training to enhance robustness. Compared with the traditional TDA method with a Critical Success Index (CSI) of 0.15, the proposed method successfully improves the CSI to 0.54, which highlights the potentially advantages of deep learning methods in identification tasks. Even compared with the classical deep learning model UNet, which has a Probability of Detection (POD) of 0.62 and a False Alarm Rate (FAR) of 0.50, the proposed method achieves 0.75 and 0.32, respectively, and possesses more superior accuracy and robustness. The innovative TS-MINet model provides new insights and solutions for tornado detection, providing strong support for accurate prediction and timely response to future weather events. 
Five years of change of two debris-covered glaciers monitored by unmanned aerial system
Authors: Kraaijenbrink Philip , Immerzeel Walter
Published: March 2024

Glaciers in the Himalaya are often covered by debris, which affects melt rates and causes high spatial heterogeneity in surface elevation changes. In the past decade years, unmanned aerial system (UAS) data have been shown to be indispensable in mapping and monitoring this type of glacier and catalysed new research focusing on process understanding of ablation processes at unprecedented detail. In this study, we present the results of a five-year biannual UAS monitoring campaign in the Langtang Catchment in the Nepalese Himalaya in which we surveyed Lirung Glacier (9 surveys, 2013–2018) and Langtang Glacier (7 surveys, 2014–2018). Optical UAS imagery was processed into high-resolution image mosaics and elevation data, accurately positioned using ground control data and co-registered using tie points. Derived glacier surface velocities and modelled bed topography were used to perform fully distributed corrections for ice flow and emergence velocity. The resulting flow-corrected surface changes of the glacier were analysed and used to evaluate supraglacial ice cliff evolution, glacier retreat, and melt. Results show that on average the surveyed areas of Lirung Glacier and Langtang Glacier had comparable surface velocities ranging from about 1.0 to 3.5 m a-1 and a melt of −1.40 ± 0.05 m a-1 and -1.22 ± 0.08 m a-1, respectively, with both glaciers having strong spatial heterogeneity and temporal variability. Supraglacial ice cliffs on both glaciers exhibit variable (rates of) change in morphology, largely irrespective of aspect. The terminus of Lirung Glacier, which is characterized by a debris-free ice cliff, experienced very fast retreat of 41 m a-1. The five-year time series of UAS data presented in this study has provided unique insights in surface changes of debris-covered glaciers. UAS surveys are and continue to remain highly valuable tool to study such glaciers, with potential still to be unlocked.
Decreased water availability reduces the CO2 sink of a semi-arid savanna in Sahel based on a thirteen-year eddy covariance measurement  
Authors: Wieckowski Aleksander , Tagesson Torbern , Ardö Jonas , Vestin Patrik , Diatta Ousmane
Published: March 2024

The Sahel is a semi-arid savanna region located as a transition zone between the dry Sahara Desert in the north and the humid Sudanian savanna in the south. It is one of the poorest and most understudied regions in the world and highly affected by climate change. Remote sensing studies found that the majority of Sahel is greening in the 21st century, with some areas experiencing browning, which is closely linked to the annual rainfall. Yet, there is a scarcity of in-situ data of the responses of ecosystem to the ongoing changes, which makes it hard to validate Earth Observation findings. In this study, we have quantified Net Ecosystem Exchange (NEE) and its components - Gross Primary Production (GPP) and Ecosystem Respiration (Reco) using 13-year long time series of Eddy Covariance data from Dahra, Senegal. We have found decreasing trends in the carbon sink over the period 2010-2022 and a link to the decreasing water availability. 
How quickly are canopy temperatures approaching their critical limit in the tropics?
Authors: Lenczner Gaston , van Tiel Nina , Tuia Devis , Grossiord Charlotte
Published: March 2024

Tropical forests host Earth’s highest biodiversity and act as global climate regulators more than any other biome. In a world where heat waves become increasingly severe and recurrent, especially in the Amazon, it becomes crucial to know how close tropical species are getting to their critical temperatures. Indeed, while plant leaves operate within a broad range of air temperatures, they must stay under a species-specific critical temperature (Tcrit) to sustain their function. In this context, we study how quickly the canopy temperature (Tc) approaches the critical temperature of tree species in the tropics.We specifically focus on the evolution of the thermal safety margin (Δ = Tc − Tcrit) during the period 2001- 2020 across tropical forest biomes in South America, Southeast Asia, and Central Africa. Data analysis (~ 1km resolution) was conducted by combining (1) tree species distribution maps, (2) Tcrit databases, (3) MODIS-derived maximal Land Surface Temperature per month, and (4) a dense vegetation map to obtain the Tc maps. Given that the exposure time to Tcrit required to cause the leaves to die is short, we focus on the heatwaves and select the warmest month per year to study the Δ evolution. We fit a linear regression at each geographic coordinate to obtain trend maps based on their coefficients.Our results indicate a consistent trend wherein Tc progressively approaches critical thresholds. On average over the three studied regions, the median increase in Tc is around 0.11 °C per year, with a median Δ of 9.5 °C in 2020.More sensitive locations exhibiting initial proximity to Tcrit show an accelerated rate of gap closure. For instance, in South America, while the median increase per year in Tc is about 0.1 °C, the 90th percentile is about 0.19 °C: in 2001, 10% of the locations were 4.5 °C away from the critical temperature of their most sensitive species, dropping to 0.3 °C in 2020. Central Africa has a less severe but still concerning trend, with the hottest 10% experiencing a 0.16 °C increase per year and a thermal safety margin of 2.5 °C in 2020.Our findings suggest that, although most areas in the tropical biomes still have a rather large safety margin before reaching the Tcrit associated with their species, sensitive areas are getting dangerously close to these critical thresholds, suggesting enhanced vulnerability to global warming.
Utilization of steelmaking waste as a sustainable low-cost adsorbent for cationic and anionic dyes removal 
Authors: Basaleh Abdullah , Al-Malack Muhammad , Saleh Tawfik , Tawabini Bassam
Published: March 2024

An effective magnetic polymeric composite was produced from steelmaking waste in this work. For the elimination of methyl orange MO and methylene blue MB from synthetic solutions, steel slag was treated with an acrylamide acrylic acid (SSAA) copolymer. TGA thermogravimetric analysis, SEM scanning electron microscope, XRD X-ray diffraction, BET Brunauer-Emmett-Teller surface area, and FTIR Fourier transform infrared were used to analyze the SSAA composite. The SSAA adsorption behavior for MO and MB was studied, and the impact of various factors was analyzed using one factor at a time (OFAT) and the RSM-BBD response surface method-Box Behnken Design. The second-order kinetic model accurately described the kinetic data of MO and MB, and the primary rate-limiting phase is film diffusion. The Dubinin-Raudshkevish (D-R) and Freundlich isotherms accurately characterized the MB and MO experimental outcomes, respectively. MO and MB had maximal absorption efficiencies of 97% and 94%, respectively, and capacities of 47 and 463 mg/g. The thermodynamic studies revealed that MO and MB adsorption on the SSAA was favorable and spontaneous. Physical adsorption was discovered to be the dominant mechanism for MB, whereas chemisorption was identified for MO. The regeneration investigation verified these mechanisms, in which SSAA was regenerated for MB and a negligible decline in adsorption capacity was seen after five cycles. However, for MO ions, a minor renewal of the SSAA was achieved, confirming the chemisorption mechanism. According to the thermodynamic study, the SSAA composite might be employed for the removal of cationic and anionic dyes from wastewater spontaneously and feasibly.
Studying the Earth's magnetopause at High Latitudes With CLUSTER
Authors: Grimmich Niklas , Plaschke Ferdinand , Escoubet C. Philippe , Archer Martin O. , Nakamura Rumi , Sibeck David G. , Constantinescu O. Dragos
Published: March 2024

The boundary between the interplanetary magnetic field and the terrestrial magnetic field is the magnetopause. This magnetopause is influenced by dynamic changes in the solar wind, i.e. different solar wind conditions lead to a change in the shape and location of the magnetopause. The interaction between the solar wind and the magnetosphere can be studied from in-situ spacecraft observations. Many studies focus on the equatorial plane, as this is where recent spacecraft constellations such as THEMIS or MMS operate. However, to fully capture the interaction, it is important to study the high latitude regions as well. The Cluster spacecraft allow us to collect a database of high-latitude magnetopause crossings and study magnetopause motion in this region, as well as deviations from established magnetopause models. We use multi-spacecraft analysis tools to investigate the direction of magnetopause motion in the high latitudes and compare the occurrence of crossings at different locations with the result in the equatorial plane. Our results will be useful for the interpretation of plasma measurements from the upcoming SMILE mission, as this spacecraft will also fly frequently through the high-latitude magnetopause.
Distinct Magma Differentiation Pathways for the Eastern Snake River Plain and Craters of the Moon, Idaho, from Zircon Geochronology and Geochemistry
Authors: Angeles-De La Torre Carlos A. , Schmitt Axel K. , McCurry Michael , Danisik Martin , Lovera Oscar M. , Hertwig Andreas , Gerdes Axel
Published: March 2024

The Snake River Plain plateau and the adjacent Columbia River and Yellowstone volcanic fields form one of the world largest flood basalt provinces. Eruptive centers migrated eastward since the late Cenozoic following the Yellowstone hotspot, erupting an archetypical bimodal volcanic suite with compositions ranging from olivine-tholeiite to rhyolite. Up to 80% of the ~1600 km2 eastern portion of the Snake River Plain (ESRP) is covered by mafic lava flows, from which four prominent Pleistocene rhyolite domes emerge. Closely associated with the ESPR is the Craters of the Moon (COM) volcanic field, which is considered the largest Holocene lava field in the ESRP and the United States, with more than 60 eruptions over the past ~15,000 years. Geochemically, COM lavas range from basalt and trachybasalt to trachyte.To elucidate processes and timescales of evolved magma production, zircon from Quaternary rhyolites from the ESRP was investigated along with zircon from three of the most recent and evolved COM lava flows and those from a COM crustal xenolith. Approximately 300 individual zircon crystals were analyzed for U-Pb and U-Th geochronology, respectively, and paired with crystal-scale δ18O, ɛHf, and trace element analyses. Composite zircon separates from a COM lava flow were also analyzed by combined (U-Th)/He and U-Th dating to constrain its eruption age.U-Pb zircon dating indicates crystallization ages between 1.54 ±0.01 Ma in the oldest and 0.335 ± 0.003 Ma in the youngest ESRP rhyolite dome, with ages increasing from west to east. For COM trachyte lavas, zircon U-Th disequilibrium corresponds to an age of  ka which along with an indistinguishable (U-Th)/He zircon age demonstrates that zircons crystallized in the evolved magma shortly before the eruption. With the exception of rare Precambrian basement-derived xenocrysts, evolved COM lavas have zircon δ18O values ranging from +5.33 to +6.02, consistent with fractionation from ESRP mantle-derived mafic magmas. On the other hand, δ18O(VSMOW) zircon composition between +1.73‰ to +4.51‰ for ESRP agree with low δ18O Yellowstone rhyolites with decreasing values from west to east. COM lavas display ɛHf zircon values between -12.0 to -8.9, whereas ESPR rhyolite ɛHf zircon ranges from -6.3 to -1.3. The crustal xenolith from COM yielded U-Pb zircon ages between 1.9 and 3.4 Ga, consistent with low ɛHf > -35. These results indicate different pathways of evolved magma production that differ between ESRP and COM.
Do tragedies of the commons contribute to the premature depletion of transboundary aquifers?
Authors: Muller Marc F. , Hung Fenwei , Davis Kyle , Chiarelli Davide
Published: March 2024

Many of the 500+ internationally shared aquifers are rapidly depleting but poorly regulated with less than 10 international treaties focusing on shared groundwater. The common-pool nature of groundwater has long been identified as an important complicating factor.  Pumping by any user increases pumping costs for all users by decreasing groundwater levels throughout the aquifer. This creates a tragedy of the commons, where all users have incentives to over-pump, thus prematurely depleting the resource. While this mechanism is well documented in domestic aquifers, large geographic distances between demand centers and heterogeneous economic and hydrogeologic conditions on either side of the border affects  incentives to over-pump in transboundary aquifers.   Whether -- and where -- common-pool incentives might lead to the premature depletion of transboundary aquifers remain poorly understood. We fill these gaps by combining remote sensing and large scale hydrologic and agricultural modeling datasets in a global analysis of known transboundary aquifers. We first evaluate the proportion of global irrigation water demand that is sourced from transboundary aquifers, and the proportion of these withdrawals associated with unsustainable pumping. We then identify regions, where unsustainable irrigation arises close enough to a political border to affect transboundary groundwater levels and pumping costs. Finally, we leverage recent theoretical results to identify the subset of these regions where heterogeneous economic conditions on either side of the border creates substantial incentives to over-pump. Results provide key insights on the role played by common-pool overdraft incentives on the premature depletion of transboundary aquifers and identify hotspots where international groundwater regulation is most urgently needed. 
Improving water-related ecosystem services to developing country communities through nature-based solutions
Authors: Fonseca Kalina , Ilbay Mercy , Espitia-Sarmiento Edgar , Breuer Lutz
Published: March 2024

The political, economic, social, technological, environmental, and legal (PESTEL) dimensions in a local community shape the adoption of specific nature-based solutions (NbS) to improve water ecosystem services. This study provides crucial insights on integrating NbS tailored to smallholder indigenous and peasant communities in four central Ecuadorian provinces, covering 43.2% of the Andean region. These communities are located in the páramo, a highly valued ecosystem for water-related ecosystem services. However, they face high levels of poverty and malnutrition. Combining a participatory multi-stakeholder approach with a literature review, we gathered insights into PESTEL dimensions impacting páramo ecosystem services. A bibliometric and decision tree analysis was then employed to reveal NbS aligned with PESTEL dimensions in these communities. As a result, limited financial support, urban-centric environmental investment, and insufficient acknowledgment of water-related ecosystem services significantly impact the health of páramo ecosystems from economic and political dimensions, respectively. In the environmental dimension, the overexploitation of this ecosystem, driven by high soil carbon storage combined with superior water quality and the high vulnerability to climate change, contributes to the decline of the páramo remnants. Social, legal, and technological dimensions involve community dissatisfaction and resistance to conservation, lack of sustainable land and water management, and the mismatch between technology, the economy, and data availability. These impacts on páramo ecosystem services occur directly through water purification, regulating soil formation, and maintaining populations and habitats. Indirectly, they affect the provision of water for drinking and non-drinking purposes, fishing and aquaculture, recreation, and spiritual and symbolic appreciation. To enhance water-related ecosystem services, we propose the establishment of artificial floating islands such as NbS. These islands are seen as an innovative restoration method with multiple benefits, such as the need for only limited financial support, the engagement of local communities, the lack of land requirements for implementation, and the use of indigenous community knowledge of appropriate plant species for water treatment, which can even generate additional income. Passive restoration complements this by removing disturbances in the páramo, allowing natural regeneration in basins by state-led land purchase initiatives to ensure the protection by Ecuadorian conservation laws. Our study offers decision-makers a practical approach to secure ecosystem services for vulnerable populations, critically assessing alternatives based on the dimensions and needs of these communities.
Correlation between Frequency-Divided Magnetic Field and Channel-Base Current for Triggered Lightning
Authors: Fan Yanfeng , Zhang Yang , Lyu Weitao
Published: March 2024

Different discharge processes of triggered lightning can radiate the electromagnetic signals with different frequency bands. During the triggered lightning experiment conducted at the Field Experiment Base on Lightning Sciences of China Meteorological Administration (CMA-FEBLS), three magnetic field (B-field) antennas with different frequency responses were deployed at about 80 m from the launching site. By using the synchronous observations, the quantitative relationship between the close-range B-field measurement and the channel-base current at different stages of triggered lightning were established. The initial continuous current (ICC) waveform can be reconstructed by numerically integrating the B-field signals measured with the dB/dt antenna. However, the slow variations of ICC cannot be retrieved by the B-field signals measured with the LF-MF antenna, because the antenna bandwidth cannot cover the frequency below 500 Hz. The B-field signals of return stroke measured with the low sensitivity antenna can be simulated by the MTLL return stroke model, and the B-field signal shows fairly good consistency with return stroke current. The analyses suggest that the current waveform of natural return stroke that occurred within 1.5 km can be retrieved or at least its peak value can be estimated by using the B-field measurements.
Reconstructing stream water oxygen isotopes using freshwater pearl mussels (Margaritifera margaritifera): Toward an exploration of sub-seasonal watershed dynamics over the past 200 years
Authors: Gey Christoph J. , Pfister Laurent , Türk Guilhem , Thielen Frankie , Leonard Loic , Schöne Bernd R.
Published: March 2024

Stream water oxygen isotopes are a powerful natural tracer of watershed functions (e.g., water collection, storage, mixing, and release). However, instrumental δ18Owater records have limited spatial coverage and rarely span over more than a decade. Long-lived (> 200 years) freshwater pearl mussels (Margaritifera margaritifera) are a promising natural archive for complementing these δ18O chronicles because their shells faithfully capture the isotope composition of the water in which the mussel lived. The reconstruction of reliable shell-based δ18Owater chronologies relies on several steps: (i) identifying which layer of the shell biomineralizes in thermodynamic equilibrium with the ambient water, (ii) determining the seasonal timing and rate of shell growth to assign each isotope sample to a precise calendar date, and (iii) employing a temperature record or temperature reconstruction to resolve the thermodynamic relationship between δ18Oshell and δ18Owater. First, we assessed the oxygen isotope fractionation between the ambient water and both sublayers of the outer shell layer, i.e., the outer prismatic and inner nacreous portion. We found that reconstructions based on δ18Oshell of the prismatic sublayer provided excellent δ18Owater data, whereas the nacreous portions showed evidence of growth rate-induced (kinetic) effects. Second, we carried out tank experiments to quantify temperature controls on biomineralization rates, constrain the seasonal timing and rate of shell formation, and construct a monthly resolved seasonal growth model. Third, we assessed the temperature sensitivity of shell ultrastructural properties and observed a poor relationship between water temperature and the nacre table thickness, strongly masked by pH fluctuations in stream water. Based on these findings, we have reconstructed sub-seasonal δ18Owater records of streams in Luxembourg, Germany and Sweden extending back to the early 19th century. These unprecedented reconstructions of stream water δ18O chronicles will open new vistas on multidecadal to centennial dynamics in the continental water cycle (e.g., for the assessment of watershed sensitivity to global change).
The Cartwheel CME’s Evolution in the Low Solar Corona Simulated with Non-Equilibrium Charge States and Spectra for Comparison to High-Resolution EUV Spectroscopic Observations
Authors: Wraback Elizabeth , Landi Enrico , Manchester Ward , Szente Judit
Published: March 2024

High-resolution EUV spectroscopy of the corona provides the most informative diagnostic tool for the early evolution of coronal mass ejections (CMEs) since it can directly measure many physical properties of CME plasma close to the Sun, which cannot be determined from coronagraphs and full-disk imagers. Hinode/EIS captured its full range of high-resolution EUV spectra of the April 9th, 2008 event, also known as the Cartwheel CME, during its initial acceleration period. Unique to this work, simulations of the Cartwheel CME with the Alfven Wave Solar atmosphere Model (AWSoM) and the Gibson-Low flux rope model, were performed to provide insight into the plasma structure and dynamics during the early evolution of this CME. We combined self-consistent non-equilibrium charge state calculations in the EUV spectral line synthesis for the first time, to account for the plasma departures from ionization equilibrium everywhere in the CME. Overall, the model is able to reproduce the dynamics of the CME, including the eruption of cold, dense prominence material. We discuss the thermodynamic evolution of CME’s plasma structure in the low solar corona, with particular attention given to the cold prominence material, and how the non-equilibrium charge states and EUV spectra evolve.
Heatwave social vulnerability index validated on mortality data in Europe
Authors: Sestito Benedetta , Reimann Lena , Mazzoleni Maurizio , Botzen Wouter , Aerts Jeroen
Published: March 2024

Climate change projections underscore an imminent temperature escalation of 1.1°C to 6.4°C above the 1990 baseline by 2100, leading to heatwaves of higher frequency, intensity, and duration. In the last decades, Europe has experienced severe heatwave events, such as the catastrophic one in summer 2003 that claimed over 70,000 lives. Thus, it is of pivotal importance to better understand the drivers of heatwave impacts to promote effective adaptation and mitigation strategies. While many studies have been carried out to explore the social vulnerability to heat-related impacts at local and regional scales, a large-scale continental analysis is still missing. This study aims at exploring the temporal and spatial dynamics of social vulnerability to heatwaves in Europe. This will be achieved by developing a dynamic spatial and temporal social vulnerability index for heatwaves in Europe. The index is validated against impact metrics such as mortality, which remains underexplored in large-scale assessments. In particular, a regression analysis between heatwave mortality and socio-economic and demographic factors, including population changes, income variations, and alterations in social infrastructure is carried out to assess the degree to which these factors are associated with heatwave mortality. The regression coefficients serve as the weights in the composite social vulnerability index. Such validation enhances the credibility, accuracy, and applicability of social vulnerability indices, bridging the divide between theoretical assessments and real-world consequences. Our empirical results indicate that diverse socio-economic and demographic variables exhibit distinct correlations with heatwave mortality. Consequently, an index incorporating ad hoc weighting of its constituent terms more effectively captures the social vulnerability component to heatwaves. This research provided new insights to better understand social vulnerability to heatwaves and allow better-informed decision-making to enable the development of resilient communities. Moreover, our findings advanced the understanding of heat risks in the broader context of escalating climate change challenges across Europe.
Establishing the Photochemical Reflectance Index (PRI) as a reliable proxy for Non-Photochemical Quenching (NPQ)
Authors: Hänchen Lorenz , Martini David , Sakowska Karolina , Migliavacca Mirco , Pacheco-Labrador Javier , Duveiller Gregory , Schwarz Michaela , Hammerle Albin , Scholz Katharina , Galvagno Marta , Julitta Tommaso , Spielmann Felix , Van Wittenberghe Shari , Wohlfahrt Georg
Published: March 2024

On a global scale, the scientific community is to date unable to close the CO2 budget, with implications for policymakers in regard to limiting global warming to internationally agreed levels. Recently, remote sensing of Solar-Induced Chlorophyll Fluorescence (SIF) has emerged as a promising proxy for Gross Primary Productivity (GPP). The upcoming Fluorescence Explorer (FLEX) mission by the European Space Agency (ESA) is anticipated to offer unprecedented spatio-temporal and spectral resolution of SIF data, raising high expectations towards assessing GPP on a global scale. However, the relationship between SIF and GPP is intricate, varying with environmental conditions due to the influence of a third process — Nonphotochemical Quenching (NPQ). NPQ critically affects this relationship by utilizing the same energy pool. Hence, NPQ is not unfortunately not directly measurable through remote sensing but previous studies have employed the Photochemical Reflectance Index (PRI) as a proxy for NPQ. Yet, a systematic assessment of the PRI-NPQ relationship is still lacking, as previous works were limited to case studies, confined to the studied ecosystem and the environmental conditions during the study period.In this contribution, our primary aim is to contribute to enhancing SIF as a remotely sensed proxy for GPP. We present the initial findings of our investigation into the robustness of the PRI-NPQ correlation under diverse environmental conditions. To achieve this goal, we leverage a unique dataset that includes joint measurements of hyperspectral reflectance (Data: Fluorescence BoX, JB Hyperspectral Devices GmbH) and active chlorophyll fluorescence (Data: MONI-TORING-PAM Multi-Channel Chlorophyll Fluorometer, Walz) from seven European ecosystems spanning the years 2018 to 2022. 
Evaluating MODIS snow products using an extensive wildlife camera network
Authors: Breen Catherine , Vuyovich Carrie , Odden John , Hall Dorothy , Prugh Laura
Published: March 2024

Snow covers a maximum of 47 million km2 of Earth ’s northern hemisphere each winter and is an important component of the planet ’s energy balance, hydrology cycles, and ecosystems. Monitoring regional and global snow cover has increased in urgency in recent years due to warming temperatures and declines in snow cover extent. Optical satellite instruments provide large-scale observations of snow cover, but cloud cover and dense forest canopy can reduce accuracy in mapping snow cover. Remote camera networks deployed for wildlife monitoring operate below cloud cover and in forests, representing a virtually untapped source of snow cover observations to supplement satellite observations. Using images from 1181 wildlife cameras deployed by the Norwegian Institute for Nature Research (NINA), we compared snow cover extracted from camera images to Moderate Resolution Imaging Spectroradiometer (MODIS) snow cover products during winter months of 2018–2020. Ordinal snow classifications (scale = 0–4) from cameras were closely related to normalized difference snow index (NDSI) values from the MODIS Terra Snow Cover Daily L3 Global 500 m (MOD10A1) Collection 6 product (R2 = 0.70). Tree canopy cover, the normalized difference vegetation index (NDVI), and image color mode influenced agreement between camera images and MOD10A1 NDSI values. For MOD10A1F, MOD10A1’s corresponding cloud-gap filled product, agreement with cloud-gap filled values decreased from 78.5% to 56.4% in the first three days of cloudy periods and stabilized thereafter. Using our camera data as validation, we derived a threshold to create daily binary maps of snow cover from the MOD10A1 product. The threshold corresponding to snow presence was an NDSI value of 40.50, which closely matched a previously defined global binary threshold of 40 using the MOD10A2 8-day product. These analyses demonstrate the utility of camera trap networks for validation of snow cover products from satellite remote sensing, as well as their potential to identify sources of inaccuracy.
Carbon dynamics shift in changing cryosphere and hydrosphere of the Third Pole
Authors: Zhang Yulan , Gao Tanguang
Published: March 2024

The Third Pole (TP) represent the largest alpine mountains on Earth. Its cryosphere is shrinking and collapsing and the hydrosphere is subsequently expanding under a warming climate in recent decades, posing potential impacts on biogeochemical cycles. In particular, the carbon cycles there have experienced dramatic changes, primarily with the alterations of cryosphere and hydrosphere. Carbon emissions from the melting glaciers and thawing permafrost can further trigger feedback on climate change. However, their current status and future fate in this region still need clarification comprehensively. Here, we review the current state of carbon stocks in the changing TP cryosphere and hydrosphere, focusing on their variations in permafrost, glaciers, and related inland waters (upper river streams, thermokarst lakes, and glacial lakes). We also considered their release pathways and the amounts of carbon released into aquatic ecosystems and the atmosphere. Finally, we recommend research priorities to address dynamics in carbon cycling and possible future impacts on the TP. This review will highlight the important of dynamics of carbon cycle on the TP under climate change in future.
Enhanced seasonality of surface air temperature over China during the mid-Holocene
Authors: Tian Zhiping
Published: March 2024

Using all available simulations performed by climate models participating in PMIP4 (Paleoclimate Modelling Intercomparison Project – Phase 4), we quantify the seasonality change of surface air temperature over China during the mid-Holocene (6000 years ago) and the associated physical mechanisms. Relative to the preindustrial period, all 16 models consistently show an enhanced temperature seasonality (i.e., summer minus winter temperature) across China during that interglacial period, with a nationally averaged enhancement of 2.44°C or 9% for the multimodel mean. The temperature seasonality change is closely related with the seasonal contrast variation of surface energy fluxes mainly due to the mid-Holocene orbital forcing. Specifically, the summer–winter increase in surface net shortwave radiation dominates the intensified temperature seasonality at the large scale of China during the mid-Holocene; the surface net longwave radiation has a minor positive contribution in most of the Tibetan Plateau and eastern China; and both the surface latent and sensible heat fluxes show partial offset effects in most of the country. There are uncertainties in the reconstructed temperature seasonality over China during the mid-Holocene based on the proxy data that can reflect seasonal signals.
Hydrometeor classification using dual-polarized C-band Doppler weather radars: comparison to a dual-polarization Doppler profiler
Authors: Bogerd Linda , Leijnse Hidde , Overeeem Aart , Uijlenhoet Remko , van der Veen Sibbo
Published: March 2024

The innovation of dual-polarization Doppler weather radars has improved the accuracy of precipitation estimates over the past decades. Retrieving hydrometeor types from dual-polarization weather radar data, however, remains challenging. In this study, we used a hydrometeor classification scheme from wradlib to identify hydrometeor types aloft from two C-band weather radars in the Netherlands. Four recent case studies, from 2022 and 2023, were selected. A dual-polarization Doppler profiling radar, operating at Ka-band and W-band at an elevation angle of 45 degrees, was employed as a reference. First, the output of the wradlib scheme was used to determine the hydrometeor type. Based on this classification, we selected computed scattering properties from the open access ARTS Microwave Single Scattering Properties Database. Furthermore, mixing ratios of the hydrometeors were computed by combining measured C-band reflectivities using the hydrometeor type probabilities from wradlib. The hydrometeor type determines the scattering behavior of a single precipitation particle while the mixing ratio prescribes the particle size distribution (PSD), which is determined using parametrizations as employed in the Harmonie weather model. With the PSD and the hydrometeors’ terminal fall speeds, which are also taken from Harmonie, we produced spectra of various polarimetric variables that could be compared to those derived from the profiling radar. Besides incorrect classifications resulting from the wradlib algorithm, differences between constructed and observed spectra stem from various uncertainties associated with the retrievals from the profiler. Firstly, the hydrometeor canting angle distribution affects the backscattering to the radar. Secondly, the PSD parametrizations as employed in HARMONIE have been employed, while numerous alternatives exist that could yield different results. Finally, uncertainties are associated with the conversion of 45-degree measurements from the profiling radar to vertically-pointing spectra. Nonetheless, this study offers important insights into the performance of dual-polarization C-band weather radars regarding the classification of hydrometeor types.
Tsunami Impacts Scenarios for the Albanian Coasts: Durres City case study
Authors: Xhafaj Edlira , Scaini Chiara , Peresan Antonella , Hassan Hany M.
Published: March 2024

The ultimate aims of this study is to assess the risk associated with plausible earthquake generated tsunamis along the coasts of Albania, adopting a case study approach based on the modelling of tsunamigenic earthquake scenarios based on the maximum moment magnitude (Mmax) reported in DISS-3.3 joint with the 2019 Mw6.4 Durres earthquake source models. In order to assess the expected impact, we computed the tsunami hazard in terms of maximum amplitude, estimated time of arrivals and inundation zone on the Albanian coast for a set of tsunamis resulting from potential earthquakes generated by the major identified seismogenic sources (namely, Lushnje source from DISS-3.3 database) in the eastern Adriatic Sea. Our approach combines current available information on regional tectonics, recent earthquake swarms in 2019 in scenario-based approach to contribute to tsunami risk assessment for the selected urban area along the Albanian Adriatic coast. The goal is to analyse the propagation of tsunami waves generated by the source set of scenarios, which is potentially able to generate an aggregated scenario of Mmax 7.5, that could cause significant impacts in the region. The modelling are performed by NAMI DANCE numerical code (e.g., Dogan et al., 2021, Natural Hazards, 106(2), 1195–1221; and references therein). For the exposure analysis concerning buildings, landuse and infrastructure, a Geographic Information System (GIS) formatted database is created for the Durres municipality. The Durres exposure analysis in terms of population and built environment were presented in the form of maps, and provide insights for future evacuation plans. Approximately 63% of the buildings consist of single-storey structures, and the number of exposed buildings strongly increased during the period 2000 to 2010. Understanding the composition and construction timelines of the buildings is crucial in assessing their vulnerability and potential impact associated to the simulated tsunamis scenarios. Regarding human impact, the exposure analysis indicates vulnerability in residential, commercial, and public service areas. In Durres city only, the expected population by 2036, estimated at 138,000 inhabitants according to the National Agency of Territorial Planning (AKTP, 2022), will be located in vulnerable urban areas. The results highlight the significant vulnerability of the most important sectors in Durres to possible tsunamis and the need for a rigorous urban planning and enforcement to mitigate future seismic related hazards. This study provides the first extensive examination of urban-scale tsunami risk assessment for cities along the Albanian coastline, highlighting the paramount role of exposure and vulnerability assessment to increase preparedness and inform resilient urban planning.
Delineation of Subsurface Tectonic Structures Using Gravity, Magnetic and Geological Data, in the Sarir-Hameimat Arm of the Sirt Basin, NE Libya
Authors: Saleem Mohamed , Ellafi Hana ,   Mohamed Saleem
Published: March 2024

Delineation of Subsurface Tectonic Structures Using Gravity, Magnetic and Geological Data in the Sarir-Hameimat Arm of the Sirt Basin, NE LibyaByMohamed Saleem1 and Hana Ellafi21 &2 Petroleum Research Center  ABSTRACTThe study area is located in the eastern part of the Sirt Basin, in the Sarir-Hameimat arm of the basin, south of Amal High. The area covers the northern part of the Hamemat Trough and the Rakb High. All of these tectonic elements are part of the major and common tectonics that were created when the old Sirt Arch collapsed, and most of them are trending NW-SE. This study has been conducted to investigate the subsurface structures and the sedimentology characterization of the area and attempt to define its development tectonically and stratigraphically.About 7600 land gravity measurements, 22500 gridded magnetic data, and petrographic core data from some wells were used to investigate the subsurface structural features both vertically and laterally. A third-order separation of the regional trends from the original Bouguer gravity data has been chosen. The residual gravity map reveals a significant number of high anomalies distributed in the area, separated by a group of thick sediment centers. The reduction to the pole magnetic map also shows nearly the same major trends and anomalies in the area. Applying the further interpretation filters reveals that these high anomalies are sourced from different depth levels; some are deep-rooted, and others are intruded igneous bodies within the sediment layers. The petrographic sedimentology study for some wells in the area confirmed the presence of these igneous bodies and defined their composition as most likely to be gabbro hosted by marine shale layers. Depth investigation of these anomalies by the average depth spectrum shows that the average basement depth is about 7.7 km, while the top of the intrusions is about 2.65 km, and some near-surface magnetic sources are about 1.86 km. The depth values of the magnetic anomalies and their location were estimated specifically using the 3D Euler deconvolution technique. The obtained results suggest that the maximum depth of the sources is about 4938m.The total horizontal gradient of the magnetic data shows that the trends are mostly extending NW-SE, others are NE-SW, and a third group has an N-S extension. This variety in trend direction shows that the area experienced different tectonic regimes throughout its geological history.
"Submersion": A board game for coastal risk exploration and adaptation planning
Authors: Chapuis Anne , Foucher Clémence , Burgard Clara , Ducasse Etienne , Mathiot Pierre , Mondy Gabrielle , Durand Gaël
Published: March 2024

In the face of climate change and rising sea levels, "Submersion" is a strategic collaborative board game designed by H2020-PROTECT to deepen understanding and foster proactive decision-making regarding the risk of coastal submersion. Tailored for a high-school audience and above, the game prompts players to manage a coastal city, grappling with the challenges posed by the risk of marine submersion. The objective is clear: safeguard the city's future by minimizing the impact of this risk.The game unfolds in Mer-Ville, a picturesque coastal town threatened by climate-induced changes. Players, acting as members of the City Council, navigate the delicate balance between preserving the city's historical treasures, sustaining its economic activities, and implementing effective adaptation measures. As climate scenarios unfold, players must grapple with varying degrees of sea-level rise, emphasizing the importance of strategic planning and resource allocation.Key Objectives:Understanding Risk: Explore the concept of risk and its reduction strategies.
Adaptation Responses: Learn about diverse responses to the risk of marine submersion
Climate Scenarios: Grasp the impact of different climate scenarios on sea level rise and adaptation difficulty.
Limits of Adaptation: Understand the constraints and limitations associated with adaptation measures.
Temporal Aspect: Recognize that adaptation requires time and advance planning.